$TTEK
TETRA TECH INC Stock $ttek

$ttek Overview Financials Valuation SEC Filings Company Website

2022 Q4 Form 10-K Financial Statement

#000083164122000123 Filed on November 25, 2022

Income Statement

Concept	2022 Q4	2022
Revenue	$736.1M	$2.836B
YoY Change	3.81%	-11.76%
Cost Of Revenue	$580.1M	$2.260B
YoY Change	2.63%	10.04%
Gross Profit	$156.0M	$575.6M
YoY Change	8.43%	15.48%
Gross Profit Margin	21.2%	20.3%
Selling, General & Admin	$61.23M	$235.1M
YoY Change	-6.06%	5.45%
% of Gross Profit	39.24%	40.85%
Research & Development
YoY Change
% of Gross Profit
Depreciation & Amortization	$7.488M	$27.03M
YoY Change	7.06%	13.56%
% of Gross Profit	4.8%	4.7%
Operating Expenses	$61.23M	$235.1M
YoY Change	-1.35%	7.02%
Operating Profit	$94.80M	$340.4M
YoY Change	15.84%	22.15%
Interest Expense	-$2.618M	-$11.58M
YoY Change	-19.35%	-190.87%
% of Operating Profit	-2.76%	-3.4%
Other Income/Expense, Net	$19.90M	$19.90M
YoY Change
Pretax Income	$112.1M	$348.8M
YoY Change	42.62%	30.69%
Income Tax	$29.13M	$85.60M
% Of Pretax Income	25.99%	24.54%
Net Earnings	$82.95M	$263.1M
YoY Change	-0.01%	13.01%
Net Earnings / Revenue	11.27%	9.28%
Basic Earnings Per Share	$1.56	$4.91
Diluted Earnings Per Share	$1.546M	$4.858M
COMMON SHARES
Basic Shares Outstanding	53.15M shares	53.62M shares
Diluted Shares Outstanding	53.67M shares	54.16M shares

Balance Sheet

Concept	2022 Q4	2022
SHORT-TERM ASSETS
Cash & Short-Term Investments	$185.1M	$185.1M
YoY Change	11.12%	11.12%
Cash & Equivalents	$185.1M	$185.1M
Short-Term Investments
Other Short-Term Assets	$115.4M	$115.4M
YoY Change	2.73%	2.73%
Inventory
Prepaid Expenses
Receivables	$847.5M	$847.5M
Other Receivables	$10.20M	$10.20M
Total Short-Term Assets	$1.158B	$1.158B
YoY Change	8.66%	8.66%
LONG-TERM ASSETS
Property, Plant & Equipment	$214.6M	$214.6M
YoY Change	468.83%	-15.22%
Goodwill	$1.110B
YoY Change	0.17%
Intangibles
YoY Change
Long-Term Investments	$4.570M	$4.570M
YoY Change	39.24%	39.24%
Other Assets	$105.8M	$105.8M
YoY Change	98.85%	-1.7%
Total Long-Term Assets	$1.465B	$1.465B
YoY Change	-3.05%	-3.05%
TOTAL ASSETS
Total Short-Term Assets	$1.158B	$1.158B
Total Long-Term Assets	$1.465B	$1.465B
Total Assets	$2.623B	$2.623B
YoY Change	1.79%	1.79%
SHORT-TERM LIABILITIES
YoY Change
Accounts Payable	$147.4M	$147.4M
YoY Change	14.5%	14.5%
Accrued Expenses	$295.5M	$295.5M
YoY Change	7.95%	7.95%
Deferred Revenue	$241.3M
YoY Change	26.75%
Short-Term Debt	$0.00	$0.00
YoY Change
Long-Term Debt Due	$12.50M	$12.50M
YoY Change	0.03%	0.0%
Total Short-Term Liabilities	$916.0M	$916.0M
YoY Change	7.96%	7.96%
LONG-TERM LIABILITIES
Long-Term Debt	$246.3M	$246.3M
YoY Change	23.13%	23.13%
Other Long-Term Liabilities	$262.2M	$262.2M
YoY Change	279.12%	-7.42%
Total Long-Term Liabilities	$508.5M	$508.5M
YoY Change	88.9%	5.22%
TOTAL LIABILITIES
Total Short-Term Liabilities	$916.0M	$916.0M
Total Long-Term Liabilities	$508.5M	$508.5M
Total Liabilities	$1.440B	$1.440B
YoY Change	28.81%	7.25%
SHAREHOLDERS EQUITY
Retained Earnings	$1.391B
YoY Change	2.35%
Common Stock	$530.0K
YoY Change	-1.85%
Preferred Stock
YoY Change
Treasury Stock (at cost)
YoY Change
Treasury Stock Shares
Shareholders Equity	$1.183B	$1.183B
YoY Change
Total Liabilities & Shareholders Equity	$2.623B	$2.623B
YoY Change	1.79%	1.79%

Cashflow Statement

Concept	2022 Q4	2022
OPERATING ACTIVITIES
Net Income	$82.95M	$263.1M
YoY Change	-0.01%	13.01%
Depreciation, Depletion And Amortization	$7.488M	$27.03M
YoY Change	7.06%	13.56%
Cash From Operating Activities	$60.21M	$336.2M
YoY Change	-22.64%	10.45%
INVESTING ACTIVITIES
Capital Expenditures	-$2.181M	-$10.58M
YoY Change	-6.76%	-223.43%
Acquisitions		$49.12M
YoY Change		-42.15%
Other Investing Activities	-$15.29M	-$45.16M
YoY Change	-77.38%	-46.51%
Cash From Investing Activities	-$17.47M	-$55.74M
YoY Change	-75.02%	-40.06%
FINANCING ACTIVITIES
Cash Dividend Paid
YoY Change
Common Stock Issuance & Retirement, Net	-$49.40M	-$198.2M
YoY Change		-430.32%
Debt Paid & Issued, Net		$117.1M
YoY Change		-71.74%
Cash From Financing Activities	-67.12M	-249.6M
YoY Change	-7.54%	18.8%
NET CHANGE
Cash From Operating Activities	60.21M	336.2M
Cash From Investing Activities	-17.47M	-55.74M
Cash From Financing Activities	-67.12M	-249.6M
Net Change In Cash	-24.38M	30.84M
YoY Change	-62.32%	240.66%
FREE CASH FLOW
Cash From Operating Activities	$60.21M	$336.2M
Capital Expenditures	-$2.181M	-$10.58M
Free Cash Flow	$62.39M	$346.8M
YoY Change	-22.18%	17.23%

Facts In Submission

Frame	Concept Type	Concept / XBRL Key	Value	Unit
CY2022	dei	Entity Central Index Key EntityCentralIndexKey	0000831641
CY2022	dei	Document Fiscal Year Focus DocumentFiscalYearFocus	2022
CY2022	dei	Document Fiscal Period Focus DocumentFiscalPeriodFocus	FY
CY2022	dei	Amendment Flag AmendmentFlag	false
CY2022	us-gaap	Fair Value Recurring Basis Unobservable Input Reconciliation Liability Gain Loss Statement Of Income Extensible List FairValueRecurringBasisUnobservableInputReconciliationLiabilityGainLossStatementOfIncomeExtensibleList	http://fasb.org/us-gaap/2021-01-31#OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax
CY2020	us-gaap	Fair Value Recurring Basis Unobservable Input Reconciliation Liability Gain Loss Statement Of Income Extensible List FairValueRecurringBasisUnobservableInputReconciliationLiabilityGainLossStatementOfIncomeExtensibleList	http://fasb.org/us-gaap/2021-01-31#OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax
CY2021	us-gaap	Fair Value Recurring Basis Unobservable Input Reconciliation Liability Gain Loss Statement Of Income Extensible List FairValueRecurringBasisUnobservableInputReconciliationLiabilityGainLossStatementOfIncomeExtensibleList	http://fasb.org/us-gaap/2021-01-31#OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax
CY2022Q4	us-gaap	Revenue Remaining Performance Obligation Expected Timing Of Satisfaction Period1 RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1	P1Y
CY2022Q4	us-gaap	Revenue Remaining Performance Obligation Expected Timing Of Satisfaction Period1 RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1
CY2022	dei	Document Type DocumentType	10-K
CY2022	dei	Document Annual Report DocumentAnnualReport	true
CY2022	dei	Document Period End Date DocumentPeriodEndDate	2022-10-02
CY2022	dei	Current Fiscal Year End Date CurrentFiscalYearEndDate	--10-02
CY2022	dei	Document Transition Report DocumentTransitionReport	false
CY2022	dei	Entity File Number EntityFileNumber	0-19655
CY2022	dei	Entity Registrant Name EntityRegistrantName	TETRA TECH, INC.
CY2022	dei	Entity Incorporation State Country Code EntityIncorporationStateCountryCode	DE
CY2022	dei	Entity Shell Company EntityShellCompany	false
CY2022Q2	dei	Entity Public Float EntityPublicFloat	8900000000	usd
CY2022	dei	Entity Tax Identification Number EntityTaxIdentificationNumber	95-4148514
CY2022	dei	Entity Address Address Line1 EntityAddressAddressLine1	3475 East Foothill Boulevard
CY2022	dei	Entity Address City Or Town EntityAddressCityOrTown	Pasadena
CY2022	dei	Entity Address State Or Province EntityAddressStateOrProvince	CA
CY2022	dei	Entity Address Postal Zip Code EntityAddressPostalZipCode	91107
CY2022	dei	City Area Code CityAreaCode	626
CY2022	dei	Local Phone Number LocalPhoneNumber	351-4664
CY2022	dei	Security12b Title Security12bTitle	Common Stock, $0.01 par value
CY2022	dei	Trading Symbol TradingSymbol	TTEK
CY2022	dei	Security Exchange Name SecurityExchangeName	NASDAQ
CY2022	dei	Entity Well Known Seasoned Issuer EntityWellKnownSeasonedIssuer	Yes
CY2022	dei	Entity Voluntary Filers EntityVoluntaryFilers	No
CY2022	dei	Entity Current Reporting Status EntityCurrentReportingStatus	Yes
CY2022	dei	Entity Interactive Data Current EntityInteractiveDataCurrent	Yes
CY2022	dei	Entity Filer Category EntityFilerCategory	Large Accelerated Filer
CY2022	dei	Entity Small Business EntitySmallBusiness	false
CY2022	dei	Entity Emerging Growth Company EntityEmergingGrowthCompany	false
CY2022	dei	Icfr Auditor Attestation Flag IcfrAuditorAttestationFlag	true
CY2022	dei	Auditor Location AuditorLocation	Los Angeles, California
CY2021Q4	us-gaap	Income Taxes Receivable IncomeTaxesReceivable	14260000	usd
CY2022Q4	dei	Entity Common Stock Shares Outstanding EntityCommonStockSharesOutstanding	52981143	shares
CY2021	dei	Auditor Name AuditorName	PricewaterhouseCoopers
CY2022	dei	Auditor Name AuditorName	PricewaterhouseCoopers
CY2021	dei	Auditor Location AuditorLocation	Los Angeles, California
CY2022Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	185094000	usd
CY2021Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	166568000	usd
CY2022Q4	us-gaap	Accounts Receivable Net Current AccountsReceivableNetCurrent	755112000	usd
CY2021Q4	us-gaap	Accounts Receivable Net Current AccountsReceivableNetCurrent	668998000	usd
CY2022Q4	us-gaap	Contract With Customer Asset Net Current ContractWithCustomerAssetNetCurrent	92405000	usd
CY2021Q4	us-gaap	Contract With Customer Asset Net Current ContractWithCustomerAssetNetCurrent	103784000	usd
CY2022Q4	us-gaap	Prepaid Expense And Other Assets Current PrepaidExpenseAndOtherAssetsCurrent	115400000	usd
CY2021Q4	us-gaap	Prepaid Expense And Other Assets Current PrepaidExpenseAndOtherAssetsCurrent	112338000	usd
CY2022Q4	us-gaap	Income Taxes Receivable IncomeTaxesReceivable	10205000	usd
CY2022Q4	us-gaap	Assets Current AssetsCurrent	1158216000	usd
CY2021Q4	us-gaap	Assets Current AssetsCurrent	1065948000	usd
CY2022Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	32316000	usd
CY2021Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	37733000	usd
CY2022Q4	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	182319000	usd
CY2021Q4	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	215422000	usd
CY2022Q4	us-gaap	Equity Method Investments EquityMethodInvestments	4570000	usd
CY2021Q4	us-gaap	Equity Method Investments EquityMethodInvestments	3282000	usd
CY2022Q4	us-gaap	Goodwill Goodwill	1110412000	usd
CY2021Q4	us-gaap	Goodwill Goodwill	1108578000	usd
CY2022Q4	us-gaap	Finite Lived Intangible Assets Net FiniteLivedIntangibleAssetsNet	29163000	usd
CY2021Q4	us-gaap	Finite Lived Intangible Assets Net FiniteLivedIntangibleAssetsNet	37990000	usd
CY2022Q4	us-gaap	Deferred Income Tax Assets Net DeferredIncomeTaxAssetsNet	47804000	usd
CY2021Q4	us-gaap	Deferred Income Tax Assets Net DeferredIncomeTaxAssetsNet	54413000	usd
CY2022Q4	us-gaap	Other Assets Noncurrent OtherAssetsNoncurrent	57976000	usd
CY2021Q4	us-gaap	Other Assets Noncurrent OtherAssetsNoncurrent	53196000	usd
CY2022Q4	us-gaap	Employee Related Liabilities Current EmployeeRelatedLiabilitiesCurrent	237669000	usd
CY2022Q4	us-gaap	Assets Assets	2622776000	usd
CY2021Q4	us-gaap	Assets Assets	2576562000	usd
CY2022Q4	us-gaap	Accounts Payable Current AccountsPayableCurrent	147436000	usd
CY2021Q4	us-gaap	Accounts Payable Current AccountsPayableCurrent	128767000	usd
CY2021Q4	us-gaap	Employee Related Liabilities Current EmployeeRelatedLiabilitiesCurrent	206322000	usd
CY2022Q4	us-gaap	Contract With Customer Liability Current ContractWithCustomerLiabilityCurrent	241340000	usd
CY2021Q4	us-gaap	Contract With Customer Liability Current ContractWithCustomerLiabilityCurrent	190403000	usd
CY2022Q4	us-gaap	Operating Lease Liability Current OperatingLeaseLiabilityCurrent	57865000	usd
CY2021Q4	us-gaap	Operating Lease Liability Current OperatingLeaseLiabilityCurrent	67452000	usd
CY2022Q4	us-gaap	Debt Current DebtCurrent	12504000	usd
CY2021Q4	us-gaap	Debt Current DebtCurrent	12504000	usd
CY2022Q4	us-gaap	Business Combination Contingent Consideration Liability Current BusinessCombinationContingentConsiderationLiabilityCurrent	28797000	usd
CY2021Q4	us-gaap	Business Combination Contingent Consideration Liability Current BusinessCombinationContingentConsiderationLiabilityCurrent	19520000	usd
CY2022Q4	us-gaap	Other Liabilities Current OtherLiabilitiesCurrent	190406000	usd
CY2021Q4	us-gaap	Other Liabilities Current OtherLiabilitiesCurrent	223515000	usd
CY2022Q4	us-gaap	Liabilities Current LiabilitiesCurrent	916017000	usd
CY2021Q4	us-gaap	Liabilities Current LiabilitiesCurrent	848483000	usd
CY2022Q4	us-gaap	Deferred Income Tax Liabilities Net DeferredIncomeTaxLiabilitiesNet	15161000	usd
CY2021Q4	us-gaap	Deferred Income Tax Liabilities Net DeferredIncomeTaxLiabilitiesNet	10563000	usd
CY2022Q4	us-gaap	Long Term Debt Noncurrent LongTermDebtNoncurrent	246250000	usd
CY2021Q4	us-gaap	Long Term Debt Noncurrent LongTermDebtNoncurrent	200000000	usd
CY2022Q4	us-gaap	Operating Lease Liability Noncurrent OperatingLeaseLiabilityNoncurrent	146285000	usd
CY2021Q4	us-gaap	Operating Lease Liability Noncurrent OperatingLeaseLiabilityNoncurrent	174285000	usd
CY2022Q4	us-gaap	Business Combination Contingent Consideration Liability Noncurrent BusinessCombinationContingentConsiderationLiabilityNoncurrent	36769000	usd
CY2021Q4	us-gaap	Business Combination Contingent Consideration Liability Noncurrent BusinessCombinationContingentConsiderationLiabilityNoncurrent	39777000	usd
CY2022Q4	us-gaap	Other Liabilities Noncurrent OtherLiabilitiesNoncurrent	79157000	usd
CY2021Q4	us-gaap	Other Liabilities Noncurrent OtherLiabilitiesNoncurrent	69163000	usd
CY2022Q4	us-gaap	Commitments And Contingencies CommitmentsAndContingencies		usd
CY2021Q4	us-gaap	Commitments And Contingencies CommitmentsAndContingencies		usd
CY2022Q4	us-gaap	Preferred Stock Shares Authorized PreferredStockSharesAuthorized	2000000	shares
CY2021Q4	us-gaap	Preferred Stock Shares Authorized PreferredStockSharesAuthorized	2000000	shares
CY2022Q4	us-gaap	Preferred Stock Par Or Stated Value Per Share PreferredStockParOrStatedValuePerShare	0.01
CY2021Q4	us-gaap	Preferred Stock Par Or Stated Value Per Share PreferredStockParOrStatedValuePerShare	0.01
CY2021Q4	us-gaap	Preferred Stock Shares Outstanding PreferredStockSharesOutstanding	0	shares
CY2021Q4	us-gaap	Preferred Stock Shares Issued PreferredStockSharesIssued	0	shares
CY2022Q4	us-gaap	Preferred Stock Shares Issued PreferredStockSharesIssued	0	shares
CY2022Q4	us-gaap	Preferred Stock Shares Outstanding PreferredStockSharesOutstanding	0	shares
CY2022Q4	us-gaap	Preferred Stock Value PreferredStockValue	0	usd
CY2021Q4	us-gaap	Preferred Stock Value PreferredStockValue	0	usd
CY2021Q4	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	150000000	shares
CY2022Q4	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	150000000	shares
CY2021Q4	us-gaap	Common Stock Par Or Stated Value Per Share CommonStockParOrStatedValuePerShare	0.01
CY2022Q4	us-gaap	Common Stock Par Or Stated Value Per Share CommonStockParOrStatedValuePerShare	0.01
CY2022Q4	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	52981000	shares
CY2022Q4	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	52981000	shares
CY2021Q4	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	53981000	shares
CY2021Q4	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	53981000	shares
CY2022Q4	us-gaap	Common Stock Value CommonStockValue	530000	usd
CY2021Q4	us-gaap	Common Stock Value CommonStockValue	540000	usd
CY2022Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-208144000	usd
CY2021Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-125028000	usd
CY2022Q4	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	1390701000	usd
CY2021Q4	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	1358726000	usd
CY2022Q4	us-gaap	Stockholders Equity StockholdersEquity	1183087000	usd
CY2021Q4	us-gaap	Stockholders Equity StockholdersEquity	1234238000	usd
CY2022Q4	us-gaap	Minority Interest MinorityInterest	50000	usd
CY2021Q4	us-gaap	Minority Interest MinorityInterest	53000	usd
CY2022Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	1183137000	usd
CY2021Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	1234291000	usd
CY2022Q4	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	2622776000	usd
CY2021Q4	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	2576562000	usd
CY2022	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	3504048000	usd
CY2021	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	3213513000	usd
CY2020	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	2994891000	usd
CY2022	us-gaap	Gross Profit GrossProfit	575559000	usd
CY2021	us-gaap	Gross Profit GrossProfit	498400000	usd
CY2020	us-gaap	Gross Profit GrossProfit	446535000	usd
CY2022	ttek	Selling General And Administrative Expenses Including Depreciation And Amortization Of Intangible Assets SellingGeneralAndAdministrativeExpensesIncludingDepreciationAndAmortizationOfIntangibleAssets	234784000	usd
CY2021	ttek	Selling General And Administrative Expenses Including Depreciation And Amortization Of Intangible Assets SellingGeneralAndAdministrativeExpensesIncludingDepreciationAndAmortizationOfIntangibleAssets	222972000	usd
CY2020	ttek	Selling General And Administrative Expenses Including Depreciation And Amortization Of Intangible Assets SellingGeneralAndAdministrativeExpensesIncludingDepreciationAndAmortizationOfIntangibleAssets	204615000	usd
CY2022	ttek	Fair Value Adjustments To Contingent Consideration FairValueAdjustmentsToContingentConsideration	-329000	usd
CY2021	ttek	Fair Value Adjustments To Contingent Consideration FairValueAdjustmentsToContingentConsideration	3273000	usd
CY2020	ttek	Fair Value Adjustments To Contingent Consideration FairValueAdjustmentsToContingentConsideration	14971000	usd
CY2022	us-gaap	Goodwill Impairment Loss GoodwillImpairmentLoss	0	usd
CY2021	us-gaap	Goodwill Impairment Loss GoodwillImpairmentLoss	0	usd
CY2020	us-gaap	Goodwill Impairment Loss GoodwillImpairmentLoss	15800000	usd
CY2022	us-gaap	Operating Income Loss OperatingIncomeLoss	340446000	usd
CY2021	us-gaap	Operating Income Loss OperatingIncomeLoss	278701000	usd
CY2020	us-gaap	Operating Income Loss OperatingIncomeLoss	241091000	usd
CY2022	us-gaap	Investment Income Interest InvestmentIncomeInterest	1780000	usd
CY2021	us-gaap	Investment Income Interest InvestmentIncomeInterest	917000	usd
CY2020	us-gaap	Investment Income Interest InvestmentIncomeInterest	1375000	usd
CY2022	us-gaap	Interest Expense InterestExpense	13364000	usd
CY2021	us-gaap	Interest Expense InterestExpense	12748000	usd
CY2020	us-gaap	Interest Expense InterestExpense	14475000	usd
CY2022	us-gaap	Other Nonoperating Income OtherNonoperatingIncome	19904000	usd
CY2021	us-gaap	Other Nonoperating Income OtherNonoperatingIncome	0	usd
CY2020	us-gaap	Other Nonoperating Income OtherNonoperatingIncome	0	usd
CY2022	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	348766000	usd
CY2021	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	266870000	usd
CY2020	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	227991000	usd
CY2022	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	85602000	usd
CY2021	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	34039000	usd
CY2020	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	54101000	usd
CY2022	us-gaap	Profit Loss ProfitLoss	263164000	usd
CY2021	us-gaap	Profit Loss ProfitLoss	232831000	usd
CY2020	us-gaap	Profit Loss ProfitLoss	173890000	usd
CY2022	us-gaap	Net Income Loss Attributable To Noncontrolling Interest NetIncomeLossAttributableToNoncontrollingInterest	39000	usd
CY2021	us-gaap	Net Income Loss Attributable To Noncontrolling Interest NetIncomeLossAttributableToNoncontrollingInterest	21000	usd
CY2020	us-gaap	Net Income Loss Attributable To Noncontrolling Interest NetIncomeLossAttributableToNoncontrollingInterest	31000	usd
CY2022	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	263125000	usd
CY2022	us-gaap	Net Income Loss Available To Common Stockholders Diluted NetIncomeLossAvailableToCommonStockholdersDiluted	263125000	usd
CY2021	us-gaap	Net Income Loss Available To Common Stockholders Diluted NetIncomeLossAvailableToCommonStockholdersDiluted	232810000	usd
CY2021	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	232810000	usd
CY2020	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	173859000	usd
CY2020	us-gaap	Net Income Loss Available To Common Stockholders Diluted NetIncomeLossAvailableToCommonStockholdersDiluted	173859000	usd
CY2022	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	4.91
CY2021	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	4.31
CY2020	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	3.21
CY2022	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	4.86
CY2021	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	4.26
CY2020	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	3.16
CY2022	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	53620000	shares
CY2021	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	54078000	shares
CY2020	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	54235000	shares
CY2022	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	54163000	shares
CY2021	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	54675000	shares
CY2020	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	55022000	shares
CY2022	us-gaap	Profit Loss ProfitLoss	263164000	usd
CY2021	us-gaap	Profit Loss ProfitLoss	232831000	usd
CY2020	us-gaap	Profit Loss ProfitLoss	173890000	usd
CY2022	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax	-94933000	usd
CY2021	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax	30644000	usd
CY2020	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax	3435000	usd
CY2022	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification And Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax	11806000	usd
CY2021	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification And Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax	6117000	usd
CY2020	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification And Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax	-4638000	usd
CY2022	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-83127000	usd
CY2021	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	36761000	usd
CY2020	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-1203000	usd
CY2022	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	180037000	usd
CY2021	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	269592000	usd
CY2020	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	172687000	usd
CY2022	us-gaap	Comprehensive Income Net Of Tax Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest	28000	usd
CY2021	us-gaap	Comprehensive Income Net Of Tax Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest	24000	usd
CY2020	us-gaap	Comprehensive Income Net Of Tax Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest	30000	usd
CY2022	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	180009000	usd
CY2021	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	269568000	usd
CY2020	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	172657000	usd
CY2022	us-gaap	Profit Loss ProfitLoss	263164000	usd
CY2021	us-gaap	Profit Loss ProfitLoss	232831000	usd
CY2020	us-gaap	Profit Loss ProfitLoss	173890000	usd
CY2022	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	27033000	usd
CY2021	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	23805000	usd
CY2020	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	24611000	usd
CY2022	us-gaap	Income Loss From Equity Method Investments IncomeLossFromEquityMethodInvestments	7525000	usd
CY2021	us-gaap	Income Loss From Equity Method Investments IncomeLossFromEquityMethodInvestments	4990000	usd
CY2020	us-gaap	Income Loss From Equity Method Investments IncomeLossFromEquityMethodInvestments	6605000	usd
CY2022	us-gaap	Equity Method Investment Dividends Or Distributions EquityMethodInvestmentDividendsOrDistributions	6177000	usd
CY2021	us-gaap	Equity Method Investment Dividends Or Distributions EquityMethodInvestmentDividendsOrDistributions	4604000	usd
CY2020	us-gaap	Equity Method Investment Dividends Or Distributions EquityMethodInvestmentDividendsOrDistributions	6310000	usd
CY2022	us-gaap	Share Based Compensation ShareBasedCompensation	26227000	usd
CY2021	us-gaap	Share Based Compensation ShareBasedCompensation	23067000	usd
CY2020	us-gaap	Share Based Compensation ShareBasedCompensation	19424000	usd
CY2022	us-gaap	Deferred Income Taxes And Tax Credits DeferredIncomeTaxesAndTaxCredits	2175000	usd
CY2021	us-gaap	Deferred Income Taxes And Tax Credits DeferredIncomeTaxesAndTaxCredits	-38494000	usd
CY2020	us-gaap	Deferred Income Taxes And Tax Credits DeferredIncomeTaxesAndTaxCredits	565000	usd
CY2022	us-gaap	Goodwill Impairment Loss GoodwillImpairmentLoss	0	usd
CY2021	us-gaap	Goodwill Impairment Loss GoodwillImpairmentLoss	0	usd
CY2020	us-gaap	Goodwill Impairment Loss GoodwillImpairmentLoss	15800000	usd
CY2022	ttek	Fair Value Adjustments To Contingent Consideration FairValueAdjustmentsToContingentConsideration	-329000	usd
CY2021	ttek	Fair Value Adjustments To Contingent Consideration FairValueAdjustmentsToContingentConsideration	3273000	usd
CY2020	ttek	Fair Value Adjustments To Contingent Consideration FairValueAdjustmentsToContingentConsideration	14971000	usd
CY2022	us-gaap	Gain Loss On Disposition Of Assets GainLossOnDispositionOfAssets	-103000	usd
CY2021	us-gaap	Gain Loss On Disposition Of Assets GainLossOnDispositionOfAssets	110000	usd
CY2020	us-gaap	Gain Loss On Disposition Of Assets GainLossOnDispositionOfAssets	11066000	usd
CY2022	us-gaap	Unrealized Gain Loss On Foreign Currency Derivatives Net Before Tax UnrealizedGainLossOnForeignCurrencyDerivativesNetBeforeTax	19904000	usd
CY2021	us-gaap	Unrealized Gain Loss On Foreign Currency Derivatives Net Before Tax UnrealizedGainLossOnForeignCurrencyDerivativesNetBeforeTax	0	usd
CY2020	us-gaap	Unrealized Gain Loss On Foreign Currency Derivatives Net Before Tax UnrealizedGainLossOnForeignCurrencyDerivativesNetBeforeTax	0	usd
CY2022	ttek	Increase Decrease In Accounts Receivable And Contract With Customer Asset IncreaseDecreaseInAccountsReceivableAndContractWithCustomerAsset	89781000	usd
CY2021	ttek	Increase Decrease In Accounts Receivable And Contract With Customer Asset IncreaseDecreaseInAccountsReceivableAndContractWithCustomerAsset	-13301000	usd
CY2020	ttek	Increase Decrease In Accounts Receivable And Contract With Customer Asset IncreaseDecreaseInAccountsReceivableAndContractWithCustomerAsset	-156015000	usd
CY2022	us-gaap	Increase Decrease In Prepaid Deferred Expense And Other Assets IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets	-69697000	usd
CY2021	us-gaap	Increase Decrease In Prepaid Deferred Expense And Other Assets IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets	582000	usd
CY2020	us-gaap	Increase Decrease In Prepaid Deferred Expense And Other Assets IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets	11321000	usd
CY2022	us-gaap	Increase Decrease In Accounts Payable IncreaseDecreaseInAccountsPayable	17099000	usd
CY2021	us-gaap	Increase Decrease In Accounts Payable IncreaseDecreaseInAccountsPayable	13551000	usd
CY2020	us-gaap	Increase Decrease In Accounts Payable IncreaseDecreaseInAccountsPayable	-102162000	usd
CY2022	ttek	Increase Decrease In Accrued Compensation IncreaseDecreaseInAccruedCompensation	27458000	usd
CY2021	ttek	Increase Decrease In Accrued Compensation IncreaseDecreaseInAccruedCompensation	5425000	usd
CY2020	ttek	Increase Decrease In Accrued Compensation IncreaseDecreaseInAccruedCompensation	-8173000	usd
CY2022	us-gaap	Increase Decrease In Contract With Customer Liability IncreaseDecreaseInContractWithCustomerLiability	55915000	usd
CY2021	us-gaap	Increase Decrease In Contract With Customer Liability IncreaseDecreaseInContractWithCustomerLiability	13407000	usd
CY2020	us-gaap	Increase Decrease In Contract With Customer Liability IncreaseDecreaseInContractWithCustomerLiability	5894000	usd
CY2022	us-gaap	Increase Decrease In Other Operating Liabilities IncreaseDecreaseInOtherOperatingLiabilities	-56606000	usd
CY2021	us-gaap	Increase Decrease In Other Operating Liabilities IncreaseDecreaseInOtherOperatingLiabilities	8740000	usd
CY2020	us-gaap	Increase Decrease In Other Operating Liabilities IncreaseDecreaseInOtherOperatingLiabilities	19460000	usd
CY2022	us-gaap	Increase Decrease In Income Taxes Payable Net Of Income Taxes Receivable IncreaseDecreaseInIncomeTaxesPayableNetOfIncomeTaxesReceivable	14627000	usd
CY2021	us-gaap	Increase Decrease In Income Taxes Payable Net Of Income Taxes Receivable IncreaseDecreaseInIncomeTaxesPayableNetOfIncomeTaxesReceivable	13090000	usd
CY2020	us-gaap	Increase Decrease In Income Taxes Payable Net Of Income Taxes Receivable IncreaseDecreaseInIncomeTaxesPayableNetOfIncomeTaxesReceivable	-5192000	usd
CY2022	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	336188000	usd
CY2021	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	304372000	usd
CY2020	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	262479000	usd
CY2022	us-gaap	Payments To Acquire Businesses Net Of Cash Acquired PaymentsToAcquireBusinessesNetOfCashAcquired	49124000	usd
CY2021	us-gaap	Payments To Acquire Businesses Net Of Cash Acquired PaymentsToAcquireBusinessesNetOfCashAcquired	84911000	usd
CY2020	us-gaap	Payments To Acquire Businesses Net Of Cash Acquired PaymentsToAcquireBusinessesNetOfCashAcquired	68488000	usd
CY2022	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	10582000	usd
CY2021	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	8573000	usd
CY2020	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	12245000	usd
CY2022	us-gaap	Proceeds From Sale Of Property Plant And Equipment ProceedsFromSaleOfPropertyPlantAndEquipment	3966000	usd
CY2021	us-gaap	Proceeds From Sale Of Property Plant And Equipment ProceedsFromSaleOfPropertyPlantAndEquipment	492000	usd
CY2020	us-gaap	Proceeds From Sale Of Property Plant And Equipment ProceedsFromSaleOfPropertyPlantAndEquipment	17710000	usd
CY2022	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-55740000	usd
CY2021	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-92992000	usd
CY2020	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-63023000	usd
CY2022	us-gaap	Proceeds From Issuance Of Long Term Debt And Capital Securities Net ProceedsFromIssuanceOfLongTermDebtAndCapitalSecuritiesNet	161456000	usd
CY2021	us-gaap	Proceeds From Issuance Of Long Term Debt And Capital Securities Net ProceedsFromIssuanceOfLongTermDebtAndCapitalSecuritiesNet	370222000	usd
CY2020	us-gaap	Proceeds From Issuance Of Long Term Debt And Capital Securities Net ProceedsFromIssuanceOfLongTermDebtAndCapitalSecuritiesNet	308364000	usd
CY2022	us-gaap	Repayments Of Long Term Debt RepaymentsOfLongTermDebt	117080000	usd
CY2021	us-gaap	Repayments Of Long Term Debt RepaymentsOfLongTermDebt	414308000	usd
CY2020	us-gaap	Repayments Of Long Term Debt RepaymentsOfLongTermDebt	331066000	usd
CY2022	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	200000000	usd
CY2021	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	60000000	usd
CY2020	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	117188000	usd
CY2022	us-gaap	Payments Related To Tax Withholding For Share Based Compensation PaymentsRelatedToTaxWithholdingForShareBasedCompensation	25223000	usd
CY2021	us-gaap	Payments Related To Tax Withholding For Share Based Compensation PaymentsRelatedToTaxWithholdingForShareBasedCompensation	17630000	usd
CY2020	us-gaap	Payments Related To Tax Withholding For Share Based Compensation PaymentsRelatedToTaxWithholdingForShareBasedCompensation	11166000	usd
CY2022	us-gaap	Payment For Contingent Consideration Liability Financing Activities PaymentForContingentConsiderationLiabilityFinancingActivities	20124000	usd
CY2021	us-gaap	Payment For Contingent Consideration Liability Financing Activities PaymentForContingentConsiderationLiabilityFinancingActivities	20251000	usd
CY2020	us-gaap	Payment For Contingent Consideration Liability Financing Activities PaymentForContingentConsiderationLiabilityFinancingActivities	22900000	usd
CY2022	us-gaap	Proceeds From Stock Options Exercised ProceedsFromStockOptionsExercised	1806000	usd
CY2021	us-gaap	Proceeds From Stock Options Exercised ProceedsFromStockOptionsExercised	11250000	usd
CY2020	us-gaap	Proceeds From Stock Options Exercised ProceedsFromStockOptionsExercised	10334000	usd
CY2022	us-gaap	Increase Decrease In Book Overdrafts IncreaseDecreaseInBookOverdrafts	0	usd
CY2021	us-gaap	Increase Decrease In Book Overdrafts IncreaseDecreaseInBookOverdrafts	-36627000	usd
CY2020	us-gaap	Increase Decrease In Book Overdrafts IncreaseDecreaseInBookOverdrafts	36627000	usd
CY2022	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	46099000	usd
CY2021	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	40041000	usd
CY2020	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	34743000	usd
CY2022	us-gaap	Finance Lease Principal Payments FinanceLeasePrincipalPayments	4344000	usd
CY2021	us-gaap	Finance Lease Principal Payments FinanceLeasePrincipalPayments	2714000	usd
CY2020	us-gaap	Finance Lease Principal Payments FinanceLeasePrincipalPayments	1311000	usd
CY2022	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-249608000	usd
CY2021	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-210099000	usd
CY2020	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-163049000	usd
CY2022	us-gaap	Effect Of Exchange Rate On Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	-12314000	usd
CY2021	us-gaap	Effect Of Exchange Rate On Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	7772000	usd
CY2020	us-gaap	Effect Of Exchange Rate On Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	207000	usd
CY2022	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	18526000	usd
CY2021	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	9053000	usd
CY2020	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	36614000	usd
CY2021Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	166568000	usd
CY2020Q3	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	157515000	usd
CY2019Q3	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	120901000	usd
CY2022Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	185094000	usd
CY2021Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	166568000	usd
CY2020Q3	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	157515000	usd
CY2022	us-gaap	Interest Paid Net InterestPaidNet	13378000	usd
CY2021	us-gaap	Interest Paid Net InterestPaidNet	10330000	usd
CY2020	us-gaap	Interest Paid Net InterestPaidNet	13256000	usd
CY2022	us-gaap	Proceeds From Income Tax Refunds ProceedsFromIncomeTaxRefunds	4800000	usd
CY2021	us-gaap	Proceeds From Income Tax Refunds ProceedsFromIncomeTaxRefunds	2100000	usd
CY2020	us-gaap	Proceeds From Income Tax Refunds ProceedsFromIncomeTaxRefunds	1400000	usd
CY2022	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	70799000	usd
CY2021	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	59111000	usd
CY2020	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	55039000	usd
CY2019Q3	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	989464000	usd
CY2020	us-gaap	Profit Loss ProfitLoss	173890000	usd
CY2020	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax	3435000	usd
CY2020	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification And Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax	-4638000	usd
CY2020	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	172687000	usd
CY2020	us-gaap	Minority Interest Decrease From Distributions To Noncontrolling Interest Holders MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders	154000	usd
CY2020	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.64
CY2020	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	34743000	usd
CY2020	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	19424000	usd
CY2020	us-gaap	Stock Issued During Period Value Restricted Stock Award Net Of Forfeitures StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures	-11166000	usd
CY2020	us-gaap	Stock Issued During Period Value Stock Options Exercised StockIssuedDuringPeriodValueStockOptionsExercised	10334000	usd
CY2020	us-gaap	Stock Issued During Period Value Employee Stock Purchase Plan StockIssuedDuringPeriodValueEmployeeStockPurchasePlan	8715000	usd
CY2020	us-gaap	Stock Repurchased And Retired During Period Value StockRepurchasedAndRetiredDuringPeriodValue	117188000	usd
CY2020Q3	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	1037373000	usd
CY2021	us-gaap	Profit Loss ProfitLoss	232831000	usd
CY2021	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax	30644000	usd
CY2021	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification And Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax	6117000	usd
CY2021	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	269592000	usd
CY2021	us-gaap	Minority Interest Decrease From Distributions To Noncontrolling Interest Holders MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders	25000	usd
CY2021	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.74
CY2021	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	40041000	usd
CY2021	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	23067000	usd
CY2021	us-gaap	Stock Issued During Period Value Restricted Stock Award Net Of Forfeitures StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures	-17630000	usd
CY2021	us-gaap	Stock Issued During Period Value Stock Options Exercised StockIssuedDuringPeriodValueStockOptionsExercised	11250000	usd
CY2022Q4	ttek	Percentage Of Account Receivables Due From Agencies PercentageOfAccountReceivablesDueFromAgencies	0.23
CY2021	us-gaap	Stock Issued During Period Value Employee Stock Purchase Plan StockIssuedDuringPeriodValueEmployeeStockPurchasePlan	10705000	usd
CY2021	us-gaap	Stock Repurchased And Retired During Period Value StockRepurchasedAndRetiredDuringPeriodValue	60000000	usd
CY2021Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	1234291000	usd
CY2022	us-gaap	Profit Loss ProfitLoss	263164000	usd
CY2022	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax	-94933000	usd
CY2022	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification And Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax	11806000	usd
CY2022	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	180037000	usd
CY2022	us-gaap	Minority Interest Decrease From Distributions To Noncontrolling Interest Holders MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders	31000	usd
CY2022	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.86
CY2022	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	46099000	usd
CY2022	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	26227000	usd
CY2022	us-gaap	Stock Issued During Period Value Restricted Stock Award Net Of Forfeitures StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures	-25223000	usd
CY2022	us-gaap	Stock Issued During Period Value Stock Options Exercised StockIssuedDuringPeriodValueStockOptionsExercised	1806000	usd
CY2022	us-gaap	Stock Issued During Period Value Employee Stock Purchase Plan StockIssuedDuringPeriodValueEmployeeStockPurchasePlan	12129000	usd
CY2022	us-gaap	Stock Repurchased And Retired During Period Value StockRepurchasedAndRetiredDuringPeriodValue	200000000	usd
CY2022Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	1183137000	usd
CY2022	us-gaap	Nature Of Operations NatureOfOperations	Description of Business<div style="margin-bottom:6pt;margin-top:6pt;text-align:justify;text-indent:36pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">We are a leading global provider of high-end consulting and engineering services that focuses on water, environment, sustainable infrastructure, renewable energy and international development. We are a global company that is </span><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-style:italic;font-weight:400;line-height:120%">Leading with Science® </span><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">to provide innovative solutions for our public and private clients. We typically begin at the earliest stage of a project by identifying technical solutions and developing execution plans tailored to our clients’ needs and resources. </span><span style="background-color:#ffffff;color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">Our solutions may span the entire life cycle of high-end consulting and engineering projects and include applied science, data analysis, research, engineering, design, project management and operations and maintenance.</span></div><div style="margin-bottom:6pt;margin-top:6pt;text-align:justify;text-indent:36pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">We manage our business under two reportable segments. Our Government Services Group (“GSG”) reportable segment primarily includes activities with U.S. government clients (federal, state and local) and all activities with development agencies worldwide. Our Commercial/International Services Group (“CIG”) reportable segment primarily includes activities with U.S. commercial clients and international clients other than development agencies. </span><span style="background-color:#ffffff;color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">Beginning in fiscal 2022, we aligned our operations to better serve our clients and markets, and created a new High Performance Buildings </span><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">("HPB") </span><span style="background-color:#ffffff;color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">division in our CIG reportable segment. As a result, we transferred some related operations in our GSG reportable segment to our CIG reportable segment. Prior year amounts for reportable segments have been reclassified to conform to the current year presentation.</span></div>
CY2022	us-gaap	Number Of Reportable Segments NumberOfReportableSegments	2	segment
CY2022	us-gaap	Fiscal Period FiscalPeriod	Fiscal Year. We report results of operations based on 52 or 53-week periods ending on the Sunday nearest September 30. Fiscal years 2022, 2021 and 2020 contained 52, 53 and 52 weeks, respectively.
CY2022	us-gaap	Use Of Estimates UseOfEstimates	<span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-style:italic;font-weight:700;line-height:120%">Use of Estimates.</span><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%"> The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America ("U.S. GAAP") requires us to make estimates and assumptions. These estimates and assumptions affect the amounts reported in our consolidated financial statements and accompanying notes. Although such estimates and assumptions are based on management's best knowledge of current events and actions we may take in the future, actual results could differ materially from those estimates.</span>
CY2022	ttek	Maximum Term Of Original Maturity To Classify An Instrument As Cash Equivalent MaximumTermOfOriginalMaturityToClassifyAnInstrumentAsCashEquivalent	P90D
CY2021Q4	us-gaap	Contract With Customer Asset Net Current ContractWithCustomerAssetNetCurrent	103784000	usd
CY2022	ttek	Unbilled Contracts Receivable Period For Billing And Collection UnbilledContractsReceivablePeriodForBillingAndCollection	P12M
CY2022	ttek	Unbilled Contracts Receivable Period For Billing And Collection UnbilledContractsReceivablePeriodForBillingAndCollection	P12M
CY2022	ttek	Number Of Levels Below Segments For Goodwill Impairment Testing NumberOfLevelsBelowSegmentsForGoodwillImpairmentTesting	1	level
CY2022	ttek	Number Of Levels Below Segments For Goodwill Impairment Testing NumberOfLevelsBelowSegmentsForGoodwillImpairmentTesting	1	level
CY2022	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	3504048000	usd
CY2021	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	3213513000	usd
CY2022	ttek	Concentration Of Credit Risk Number Of Financial Institutions For Investment Exposure ConcentrationOfCreditRiskNumberOfFinancialInstitutionsForInvestmentExposure	1	institution
CY2022Q4	ttek	Government Assistance Amount Cumulative Current GovernmentAssistanceAmountCumulativeCurrent	26000000	usd
CY2022Q4	ttek	Government Assistance Amount Expected To Be Recognized In Next Twelve Months GovernmentAssistanceAmountExpectedToBeRecognizedInNextTwelveMonths	9000000	usd
CY2022Q4	ttek	Government Assistance Amount Cumulative Noncurrent GovernmentAssistanceAmountCumulativeNoncurrent	17000000	usd
CY2020	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	2994891000	usd
CY2022	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	3504048000	usd
CY2021	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	3213513000	usd
CY2020	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	2994891000	usd
CY2022Q4	us-gaap	Contract With Customer Asset Net Current ContractWithCustomerAssetNetCurrent	92405000	usd
CY2022Q4	us-gaap	Contract With Customer Liability Current ContractWithCustomerLiabilityCurrent	241340000	usd
CY2021Q4	us-gaap	Contract With Customer Liability Current ContractWithCustomerLiabilityCurrent	190403000	usd
CY2022Q4	ttek	Contract With Customer Asset Liability Net Current ContractWithCustomerAssetLiabilityNetCurrent	-148935000	usd
CY2021Q4	ttek	Contract With Customer Asset Liability Net Current ContractWithCustomerAssetLiabilityNetCurrent	-86619000	usd
CY2022	us-gaap	Contract With Customer Liability Revenue Recognized ContractWithCustomerLiabilityRevenueRecognized	125000000	usd
CY2021	us-gaap	Contract With Customer Liability Revenue Recognized ContractWithCustomerLiabilityRevenueRecognized	119000000	usd
CY2022Q4	us-gaap	Provision For Loss On Contracts ProvisionForLossOnContracts	10000000	usd
CY2021Q4	us-gaap	Provision For Loss On Contracts ProvisionForLossOnContracts	12700000	usd
CY2022Q4	ttek	Revenue Recognition Estimated Cost To Complete Related Contracts RevenueRecognitionEstimatedCostToCompleteRelatedContracts	80000000	usd
CY2021Q4	ttek	Revenue Recognition Estimated Cost To Complete Related Contracts RevenueRecognitionEstimatedCostToCompleteRelatedContracts	104000000	usd
CY2022Q4	us-gaap	Billed Contract Receivables BilledContractReceivables	491700000	usd
CY2021Q4	us-gaap	Billed Contract Receivables BilledContractReceivables	432814000	usd
CY2022Q4	us-gaap	Unbilled Contracts Receivable UnbilledContractsReceivable	267161000	usd
CY2021Q4	us-gaap	Unbilled Contracts Receivable UnbilledContractsReceivable	240536000	usd
CY2022Q4	us-gaap	Accounts Receivable Gross Current AccountsReceivableGrossCurrent	758861000	usd
CY2021Q4	us-gaap	Accounts Receivable Gross Current AccountsReceivableGrossCurrent	673350000	usd
CY2022Q4	us-gaap	Allowance For Doubtful Accounts Receivable Current AllowanceForDoubtfulAccountsReceivableCurrent	3749000	usd
CY2021Q4	us-gaap	Allowance For Doubtful Accounts Receivable Current AllowanceForDoubtfulAccountsReceivableCurrent	4352000	usd
CY2022Q4	us-gaap	Accounts Receivable Net Current AccountsReceivableNetCurrent	755112000	usd
CY2021Q4	us-gaap	Accounts Receivable Net Current AccountsReceivableNetCurrent	668998000	usd
CY2021Q4	ttek	Government Contract Receivable Unbilled Amounts Related To Claims And Requests For Equitable Adjustment On Contract GovernmentContractReceivableUnbilledAmountsRelatedToClaimsAndRequestsForEquitableAdjustmentOnContract	11000000	usd
CY2022Q4	ttek	Government Contract Receivable Unbilled Amounts Related To Claims And Requests For Equitable Adjustment On Contract GovernmentContractReceivableUnbilledAmountsRelatedToClaimsAndRequestsForEquitableAdjustmentOnContract	0	usd
CY2022Q4	us-gaap	Revenue Remaining Performance Obligation RevenueRemainingPerformanceObligation	3700000000	usd
CY2022Q4	us-gaap	Revenue Remaining Performance Obligation RevenueRemainingPerformanceObligation	2394090000	usd
CY2022Q4	us-gaap	Revenue Remaining Performance Obligation RevenueRemainingPerformanceObligation	1327544000	usd
CY2022Q4	us-gaap	Revenue Remaining Performance Obligation RevenueRemainingPerformanceObligation	3721634000	usd
CY2022	ttek	Revenue Remaining Performance Obligation Termination Notice Period One RevenueRemainingPerformanceObligationTerminationNoticePeriodOne	P30D
CY2022	ttek	Revenue Remaining Performance Obligation Termination Notice Period Two RevenueRemainingPerformanceObligationTerminationNoticePeriodTwo	P60Y
CY2022	ttek	Revenue Remaining Performance Obligation Termination Notice Period Three RevenueRemainingPerformanceObligationTerminationNoticePeriodThree	P90D
CY2022	us-gaap	Stock Repurchased During Period Shares StockRepurchasedDuringPeriodShares	1341679	shares
CY2022	us-gaap	Treasury Stock Acquired Average Cost Per Share TreasuryStockAcquiredAverageCostPerShare	149.07
CY2022	us-gaap	Stock Repurchased During Period Value StockRepurchasedDuringPeriodValue	200000000	usd
CY2021Q4	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.20
CY2021Q4	us-gaap	Dividends Dividends	10793000	usd
CY2022Q1	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.20
CY2022Q1	us-gaap	Dividends Dividends	10769000	usd
CY2022Q2	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.23
CY2022Q2	us-gaap	Dividends Dividends	12311000	usd
CY2022Q3	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.23
CY2022Q3	us-gaap	Dividends Dividends	12226000	usd
CY2022	us-gaap	Dividends Dividends	46099000	usd
CY2020Q4	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.17
CY2020Q4	us-gaap	Dividends Dividends	9198000	usd
CY2021Q1	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.17
CY2021Q1	us-gaap	Dividends Dividends	9212000	usd
CY2021Q2	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.20
CY2021Q2	us-gaap	Dividends Dividends	10831000	usd
CY2021Q3	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.20
CY2021Q3	us-gaap	Dividends Dividends	10800000	usd
CY2021	us-gaap	Dividends Dividends	40041000	usd
CY2022	ttek	Number Of Acquisitions NumberOfAcquisitions	4	acquisition
CY2021	ttek	Fair Value Adjustments To Contingent Consideration FairValueAdjustmentsToContingentConsideration	3300000	usd
CY2020	ttek	Fair Value Adjustments To Contingent Consideration FairValueAdjustmentsToContingentConsideration	15000000	usd
CY2022Q4	us-gaap	Business Combination Contingent Consideration Liability BusinessCombinationContingentConsiderationLiability	65600000	usd
CY2022Q4	us-gaap	Goodwill Goodwill	1110412000	usd
CY2022Q3	us-gaap	Goodwill Impairment Loss GoodwillImpairmentLoss	0	usd
CY2020Q3	us-gaap	Goodwill Goodwill	993498000	usd
CY2021	us-gaap	Goodwill Acquired During Period GoodwillAcquiredDuringPeriod	90591000	usd
CY2021	us-gaap	Goodwill Translation And Purchase Accounting Adjustments GoodwillTranslationAndPurchaseAccountingAdjustments	24489000	usd
CY2021Q4	us-gaap	Goodwill Goodwill	1108578000	usd
CY2022	us-gaap	Goodwill Transfers GoodwillTransfers	0	usd
CY2022	us-gaap	Goodwill Acquired During Period GoodwillAcquiredDuringPeriod	68683000	usd
CY2022	us-gaap	Goodwill Translation And Purchase Accounting Adjustments GoodwillTranslationAndPurchaseAccountingAdjustments	-66849000	usd
CY2022Q3	us-gaap	Reporting Unit Percentage Of Fair Value In Excess Of Carrying Amount ReportingUnitPercentageOfFairValueInExcessOfCarryingAmount	1.65
CY2022Q4	us-gaap	Finite Lived Intangible Assets Gross FiniteLivedIntangibleAssetsGross	87673000	usd
CY2022Q4	us-gaap	Finite Lived Intangible Assets Accumulated Amortization FiniteLivedIntangibleAssetsAccumulatedAmortization	58510000	usd
CY2022Q4	us-gaap	Finite Lived Intangible Assets Net FiniteLivedIntangibleAssetsNet	29163000	usd
CY2021Q4	us-gaap	Finite Lived Intangible Assets Gross FiniteLivedIntangibleAssetsGross	118971000	usd
CY2021Q4	us-gaap	Finite Lived Intangible Assets Accumulated Amortization FiniteLivedIntangibleAssetsAccumulatedAmortization	80981000	usd
CY2021Q4	us-gaap	Finite Lived Intangible Assets Net FiniteLivedIntangibleAssetsNet	37990000	usd
CY2022	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	13200000	usd
CY2021	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	11500000	usd
CY2020	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	11600000	usd
CY2022	us-gaap	Finite Lived Intangible Assets Translation And Purchase Accounting Adjustments FiniteLivedIntangibleAssetsTranslationAndPurchaseAccountingAdjustments	-5300000	usd
CY2022Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Next Twelve Months FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths	9788000	usd
CY2022Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Two FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo	5244000	usd
CY2022Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Three FiniteLivedIntangibleAssetsAmortizationExpenseYearThree	4411000	usd
CY2022Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Four FiniteLivedIntangibleAssetsAmortizationExpenseYearFour	3590000	usd
CY2022Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Five FiniteLivedIntangibleAssetsAmortizationExpenseYearFive	2168000	usd
CY2022Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense After Year Five FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive	3962000	usd
CY2022Q4	us-gaap	Finite Lived Intangible Assets Net FiniteLivedIntangibleAssetsNet	29163000	usd
CY2022	us-gaap	Income Loss From Continuing Operations Before Income Taxes Domestic IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic	262428000	usd
CY2022Q4	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	129138000	usd
CY2021Q4	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	131242000	usd
CY2022Q4	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	96822000	usd
CY2021Q4	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	93509000	usd
CY2022Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	32316000	usd
CY2021Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	37733000	usd
CY2022	us-gaap	Depreciation Depreciation	13900000	usd
CY2021	us-gaap	Depreciation Depreciation	12300000	usd
CY2020	us-gaap	Depreciation Depreciation	13000000	usd
CY2021	us-gaap	Income Loss From Continuing Operations Before Income Taxes Domestic IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic	211222000	usd
CY2020	us-gaap	Income Loss From Continuing Operations Before Income Taxes Domestic IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic	209443000	usd
CY2022	us-gaap	Income Loss From Continuing Operations Before Income Taxes Foreign IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign	86338000	usd
CY2021	us-gaap	Income Loss From Continuing Operations Before Income Taxes Foreign IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign	55648000	usd
CY2020	us-gaap	Income Loss From Continuing Operations Before Income Taxes Foreign IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign	18548000	usd
CY2022	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	348766000	usd
CY2021	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	266870000	usd
CY2020	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	227991000	usd
CY2022	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	47447000	usd
CY2021	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	41056000	usd
CY2020	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	24102000	usd
CY2022	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	9613000	usd
CY2021	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	9893000	usd
CY2020	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	6872000	usd
CY2022	us-gaap	Current Foreign Tax Expense Benefit CurrentForeignTaxExpenseBenefit	26332000	usd
CY2021	us-gaap	Current Foreign Tax Expense Benefit CurrentForeignTaxExpenseBenefit	18887000	usd
CY2020	us-gaap	Current Foreign Tax Expense Benefit CurrentForeignTaxExpenseBenefit	20398000	usd
CY2022	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	83392000	usd
CY2021	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	69836000	usd
CY2020	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	51372000	usd
CY2022	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	-424000	usd
CY2021	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	-6034000	usd
CY2020	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	2187000	usd
CY2022	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	-382000	usd
CY2021	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	-2060000	usd
CY2020	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	870000	usd
CY2022	us-gaap	Deferred Foreign Income Tax Expense Benefit DeferredForeignIncomeTaxExpenseBenefit	3016000	usd
CY2021	us-gaap	Deferred Foreign Income Tax Expense Benefit DeferredForeignIncomeTaxExpenseBenefit	-27703000	usd
CY2020	us-gaap	Deferred Foreign Income Tax Expense Benefit DeferredForeignIncomeTaxExpenseBenefit	-328000	usd
CY2022	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	2210000	usd
CY2021	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-35797000	usd
CY2020	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	2729000	usd
CY2022	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	85602000	usd
CY2021	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	34039000	usd
CY2020	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	54101000	usd
CY2022	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.210
CY2021	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.210
CY2020	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.210
CY2022	us-gaap	Effective Income Tax Rate Reconciliation State And Local Income Taxes EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes	0.021
CY2021	us-gaap	Effective Income Tax Rate Reconciliation State And Local Income Taxes EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes	0.023
CY2020	us-gaap	Effective Income Tax Rate Reconciliation State And Local Income Taxes EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes	0.027
CY2022	us-gaap	Effective Income Tax Rate Reconciliation Tax Credits Research EffectiveIncomeTaxRateReconciliationTaxCreditsResearch	0.010
CY2021	us-gaap	Effective Income Tax Rate Reconciliation Tax Credits Research EffectiveIncomeTaxRateReconciliationTaxCreditsResearch	0.026
CY2020	us-gaap	Tax Adjustments Settlements And Unusual Provisions TaxAdjustmentsSettlementsAndUnusualProvisions	0	usd
CY2020	us-gaap	Effective Income Tax Rate Reconciliation Tax Credits Research EffectiveIncomeTaxRateReconciliationTaxCreditsResearch	0.022
CY2022	us-gaap	Effective Income Tax Rate Reconciliation Foreign Income Tax Rate Differential EffectiveIncomeTaxRateReconciliationForeignIncomeTaxRateDifferential	0.010
CY2021	us-gaap	Effective Income Tax Rate Reconciliation Foreign Income Tax Rate Differential EffectiveIncomeTaxRateReconciliationForeignIncomeTaxRateDifferential	0.009
CY2020	us-gaap	Effective Income Tax Rate Reconciliation Foreign Income Tax Rate Differential EffectiveIncomeTaxRateReconciliationForeignIncomeTaxRateDifferential	0.007
CY2022	us-gaap	Effective Income Tax Rate Reconciliation Tax Exempt Income EffectiveIncomeTaxRateReconciliationTaxExemptIncome	0
CY2021	us-gaap	Effective Income Tax Rate Reconciliation Tax Exempt Income EffectiveIncomeTaxRateReconciliationTaxExemptIncome	0.010
CY2020	us-gaap	Effective Income Tax Rate Reconciliation Tax Exempt Income EffectiveIncomeTaxRateReconciliationTaxExemptIncome	0.011
CY2022	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense Impairment Losses EffectiveIncomeTaxRateReconciliationNondeductibleExpenseImpairmentLosses	0
CY2021	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense Impairment Losses EffectiveIncomeTaxRateReconciliationNondeductibleExpenseImpairmentLosses	0
CY2020	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense Impairment Losses EffectiveIncomeTaxRateReconciliationNondeductibleExpenseImpairmentLosses	0.015
CY2022	ttek	Effective Income Tax Rate Reconciliation Sharebased Payment Arrangement Percent EffectiveIncomeTaxRateReconciliationSharebasedPaymentArrangementPercent	-0.020
CY2021	ttek	Effective Income Tax Rate Reconciliation Sharebased Payment Arrangement Percent EffectiveIncomeTaxRateReconciliationSharebasedPaymentArrangementPercent	-0.033
CY2020	ttek	Effective Income Tax Rate Reconciliation Sharebased Payment Arrangement Percent EffectiveIncomeTaxRateReconciliationSharebasedPaymentArrangementPercent	-0.022
CY2022	us-gaap	Effective Income Tax Rate Reconciliation Change In Deferred Tax Assets Valuation Allowance EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance	0.002
CY2021	us-gaap	Effective Income Tax Rate Reconciliation Change In Deferred Tax Assets Valuation Allowance EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance	-0.093
CY2020	us-gaap	Effective Income Tax Rate Reconciliation Change In Deferred Tax Assets Valuation Allowance EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance	0.016
CY2022	ttek	Effective Income Tax Rate Reconciliation Change In Uncertain Tax Positions Percent EffectiveIncomeTaxRateReconciliationChangeInUncertainTaxPositionsPercent	-0.011
CY2021	ttek	Effective Income Tax Rate Reconciliation Change In Uncertain Tax Positions Percent EffectiveIncomeTaxRateReconciliationChangeInUncertainTaxPositionsPercent	0.017
CY2020	ttek	Effective Income Tax Rate Reconciliation Change In Uncertain Tax Positions Percent EffectiveIncomeTaxRateReconciliationChangeInUncertainTaxPositionsPercent	0.004
CY2022	us-gaap	Effective Income Tax Rate Reconciliation Prior Year Income Taxes EffectiveIncomeTaxRateReconciliationPriorYearIncomeTaxes	0.014
CY2021	us-gaap	Effective Income Tax Rate Reconciliation Prior Year Income Taxes EffectiveIncomeTaxRateReconciliationPriorYearIncomeTaxes	-0.037
CY2020	us-gaap	Effective Income Tax Rate Reconciliation Prior Year Income Taxes EffectiveIncomeTaxRateReconciliationPriorYearIncomeTaxes	0.008
CY2022	ttek	Effective Income Tax Rate Reconciliation Nondeductible Expense Employee Compensation Percent EffectiveIncomeTaxRateReconciliationNondeductibleExpenseEmployeeCompensationPercent	0.019
CY2021	ttek	Effective Income Tax Rate Reconciliation Nondeductible Expense Employee Compensation Percent EffectiveIncomeTaxRateReconciliationNondeductibleExpenseEmployeeCompensationPercent	0.020
CY2020	ttek	Effective Income Tax Rate Reconciliation Nondeductible Expense Employee Compensation Percent EffectiveIncomeTaxRateReconciliationNondeductibleExpenseEmployeeCompensationPercent	0.002
CY2022	us-gaap	Effective Income Tax Rate Reconciliation Repatriation Of Foreign Earnings EffectiveIncomeTaxRateReconciliationRepatriationOfForeignEarnings	0.001
CY2021	us-gaap	Effective Income Tax Rate Reconciliation Repatriation Of Foreign Earnings EffectiveIncomeTaxRateReconciliationRepatriationOfForeignEarnings	0.021
CY2020	us-gaap	Effective Income Tax Rate Reconciliation Repatriation Of Foreign Earnings EffectiveIncomeTaxRateReconciliationRepatriationOfForeignEarnings	0
CY2022	ttek	Effective Income Tax Rate Reconciliation Unremitted Foreign Earnings Percent EffectiveIncomeTaxRateReconciliationUnremittedForeignEarningsPercent	-0.002
CY2021	ttek	Effective Income Tax Rate Reconciliation Unremitted Foreign Earnings Percent EffectiveIncomeTaxRateReconciliationUnremittedForeignEarningsPercent	0.010
CY2020	ttek	Effective Income Tax Rate Reconciliation Unremitted Foreign Earnings Percent EffectiveIncomeTaxRateReconciliationUnremittedForeignEarningsPercent	0
CY2022	ttek	Effective Income Tax Rate Reconciliation Other Non Recurring Adjustments To Deferred Taxes Percent EffectiveIncomeTaxRateReconciliationOtherNonRecurringAdjustmentsToDeferredTaxesPercent	0.001
CY2021	ttek	Effective Income Tax Rate Reconciliation Other Non Recurring Adjustments To Deferred Taxes Percent EffectiveIncomeTaxRateReconciliationOtherNonRecurringAdjustmentsToDeferredTaxesPercent	0.008
CY2020	ttek	Effective Income Tax Rate Reconciliation Other Non Recurring Adjustments To Deferred Taxes Percent EffectiveIncomeTaxRateReconciliationOtherNonRecurringAdjustmentsToDeferredTaxesPercent	-0.013
CY2022	us-gaap	Effective Income Tax Rate Reconciliation Other Adjustments EffectiveIncomeTaxRateReconciliationOtherAdjustments	0.010
CY2021	us-gaap	Effective Income Tax Rate Reconciliation Other Adjustments EffectiveIncomeTaxRateReconciliationOtherAdjustments	0.009
CY2020	us-gaap	Effective Income Tax Rate Reconciliation Other Adjustments EffectiveIncomeTaxRateReconciliationOtherAdjustments	0.016
CY2022	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.245
CY2021	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.128
CY2020	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.237
CY2022	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.245
CY2021	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.128
CY2020	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.237
CY2022	us-gaap	Effective Income Tax Rate Reconciliation Share Based Compensation Excess Tax Benefit Amount EffectiveIncomeTaxRateReconciliationShareBasedCompensationExcessTaxBenefitAmount	-10300000	usd
CY2021	us-gaap	Effective Income Tax Rate Reconciliation Share Based Compensation Excess Tax Benefit Amount EffectiveIncomeTaxRateReconciliationShareBasedCompensationExcessTaxBenefitAmount	-12900000	usd
CY2020	us-gaap	Effective Income Tax Rate Reconciliation Share Based Compensation Excess Tax Benefit Amount EffectiveIncomeTaxRateReconciliationShareBasedCompensationExcessTaxBenefitAmount	-8300000	usd
CY2022	ttek	Effective Income Tax Rate Reconciliation Excluding Valuation Allowance Release Non Deductible Goodwill Impairment Transaction Costs And Excess Tax Benefits On Share Based Payments Percent EffectiveIncomeTaxRateReconciliationExcludingValuationAllowanceReleaseNonDeductibleGoodwillImpairmentTransactionCostsAndExcessTaxBenefitsOnShareBasedPaymentsPercent	0.275
CY2021	ttek	Effective Income Tax Rate Reconciliation Excluding Valuation Allowance Release Non Deductible Goodwill Impairment Transaction Costs And Excess Tax Benefits On Share Based Payments Percent EffectiveIncomeTaxRateReconciliationExcludingValuationAllowanceReleaseNonDeductibleGoodwillImpairmentTransactionCostsAndExcessTaxBenefitsOnShareBasedPaymentsPercent	0.257
CY2020	ttek	Effective Income Tax Rate Reconciliation Excluding Valuation Allowance Release Non Deductible Goodwill Impairment Transaction Costs And Excess Tax Benefits On Share Based Payments Percent EffectiveIncomeTaxRateReconciliationExcludingValuationAllowanceReleaseNonDeductibleGoodwillImpairmentTransactionCostsAndExcessTaxBenefitsOnShareBasedPaymentsPercent	0.256
CY2022Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards State And Local DeferredTaxAssetsOperatingLossCarryforwardsStateAndLocal	1238000	usd
CY2021Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards State And Local DeferredTaxAssetsOperatingLossCarryforwardsStateAndLocal	1342000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Reserves DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsReserves	5023000	usd
CY2021Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Reserves DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsReserves	6662000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Allowance For Doubtful Accounts DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAllowanceForDoubtfulAccounts	4986000	usd
CY2021Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Allowance For Doubtful Accounts DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAllowanceForDoubtfulAccounts	5917000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Accrued Liabilities DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAccruedLiabilities	35973000	usd
CY2021Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Accrued Liabilities DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAccruedLiabilities	41657000	usd
CY2022Q4	ttek	Deferred Tax Assets Leasing Arrangements DeferredTaxAssetsLeasingArrangements	49618000	usd
CY2021Q4	ttek	Deferred Tax Assets Leasing Arrangements DeferredTaxAssetsLeasingArrangements	60181000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Share Based Compensation Cost DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost	2925000	usd
CY2021Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Share Based Compensation Cost DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost	3560000	usd
CY2022Q4	ttek	Deferred Tax Assets Unbilled Revenue DeferredTaxAssetsUnbilledRevenue	4885000	usd
CY2021Q4	ttek	Deferred Tax Assets Unbilled Revenue DeferredTaxAssetsUnbilledRevenue	0	usd
CY2022Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards Domestic DeferredTaxAssetsOperatingLossCarryforwardsDomestic	41648000	usd
CY2021Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards Domestic DeferredTaxAssetsOperatingLossCarryforwardsDomestic	54825000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	12286000	usd
CY2021Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	13040000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Net DeferredTaxAssetsNet	134010000	usd
CY2021Q4	us-gaap	Deferred Tax Assets Net DeferredTaxAssetsNet	161104000	usd
CY2022Q4	us-gaap	Deferred Tax Liabilities Tax Deferred Income DeferredTaxLiabilitiesTaxDeferredIncome	0	usd
CY2021Q4	us-gaap	Deferred Tax Liabilities Tax Deferred Income DeferredTaxLiabilitiesTaxDeferredIncome	5595000	usd
CY2022Q4	us-gaap	Deferred Tax Liabilities Prepaid Expenses DeferredTaxLiabilitiesPrepaidExpenses	6065000	usd
CY2021Q4	us-gaap	Deferred Tax Liabilities Prepaid Expenses DeferredTaxLiabilitiesPrepaidExpenses	8136000	usd
CY2022Q4	us-gaap	Deferred Tax Liabilities Leasing Arrangements DeferredTaxLiabilitiesLeasingArrangements	49618000	usd
CY2021Q4	us-gaap	Deferred Tax Liabilities Leasing Arrangements DeferredTaxLiabilitiesLeasingArrangements	60181000	usd
CY2022Q4	us-gaap	Deferred Tax Liabilities Goodwill And Intangible Assets Intangible Assets DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets	42863000	usd
CY2021Q4	us-gaap	Deferred Tax Liabilities Goodwill And Intangible Assets Intangible Assets DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets	40121000	usd
CY2022Q4	us-gaap	Deferred Tax Liabilities Undistributed Foreign Earnings DeferredTaxLiabilitiesUndistributedForeignEarnings	2200000	usd
CY2021Q4	us-gaap	Deferred Tax Liabilities Undistributed Foreign Earnings DeferredTaxLiabilitiesUndistributedForeignEarnings	3136000	usd
CY2022Q4	us-gaap	Deferred Tax Liabilities Property Plant And Equipment DeferredTaxLiabilitiesPropertyPlantAndEquipment	621000	usd
CY2021Q4	us-gaap	Deferred Tax Liabilities Property Plant And Equipment DeferredTaxLiabilitiesPropertyPlantAndEquipment	85000	usd
CY2022Q4	us-gaap	Deferred Income Tax Liabilities DeferredIncomeTaxLiabilities	101367000	usd
CY2021Q4	us-gaap	Deferred Income Tax Liabilities DeferredIncomeTaxLiabilities	117254000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Liabilities Net DeferredTaxAssetsLiabilitiesNet	32643000	usd
CY2021Q4	us-gaap	Deferred Tax Assets Liabilities Net DeferredTaxAssetsLiabilitiesNet	43850000	usd
CY2022Q4	us-gaap	Undistributed Earnings Of Foreign Subsidiaries UndistributedEarningsOfForeignSubsidiaries	81700000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	12300000	usd
CY2022Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	8900000	usd
CY2021Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	12899000	usd
CY2020Q3	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	9228000	usd
CY2019Q3	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	9169000	usd
CY2022	us-gaap	Unrecognized Tax Benefits Increases Resulting From Current Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions	0	usd
CY2021	us-gaap	Unrecognized Tax Benefits Increases Resulting From Current Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions	2171000	usd
CY2020	us-gaap	Unrecognized Tax Benefits Increases Resulting From Current Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions	700000	usd
CY2022	us-gaap	Unrecognized Tax Benefits Increases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions	0	usd
CY2021	us-gaap	Unrecognized Tax Benefits Increases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions	1500000	usd
CY2020	us-gaap	Unrecognized Tax Benefits Increases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions	0	usd
CY2022	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions	3014000	usd
CY2021	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions	0	usd
CY2022	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Gross ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross	0	shares
CY2020	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions	641000	usd
CY2022	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Settlements With Taxing Authorities UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities	977000	usd
CY2021	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Settlements With Taxing Authorities UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities	0	usd
CY2020	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Settlements With Taxing Authorities UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities	0	usd
CY2022Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	8908000	usd
CY2021Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	12899000	usd
CY2020Q3	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	9228000	usd
CY2022	us-gaap	Unrecognized Tax Benefits Income Tax Penalties And Interest Expense UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestExpense	500000	usd
CY2021	us-gaap	Unrecognized Tax Benefits Income Tax Penalties And Interest Expense UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestExpense	800000	usd
CY2020	us-gaap	Unrecognized Tax Benefits Income Tax Penalties And Interest Expense UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestExpense	800000	usd
CY2022	us-gaap	Tax Adjustments Settlements And Unusual Provisions TaxAdjustmentsSettlementsAndUnusualProvisions	-400000	usd
CY2021	us-gaap	Tax Adjustments Settlements And Unusual Provisions TaxAdjustmentsSettlementsAndUnusualProvisions	0	usd
CY2022Q4	us-gaap	Unrecognized Tax Benefits Income Tax Penalties And Interest Accrued UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued	5300000	usd
CY2021Q4	us-gaap	Unrecognized Tax Benefits Income Tax Penalties And Interest Accrued UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued	5200000	usd
CY2020Q3	us-gaap	Unrecognized Tax Benefits Income Tax Penalties And Interest Accrued UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued	4400000	usd
CY2022Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Two LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo	12500000	usd
CY2022Q4	us-gaap	Long Term Debt LongTermDebt	258754000	usd
CY2021Q4	us-gaap	Long Term Debt LongTermDebt	212500000	usd
CY2022Q4	us-gaap	Long Term Debt Current LongTermDebtCurrent	12504000	usd
CY2021Q4	us-gaap	Long Term Debt Current LongTermDebtCurrent	12500000	usd
CY2022Q4	us-gaap	Long Term Debt Noncurrent LongTermDebtNoncurrent	246250000	usd
CY2021Q4	us-gaap	Long Term Debt Noncurrent LongTermDebtNoncurrent	200000000	usd
CY2022Q1	ttek	Debt Instrument Annual Principal Payment Amortization Percentage DebtInstrumentAnnualPrincipalPaymentAmortizationPercentage	0.05
CY2022Q4	us-gaap	Bank Overdrafts BankOverdrafts	0	usd
CY2021	us-gaap	Operating Lease Cost OperatingLeaseCost	91076000	usd
CY2022	us-gaap	Sublease Income SubleaseIncome	150000	usd
CY2022Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Next Twelve Months LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths	12504000	usd
CY2022Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Three LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree	12500000	usd
CY2022Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Four LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour	12500000	usd
CY2022Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Five LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive	208750000	usd
CY2022Q4	us-gaap	Debt Longterm And Shortterm Combined Amount DebtLongtermAndShorttermCombinedAmount	258754000	usd
CY2022Q4	us-gaap	Lessee Operating Lease Renewal Term LesseeOperatingLeaseRenewalTerm	P5Y
CY2022	us-gaap	Operating Lease Cost OperatingLeaseCost	86725000	usd
CY2021	us-gaap	Sublease Income SubleaseIncome	106000	usd
CY2022	us-gaap	Lease Cost LeaseCost	86575000	usd
CY2021	us-gaap	Lease Cost LeaseCost	90970000	usd
CY2022	us-gaap	Operating Lease Payments OperatingLeasePayments	71365000	usd
CY2021	us-gaap	Operating Lease Payments OperatingLeasePayments	81943000	usd
CY2022	us-gaap	Right Of Use Asset Obtained In Exchange For Operating Lease Liability RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability	44096000	usd
CY2021	us-gaap	Right Of Use Asset Obtained In Exchange For Operating Lease Liability RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability	72076000	usd
CY2022Q4	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	182319000	usd
CY2021Q4	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	215422000	usd
CY2022Q4	us-gaap	Operating Lease Liability Current OperatingLeaseLiabilityCurrent	57865000	usd
CY2021Q4	us-gaap	Operating Lease Liability Current OperatingLeaseLiabilityCurrent	67452000	usd
CY2022Q4	us-gaap	Operating Lease Liability Noncurrent OperatingLeaseLiabilityNoncurrent	146285000	usd
CY2021Q4	us-gaap	Operating Lease Liability Noncurrent OperatingLeaseLiabilityNoncurrent	174285000	usd
CY2022Q4	us-gaap	Operating Lease Liability OperatingLeaseLiability	204150000	usd
CY2021Q4	us-gaap	Operating Lease Liability OperatingLeaseLiability	241737000	usd
CY2022Q4	us-gaap	Operating Lease Weighted Average Remaining Lease Term1 OperatingLeaseWeightedAverageRemainingLeaseTerm1	P5Y
CY2021Q4	us-gaap	Operating Lease Weighted Average Remaining Lease Term1 OperatingLeaseWeightedAverageRemainingLeaseTerm1	P5Y
CY2022Q4	us-gaap	Operating Lease Weighted Average Discount Rate Percent OperatingLeaseWeightedAverageDiscountRatePercent	0.022
CY2021Q4	us-gaap	Operating Lease Weighted Average Discount Rate Percent OperatingLeaseWeightedAverageDiscountRatePercent	0.022
CY2022Q4	us-gaap	Lessee Operating Lease Liability Payments Due Next Twelve Months LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths	61703000	usd
CY2022Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Two LesseeOperatingLeaseLiabilityPaymentsDueYearTwo	47520000	usd
CY2022Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Three LesseeOperatingLeaseLiabilityPaymentsDueYearThree	35466000	usd
CY2022Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Four LesseeOperatingLeaseLiabilityPaymentsDueYearFour	23481000	usd
CY2022Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Five LesseeOperatingLeaseLiabilityPaymentsDueYearFive	16961000	usd
CY2022Q4	us-gaap	Lessee Operating Lease Liability Payments Due After Year Five LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive	31927000	usd
CY2022Q4	us-gaap	Lessee Operating Lease Liability Payments Due LesseeOperatingLeaseLiabilityPaymentsDue	217058000	usd
CY2022Q4	us-gaap	Lessee Operating Lease Liability Undiscounted Excess Amount LesseeOperatingLeaseLiabilityUndiscountedExcessAmount	12908000	usd
CY2022Q4	us-gaap	Operating Lease Liability OperatingLeaseLiability	204150000	usd
CY2022Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber	168000	shares
CY2022	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	26227000	usd
CY2021	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	23067000	usd
CY2020	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	19424000	usd
CY2022	us-gaap	Employee Service Share Based Compensation Tax Benefit From Compensation Expense EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense	5377000	usd
CY2021	us-gaap	Employee Service Share Based Compensation Tax Benefit From Compensation Expense EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense	4910000	usd
CY2020	us-gaap	Employee Service Share Based Compensation Tax Benefit From Compensation Expense EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense	4318000	usd
CY2022	us-gaap	Allocated Share Based Compensation Expense Net Of Tax AllocatedShareBasedCompensationExpenseNetOfTax	20850000	usd
CY2021	us-gaap	Allocated Share Based Compensation Expense Net Of Tax AllocatedShareBasedCompensationExpenseNetOfTax	18157000	usd
CY2020	us-gaap	Allocated Share Based Compensation Expense Net Of Tax AllocatedShareBasedCompensationExpenseNetOfTax	15106000	usd
CY2022Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Vested And Expected To Vest Outstanding Aggregate Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingAggregateIntrinsicValue	15086000	usd
CY2022Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice	38.62
CY2022	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Exercisable Weighted Average Remaining Contractual Term1 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1	P4Y14D
CY2022Q4	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Exercisable Intrinsic Value1 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1	15086000	usd
CY2021Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	214000	shares
CY2021Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice	38.80
CY2022	us-gaap	Stock Issued During Period Shares Stock Options Exercised StockIssuedDuringPeriodSharesStockOptionsExercised	46000	shares
CY2022	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Exercises In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice	39.44
CY2022	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Forfeitures In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod	0	shares
CY2022	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Forfeitures In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice	0
CY2022Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	168000	shares
CY2022Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice	38.62
CY2022	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Outstanding Weighted Average Remaining Contractual Term2 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2	P4Y14D
CY2022Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue	15086000	usd
CY2022Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Vested And Expected To Vest Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingNumber	168000	shares
CY2022Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Vested And Expected To Vest Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageExercisePrice	38.62
CY2022	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Vested And Expected To Vest Outstanding Weighted Average Remaining Contractual Term1 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageRemainingContractualTerm1	P4Y14D
CY2021	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Gross ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross	0	shares
CY2022	us-gaap	Defined Contribution Plan Cost Recognized DefinedContributionPlanCostRecognized	29300000	usd
CY2021	us-gaap	Defined Contribution Plan Cost Recognized DefinedContributionPlanCostRecognized	26900000	usd
CY2020	us-gaap	Defined Contribution Plan Cost Recognized DefinedContributionPlanCostRecognized	25000000	usd
CY2022Q4	us-gaap	Deferred Compensation Plan Assets DeferredCompensationPlanAssets	36700000	usd
CY2021Q4	us-gaap	Deferred Compensation Plan Assets DeferredCompensationPlanAssets	41400000	usd
CY2022Q4	us-gaap	Deferred Compensation Liability Classified Noncurrent DeferredCompensationLiabilityClassifiedNoncurrent	36300000	usd
CY2021Q4	us-gaap	Deferred Compensation Liability Classified Noncurrent DeferredCompensationLiabilityClassifiedNoncurrent	41100000	usd
CY2022Q4	ttek	Defined Benefit Plan Pension Plan Open For New Entrants Maximum Age DefinedBenefitPlanPensionPlanOpenForNewEntrantsMaximumAge	P24Y
CY2022Q4	us-gaap	Defined Benefit Plan Fair Value Of Plan Assets DefinedBenefitPlanFairValueOfPlanAssets	36250000	usd
CY2021Q4	us-gaap	Defined Benefit Plan Fair Value Of Plan Assets DefinedBenefitPlanFairValueOfPlanAssets	65836000	usd
CY2022Q4	us-gaap	Defined Benefit Plan Benefit Obligation DefinedBenefitPlanBenefitObligation	33006000	usd
CY2021Q4	us-gaap	Defined Benefit Plan Benefit Obligation DefinedBenefitPlanBenefitObligation	64830000	usd
CY2022Q4	us-gaap	Defined Benefit Plan Funded Status Of Plan DefinedBenefitPlanFundedStatusOfPlan	3244000	usd
CY2021Q4	us-gaap	Defined Benefit Plan Funded Status Of Plan DefinedBenefitPlanFundedStatusOfPlan	1006000	usd
CY2022	us-gaap	Defined Benefit Plan Benefit Obligation Benefits Paid DefinedBenefitPlanBenefitObligationBenefitsPaid	1000000	usd
CY2022	us-gaap	Net Income Loss Available To Common Stockholders Diluted NetIncomeLossAvailableToCommonStockholdersDiluted	263125000	usd
CY2021	us-gaap	Net Income Loss Available To Common Stockholders Diluted NetIncomeLossAvailableToCommonStockholdersDiluted	232810000	usd
CY2022Q4	us-gaap	Defined Benefit Plan Fair Value Of Plan Assets DefinedBenefitPlanFairValueOfPlanAssets	36250000	usd
CY2021Q4	us-gaap	Defined Benefit Plan Fair Value Of Plan Assets DefinedBenefitPlanFairValueOfPlanAssets	65836000	usd
CY2022	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	263125000	usd
CY2021	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	232810000	usd
CY2020	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	173859000	usd
CY2020	us-gaap	Net Income Loss Available To Common Stockholders Diluted NetIncomeLossAvailableToCommonStockholdersDiluted	173859000	usd
CY2021	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	0	shares
CY2022	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	53620000	shares
CY2021	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	54078000	shares
CY2020	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	54235000	shares
CY2022	us-gaap	Incremental Common Shares Attributable To Share Based Payment Arrangements IncrementalCommonSharesAttributableToShareBasedPaymentArrangements	543000	shares
CY2021	us-gaap	Incremental Common Shares Attributable To Share Based Payment Arrangements IncrementalCommonSharesAttributableToShareBasedPaymentArrangements	597000	shares
CY2020	us-gaap	Incremental Common Shares Attributable To Share Based Payment Arrangements IncrementalCommonSharesAttributableToShareBasedPaymentArrangements	787000	shares
CY2022	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	54163000	shares
CY2021	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	54675000	shares
CY2020	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	55022000	shares
CY2022	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	4.91
CY2021	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	4.31
CY2020	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	3.21
CY2022	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	4.86
CY2021	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	4.26
CY2020	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	3.16
CY2022	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	0	shares
CY2020	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	0	shares
CY2022	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification And Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax	11800000	usd
CY2021	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification And Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax	6100000	usd
CY2020	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification And Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax	-4600000	usd
CY2022	ttek	Fair Value Adjustments To Contingent Consideration FairValueAdjustmentsToContingentConsideration	-300000	usd
CY2021	ttek	Fair Value Adjustments To Contingent Consideration FairValueAdjustmentsToContingentConsideration	3300000	usd
CY2020	ttek	Fair Value Adjustments To Contingent Consideration FairValueAdjustmentsToContingentConsideration	15000000	usd
CY2019Q3	ttek	Loss Contingency Number Of Actions LossContingencyNumberOfActions	3	action
CY2022	us-gaap	Number Of Reportable Segments NumberOfReportableSegments	2	segment
CY2022	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	3504048000	usd
CY2021	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	3213513000	usd
CY2020	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	2994891000	usd
CY2022	us-gaap	Operating Income Loss OperatingIncomeLoss	340446000	usd
CY2021	us-gaap	Operating Income Loss OperatingIncomeLoss	278701000	usd
CY2020	us-gaap	Operating Income Loss OperatingIncomeLoss	241091000	usd
CY2022	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	13200000	usd
CY2021	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	11500000	usd
CY2020	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	11600000	usd
CY2020	us-gaap	Goodwill Impairment Loss GoodwillImpairmentLoss	15800000	usd
CY2022Q4	us-gaap	Assets Assets	2622776000	usd
CY2021Q4	us-gaap	Assets Assets	2576562000	usd
CY2022	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	3504048000	usd
CY2021	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	3213513000	usd
CY2020	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	2994891000	usd
CY2022Q4	us-gaap	Noncurrent Assets NoncurrentAssets	277180000	usd
CY2021Q4	us-gaap	Noncurrent Assets NoncurrentAssets	303460000	usd
CY2022	us-gaap	Related Party Transaction Other Revenues From Transactions With Related Party RelatedPartyTransactionOtherRevenuesFromTransactionsWithRelatedParty	96000000	usd
CY2021	us-gaap	Related Party Transaction Other Revenues From Transactions With Related Party RelatedPartyTransactionOtherRevenuesFromTransactionsWithRelatedParty	95500000	usd
CY2020	us-gaap	Related Party Transaction Other Revenues From Transactions With Related Party RelatedPartyTransactionOtherRevenuesFromTransactionsWithRelatedParty	88200000	usd
CY2022	us-gaap	Related Party Transaction Expenses From Transactions With Related Party RelatedPartyTransactionExpensesFromTransactionsWithRelatedParty	91700000	usd
CY2021	us-gaap	Related Party Transaction Expenses From Transactions With Related Party RelatedPartyTransactionExpensesFromTransactionsWithRelatedParty	92400000	usd
CY2020	us-gaap	Related Party Transaction Expenses From Transactions With Related Party RelatedPartyTransactionExpensesFromTransactionsWithRelatedParty	86400000	usd
CY2022Q1	us-gaap	Operating Income Loss OperatingIncomeLoss	87220000	usd
CY2022Q2	us-gaap	Operating Income Loss OperatingIncomeLoss	74520000	usd
CY2022Q4	us-gaap	Accounts Receivable Related Parties AccountsReceivableRelatedParties	16818000	usd
CY2021Q4	us-gaap	Accounts Receivable Related Parties AccountsReceivableRelatedParties	19082000	usd
CY2022Q4	ttek	Contract With Customer Asset Related Party ContractWithCustomerAssetRelatedParty	2935000	usd
CY2021Q4	ttek	Contract With Customer Asset Related Party ContractWithCustomerAssetRelatedParty	5092000	usd
CY2022Q4	us-gaap	Due To Related Parties Current And Noncurrent DueToRelatedPartiesCurrentAndNoncurrent	3464000	usd
CY2021Q4	us-gaap	Due To Related Parties Current And Noncurrent DueToRelatedPartiesCurrentAndNoncurrent	3026000	usd
CY2022Q4	us-gaap	Unrealized Gain Loss On Foreign Currency Derivatives Net Before Tax UnrealizedGainLossOnForeignCurrencyDerivativesNetBeforeTax	19900000	usd
CY2022Q1	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	858510000	usd
CY2022Q2	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	852744000	usd
CY2022Q3	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	890231000	usd
CY2022Q4	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	902562000	usd
CY2022Q3	us-gaap	Operating Income Loss OperatingIncomeLoss	83905000	usd
CY2022Q4	us-gaap	Operating Income Loss OperatingIncomeLoss	94802000	usd
CY2022Q1	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	68489000	usd
CY2022Q1	us-gaap	Net Income Loss Available To Common Stockholders Diluted NetIncomeLossAvailableToCommonStockholdersDiluted	68489000	usd
CY2022Q2	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	53040000	usd
CY2022Q2	us-gaap	Net Income Loss Available To Common Stockholders Diluted NetIncomeLossAvailableToCommonStockholdersDiluted	53040000	usd
CY2022Q3	us-gaap	Net Income Loss Available To Common Stockholders Diluted NetIncomeLossAvailableToCommonStockholdersDiluted	58650000	usd
CY2022Q3	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	58650000	usd
CY2022Q4	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	82947000	usd
CY2022Q4	us-gaap	Net Income Loss Available To Common Stockholders Diluted NetIncomeLossAvailableToCommonStockholdersDiluted	82947000	usd
CY2022Q1	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.27
CY2022Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.99
CY2022Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.10
CY2022Q4	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.56
CY2022Q1	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.25
CY2022Q2	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.98
CY2022Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.09
CY2022Q4	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.55
CY2022Q1	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	53937000	shares
CY2022Q2	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	53834000	shares
CY2022Q3	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	53507000	shares
CY2022Q4	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	53148000	shares
CY2022Q1	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	54577000	shares
CY2022Q2	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	54346000	shares
CY2022Q3	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	54006000	shares
CY2022Q4	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	53667000	shares
CY2020Q4	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	765104000	usd
CY2021Q1	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	754764000	usd
CY2021Q2	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	801633000	usd
	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	892012000	usd
CY2020Q4	us-gaap	Operating Income Loss OperatingIncomeLoss	66252000	usd
CY2021Q1	us-gaap	Operating Income Loss OperatingIncomeLoss	60807000	usd
CY2021Q2	us-gaap	Operating Income Loss OperatingIncomeLoss	69807000	usd
	us-gaap	Operating Income Loss OperatingIncomeLoss	81836000	usd
CY2020Q4	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	52436000	usd
CY2020Q4	us-gaap	Net Income Loss Available To Common Stockholders Diluted NetIncomeLossAvailableToCommonStockholdersDiluted	52436000	usd
CY2021Q1	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	45517000	usd
CY2021Q1	us-gaap	Net Income Loss Available To Common Stockholders Diluted NetIncomeLossAvailableToCommonStockholdersDiluted	45517000	usd
CY2021Q2	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	51903000	usd
CY2021Q2	us-gaap	Net Income Loss Available To Common Stockholders Diluted NetIncomeLossAvailableToCommonStockholdersDiluted	51903000	usd
	us-gaap	Net Income Loss Available To Common Stockholders Diluted NetIncomeLossAvailableToCommonStockholdersDiluted	82954000	usd
	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	82954000	usd
CY2020Q4	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.97
CY2021Q1	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.84
CY2021Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.96
	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.54
CY2020Q4	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.96
CY2021Q1	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.83
CY2021Q2	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.95
	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.52
CY2020Q4	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	53927000	shares
CY2021Q1	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	54187000	shares
CY2021Q2	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	54117000	shares
	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	54019000	shares
CY2020Q4	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	54637000	shares
CY2021Q1	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	54736000	shares
CY2021Q2	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	54666000	shares
	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	54597000	shares
CY2022	dei	Auditor Firm AuditorFirmId	238

Files In Submission

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$TTEK
TETRA TECH INC Stock $ttek

2022 Q4 Form 10-K Financial Statement

#000083164122000123 Filed on November 25, 2022

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

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$TTEK TETRA TECH INC Stock $ttek

2022 Q4 Form 10-K Financial Statement

#000083164122000123 Filed on November 25, 2022

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$TTEK
TETRA TECH INC Stock $ttek