$ATKR
Atkore Inc. Stock $atkr

$atkr Overview Financials Valuation SEC Filings Company Website

2021 Q3 Form 10-K Financial Statement

#000166613821000163 Filed on November 18, 2021

Income Statement

Concept	2021 Q3	2021	2020 Q3
Revenue	$923.7M	$2.928B	$477.4M
YoY Change	93.49%	65.85%	-4.85%
Cost Of Revenue	$566.4M	$1.802B	$330.4M
YoY Change	71.44%	41.46%	-7.71%
Gross Profit	$357.3M	$1.126B	$147.1M
YoY Change	142.9%	129.1%	2.35%
Gross Profit Margin	38.68%	38.44%	30.81%
Selling, General & Admin	$82.77M	$293.0M	$54.80M
YoY Change	51.04%	33.5%	-19.77%
% of Gross Profit	23.17%	26.03%	37.25%
Research & Development
YoY Change
% of Gross Profit
Depreciation & Amortization	$24.05M	$78.56M	$22.80M
YoY Change	5.49%	5.49%	25.27%
% of Gross Profit	6.73%	6.98%	15.5%
Operating Expenses	$91.35M	$293.0M	$62.90M
YoY Change	45.23%	33.5%	-18.21%
Operating Profit	$266.0M	$799.0M	$84.20M
YoY Change	215.86%	233.51%	26.01%
Interest Expense	-$8.479M	-$32.90M	-$9.600M
YoY Change	-11.68%	-17.88%	26.32%
% of Operating Profit	-3.19%	-4.12%	-11.4%
Other Income/Expense, Net	$812.0K	$18.15M	$400.0K
YoY Change	103.0%	553.66%	-110.26%
Pretax Income	$267.8M	$780.0M	$74.80M
YoY Change	258.0%	286.14%	20.45%
Income Tax	$65.22M	$192.1M	$20.60M
% Of Pretax Income	24.36%	24.63%	27.54%
Net Earnings	$202.6M	$587.9M	$54.20M
YoY Change	273.73%	285.98%	17.83%
Net Earnings / Revenue	21.93%	20.08%	11.35%
Basic Earnings Per Share		$12.38
Diluted Earnings Per Share	$4.339M	$12.19	$1.132M
COMMON SHARES
Basic Shares Outstanding	46.10M shares	46.57M shares	47.26M shares
Diluted Shares Outstanding		47.31M shares

Balance Sheet

Concept	2021 Q3	2021	2020 Q3
SHORT-TERM ASSETS
Cash & Short-Term Investments	$576.3M	$576.3M	$284.5M
YoY Change	102.56%	102.56%	130.55%
Cash & Equivalents	$576.3M	$576.3M	$284.5M
Short-Term Investments
Other Short-Term Assets	$34.25M	$34.25M	$46.90M
YoY Change	-26.98%	-26.98%	35.16%
Inventory	$286.0M	$286.0M	$199.1M
Prepaid Expenses
Receivables	$524.9M	$524.9M	$298.2M
Other Receivables	$0.00	$0.00	$0.00
Total Short-Term Assets	$1.421B	$1.421B	$828.7M
YoY Change	71.53%	71.53%	18.46%
LONG-TERM ASSETS
Property, Plant & Equipment	$275.6M	$316.7M	$243.9M
YoY Change	13.01%	12.08%	-6.45%
Goodwill	$199.0M		$188.2M
YoY Change	5.74%		1.08%
Intangibles	$241.2M		$255.3M
YoY Change	-5.54%		-10.62%
Long-Term Investments
YoY Change
Other Assets	$1.967M	$31.66M	$2.991M
YoY Change	-34.24%	755.68%	-29.84%
Total Long-Term Assets	$788.6M	$788.6M	$729.8M
YoY Change	8.06%	8.06%	-1.03%
TOTAL ASSETS
Total Short-Term Assets	$1.421B	$1.421B	$828.7M
Total Long-Term Assets	$788.6M	$788.6M	$729.8M
Total Assets	$2.210B	$2.210B	$1.559B
YoY Change	41.81%	41.81%	8.46%
SHORT-TERM LIABILITIES
YoY Change
Accounts Payable	$243.2M	$243.2M	$142.6M
YoY Change	70.52%	70.52%	-5.36%
Accrued Expenses	$59.27M	$148.6M	$47.79M
YoY Change	24.04%	76.95%	-11.42%
Deferred Revenue	$80.32M		$35.80M
YoY Change	124.36%		-20.41%
Short-Term Debt	$0.00	$0.00	$0.00
YoY Change
Long-Term Debt Due		$912.0K	$400.0K
YoY Change		128.0%
Total Short-Term Liabilities	$524.9M	$524.9M	$276.2M
YoY Change	90.08%	90.06%	-3.95%
LONG-TERM LIABILITIES
Long-Term Debt	$758.4M	$760.2M	$803.7M
YoY Change	-5.64%	-5.51%	-4.92%
Other Long-Term Liabilities	$11.24M	$42.76M	$11.90M
YoY Change	-5.54%	-43.22%	-8.78%
Total Long-Term Liabilities	$769.6M	$802.9M	$815.6M
YoY Change	-5.64%	-8.74%	-4.98%
TOTAL LIABILITIES
Total Short-Term Liabilities	$524.9M	$524.9M	$276.2M
Total Long-Term Liabilities	$769.6M	$802.9M	$815.6M
Total Liabilities	$1.345B	$1.345B	$1.180B
YoY Change	14.0%	14.0%	-1.99%
SHAREHOLDERS EQUITY
Retained Earnings	$388.7M		-$64.15M
YoY Change	-705.82%		-67.99%
Common Stock	$507.4M		$487.7M
YoY Change	4.04%		2.11%
Preferred Stock
YoY Change
Treasury Stock (at cost)	$2.580M		$2.580M
YoY Change	0.0%		0.0%
Treasury Stock Shares	290.6K shares		260.9K shares
Shareholders Equity	$864.7M	$864.7M	$378.4M
YoY Change
Total Liabilities & Shareholders Equity	$2.210B	$2.210B	$1.559B
YoY Change	41.81%	41.81%	8.46%

Cashflow Statement

Concept	2021 Q3	2021	2020 Q3
OPERATING ACTIVITIES
Net Income	$202.6M	$587.9M	$54.20M
YoY Change	273.73%	285.98%	17.83%
Depreciation, Depletion And Amortization	$24.05M	$78.56M	$22.80M
YoY Change	5.49%	5.49%	25.27%
Cash From Operating Activities	$254.3M	$572.9M	$92.80M
YoY Change	174.01%	130.3%	3.69%
INVESTING ACTIVITIES
Capital Expenditures	-$30.23M	$64.47M	-$8.200M
YoY Change	268.68%	90.92%	-38.35%
Acquisitions		$43.20M
YoY Change
Other Investing Activities	$6.574M	$0.00	$5.500M
YoY Change	19.53%		-137.67%
Cash From Investing Activities	-$23.66M	-$97.96M	-$2.700M
YoY Change	776.22%	256.05%	-90.32%
FINANCING ACTIVITIES
Cash Dividend Paid
YoY Change
Common Stock Issuance & Retirement, Net		$135.1M
YoY Change		1166.56%
Debt Paid & Issued, Net		$835.1M
YoY Change		1987.8%
Cash From Financing Activities	-49.04M	-$184.5M	-44.30M
YoY Change	10.71%	201.5%	16.89%
NET CHANGE
Cash From Operating Activities	254.3M	$572.9M	92.80M
Cash From Investing Activities	-23.66M	-$97.96M	-2.700M
Cash From Financing Activities	-49.04M	-$184.5M	-44.30M
Net Change In Cash	181.6M	$291.8M	45.80M
YoY Change	296.46%	81.19%	93.25%
FREE CASH FLOW
Cash From Operating Activities	$254.3M	$572.9M	$92.80M
Capital Expenditures	-$30.23M	$64.47M	-$8.200M
Free Cash Flow	$284.5M	$508.4M	$101.0M
YoY Change	181.7%	136.49%	-1.75%

Facts In Submission

Frame	Concept Type	Concept / XBRL Key	Value	Unit
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CY2021	dei	Document Fiscal Year Focus DocumentFiscalYearFocus	2021
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CY2021	dei	Current Fiscal Year End Date CurrentFiscalYearEndDate	--09-30
CY2021	dei	City Area Code CityAreaCode	708
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CY2020Q3	us-gaap	Finance Lease Liability Current Statement Of Financial Position Extensible List FinanceLeaseLiabilityCurrentStatementOfFinancialPositionExtensibleList	http://atkore.com/20210930#OperatingAndFinanceLeaseLiabilityCurrent
CY2020Q3	us-gaap	Operating Lease Liability Noncurrent Statement Of Financial Position Extensible List OperatingLeaseLiabilityNoncurrentStatementOfFinancialPositionExtensibleList	http://atkore.com/20210930#OperatingAndFinanceLeaseLiabilityNoncurrent
CY2021Q3	us-gaap	Operating Lease Liability Noncurrent Statement Of Financial Position Extensible List OperatingLeaseLiabilityNoncurrentStatementOfFinancialPositionExtensibleList	http://atkore.com/20210930#OperatingAndFinanceLeaseLiabilityNoncurrent
CY2020Q3	us-gaap	Finance Lease Liability Noncurrent Statement Of Financial Position Extensible List FinanceLeaseLiabilityNoncurrentStatementOfFinancialPositionExtensibleList	http://atkore.com/20210930#OperatingAndFinanceLeaseLiabilityNoncurrent
CY2021Q3	us-gaap	Finance Lease Liability Noncurrent Statement Of Financial Position Extensible List FinanceLeaseLiabilityNoncurrentStatementOfFinancialPositionExtensibleList	http://atkore.com/20210930#OperatingAndFinanceLeaseLiabilityNoncurrent
CY2021	dei	Document Type DocumentType	10-K
CY2021	dei	Document Annual Report DocumentAnnualReport	true
CY2021	dei	Document Period End Date DocumentPeriodEndDate	2021-09-30
CY2021	dei	Document Transition Report DocumentTransitionReport	false
CY2021	dei	Entity File Number EntityFileNumber	001-37793
CY2021	dei	Entity Registrant Name EntityRegistrantName	Atkore Inc.
CY2021	dei	Entity Incorporation State Country Code EntityIncorporationStateCountryCode	DE
CY2021	dei	Entity Tax Identification Number EntityTaxIdentificationNumber	90-0631463
CY2021	dei	Local Phone Number LocalPhoneNumber	339-1610
CY2021	dei	Entity Address Address Line1 EntityAddressAddressLine1	16100 South Lathrop Avenue
CY2021	dei	Entity Address City Or Town EntityAddressCityOrTown	Harvey
CY2021	dei	Entity Address State Or Province EntityAddressStateOrProvince	IL
CY2021	dei	Entity Address Postal Zip Code EntityAddressPostalZipCode	60426
CY2021	dei	Security12b Title Security12bTitle	Common stock, par value $0.01 per share
CY2021	dei	Trading Symbol TradingSymbol	ATKR
CY2021	dei	Security Exchange Name SecurityExchangeName	NYSE
CY2021	dei	Entity Well Known Seasoned Issuer EntityWellKnownSeasonedIssuer	Yes
CY2021	dei	Entity Voluntary Filers EntityVoluntaryFilers	No
CY2021	dei	Entity Current Reporting Status EntityCurrentReportingStatus	Yes
CY2021	dei	Entity Interactive Data Current EntityInteractiveDataCurrent	Yes
CY2021	dei	Entity Filer Category EntityFilerCategory	Large Accelerated Filer
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CY2021Q1	dei	Entity Public Float EntityPublicFloat	3300000000	USD
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CY2021Q3	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	1000000000	shares
CY2020Q3	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	1000000000	shares
CY2021Q3	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	45997159	shares
CY2021Q3	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	45997159	shares
CY2020Q3	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	47407023	shares
CY2020Q3	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	47407023	shares
CY2021Q3	us-gaap	Common Stock Value CommonStockValue	461000	USD
CY2020Q3	us-gaap	Common Stock Value CommonStockValue	475000	USD
CY2021Q3	us-gaap	Treasury Stock Shares TreasuryStockShares	260900	shares
CY2020Q3	us-gaap	Treasury Stock Shares TreasuryStockShares	260900	shares
CY2021Q3	us-gaap	Treasury Stock Value TreasuryStockValue	2580000	USD
CY2020Q3	us-gaap	Treasury Stock Value TreasuryStockValue	2580000	USD
CY2021Q3	us-gaap	Additional Paid In Capital Common Stock AdditionalPaidInCapitalCommonStock	506921000	USD
CY2020Q3	us-gaap	Additional Paid In Capital Common Stock AdditionalPaidInCapitalCommonStock	487223000	USD
CY2021Q3	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	388660000	USD
CY2020Q3	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	-64154000	USD
CY2021Q3	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-28726000	USD
CY2020Q3	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-42554000	USD
CY2021Q3	us-gaap	Stockholders Equity StockholdersEquity	864736000	USD
CY2020Q3	us-gaap	Stockholders Equity StockholdersEquity	378410000	USD
CY2021Q3	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	2210099000	USD
CY2020Q3	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	1558525000	USD
CY2021	us-gaap	Net Income Loss NetIncomeLoss	587857000	USD
CY2020	us-gaap	Net Income Loss NetIncomeLoss	152302000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	139051000	USD
CY2021	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	78557000	USD
CY2020	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	74470000	USD
CY2019	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	72347000	USD
CY2021	us-gaap	Amortization Of Financing Costs And Discounts AmortizationOfFinancingCostsAndDiscounts	2497000	USD
CY2020	us-gaap	Amortization Of Financing Costs And Discounts AmortizationOfFinancingCostsAndDiscounts	1876000	USD
CY2019	us-gaap	Amortization Of Financing Costs And Discounts AmortizationOfFinancingCostsAndDiscounts	1804000	USD
CY2021	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-43306000	USD
CY2020	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	4483000	USD
CY2019	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-796000	USD
CY2021	us-gaap	Gains Losses On Extinguishment Of Debt GainsLossesOnExtinguishmentOfDebt	-4202000	USD
CY2020	us-gaap	Gains Losses On Extinguishment Of Debt GainsLossesOnExtinguishmentOfDebt	-273000	USD
CY2019	us-gaap	Gains Losses On Extinguishment Of Debt GainsLossesOnExtinguishmentOfDebt	0	USD
CY2021	atkr	Provisionfor Doubtful Accountsand Inventory Writedown ProvisionforDoubtfulAccountsandInventoryWritedown	645000	USD
CY2020	atkr	Provisionfor Doubtful Accountsand Inventory Writedown ProvisionforDoubtfulAccountsandInventoryWritedown	5014000	USD
CY2019	atkr	Provisionfor Doubtful Accountsand Inventory Writedown ProvisionforDoubtfulAccountsandInventoryWritedown	4656000	USD
CY2021	us-gaap	Share Based Compensation ShareBasedCompensation	17047000	USD
CY2020	us-gaap	Share Based Compensation ShareBasedCompensation	13064000	USD
CY2019	us-gaap	Share Based Compensation ShareBasedCompensation	11798000	USD
CY2021	us-gaap	Finance Lease Right Of Use Asset Amortization FinanceLeaseRightOfUseAssetAmortization	14515000	USD
CY2020	us-gaap	Finance Lease Right Of Use Asset Amortization FinanceLeaseRightOfUseAssetAmortization	14803000	USD
CY2019	us-gaap	Finance Lease Right Of Use Asset Amortization FinanceLeaseRightOfUseAssetAmortization	0	USD
CY2021	us-gaap	Gain Loss On Sale Of Property Plant Equipment GainLossOnSaleOfPropertyPlantEquipment	-141000	USD
CY2020	us-gaap	Gain Loss On Sale Of Property Plant Equipment GainLossOnSaleOfPropertyPlantEquipment	-3001000	USD
CY2019	us-gaap	Gain Loss On Sale Of Property Plant Equipment GainLossOnSaleOfPropertyPlantEquipment	0	USD
CY2021	us-gaap	Business Combination Bargain Purchase Gain Recognized Amount BusinessCombinationBargainPurchaseGainRecognizedAmount	731000	USD
CY2020	us-gaap	Business Combination Bargain Purchase Gain Recognized Amount BusinessCombinationBargainPurchaseGainRecognizedAmount	0	USD
CY2019	us-gaap	Business Combination Bargain Purchase Gain Recognized Amount BusinessCombinationBargainPurchaseGainRecognizedAmount	7384000	USD
CY2021	us-gaap	Other Operating Activities Cash Flow Statement OtherOperatingActivitiesCashFlowStatement	382000	USD
CY2020	us-gaap	Other Operating Activities Cash Flow Statement OtherOperatingActivitiesCashFlowStatement	-844000	USD
CY2019	us-gaap	Other Operating Activities Cash Flow Statement OtherOperatingActivitiesCashFlowStatement	-1938000	USD
CY2021	us-gaap	Increase Decrease In Accounts Receivable IncreaseDecreaseInAccountsReceivable	219659000	USD
CY2020	us-gaap	Increase Decrease In Accounts Receivable IncreaseDecreaseInAccountsReceivable	-16920000	USD
CY2019	us-gaap	Increase Decrease In Accounts Receivable IncreaseDecreaseInAccountsReceivable	-6026000	USD
CY2021	us-gaap	Increase Decrease In Inventories IncreaseDecreaseInInventories	81544000	USD
CY2020	us-gaap	Increase Decrease In Inventories IncreaseDecreaseInInventories	-24642000	USD
CY2019	us-gaap	Increase Decrease In Inventories IncreaseDecreaseInInventories	-9002000	USD
CY2021	us-gaap	Increase Decrease In Prepaid Deferred Expense And Other Assets IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets	6462000	USD
CY2020	us-gaap	Increase Decrease In Prepaid Deferred Expense And Other Assets IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets	11164000	USD
CY2019	us-gaap	Increase Decrease In Prepaid Deferred Expense And Other Assets IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets	3054000	USD
CY2021	us-gaap	Increase Decrease In Accounts Payable IncreaseDecreaseInAccountsPayable	98444000	USD
CY2020	us-gaap	Increase Decrease In Accounts Payable IncreaseDecreaseInAccountsPayable	-5835000	USD
CY2019	us-gaap	Increase Decrease In Accounts Payable IncreaseDecreaseInAccountsPayable	-21981000	USD
CY2021	us-gaap	Increase Decrease In Accrued Income Taxes Payable IncreaseDecreaseInAccruedIncomeTaxesPayable	80291000	USD
CY2020	us-gaap	Increase Decrease In Accrued Income Taxes Payable IncreaseDecreaseInAccruedIncomeTaxesPayable	-6261000	USD
CY2019	us-gaap	Increase Decrease In Accrued Income Taxes Payable IncreaseDecreaseInAccruedIncomeTaxesPayable	4511000	USD
CY2021	us-gaap	Increase Decrease In Accrued Liabilities IncreaseDecreaseInAccruedLiabilities	63459000	USD
CY2020	us-gaap	Increase Decrease In Accrued Liabilities IncreaseDecreaseInAccruedLiabilities	-32942000	USD
CY2019	us-gaap	Increase Decrease In Accrued Liabilities IncreaseDecreaseInAccruedLiabilities	-2782000	USD
CY2021	us-gaap	Increase Decrease In Other Operating Capital Net IncreaseDecreaseInOtherOperatingCapitalNet	23433000	USD
CY2020	us-gaap	Increase Decrease In Other Operating Capital Net IncreaseDecreaseInOtherOperatingCapitalNet	5040000	USD
CY2019	us-gaap	Increase Decrease In Other Operating Capital Net IncreaseDecreaseInOtherOperatingCapitalNet	1566000	USD
CY2021	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	572902000	USD
CY2020	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	248762000	USD
CY2019	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	209694000	USD
CY2021	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	64474000	USD
CY2020	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	33770000	USD
CY2019	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	34860000	USD
CY2021	us-gaap	Proceeds From Insurance Settlement Investing Activities ProceedsFromInsuranceSettlementInvestingActivities	9627000	USD
CY2020	us-gaap	Proceeds From Insurance Settlement Investing Activities ProceedsFromInsuranceSettlementInvestingActivities	2337000	USD
CY2019	us-gaap	Proceeds From Insurance Settlement Investing Activities ProceedsFromInsuranceSettlementInvestingActivities	0	USD
CY2021	us-gaap	Proceeds From Sale Of Property Plant And Equipment ProceedsFromSaleOfPropertyPlantAndEquipment	81000	USD
CY2020	us-gaap	Proceeds From Sale Of Property Plant And Equipment ProceedsFromSaleOfPropertyPlantAndEquipment	3920000	USD
CY2019	us-gaap	Proceeds From Sale Of Property Plant And Equipment ProceedsFromSaleOfPropertyPlantAndEquipment	80000	USD
CY2021	us-gaap	Payments To Acquire Businesses Net Of Cash Acquired PaymentsToAcquireBusinessesNetOfCashAcquired	43195000	USD
CY2020	us-gaap	Payments To Acquire Businesses Net Of Cash Acquired PaymentsToAcquireBusinessesNetOfCashAcquired	0	USD
CY2019	us-gaap	Payments To Acquire Businesses Net Of Cash Acquired PaymentsToAcquireBusinessesNetOfCashAcquired	97999000	USD
CY2021	us-gaap	Payments For Proceeds From Other Investing Activities PaymentsForProceedsFromOtherInvestingActivities	0	USD
CY2020	us-gaap	Payments For Proceeds From Other Investing Activities PaymentsForProceedsFromOtherInvestingActivities	0	USD
CY2019	us-gaap	Payments For Proceeds From Other Investing Activities PaymentsForProceedsFromOtherInvestingActivities	322000	USD
CY2021	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-97961000	USD
CY2020	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-27513000	USD
CY2019	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-133101000	USD
CY2021	us-gaap	Proceeds From Long Term Lines Of Credit ProceedsFromLongTermLinesOfCredit	0	USD
CY2020	us-gaap	Proceeds From Long Term Lines Of Credit ProceedsFromLongTermLinesOfCredit	0	USD
CY2019	us-gaap	Proceeds From Long Term Lines Of Credit ProceedsFromLongTermLinesOfCredit	39000000	USD
CY2021	us-gaap	Repayments Of Long Term Lines Of Credit RepaymentsOfLongTermLinesOfCredit	0	USD
CY2020	us-gaap	Repayments Of Long Term Lines Of Credit RepaymentsOfLongTermLinesOfCredit	0	USD
CY2019	us-gaap	Repayments Of Long Term Lines Of Credit RepaymentsOfLongTermLinesOfCredit	39000000	USD
CY2021	us-gaap	Repayments Of Short Term Debt RepaymentsOfShortTermDebt	4000000	USD
CY2020	us-gaap	Repayments Of Short Term Debt RepaymentsOfShortTermDebt	0	USD
CY2019	us-gaap	Repayments Of Short Term Debt RepaymentsOfShortTermDebt	20980000	USD
CY2021	us-gaap	Proceeds From Issuance Of Secured Debt ProceedsFromIssuanceOfSecuredDebt	798000000	USD
CY2020	us-gaap	Proceeds From Issuance Of Secured Debt ProceedsFromIssuanceOfSecuredDebt	0	USD
CY2019	us-gaap	Proceeds From Issuance Of Secured Debt ProceedsFromIssuanceOfSecuredDebt	0	USD
CY2021	us-gaap	Repayments Of Secured Debt RepaymentsOfSecuredDebt	835120000	USD
CY2020	us-gaap	Repayments Of Secured Debt RepaymentsOfSecuredDebt	40000000	USD
CY2019	us-gaap	Repayments Of Secured Debt RepaymentsOfSecuredDebt	40000000	USD
CY2021	atkr	Proceeds From Issuance Of Common Stock Net Of Taxes Withhold ProceedsFromIssuanceOfCommonStockNetOfTaxesWithhold	2660000	USD
CY2020	atkr	Proceeds From Issuance Of Common Stock Net Of Taxes Withhold ProceedsFromIssuanceOfCommonStockNetOfTaxesWithhold	-2972000	USD
CY2019	atkr	Proceeds From Issuance Of Common Stock Net Of Taxes Withhold ProceedsFromIssuanceOfCommonStockNetOfTaxesWithhold	7374000	USD
CY2021	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	135066000	USD
CY2020	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	15011000	USD
CY2019	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	24419000	USD
CY2021	us-gaap	Payments Of Debt Issuance Costs PaymentsOfDebtIssuanceCosts	10930000	USD
CY2020	us-gaap	Payments Of Debt Issuance Costs PaymentsOfDebtIssuanceCosts	3204000	USD
CY2019	us-gaap	Payments Of Debt Issuance Costs PaymentsOfDebtIssuanceCosts	0	USD
CY2021	us-gaap	Proceeds From Payments For Other Financing Activities ProceedsFromPaymentsForOtherFinancingActivities	0	USD
CY2020	us-gaap	Proceeds From Payments For Other Financing Activities ProceedsFromPaymentsForOtherFinancingActivities	8000	USD
CY2019	us-gaap	Proceeds From Payments For Other Financing Activities ProceedsFromPaymentsForOtherFinancingActivities	-155000	USD
CY2021	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-184456000	USD
CY2020	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-61179000	USD
CY2019	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-78180000	USD
CY2021	us-gaap	Effect Of Exchange Rate On Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	1333000	USD
CY2020	us-gaap	Effect Of Exchange Rate On Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	986000	USD
CY2019	us-gaap	Effect Of Exchange Rate On Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	-1660000	USD
CY2021	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	291818000	USD
CY2020	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	161056000	USD
CY2020	us-gaap	Goodwill Impairment Loss GoodwillImpairmentLoss	0	USD
CY2019	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	-3247000	USD
CY2020Q3	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	284471000	USD
CY2019Q3	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	123415000	USD
CY2018Q3	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	126662000	USD
CY2021Q3	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	576289000	USD
CY2020Q3	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	284471000	USD
CY2019Q3	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	123415000	USD
CY2021	us-gaap	Interest Paid Net InterestPaidNet	23726000	USD
CY2020	us-gaap	Interest Paid Net InterestPaidNet	38791000	USD
CY2019	us-gaap	Interest Paid Net InterestPaidNet	49879000	USD
CY2021	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	155114000	USD
CY2020	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	50993000	USD
CY2019	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	38698000	USD
CY2021	us-gaap	Capital Expenditures Incurred But Not Yet Paid CapitalExpendituresIncurredButNotYetPaid	1094000	USD
CY2020	us-gaap	Capital Expenditures Incurred But Not Yet Paid CapitalExpendituresIncurredButNotYetPaid	1278000	USD
CY2019	us-gaap	Capital Expenditures Incurred But Not Yet Paid CapitalExpendituresIncurredButNotYetPaid	3719000	USD
CY2021	atkr	Operating Cash Flows From Cash Paid On Operating Lease Liabilities OperatingCashFlowsFromCashPaidOnOperatingLeaseLiabilities	13035000	USD
CY2020	atkr	Operating Cash Flows From Cash Paid On Operating Lease Liabilities OperatingCashFlowsFromCashPaidOnOperatingLeaseLiabilities	12939000	USD
CY2021	us-gaap	Right Of Use Asset Obtained In Exchange For Operating Lease Liability RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability	13538000	USD
CY2020	us-gaap	Right Of Use Asset Obtained In Exchange For Operating Lease Liability RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability	15278000	USD
CY2018Q3	us-gaap	Stockholders Equity StockholdersEquity	122059000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	139051000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	-22927000	USD
CY2019	us-gaap	Tax Cuts And Jobs Act Of2017 Reclassification From Aoci To Retained Earnings Tax Effect TaxCutsAndJobsActOf2017ReclassificationFromAociToRetainedEarningsTaxEffect	0	USD
CY2019	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	11798000	USD
CY2019	us-gaap	Stock Issued During Period Value New Issues StockIssuedDuringPeriodValueNewIssues	7374000	USD
CY2019	us-gaap	Treasury Stock Value Acquired Cost Method TreasuryStockValueAcquiredCostMethod	24419000	USD
CY2019Q3	us-gaap	Stockholders Equity StockholdersEquity	232936000	USD
CY2020	us-gaap	Net Income Loss NetIncomeLoss	152302000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	-856000	USD
CY2020	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	13064000	USD
CY2020	us-gaap	Stock Issued During Period Value New Issues StockIssuedDuringPeriodValueNewIssues	-2972000	USD
CY2019	us-gaap	Goodwill Impairment Loss GoodwillImpairmentLoss	0	USD
CY2021Q3	atkr	Common Stock Voting Rights Number Of Vote For Each Share CommonStockVotingRightsNumberOfVoteForEachShare	1	vote
CY2020	us-gaap	Treasury Stock Value Acquired Cost Method TreasuryStockValueAcquiredCostMethod	15011000	USD
CY2020Q3	us-gaap	Stockholders Equity StockholdersEquity	378410000	USD
CY2021	us-gaap	Net Income Loss NetIncomeLoss	587857000	USD
CY2021	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	13828000	USD
CY2021	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	17047000	USD
CY2021	us-gaap	Stock Issued During Period Value New Issues StockIssuedDuringPeriodValueNewIssues	2660000	USD
CY2021	us-gaap	Treasury Stock Value Acquired Cost Method TreasuryStockValueAcquiredCostMethod	135066000	USD
CY2021Q3	us-gaap	Stockholders Equity StockholdersEquity	864736000	USD
CY2019Q1	us-gaap	Stock Repurchase Program Authorized Amount1 StockRepurchaseProgramAuthorizedAmount1	50000000	USD
CY2020Q4	us-gaap	Stock Repurchase Program Remaining Authorized Repurchase Amount1 StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1	0	USD
CY2021Q1	us-gaap	Stock Repurchase Program Authorized Amount1 StockRepurchaseProgramAuthorizedAmount1	100000000	USD
CY2021Q3	us-gaap	Stock Repurchase Program Remaining Authorized Repurchase Amount1 StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1	0	USD
CY2021	us-gaap	Goodwill Impairment Loss GoodwillImpairmentLoss	0	USD
CY2021	us-gaap	Fiscal Period FiscalPeriod	Fiscal Periods — The Company has a fiscal year that ends on September 30. The Company's fiscal quarters typically end on the last Friday in December, March and June as it follows a 4-5-4 calendar.
CY2021	us-gaap	Use Of Estimates UseOfEstimates	Use of Estimates — The preparation of the consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclose contingent assets and liabilities at the date of the consolidated financial statements and report the associated amounts of revenues and expenses. Actual results could differ materially from these estimates.
CY2020	us-gaap	Number Of Reporting Units NumberOfReportingUnits	6	reportingUnit
CY2021	us-gaap	Number Of Reporting Units NumberOfReportingUnits	6	reportingUnit
CY2019	us-gaap	Number Of Reporting Units NumberOfReportingUnits	6	reportingUnit
CY2020	us-gaap	Impairment Of Intangible Assets Indefinitelived Excluding Goodwill ImpairmentOfIntangibleAssetsIndefinitelivedExcludingGoodwill	0	USD
CY2019	us-gaap	Impairment Of Intangible Assets Indefinitelived Excluding Goodwill ImpairmentOfIntangibleAssetsIndefinitelivedExcludingGoodwill	0	USD
CY2021	us-gaap	Impairment Of Intangible Assets Indefinitelived Excluding Goodwill ImpairmentOfIntangibleAssetsIndefinitelivedExcludingGoodwill	0	USD
CY2021Q3	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	38569000	USD
CY2020Q3	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	37666000	USD
CY2021Q3	us-gaap	Finance Lease Right Of Use Asset FinanceLeaseRightOfUseAsset	4966000	USD
CY2020Q3	us-gaap	Finance Lease Right Of Use Asset FinanceLeaseRightOfUseAsset	2999000	USD
CY2021Q3	atkr	Operating And Finance Lease Rightof Use Asset Gross OperatingAndFinanceLeaseRightofUseAssetGross	43535000	USD
CY2020Q3	atkr	Operating And Finance Lease Rightof Use Asset Gross OperatingAndFinanceLeaseRightofUseAssetGross	40665000	USD
CY2021Q3	atkr	Operating And Finance Lease Rightof Use Asset Accumulated Amortization OperatingAndFinanceLeaseRightofUseAssetAccumulatedAmortization	2422000	USD
CY2020Q3	atkr	Operating And Finance Lease Rightof Use Asset Accumulated Amortization OperatingAndFinanceLeaseRightofUseAssetAccumulatedAmortization	1973000	USD
CY2021Q3	atkr	Operating And Finance Lease Rightof Use Asset Net OperatingAndFinanceLeaseRightofUseAssetNet	41113000	USD
CY2020Q3	atkr	Operating And Finance Lease Rightof Use Asset Net OperatingAndFinanceLeaseRightofUseAssetNet	38692000	USD
CY2021Q3	us-gaap	Operating Lease Liability Current OperatingLeaseLiabilityCurrent	10873000	USD
CY2020Q3	us-gaap	Operating Lease Liability Current OperatingLeaseLiabilityCurrent	15356000	USD
CY2021Q3	us-gaap	Finance Lease Liability Current FinanceLeaseLiabilityCurrent	912000	USD
CY2020Q3	us-gaap	Finance Lease Liability Current FinanceLeaseLiabilityCurrent	430000	USD
CY2021Q3	atkr	Operating And Finance Lease Liability Current OperatingAndFinanceLeaseLiabilityCurrent	11785000	USD
CY2020Q3	atkr	Operating And Finance Lease Liability Current OperatingAndFinanceLeaseLiabilityCurrent	15786000	USD
CY2021Q3	us-gaap	Operating Lease Liability Noncurrent OperatingLeaseLiabilityNoncurrent	28434000	USD
CY2020Q3	us-gaap	Operating Lease Liability Noncurrent OperatingLeaseLiabilityNoncurrent	23354000	USD
CY2021Q3	us-gaap	Finance Lease Liability Noncurrent FinanceLeaseLiabilityNoncurrent	1802000	USD
CY2020Q3	us-gaap	Finance Lease Liability Noncurrent FinanceLeaseLiabilityNoncurrent	789000	USD
CY2021Q3	atkr	Operating And Finance Lease Liability Noncurrent OperatingAndFinanceLeaseLiabilityNoncurrent	30236000	USD
CY2020Q3	atkr	Operating And Finance Lease Liability Noncurrent OperatingAndFinanceLeaseLiabilityNoncurrent	24143000	USD
CY2021Q3	atkr	Operating And Finance Lease Liability OperatingAndFinanceLeaseLiability	42021000	USD
CY2020Q3	atkr	Operating And Finance Lease Liability OperatingAndFinanceLeaseLiability	39929000	USD
CY2021	us-gaap	Finance Lease Right Of Use Asset Amortization FinanceLeaseRightOfUseAssetAmortization	14515000	USD
CY2020	us-gaap	Finance Lease Right Of Use Asset Amortization FinanceLeaseRightOfUseAssetAmortization	14803000	USD
CY2021	us-gaap	Finance Lease Interest Expense FinanceLeaseInterestExpense	49000	USD
CY2020	us-gaap	Finance Lease Interest Expense FinanceLeaseInterestExpense	41000	USD
CY2021	us-gaap	Variable Lease Cost VariableLeaseCost	938000	USD
CY2020	us-gaap	Variable Lease Cost VariableLeaseCost	714000	USD
CY2021	us-gaap	Short Term Lease Cost ShortTermLeaseCost	1815000	USD
CY2020	us-gaap	Short Term Lease Cost ShortTermLeaseCost	1451000	USD
CY2021	us-gaap	Lease Cost LeaseCost	17317000	USD
CY2020	us-gaap	Lease Cost LeaseCost	17009000	USD
CY2021Q3	us-gaap	Finance Lease Liability Payments Due Next Twelve Months FinanceLeaseLiabilityPaymentsDueNextTwelveMonths	951000	USD
CY2021Q3	us-gaap	Lessee Operating Lease Liability Payments Due Next Twelve Months LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths	12047000	USD
CY2021Q3	us-gaap	Finance Lease Liability Payments Due Year Two FinanceLeaseLiabilityPaymentsDueYearTwo	874000	USD
CY2021Q3	us-gaap	Lessee Operating Lease Liability Payments Due Year Two LesseeOperatingLeaseLiabilityPaymentsDueYearTwo	9094000	USD
CY2021Q3	us-gaap	Finance Lease Liability Payments Due Year Three FinanceLeaseLiabilityPaymentsDueYearThree	565000	USD
CY2021Q3	us-gaap	Lessee Operating Lease Liability Payments Due Year Three LesseeOperatingLeaseLiabilityPaymentsDueYearThree	7393000	USD
CY2021Q3	us-gaap	Finance Lease Liability Payments Due Year Four FinanceLeaseLiabilityPaymentsDueYearFour	257000	USD
CY2021Q3	us-gaap	Lessee Operating Lease Liability Payments Due Year Four LesseeOperatingLeaseLiabilityPaymentsDueYearFour	4879000	USD
CY2021Q3	us-gaap	Finance Lease Liability Payments Due Year Five FinanceLeaseLiabilityPaymentsDueYearFive	157000	USD
CY2021Q3	us-gaap	Lessee Operating Lease Liability Payments Due Year Five LesseeOperatingLeaseLiabilityPaymentsDueYearFive	3127000	USD
CY2021Q3	us-gaap	Finance Lease Liability Payments Due After Year Five FinanceLeaseLiabilityPaymentsDueAfterYearFive	8000	USD
CY2021Q3	us-gaap	Lessee Operating Lease Liability Payments Due After Year Five LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive	6957000	USD
CY2021Q3	us-gaap	Finance Lease Liability Payments Due FinanceLeaseLiabilityPaymentsDue	2812000	USD
CY2021Q3	us-gaap	Lessee Operating Lease Liability Payments Due LesseeOperatingLeaseLiabilityPaymentsDue	43497000	USD
CY2021Q3	us-gaap	Finance Lease Liability Undiscounted Excess Amount FinanceLeaseLiabilityUndiscountedExcessAmount	98000	USD
CY2021Q3	us-gaap	Lessee Operating Lease Liability Undiscounted Excess Amount LesseeOperatingLeaseLiabilityUndiscountedExcessAmount	4190000	USD
CY2021Q3	us-gaap	Finance Lease Liability FinanceLeaseLiability	2714000	USD
CY2021Q3	us-gaap	Operating Lease Liability OperatingLeaseLiability	39307000	USD
CY2021Q3	us-gaap	Operating Lease Weighted Average Remaining Lease Term1 OperatingLeaseWeightedAverageRemainingLeaseTerm1	P5Y2M12D
CY2020Q3	us-gaap	Operating Lease Weighted Average Remaining Lease Term1 OperatingLeaseWeightedAverageRemainingLeaseTerm1	P4Y4M24D
CY2021Q3	us-gaap	Finance Lease Weighted Average Remaining Lease Term1 FinanceLeaseWeightedAverageRemainingLeaseTerm1	P3Y3M18D
CY2020	us-gaap	Defined Contribution Plan Cost Recognized DefinedContributionPlanCostRecognized	3718000	USD
CY2020Q3	us-gaap	Finance Lease Weighted Average Remaining Lease Term1 FinanceLeaseWeightedAverageRemainingLeaseTerm1	P3Y2M12D
CY2021Q3	us-gaap	Operating Lease Weighted Average Discount Rate Percent OperatingLeaseWeightedAverageDiscountRatePercent	0.040
CY2020Q3	us-gaap	Operating Lease Weighted Average Discount Rate Percent OperatingLeaseWeightedAverageDiscountRatePercent	0.036
CY2021Q3	us-gaap	Finance Lease Weighted Average Discount Rate Percent FinanceLeaseWeightedAverageDiscountRatePercent	0.025
CY2020Q3	us-gaap	Finance Lease Weighted Average Discount Rate Percent FinanceLeaseWeightedAverageDiscountRatePercent	0.031
CY2021	atkr	Business Acquisition Goodwill Expected Tax Deductible Amount Amortization Period BusinessAcquisitionGoodwillExpectedTaxDeductibleAmountAmortizationPeriod	P15Y
CY2020	atkr	Business Acquisition Goodwill Expected Tax Deductible Amount Amortization Period BusinessAcquisitionGoodwillExpectedTaxDeductibleAmountAmortizationPeriod	P15Y
CY2019	atkr	Business Acquisition Goodwill Expected Tax Deductible Amount Amortization Period BusinessAcquisitionGoodwillExpectedTaxDeductibleAmountAmortizationPeriod	P15Y
CY2021	us-gaap	Defined Benefit Plan Assumptions Used Calculating Net Periodic Benefit Cost Discount Rate DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRate	0.025
CY2020	us-gaap	Defined Benefit Plan Assumptions Used Calculating Net Periodic Benefit Cost Discount Rate DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRate	0.031
CY2019	us-gaap	Defined Benefit Plan Assumptions Used Calculating Net Periodic Benefit Cost Discount Rate DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRate	0.042
CY2021	us-gaap	Defined Benefit Plan Assumptions Used Calculating Net Periodic Benefit Cost Expected Long Term Return On Assets DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostExpectedLongTermReturnOnAssets	0.062
CY2020	us-gaap	Defined Benefit Plan Assumptions Used Calculating Net Periodic Benefit Cost Expected Long Term Return On Assets DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostExpectedLongTermReturnOnAssets	0.063
CY2019	us-gaap	Defined Benefit Plan Assumptions Used Calculating Net Periodic Benefit Cost Expected Long Term Return On Assets DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostExpectedLongTermReturnOnAssets	0.063
CY2021Q3	us-gaap	Defined Benefit Plan Pension Plans With Accumulated Benefit Obligations In Excess Of Plan Assets Aggregate Accumulated Benefit Obligation DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateAccumulatedBenefitObligation	122655000	USD
CY2020Q3	us-gaap	Defined Benefit Plan Pension Plans With Accumulated Benefit Obligations In Excess Of Plan Assets Aggregate Accumulated Benefit Obligation DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateAccumulatedBenefitObligation	146759000	USD
CY2021Q3	us-gaap	Defined Benefit Plan Pension Plan With Projected Benefit Obligation In Excess Of Plan Assets Plan Assets DefinedBenefitPlanPensionPlanWithProjectedBenefitObligationInExcessOfPlanAssetsPlanAssets	118843000	USD
CY2020Q3	us-gaap	Defined Benefit Plan Pension Plan With Projected Benefit Obligation In Excess Of Plan Assets Plan Assets DefinedBenefitPlanPensionPlanWithProjectedBenefitObligationInExcessOfPlanAssetsPlanAssets	106736000	USD
CY2021Q3	us-gaap	Defined Benefit Plan Pension Plans With Accumulated Benefit Obligations In Excess Of Plan Assets Aggregate Projected Benefit Obligation DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateProjectedBenefitObligation	122655000	USD
CY2020Q3	us-gaap	Defined Benefit Plan Pension Plans With Accumulated Benefit Obligations In Excess Of Plan Assets Aggregate Projected Benefit Obligation DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateProjectedBenefitObligation	146759000	USD
CY2021Q3	us-gaap	Defined Benefit Plan Pension Plans With Accumulated Benefit Obligations In Excess Of Plan Assets Aggregate Fair Value Of Plan Assets DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateFairValueOfPlanAssets	118843000	USD
CY2020Q3	us-gaap	Defined Benefit Plan Pension Plans With Accumulated Benefit Obligations In Excess Of Plan Assets Aggregate Fair Value Of Plan Assets DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateFairValueOfPlanAssets	106736000	USD
CY2021Q3	us-gaap	Defined Benefit Plan Expected Future Benefit Payments Next Twelve Months DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths	6411000	USD
CY2021Q3	us-gaap	Defined Benefit Plan Expected Future Benefit Payments Year Two DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo	6632000	USD
CY2021Q3	us-gaap	Defined Benefit Plan Expected Future Benefit Payments Year Three DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree	6868000	USD
CY2021Q3	us-gaap	Defined Benefit Plan Expected Future Benefit Payments Year Four DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour	7115000	USD
CY2021Q3	us-gaap	Defined Benefit Plan Expected Future Benefit Payments Year Five DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive	7344000	USD
CY2021Q3	us-gaap	Defined Benefit Plan Expected Future Benefit Payments Five Fiscal Years Thereafter DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter	37674000	USD
CY2019	us-gaap	Defined Contribution Plan Cost Recognized DefinedContributionPlanCostRecognized	3572000	USD
CY2021	us-gaap	Defined Contribution Plan Cost Recognized DefinedContributionPlanCostRecognized	3400000	USD
CY2021	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	17047000	USD
CY2020	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	13064000	USD
CY2019	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	11798000	USD
CY2021	us-gaap	Employee Service Share Based Compensation Tax Benefit From Compensation Expense EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense	2073000	USD
CY2021	us-gaap	Employee Service Share Based Compensation Tax Benefit From Compensation Expense EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense	2073000	USD
CY2020	us-gaap	Employee Service Share Based Compensation Tax Benefit From Compensation Expense EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense	3014000	USD
CY2020	us-gaap	Employee Service Share Based Compensation Tax Benefit From Compensation Expense EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense	3014000	USD
CY2019	us-gaap	Employee Service Share Based Compensation Tax Benefit From Compensation Expense EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense	2949000	USD
CY2019	us-gaap	Employee Service Share Based Compensation Tax Benefit From Compensation Expense EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense	2949000	USD
CY2018Q3	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	2605000	shares
CY2018Q3	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice	9.91
CY2018Q3	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue	43302000	USD
CY2019	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Gross ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross	342000	shares
CY2019	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Grants In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice	23.45
CY2020Q3	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	1375000	shares
CY2020Q3	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice	15.66
CY2019	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue	11.35
CY2019	us-gaap	Stock Issued During Period Shares Stock Options Exercised StockIssuedDuringPeriodSharesStockOptionsExercised	985000	shares
CY2019	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Exercises In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice	8.62
CY2019	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercises In Period Total Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue	16453000	USD
CY2019	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Forfeitures In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod	126000	shares
CY2019	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Forfeitures In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice	12.64
CY2019Q3	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	1836000	shares
CY2019Q3	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice	12.94
CY2019Q3	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue	31957000	USD
CY2020	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Gross ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross	67000	shares
CY2020	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Grants In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice	37.24
CY2020	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue	14.05
CY2020	us-gaap	Stock Issued During Period Shares Stock Options Exercised StockIssuedDuringPeriodSharesStockOptionsExercised	508000	shares
CY2020	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Exercises In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice	8.55
CY2020	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercises In Period Total Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue	14548000	USD
CY2020	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Forfeitures In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod	20000	shares
CY2020	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Forfeitures In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice	19.13
CY2020Q3	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue	11443000	USD
CY2021	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Gross ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross	72000	shares
CY2021	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Grants In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice	29.80
CY2021	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue	13.46
CY2021	us-gaap	Stock Issued During Period Shares Stock Options Exercised StockIssuedDuringPeriodSharesStockOptionsExercised	678000	shares
CY2021	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Exercises In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice	12.30
CY2021	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercises In Period Total Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue	33075000	USD
CY2021	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Forfeitures In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod	0	shares
CY2021	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Forfeitures In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice	0
CY2021Q3	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	769000	shares
CY2021Q3	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice	19.95
CY2021Q3	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue	51441000	USD
CY2021	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Outstanding Weighted Average Remaining Contractual Term2 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2	P5Y7M20D
CY2021Q3	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber	484000	shares
CY2021Q3	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice	15.25
CY2021Q3	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Exercisable Intrinsic Value1 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1	34715000	USD
CY2021	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Exercisable Weighted Average Remaining Contractual Term1 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1	P4Y4M28D
CY2021	us-gaap	Proceeds From Stock Options Exercised ProceedsFromStockOptionsExercised	8535000	USD
CY2020	us-gaap	Proceeds From Issuance Of Common Stock ProceedsFromIssuanceOfCommonStock	4347000	USD
CY2019	atkr	Proceeds From Issuance Of Common Stock Net Of Taxes Withhold ProceedsFromIssuanceOfCommonStockNetOfTaxesWithhold	7374000	USD
CY2021Q3	us-gaap	Sale Of Stock Price Per Share SaleOfStockPricePerShare	29.80
CY2020Q3	us-gaap	Sale Of Stock Price Per Share SaleOfStockPricePerShare	37.24
CY2019Q3	us-gaap	Sale Of Stock Price Per Share SaleOfStockPricePerShare	17.90
CY2021	us-gaap	Business Combination Bargain Purchase Gain Recognized Amount BusinessCombinationBargainPurchaseGainRecognizedAmount	731000	USD
CY2020	us-gaap	Business Combination Bargain Purchase Gain Recognized Amount BusinessCombinationBargainPurchaseGainRecognizedAmount	0	USD
CY2019	us-gaap	Business Combination Bargain Purchase Gain Recognized Amount BusinessCombinationBargainPurchaseGainRecognizedAmount	7384000	USD
CY2021	atkr	Undesignated Foreign Currency Derivative Instruments UndesignatedForeignCurrencyDerivativeInstruments	2201000	USD
CY2020	atkr	Undesignated Foreign Currency Derivative Instruments UndesignatedForeignCurrencyDerivativeInstruments	1269000	USD
CY2019	atkr	Undesignated Foreign Currency Derivative Instruments UndesignatedForeignCurrencyDerivativeInstruments	-5384000	USD
CY2021	us-gaap	Gain On Business Interruption Insurance Recovery GainOnBusinessInterruptionInsuranceRecovery	15500000	USD
CY2020	us-gaap	Gain On Business Interruption Insurance Recovery GainOnBusinessInterruptionInsuranceRecovery	0	USD
CY2019	us-gaap	Gain On Business Interruption Insurance Recovery GainOnBusinessInterruptionInsuranceRecovery	0	USD
CY2021	atkr	Foreign Exchange Gain Losson Intercompany Loans ForeignExchangeGainLossonIntercompanyLoans	1534000	USD
CY2020	atkr	Foreign Exchange Gain Losson Intercompany Loans ForeignExchangeGainLossonIntercompanyLoans	2342000	USD
CY2019	atkr	Foreign Exchange Gain Losson Intercompany Loans ForeignExchangeGainLossonIntercompanyLoans	-2975000	USD
CY2021	us-gaap	Pension Contributions PensionContributions	2368000	USD
CY2020	us-gaap	Pension Contributions PensionContributions	1704000	USD
CY2019	us-gaap	Pension Contributions PensionContributions	1606000	USD
CY2021	us-gaap	Other Nonoperating Income OtherNonoperatingIncome	220000	USD
CY2020	us-gaap	Other Nonoperating Income OtherNonoperatingIncome	0	USD
CY2019	us-gaap	Other Nonoperating Income OtherNonoperatingIncome	79000	USD
CY2021	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	18152000	USD
CY2020	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	2777000	USD
CY2019	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	11478000	USD
CY2021	us-gaap	Income Loss From Continuing Operations Before Income Taxes Domestic IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic	770350000	USD
CY2020	us-gaap	Income Loss From Continuing Operations Before Income Taxes Domestic IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic	201784000	USD
CY2019	us-gaap	Income Loss From Continuing Operations Before Income Taxes Domestic IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic	170780000	USD
CY2021	us-gaap	Income Loss From Continuing Operations Before Income Taxes Foreign IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign	9651000	USD
CY2020	us-gaap	Income Loss From Continuing Operations Before Income Taxes Foreign IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign	214000	USD
CY2019	us-gaap	Income Loss From Continuing Operations Before Income Taxes Foreign IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign	13889000	USD
CY2021	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	780001000	USD
CY2020	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	201998000	USD
CY2019	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	184669000	USD
CY2021	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	182105000	USD
CY2020	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	32335000	USD
CY2019	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	31431000	USD
CY2021	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	46913000	USD
CY2020	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	9668000	USD
CY2019	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	9800000	USD
CY2021	us-gaap	Current Foreign Tax Expense Benefit CurrentForeignTaxExpenseBenefit	6432000	USD
CY2020	us-gaap	Current Foreign Tax Expense Benefit CurrentForeignTaxExpenseBenefit	3210000	USD
CY2019	us-gaap	Current Foreign Tax Expense Benefit CurrentForeignTaxExpenseBenefit	5183000	USD
CY2021	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	235450000	USD
CY2020	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	45213000	USD
CY2019	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	46414000	USD
CY2021	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	-35442000	USD
CY2020	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	5102000	USD
CY2019	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	1123000	USD
CY2021	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	-7281000	USD
CY2020	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	49000	USD
CY2019	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	-340000	USD
CY2021	us-gaap	Deferred Foreign Income Tax Expense Benefit DeferredForeignIncomeTaxExpenseBenefit	-583000	USD
CY2020	us-gaap	Deferred Foreign Income Tax Expense Benefit DeferredForeignIncomeTaxExpenseBenefit	-668000	USD
CY2019	us-gaap	Deferred Foreign Income Tax Expense Benefit DeferredForeignIncomeTaxExpenseBenefit	-1579000	USD
CY2021	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-43306000	USD
CY2020	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	4483000	USD
CY2019	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-796000	USD
CY2021	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	192144000	USD
CY2020	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	49696000	USD
CY2019	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	45618000	USD
CY2021	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.21
CY2020	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.21
CY2019	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.21
CY2021	us-gaap	Effective Income Tax Rate Reconciliation State And Local Income Taxes EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes	0.04
CY2020	us-gaap	Effective Income Tax Rate Reconciliation State And Local Income Taxes EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes	0.04
CY2019	us-gaap	Effective Income Tax Rate Reconciliation State And Local Income Taxes EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes	0.04
CY2021	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense Share Based Compensation Cost EffectiveIncomeTaxRateReconciliationNondeductibleExpenseShareBasedCompensationCost	0.01
CY2020	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense Share Based Compensation Cost EffectiveIncomeTaxRateReconciliationNondeductibleExpenseShareBasedCompensationCost	0.02
CY2019	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense Share Based Compensation Cost EffectiveIncomeTaxRateReconciliationNondeductibleExpenseShareBasedCompensationCost	0.01
CY2021	us-gaap	Effective Income Tax Rate Reconciliation Other Adjustments EffectiveIncomeTaxRateReconciliationOtherAdjustments	0.01
CY2020	us-gaap	Effective Income Tax Rate Reconciliation Other Adjustments EffectiveIncomeTaxRateReconciliationOtherAdjustments	0.02
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CY2020	us-gaap	Income Tax Reconciliation State And Local Income Taxes IncomeTaxReconciliationStateAndLocalIncomeTaxes	7690000	USD
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CY2021Q3	us-gaap	Deferred Tax Assets Inventory DeferredTaxAssetsInventory	36021000	USD
CY2020Q3	us-gaap	Deferred Tax Assets Inventory DeferredTaxAssetsInventory	5240000	USD
CY2021Q3	atkr	Deferred Tax Assets Lease Obligations DeferredTaxAssetsLeaseObligations	10616000	USD
CY2020Q3	atkr	Deferred Tax Assets Lease Obligations DeferredTaxAssetsLeaseObligations	9966000	USD
CY2021Q3	us-gaap	Deferred Tax Assets Other DeferredTaxAssetsOther	633000	USD
CY2020Q3	us-gaap	Deferred Tax Assets Other DeferredTaxAssetsOther	174000	USD
CY2021Q3	us-gaap	Deferred Tax Assets Gross DeferredTaxAssetsGross	108355000	USD
CY2020Q3	us-gaap	Deferred Tax Assets Gross DeferredTaxAssetsGross	69551000	USD
CY2021Q3	us-gaap	Deferred Tax Liabilities Property Plant And Equipment DeferredTaxLiabilitiesPropertyPlantAndEquipment	21784000	USD
CY2020Q3	us-gaap	Deferred Tax Liabilities Property Plant And Equipment DeferredTaxLiabilitiesPropertyPlantAndEquipment	17648000	USD
CY2021Q3	us-gaap	Deferred Tax Liabilities Goodwill And Intangible Assets Intangible Assets DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets	43657000	USD
CY2020Q3	us-gaap	Deferred Tax Liabilities Goodwill And Intangible Assets Intangible Assets DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets	44774000	USD
CY2021Q3	us-gaap	Deferred Tax Liabilities Investments DeferredTaxLiabilitiesInvestments	5102000	USD
CY2020Q3	us-gaap	Deferred Tax Liabilities Investments DeferredTaxLiabilitiesInvestments	5153000	USD
CY2021Q3	atkr	Deferred Tax Assets Rou Asset Net DeferredTaxAssetsROUAssetNet	10247000	USD
CY2020Q3	atkr	Deferred Tax Assets Rou Asset Net DeferredTaxAssetsROUAssetNet	9546000	USD
CY2021Q3	us-gaap	Deferred Tax Liabilities Other DeferredTaxLiabilitiesOther	3095000	USD
CY2020Q3	us-gaap	Deferred Tax Liabilities Other DeferredTaxLiabilitiesOther	4065000	USD
CY2021Q3	us-gaap	Deferred Income Tax Liabilities DeferredIncomeTaxLiabilities	83885000	USD
CY2020Q3	us-gaap	Deferred Income Tax Liabilities DeferredIncomeTaxLiabilities	81186000	USD
CY2021Q3	atkr	Deferred Tax Assets Net Of Deferred Tax Liabilities Before Valuation Allowance DeferredTaxAssetsNetOfDeferredTaxLiabilitiesBeforeValuationAllowance	-24470000	USD
CY2020Q3	atkr	Deferred Tax Assets Net Of Deferred Tax Liabilities Before Valuation Allowance DeferredTaxAssetsNetOfDeferredTaxLiabilitiesBeforeValuationAllowance	11635000	USD
CY2021Q3	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	11523000	USD
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CY2019	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	135325000	USD
CY2021	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	46569000	shares
CY2020	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	47265000	shares
CY2021Q3	us-gaap	Unrecognized Tax Benefits Income Tax Penalties And Interest Accrued UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued	260000	USD
CY2019	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	46577000	shares
CY2021	us-gaap	Incremental Common Shares Attributable To Share Based Payment Arrangements IncrementalCommonSharesAttributableToShareBasedPaymentArrangements	737000	shares
CY2020	us-gaap	Incremental Common Shares Attributable To Share Based Payment Arrangements IncrementalCommonSharesAttributableToShareBasedPaymentArrangements	779000	shares
CY2019	us-gaap	Incremental Common Shares Attributable To Share Based Payment Arrangements IncrementalCommonSharesAttributableToShareBasedPaymentArrangements	1200000	shares
CY2021	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	47306000	shares
CY2020	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	48044000	shares
CY2019	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	47777000	shares
CY2020Q3	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	10203000	USD
CY2021Q3	us-gaap	Deferred Tax Assets Liabilities Net DeferredTaxAssetsLiabilitiesNet	12947000	USD
CY2020Q3	us-gaap	Deferred Tax Liabilities DeferredTaxLiabilities	21838000	USD
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CY2021	atkr	Number Of Years Cumulative Loss Position NumberOfYearsCumulativeLossPosition	P3Y
CY2021Q3	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	3333000	USD
CY2020Q3	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	1614000	USD
CY2020Q3	us-gaap	Unrecognized Tax Benefits Income Tax Penalties And Interest Accrued UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued	188000	USD
CY2018Q3	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	1364000	USD
CY2019	us-gaap	Unrecognized Tax Benefits Increases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions	244000	USD
CY2019	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Settlements With Taxing Authorities UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities	814000	USD
CY2019Q3	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	794000	USD
CY2020	us-gaap	Unrecognized Tax Benefits Increases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions	925000	USD
CY2021Q3	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	3333000	USD
CY2021	atkr	Unrecognized Tax Benefits Increase Resulting From Current Period And Current Period Tax Positions UnrecognizedTaxBenefitsIncreaseResultingFromCurrentPeriodAndCurrentPeriodTaxPositions	1949000	USD
CY2019	atkr	Unrecognized Tax Benefits Income Tax Penalties And Interest Period Increase Decrease UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestPeriodIncreaseDecrease	-25000	USD
CY2020	us-gaap	Unrecognized Tax Benefits Increases Resulting From Current Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions	122000	USD
CY2020	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Settlements With Taxing Authorities UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities	227000	USD
CY2020Q3	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	1614000	USD
CY2021	us-gaap	Unrecognized Tax Benefits Increases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions	291000	USD
CY2021	us-gaap	Unrecognized Tax Benefits Increases Resulting From Current Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions	1658000	USD
CY2021	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Settlements With Taxing Authorities UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities	230000	USD
CY2021	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Settlements With Taxing Authorities UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities	230000	USD
CY2021	atkr	Unrecognized Tax Benefits Income Tax Penalties And Interest Period Increase Decrease UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestPeriodIncreaseDecrease	72000	USD
CY2020	atkr	Unrecognized Tax Benefits Increase Resulting From Current Period And Current Period Tax Positions UnrecognizedTaxBenefitsIncreaseResultingFromCurrentPeriodAndCurrentPeriodTaxPositions	1047000	USD
CY2020	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Settlements With Taxing Authorities UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities	227000	USD
CY2020	atkr	Unrecognized Tax Benefits Income Tax Penalties And Interest Period Increase Decrease UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestPeriodIncreaseDecrease	134000	USD
CY2019	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Settlements With Taxing Authorities UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities	814000	USD
CY2019	us-gaap	Unrecognized Tax Benefits Increases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions	244000	USD
CY2021Q3	us-gaap	Undistributed Earnings Of Foreign Subsidiaries UndistributedEarningsOfForeignSubsidiaries	74813000	USD
CY2021	us-gaap	Net Income Loss NetIncomeLoss	587857000	USD
CY2020	us-gaap	Net Income Loss NetIncomeLoss	152302000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	139051000	USD
CY2021	us-gaap	Undistributed Earnings Loss Allocated To Participating Securities Basic UndistributedEarningsLossAllocatedToParticipatingSecuritiesBasic	11380000	USD
CY2020	us-gaap	Undistributed Earnings Loss Allocated To Participating Securities Basic UndistributedEarningsLossAllocatedToParticipatingSecuritiesBasic	3356000	USD
CY2019	us-gaap	Undistributed Earnings Loss Allocated To Participating Securities Basic UndistributedEarningsLossAllocatedToParticipatingSecuritiesBasic	3726000	USD
CY2021	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	576477000	USD
CY2021	us-gaap	Net Income Loss Available To Common Stockholders Diluted NetIncomeLossAvailableToCommonStockholdersDiluted	576477000	USD
CY2020	us-gaap	Net Income Loss Available To Common Stockholders Diluted NetIncomeLossAvailableToCommonStockholdersDiluted	148946000	USD
CY2020	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	148946000	USD
CY2021	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	12.38
CY2020	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	3.15
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CY2021	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	12.19
CY2020	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	3.10
CY2019	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	2.83
CY2020	us-gaap	Oci Before Reclassifications Net Of Tax Attributable To Parent OciBeforeReclassificationsNetOfTaxAttributableToParent	-1517000	USD
CY2020	us-gaap	Reclassification From Aoci Current Period Net Of Tax Attributable To Parent ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent	-661000	USD
CY2021	us-gaap	Oci Before Reclassifications Net Of Tax Attributable To Parent OciBeforeReclassificationsNetOfTaxAttributableToParent	12838000	USD
CY2021	us-gaap	Reclassification From Aoci Current Period Net Of Tax Attributable To Parent ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent	-990000	USD
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CY2020Q3	us-gaap	Percentage Of Lifo Inventory PercentageOfLIFOInventory	0.73
CY2021Q3	atkr	Inventory Raw Materialsand Purchased Parts Netof Valuation Reserves InventoryRawMaterialsandPurchasedPartsNetofValuationReserves	105460000	USD
CY2020Q3	atkr	Inventory Raw Materialsand Purchased Parts Netof Valuation Reserves InventoryRawMaterialsandPurchasedPartsNetofValuationReserves	49192000	USD
CY2021Q3	us-gaap	Inventory Work In Process Net Of Reserves InventoryWorkInProcessNetOfReserves	35043000	USD
CY2020Q3	us-gaap	Inventory Work In Process Net Of Reserves InventoryWorkInProcessNetOfReserves	24113000	USD
CY2021Q3	us-gaap	Inventory Finished Goods Net Of Reserves InventoryFinishedGoodsNetOfReserves	145486000	USD
CY2020Q3	us-gaap	Inventory Finished Goods Net Of Reserves InventoryFinishedGoodsNetOfReserves	125790000	USD
CY2021Q3	us-gaap	Inventory Net InventoryNet	285989000	USD
CY2020Q3	us-gaap	Inventory Net InventoryNet	199095000	USD
CY2021Q3	us-gaap	Inventory Lifo Reserve InventoryLIFOReserve	-108911000	USD
CY2020Q3	us-gaap	Inventory Lifo Reserve InventoryLIFOReserve	4418000	USD
CY2021	us-gaap	Effect Of Lifo Inventory Liquidation On Income EffectOfLIFOInventoryLiquidationOnIncome	6592000	USD
CY2020	us-gaap	Effect Of Lifo Inventory Liquidation On Income EffectOfLIFOInventoryLiquidationOnIncome	1837000	USD
CY2021Q3	us-gaap	Inventory Valuation Reserves InventoryValuationReserves	11780000	USD
CY2020Q3	us-gaap	Inventory Valuation Reserves InventoryValuationReserves	14533000	USD
CY2020	us-gaap	Depreciation Depreciation	42208000	USD
CY2021Q3	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	613289000	USD
CY2020Q3	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	541884000	USD
CY2021Q3	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	337667000	USD
CY2020Q3	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	297993000	USD
CY2021Q3	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	275622000	USD
CY2020Q3	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	243891000	USD
CY2021	us-gaap	Depreciation Depreciation	44913000	USD
CY2019	us-gaap	Depreciation Depreciation	39471000	USD
CY2020Q3	us-gaap	Finite Lived Intangible Assets Net FiniteLivedIntangibleAssetsNet	162469000	USD
CY2021Q3	us-gaap	Finite Lived Intangible Assets Amortization Expense After Year Five FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive	25051000	USD
CY2019Q3	us-gaap	Goodwill Goodwill	186231000	USD
CY2020	us-gaap	Goodwill Foreign Currency Translation Gain Loss GoodwillForeignCurrencyTranslationGainLoss	2008000	USD
CY2020Q3	us-gaap	Goodwill Goodwill	188239000	USD
CY2021	us-gaap	Goodwill Acquired During Period GoodwillAcquiredDuringPeriod	9948000	USD
CY2021	us-gaap	Goodwill Foreign Currency Translation Gain Loss GoodwillForeignCurrencyTranslationGainLoss	861000	USD
CY2021Q3	us-gaap	Goodwill Goodwill	199048000	USD
CY2021Q3	us-gaap	Finite Lived Intangible Assets Gross FiniteLivedIntangibleAssetsGross	394681000	USD
CY2021Q3	us-gaap	Finite Lived Intangible Assets Accumulated Amortization FiniteLivedIntangibleAssetsAccumulatedAmortization	246357000	USD
CY2021Q3	us-gaap	Finite Lived Intangible Assets Net FiniteLivedIntangibleAssetsNet	148324000	USD
CY2020Q3	us-gaap	Finite Lived Intangible Assets Gross FiniteLivedIntangibleAssetsGross	374821000	USD
CY2020Q3	us-gaap	Finite Lived Intangible Assets Accumulated Amortization FiniteLivedIntangibleAssetsAccumulatedAmortization	212352000	USD
CY2021Q3	us-gaap	Intangible Assets Gross Excluding Goodwill IntangibleAssetsGrossExcludingGoodwill	487561000	USD
CY2021Q3	us-gaap	Finite Lived Intangible Assets Accumulated Amortization FiniteLivedIntangibleAssetsAccumulatedAmortization	246357000	USD
CY2021Q3	us-gaap	Intangible Assets Net Excluding Goodwill IntangibleAssetsNetExcludingGoodwill	241204000	USD
CY2020Q3	us-gaap	Intangible Assets Gross Excluding Goodwill IntangibleAssetsGrossExcludingGoodwill	467701000	USD
CY2020Q3	us-gaap	Finite Lived Intangible Assets Accumulated Amortization FiniteLivedIntangibleAssetsAccumulatedAmortization	212352000	USD
CY2020Q3	us-gaap	Intangible Assets Net Excluding Goodwill IntangibleAssetsNetExcludingGoodwill	255349000	USD
CY2021	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	33644000	USD
CY2020	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	32262000	USD
CY2019	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	32876000	USD
CY2021Q3	us-gaap	Finite Lived Intangible Assets Amortization Expense Next Twelve Months FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths	32723000	USD
CY2021Q3	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Two FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo	32684000	USD
CY2021Q3	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Three FiniteLivedIntangibleAssetsAmortizationExpenseYearThree	28110000	USD
CY2021Q3	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Four FiniteLivedIntangibleAssetsAmortizationExpenseYearFour	15623000	USD
CY2021Q3	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Five FiniteLivedIntangibleAssetsAmortizationExpenseYearFive	14133000	USD
CY2021Q3	us-gaap	Deferred Finance Costs Net DeferredFinanceCostsNet	12709000	USD
CY2020Q3	us-gaap	Deferred Finance Costs Net DeferredFinanceCostsNet	7804000	USD
CY2021Q3	us-gaap	Long Term Debt Noncurrent LongTermDebtNoncurrent	758386000	USD
CY2020Q3	us-gaap	Long Term Debt Noncurrent LongTermDebtNoncurrent	803736000	USD
CY2021Q3	us-gaap	Contractual Obligation Due In Next Twelve Months ContractualObligationDueInNextTwelveMonths	0	USD
CY2021Q3	us-gaap	Contractual Obligation Due In Second Year ContractualObligationDueInSecondYear	0	USD
CY2021Q3	us-gaap	Contractual Obligation Due In Third Year ContractualObligationDueInThirdYear	0	USD
CY2021Q3	us-gaap	Contractual Obligation Due In Fourth Year ContractualObligationDueInFourthYear	0	USD
CY2021Q3	us-gaap	Contractual Obligation Due In Fifth Year ContractualObligationDueInFifthYear	0	USD
CY2021Q3	us-gaap	Contractual Obligation Due After Fifth Year ContractualObligationDueAfterFifthYear	773000000	USD
CY2020	us-gaap	Gains Losses On Extinguishment Of Debt GainsLossesOnExtinguishmentOfDebt	-273000	USD
CY2021Q3	us-gaap	Purchase Obligation Due In Next Twelve Months PurchaseObligationDueInNextTwelveMonths	247166000	USD
CY2021Q3	us-gaap	Purchase Obligation Due In Second Year PurchaseObligationDueInSecondYear	5333000	USD
CY2021Q3	us-gaap	Purchase Obligation Due In Third Year PurchaseObligationDueInThirdYear	5600000	USD
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CY2021	us-gaap	Gain On Business Interruption Insurance Recovery GainOnBusinessInterruptionInsuranceRecovery	15500000	USD
CY2021	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	64474000	USD
CY2020	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	33770000	USD
CY2019	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	34860000	USD
CY2021Q3	us-gaap	Assets Assets	2210099000	USD
CY2020Q3	us-gaap	Assets Assets	1558525000	USD
CY2019Q3	us-gaap	Assets Assets	1436995000	USD
CY2021	atkr	Selling Generaland Administrative Expense Unallocated SellingGeneralandAdministrativeExpenseUnallocated	58148000	USD
CY2020	atkr	Selling Generaland Administrative Expense Unallocated SellingGeneralandAdministrativeExpenseUnallocated	33995000	USD
CY2019	atkr	Selling Generaland Administrative Expense Unallocated SellingGeneralandAdministrativeExpenseUnallocated	38216000	USD
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CY2020	us-gaap	Interest Income Expense Nonoperating Net InterestIncomeExpenseNonoperatingNet	-40062000	USD
CY2019	us-gaap	Interest Income Expense Nonoperating Net InterestIncomeExpenseNonoperatingNet	-50473000	USD
CY2021	us-gaap	Gains Losses On Extinguishment Of Debt GainsLossesOnExtinguishmentOfDebt	-4202000	USD
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CY2019	us-gaap	Gains Losses On Extinguishment Of Debt GainsLossesOnExtinguishmentOfDebt	0	USD
CY2021	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	17047000	USD
CY2020	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	13064000	USD
CY2019	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	11798000	USD
CY2021	us-gaap	Business Combination Bargain Purchase Gain Recognized Amount BusinessCombinationBargainPurchaseGainRecognizedAmount	731000	USD
CY2020	us-gaap	Business Combination Bargain Purchase Gain Recognized Amount BusinessCombinationBargainPurchaseGainRecognizedAmount	0	USD
CY2019	us-gaap	Business Combination Bargain Purchase Gain Recognized Amount BusinessCombinationBargainPurchaseGainRecognizedAmount	7384000	USD
CY2021	us-gaap	Other Operating Income Expense Net OtherOperatingIncomeExpenseNet	14428000	USD
CY2020	us-gaap	Other Operating Income Expense Net OtherOperatingIncomeExpenseNet	3232000	USD
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CY2021	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	780001000	USD
CY2020	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	201998000	USD
CY2019	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	184669000	USD
CY2021Q3	us-gaap	Noncurrent Assets NoncurrentAssets	316735000	USD
CY2020Q3	us-gaap	Noncurrent Assets NoncurrentAssets	246882000	USD
CY2019Q3	us-gaap	Noncurrent Assets NoncurrentAssets	264966000	USD
CY2021	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	2928014000	USD
CY2020	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	1765421000	USD
CY2019	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	1916538000	USD
CY2021	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	2928014000	USD
CY2020	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	1765421000	USD
CY2019	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	1916538000	USD
CY2021	atkr	Concentration Risk Sales Increase Period ConcentrationRiskSalesIncreasePeriod	P60D
CY2021Q3	atkr	Employees Covered By Collective Bargaining Arrangement Percentage EmployeesCoveredByCollectiveBargainingArrangementPercentage	0.21
CY2020Q3	atkr	Employees Covered By Collective Bargaining Arrangement Number EmployeesCoveredByCollectiveBargainingArrangementNumber	350	employee
CY2014Q2	atkr	Paymentsfor Repurchaseof Common Stock Excluding Related Expense PaymentsforRepurchaseofCommonStockExcludingRelatedExpense	250000000	USD
CY2021Q3	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	11523000	USD

Files In Submission

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$ATKR
Atkore Inc. Stock $atkr

2021 Q3 Form 10-K Financial Statement

#000166613821000163 Filed on November 18, 2021

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$ATKR Atkore Inc. Stock $atkr

2021 Q3 Form 10-K Financial Statement

#000166613821000163 Filed on November 18, 2021

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$ATKR
Atkore Inc. Stock $atkr