$ATKR
Atkore Inc. Stock $atkr

$atkr Overview Financials Valuation SEC Filings Company Website

2019 Q3 Form 10-K Financial Statement

#000166613820000123 Filed on November 19, 2020

Income Statement

Concept	2019 Q3	2019 Q2	2019 Q1
Revenue	$501.7M	$493.5M	$469.3M
YoY Change	5.06%	-0.91%	5.46%
Cost Of Revenue	$358.0M	$367.4M	$352.2M
YoY Change	-2.13%	-2.73%	4.88%
Gross Profit	$143.7M	$126.1M	$117.1M
YoY Change	28.63%	4.82%	7.27%
Gross Profit Margin	28.65%	25.56%	24.95%
Selling, General & Admin	$68.30M	$59.05M	$56.35M
YoY Change	20.88%	2.73%	-6.27%
% of Gross Profit	47.52%	46.81%	48.13%
Research & Development
YoY Change
% of Gross Profit
Depreciation & Amortization	$18.20M	$17.76M	$18.28M
YoY Change	3.41%	9.68%	15.31%
% of Gross Profit	12.66%	14.08%	15.61%
Operating Expenses	$76.90M	$59.05M	$56.35M
YoY Change	19.22%	2.73%	-6.27%
Operating Profit	$66.82M	$59.22M	$52.54M
YoY Change	41.48%	7.37%	27.3%
Interest Expense	-$7.600M	-$12.79M	-$13.33M
YoY Change	-41.54%	2.79%	43.53%
% of Operating Profit	-11.37%	-21.6%	-25.37%
Other Income/Expense, Net	-$3.900M	$1.228M	$594.0K
YoY Change	-1075.0%	-33.26%	-97.71%
Pretax Income	$62.10M	$47.66M	$39.81M
YoY Change	82.11%	6.97%	-31.31%
Income Tax	$16.10M	$11.11M	$10.25M
% Of Pretax Income	25.93%	23.3%	25.76%
Net Earnings	$46.00M	$36.55M	$29.56M
YoY Change	40.67%	6.87%	-30.55%
Net Earnings / Revenue	9.17%	7.41%	6.3%
Basic Earnings Per Share	$0.96	$0.77	$0.62
Diluted Earnings Per Share	$0.94	$0.75	$0.61
COMMON SHARES
Basic Shares Outstanding	46.82M shares	46.39M shares	46.08M shares
Diluted Shares Outstanding		47.56M shares	47.37M shares

Balance Sheet

Concept	2019 Q3	2019 Q2	2019 Q1
SHORT-TERM ASSETS
Cash & Short-Term Investments	$123.4M	$100.7M	$51.50M
YoY Change	-2.6%	-8.04%	-33.03%
Cash & Equivalents	$123.4M	$100.7M	$51.50M
Short-Term Investments
Other Short-Term Assets	$34.70M	$43.20M	$47.40M
YoY Change	3.27%	60.59%	59.06%
Inventory	$226.1M	$224.8M	$220.8M
Prepaid Expenses
Receivables	$315.4M	$322.2M	$319.8M
Other Receivables	$0.00	$0.00	$0.00
Total Short-Term Assets	$699.5M	$690.9M	$639.4M
YoY Change	8.1%	14.3%	15.31%
LONG-TERM ASSETS
Property, Plant & Equipment	$260.7M	$237.6M	$240.2M
YoY Change	22.33%	11.75%	13.38%
Goodwill	$186.2M	$189.1M	$179.5M
YoY Change	9.46%	10.98%	6.14%
Intangibles	$285.7M	$291.2M	$287.8M
YoY Change	-2.13%	-3.07%	-7.21%
Long-Term Investments
YoY Change
Other Assets	$4.263M	$4.300M	$3.000M
YoY Change	136.83%	-33.85%	-53.13%
Total Long-Term Assets	$737.5M	$722.1M	$710.5M
YoY Change	8.94%	4.69%	1.86%
TOTAL ASSETS
Total Short-Term Assets	$699.5M	$690.9M	$639.4M
Total Long-Term Assets	$737.5M	$722.1M	$710.5M
Total Assets	$1.437B	$1.413B	$1.350B
YoY Change	8.53%	9.18%	7.82%
SHORT-TERM LIABILITIES
YoY Change
Accounts Payable	$150.7M	$152.9M	$143.7M
YoY Change	-3.73%	-0.93%	16.5%
Accrued Expenses	$53.94M	$42.96M	$40.66M
YoY Change	2.96%	-27.32%	-28.6%
Deferred Revenue	$44.98M	$42.92M	$42.72M
YoY Change	1232.04%
Short-Term Debt	$0.00	$0.00	$0.00
YoY Change
Long-Term Debt Due	$0.00	$0.00	$0.00
YoY Change	-100.0%	-100.0%	-100.0%
Total Short-Term Liabilities	$287.5M	$269.0M	$252.7M
YoY Change	5.42%	6.38%	16.1%
LONG-TERM LIABILITIES
Long-Term Debt	$845.3M	$884.5M	$884.1M
YoY Change	-3.69%	-1.56%	-1.83%
Other Long-Term Liabilities	$13.04M	$14.26M	$14.03M
YoY Change	-21.14%	-29.6%	-41.18%
Total Long-Term Liabilities	$858.4M	$898.8M	$898.1M
YoY Change	-4.01%	-2.18%	-2.84%
TOTAL LIABILITIES
Total Short-Term Liabilities	$287.5M	$269.0M	$252.7M
Total Long-Term Liabilities	$858.4M	$898.8M	$898.1M
Total Liabilities	$1.204B	$1.210B	$1.191B
YoY Change	0.17%	-0.82%	0.12%
SHAREHOLDERS EQUITY
Retained Earnings	-$200.4M	-$246.4M	-$282.9M
YoY Change	-36.86%	-29.29%	-20.14%
Common Stock	$477.6M	$472.6M	$464.5M
YoY Change	4.18%	6.35%	6.71%
Preferred Stock
YoY Change
Treasury Stock (at cost)	$2.580M	$2.580M	$2.580M
YoY Change	0.0%	0.0%	0.0%
Treasury Stock Shares	260.9K shares	260.9K shares	260.9K shares
Shareholders Equity	$232.9M	$202.5M	$158.5M
YoY Change
Total Liabilities & Shareholders Equity	$1.437B	$1.413B	$1.350B
YoY Change	8.53%	9.18%	7.82%

Cashflow Statement

Concept	2019 Q3	2019 Q2	2019 Q1
OPERATING ACTIVITIES
Net Income	$46.00M	$36.55M	$29.56M
YoY Change	40.67%	6.87%	-30.55%
Depreciation, Depletion And Amortization	$18.20M	$17.76M	$18.28M
YoY Change	3.41%	9.68%	15.31%
Cash From Operating Activities	$89.50M	$77.40M	$2.500M
YoY Change	256.57%	14.84%	-41.86%
INVESTING ACTIVITIES
Capital Expenditures	-$13.30M	-$6.900M	-$7.800M
YoY Change	9.02%	-24.18%	-13.33%
Acquisitions
YoY Change
Other Investing Activities	-$14.60M	-$25.50M	$0.00
YoY Change	-7400.0%	-3742.86%	-100.0%
Cash From Investing Activities	-$27.90M	-$32.40M	-$7.900M
YoY Change	134.45%	281.18%	-125.99%
FINANCING ACTIVITIES
Cash Dividend Paid
YoY Change
Common Stock Issuance & Retirement, Net
YoY Change
Debt Paid & Issued, Net
YoY Change
Cash From Financing Activities	-37.90M	4.500M	-19.60M
YoY Change	-843.14%	-117.93%	-1188.89%
NET CHANGE
Cash From Operating Activities	89.50M	77.40M	2.500M
Cash From Investing Activities	-27.90M	-32.40M	-7.900M
Cash From Financing Activities	-37.90M	4.500M	-19.60M
Net Change In Cash	23.70M	49.50M	-25.00M
YoY Change	29.51%	46.45%	-168.49%
FREE CASH FLOW
Cash From Operating Activities	$89.50M	$77.40M	$2.500M
Capital Expenditures	-$13.30M	-$6.900M	-$7.800M
Free Cash Flow	$102.8M	$84.30M	$10.30M
YoY Change	175.6%	10.2%	-22.56%

Facts In Submission

Frame	Concept Type	Concept / XBRL Key	Value	Unit
CY2019	us-gaap	Net Income Loss NetIncomeLoss	139051000	USD
CY2018	us-gaap	Net Income Loss NetIncomeLoss	136645000	USD
CY2020	dei	Entity Address State Or Province EntityAddressStateOrProvince	IL
CY2020	us-gaap	Other Comprehensive Income Foreign Currency Transaction And Translation Adjustment Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent	6087000	USD
CY2019	us-gaap	Other Comprehensive Income Foreign Currency Transaction And Translation Adjustment Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent	-7490000	USD
CY2019	us-gaap	Accounting Standards Update Extensible List AccountingStandardsUpdateExtensibleList	us-gaap:AccountingStandardsUpdate201602Member
CY2020Q3	atkr	Employees Covered By Collective Bargaining Arrangement Number EmployeesCoveredByCollectiveBargainingArrangementNumber	350	employee
CY2020	atkr	Number Of Years Cumulative Loss Position NumberOfYearsCumulativeLossPosition	P3Y
CY2020	dei	Amendment Flag AmendmentFlag	false
CY2020	dei	Current Fiscal Year End Date CurrentFiscalYearEndDate	--09-30
CY2020	dei	Document Fiscal Period Focus DocumentFiscalPeriodFocus	FY
CY2020	dei	Document Fiscal Year Focus DocumentFiscalYearFocus	2020
CY2020	dei	Entity Central Index Key EntityCentralIndexKey	0001666138
CY2020	us-gaap	Accounting Standards Update Extensible List AccountingStandardsUpdateExtensibleList	us-gaap:AccountingStandardsUpdate201602Member
CY2019Q3	us-gaap	Allowance For Doubtful Accounts Receivable Current AllowanceForDoubtfulAccountsReceivableCurrent	2608000	USD
CY2020Q3	us-gaap	Allowance For Doubtful Accounts Receivable Current AllowanceForDoubtfulAccountsReceivableCurrent	3168000	USD
CY2019Q3	us-gaap	Common Stock Par Or Stated Value Per Share CommonStockParOrStatedValuePerShare	0.01
CY2020Q3	us-gaap	Common Stock Par Or Stated Value Per Share CommonStockParOrStatedValuePerShare	0.01
CY2019Q3	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	1000000000	shares
CY2020Q3	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	1000000000	shares
CY2019Q3	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	46955163	shares
CY2020Q3	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	47407023	shares
CY2019Q3	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	46955163	shares
CY2020Q3	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	47407023	shares
CY2018	us-gaap	Goodwill Impairment Loss GoodwillImpairmentLoss	0	USD
CY2019	us-gaap	Goodwill Impairment Loss GoodwillImpairmentLoss	0	USD
CY2018	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
CY2020	us-gaap	Number Of Reportable Segments NumberOfReportableSegments	2	segment
CY2019Q3	us-gaap	Other Assets Noncurrent OtherAssetsNoncurrent	4263000	USD
CY2020Q3	us-gaap	Assets Assets	1558525000	USD
CY2019Q3	us-gaap	Assets Assets	1436995000	USD
CY2020Q3	us-gaap	Accounts Payable Current AccountsPayableCurrent	142601000	USD
CY2019Q3	us-gaap	Accounts Payable Current AccountsPayableCurrent	150681000	USD
CY2020Q3	us-gaap	Accrued Income Taxes Current AccruedIncomeTaxesCurrent	1360000	USD
CY2019Q3	us-gaap	Accrued Income Taxes Current AccruedIncomeTaxesCurrent	2157000	USD
CY2020Q3	us-gaap	Employee Related Liabilities Current EmployeeRelatedLiabilitiesCurrent	32836000	USD
CY2019Q3	us-gaap	Employee Related Liabilities Current EmployeeRelatedLiabilitiesCurrent	35770000	USD
CY2020Q3	us-gaap	Contract With Customer Liability Current ContractWithCustomerLiabilityCurrent	35802000	USD
CY2019Q3	us-gaap	Contract With Customer Liability Current ContractWithCustomerLiabilityCurrent	44983000	USD
CY2020Q3	atkr	Operating And Finance Lease Liability Current OperatingAndFinanceLeaseLiabilityCurrent	15786000	USD
CY2020Q3	us-gaap	Accrued Liabilities Current AccruedLiabilitiesCurrent	47785000	USD
CY2020Q3	us-gaap	Operating Lease Liability Current Statement Of Financial Position Extensible List OperatingLeaseLiabilityCurrentStatementOfFinancialPositionExtensibleList	atkr:OperatingAndFinanceLeaseLiabilityCurrent
CY2020Q3	us-gaap	Operating Lease Liability Noncurrent Statement Of Financial Position Extensible List OperatingLeaseLiabilityNoncurrentStatementOfFinancialPositionExtensibleList	atkr:OperatingAndFinanceLeaseLiabilityNoncurrent
CY2019Q3	us-gaap	Treasury Stock Shares TreasuryStockShares	260900	shares
CY2020Q3	us-gaap	Treasury Stock Shares TreasuryStockShares	260900	shares
CY2020	dei	Document Type DocumentType	10-K
CY2020	dei	Document Annual Report DocumentAnnualReport	true
CY2020	dei	Document Period End Date DocumentPeriodEndDate	2020-09-30
CY2020	dei	Document Transition Report DocumentTransitionReport	false
CY2020	dei	Entity File Number EntityFileNumber	001-37793
CY2020	dei	Entity Registrant Name EntityRegistrantName	Atkore International Group Inc.
CY2020	dei	Entity Incorporation State Country Code EntityIncorporationStateCountryCode	DE
CY2020	dei	Entity Tax Identification Number EntityTaxIdentificationNumber	90-0631463
CY2020	dei	Entity Address Address Line1 EntityAddressAddressLine1	16100 South Lathrop Avenue
CY2020	dei	Entity Address City Or Town EntityAddressCityOrTown	Harvey
CY2020	dei	Entity Well Known Seasoned Issuer EntityWellKnownSeasonedIssuer	Yes
CY2020	dei	Entity Voluntary Filers EntityVoluntaryFilers	No
CY2020	dei	Entity Current Reporting Status EntityCurrentReportingStatus	Yes
CY2020	dei	Entity Interactive Data Current EntityInteractiveDataCurrent	Yes
CY2020	dei	Entity Filer Category EntityFilerCategory	Large Accelerated Filer
CY2020	dei	Entity Small Business EntitySmallBusiness	false
CY2020	dei	Entity Emerging Growth Company EntityEmergingGrowthCompany	false
CY2020	dei	Icfr Auditor Attestation Flag IcfrAuditorAttestationFlag	true
CY2020	dei	Entity Shell Company EntityShellCompany	false
CY2020Q1	dei	Entity Public Float EntityPublicFloat	965100000	USD
CY2020Q4	dei	Entity Common Stock Shares Outstanding EntityCommonStockSharesOutstanding	47409886	shares
CY2018	us-gaap	Other Comprehensive Income Foreign Currency Transaction And Translation Adjustment Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent	-2853000	USD
CY2020	us-gaap	Other Comprehensive Income Defined Benefit Plans Adjustment Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeDefinedBenefitPlansAdjustmentNetOfTaxPortionAttributableToParent	6943000	USD
CY2019	us-gaap	Other Comprehensive Income Defined Benefit Plans Adjustment Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeDefinedBenefitPlansAdjustmentNetOfTaxPortionAttributableToParent	15437000	USD
CY2018	us-gaap	Other Comprehensive Income Defined Benefit Plans Adjustment Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeDefinedBenefitPlansAdjustmentNetOfTaxPortionAttributableToParent	-4397000	USD
CY2020	dei	Entity Address Postal Zip Code EntityAddressPostalZipCode	60426
CY2020	dei	City Area Code CityAreaCode	708
CY2019Q3	us-gaap	Liabilities Current LiabilitiesCurrent	287534000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	-856000	USD
CY2020Q3	us-gaap	Long Term Debt Noncurrent LongTermDebtNoncurrent	803736000	USD
CY2020	dei	Local Phone Number LocalPhoneNumber	339-1610
CY2020	dei	Security12b Title Security12bTitle	Common stock, par value $0.01 per share
CY2020	dei	Trading Symbol TradingSymbol	ATKR
CY2019Q3	us-gaap	Long Term Debt Noncurrent LongTermDebtNoncurrent	845317000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	1544000	USD
CY2020	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	151446000	USD
CY2020Q3	atkr	Operating And Finance Lease Liability Noncurrent OperatingAndFinanceLeaseLiabilityNoncurrent	24143000	USD
CY2020Q3	us-gaap	Deferred Income Tax Liabilities Net DeferredIncomeTaxLiabilitiesNet	22525000	USD
CY2019Q3	us-gaap	Deferred Income Tax Liabilities Net DeferredIncomeTaxLiabilitiesNet	19986000	USD
CY2020Q3	us-gaap	Accrued Income Taxes Noncurrent AccruedIncomeTaxesNoncurrent	1619000	USD
CY2020	dei	Security Exchange Name SecurityExchangeName	NYSE
CY2019Q3	us-gaap	Accrued Income Taxes Noncurrent AccruedIncomeTaxesNoncurrent	3669000	USD
CY2020Q3	us-gaap	Defined Benefit Pension Plan Liabilities Noncurrent DefinedBenefitPensionPlanLiabilitiesNoncurrent	40023000	USD
CY2019Q3	us-gaap	Defined Benefit Pension Plan Liabilities Noncurrent DefinedBenefitPensionPlanLiabilitiesNoncurrent	34509000	USD
CY2020Q3	us-gaap	Other Liabilities Noncurrent OtherLiabilitiesNoncurrent	11899000	USD
CY2019Q3	us-gaap	Other Liabilities Noncurrent OtherLiabilitiesNoncurrent	13044000	USD
CY2019	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	116124000	USD
CY2020Q3	us-gaap	Liabilities Liabilities	1180115000	USD
CY2019Q3	us-gaap	Liabilities Liabilities	1204059000	USD
CY2018	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	138189000	USD
CY2020Q3	us-gaap	Common Stock Value CommonStockValue	475000	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
CY2020Q3	us-gaap	Accounts Receivable Net Current AccountsReceivableNetCurrent	298242000	USD
CY2019Q3	us-gaap	Accounts Receivable Net Current AccountsReceivableNetCurrent	315353000	USD
CY2019Q3	us-gaap	Inventory Net InventoryNet	226090000	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
CY2018	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	1835139000	USD
CY2020	us-gaap	Cost Of Goods And Services Sold CostOfGoodsAndServicesSold	1274107000	USD
CY2019	us-gaap	Cost Of Goods And Services Sold CostOfGoodsAndServicesSold	1419338000	USD
CY2018	us-gaap	Cost Of Goods And Services Sold CostOfGoodsAndServicesSold	1397055000	USD
CY2020	us-gaap	Gross Profit GrossProfit	491314000	USD
CY2019	us-gaap	Gross Profit GrossProfit	497200000	USD
CY2018	us-gaap	Gross Profit GrossProfit	438084000	USD
CY2020	us-gaap	Selling General And Administrative Expense SellingGeneralAndAdministrativeExpense	219496000	USD
CY2019	us-gaap	Selling General And Administrative Expense SellingGeneralAndAdministrativeExpense	240660000	USD
CY2018	us-gaap	Selling General And Administrative Expense SellingGeneralAndAdministrativeExpense	226282000	USD
CY2020	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	32262000	USD
CY2019	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	32876000	USD
CY2018	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	32104000	USD
CY2020	us-gaap	Operating Income Loss OperatingIncomeLoss	239556000	USD
CY2019	us-gaap	Operating Income Loss OperatingIncomeLoss	223664000	USD
CY2018	us-gaap	Operating Income Loss OperatingIncomeLoss	179698000	USD
CY2020	us-gaap	Interest Income Expense Nonoperating Net InterestIncomeExpenseNonoperatingNet	-40062000	USD
CY2019	us-gaap	Interest Income Expense Nonoperating Net InterestIncomeExpenseNonoperatingNet	-50473000	USD
CY2018	us-gaap	Interest Income Expense Nonoperating Net InterestIncomeExpenseNonoperatingNet	-40694000	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
CY2018	us-gaap	Gains Losses On Extinguishment Of Debt GainsLossesOnExtinguishmentOfDebt	0	USD
CY2020	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	2777000	USD
CY2019	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	11478000	USD
CY2018	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	27348000	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
CY2018	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	166352000	USD
CY2020	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	49696000	USD
CY2019	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	45618000	USD
CY2018	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	29707000	USD
CY2020	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	3.15
CY2019	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	2.91
CY2018	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	2.59
CY2020	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	3.10
CY2020Q3	us-gaap	Prepaid Expense And Other Assets Current PrepaidExpenseAndOtherAssetsCurrent	46868000	USD
CY2019Q3	us-gaap	Prepaid Expense And Other Assets Current PrepaidExpenseAndOtherAssetsCurrent	34679000	USD
CY2020Q3	us-gaap	Deferred Income Tax Assets Net DeferredIncomeTaxAssetsNet	687000	USD
CY2020Q3	us-gaap	Assets Current AssetsCurrent	828676000	USD
CY2019Q3	us-gaap	Assets Current AssetsCurrent	699537000	USD
CY2020Q3	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	243891000	USD
CY2019Q3	us-gaap	Common Stock Value CommonStockValue	471000	USD
CY2020Q3	us-gaap	Treasury Stock Value TreasuryStockValue	2580000	USD
CY2019Q3	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	260703000	USD
CY2020Q3	us-gaap	Intangible Assets Net Excluding Goodwill IntangibleAssetsNetExcludingGoodwill	255349000	USD
CY2020Q3	us-gaap	Goodwill Goodwill	188239000	USD
CY2019	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	2.83
CY2018	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	2.48
CY2019Q3	us-gaap	Goodwill Goodwill	186231000	USD
CY2020Q3	atkr	Operating And Finance Lease Rightof Use Asset Net OperatingAndFinanceLeaseRightofUseAssetNet	38692000	USD
CY2020	us-gaap	Net Income Loss NetIncomeLoss	152302000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	-22927000	USD
CY2020Q3	us-gaap	Inventory Net InventoryNet	199095000	USD
CY2019Q3	us-gaap	Intangible Assets Net Excluding Goodwill IntangibleAssetsNetExcludingGoodwill	285684000	USD
CY2019Q3	us-gaap	Treasury Stock Value TreasuryStockValue	2580000	USD
CY2019Q3	us-gaap	Deferred Income Tax Assets Net DeferredIncomeTaxAssetsNet	577000	USD
CY2020Q3	us-gaap	Other Assets Noncurrent OtherAssetsNoncurrent	2991000	USD
CY2019Q3	us-gaap	Accrued Liabilities Current AccruedLiabilitiesCurrent	53943000	USD
CY2020Q3	us-gaap	Liabilities Current LiabilitiesCurrent	276170000	USD
CY2020Q3	us-gaap	Additional Paid In Capital Common Stock AdditionalPaidInCapitalCommonStock	487223000	USD
CY2019Q3	us-gaap	Additional Paid In Capital Common Stock AdditionalPaidInCapitalCommonStock	477139000	USD
CY2020Q3	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	-64154000	USD
CY2019Q3	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	-200396000	USD
CY2020Q3	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-42554000	USD
CY2019Q3	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-41698000	USD
CY2020Q3	us-gaap	Stockholders Equity StockholdersEquity	378410000	USD
CY2018	us-gaap	Gains Losses On Extinguishment Of Debt GainsLossesOnExtinguishmentOfDebt	0	USD
CY2019Q3	us-gaap	Stockholders Equity StockholdersEquity	232936000	USD
CY2020Q3	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	1558525000	USD
CY2019Q3	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	1436995000	USD
CY2020	us-gaap	Net Income Loss NetIncomeLoss	152302000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	139051000	USD
CY2018	us-gaap	Net Income Loss NetIncomeLoss	136645000	USD
CY2020	atkr	Gain Losson Dispositionof Property Plant Equipmentand Disposal Group Not Discontinued Operation Gain Losson Disposal GainLossonDispositionofPropertyPlantEquipmentandDisposalGroupNotDiscontinuedOperationGainLossonDisposal	0	USD
CY2019	atkr	Gain Losson Dispositionof Property Plant Equipmentand Disposal Group Not Discontinued Operation Gain Losson Disposal GainLossonDispositionofPropertyPlantEquipmentandDisposalGroupNotDiscontinuedOperationGainLossonDisposal	0	USD
CY2018	atkr	Gain Losson Dispositionof Property Plant Equipmentand Disposal Group Not Discontinued Operation Gain Losson Disposal GainLossonDispositionofPropertyPlantEquipmentandDisposalGroupNotDiscontinuedOperationGainLossonDisposal	27575000	USD
CY2020	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	74470000	USD
CY2019	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	72347000	USD
CY2018	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	66890000	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
CY2018	us-gaap	Amortization Of Financing Costs And Discounts AmortizationOfFinancingCostsAndDiscounts	1542000	USD
CY2020	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	4483000	USD
CY2019	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-796000	USD
CY2018	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-9008000	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
CY2020	atkr	Provisionfor Doubtful Accountsand Inventory Writedown ProvisionforDoubtfulAccountsandInventoryWritedown	5014000	USD
CY2019	atkr	Provisionfor Doubtful Accountsand Inventory Writedown ProvisionforDoubtfulAccountsandInventoryWritedown	4656000	USD
CY2018	atkr	Provisionfor Doubtful Accountsand Inventory Writedown ProvisionforDoubtfulAccountsandInventoryWritedown	7241000	USD
CY2020	us-gaap	Share Based Compensation ShareBasedCompensation	13064000	USD
CY2019	us-gaap	Share Based Compensation ShareBasedCompensation	11798000	USD
CY2018	us-gaap	Share Based Compensation ShareBasedCompensation	14664000	USD
CY2020	us-gaap	Finance Lease Right Of Use Asset Amortization FinanceLeaseRightOfUseAssetAmortization	14803000	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
CY2018	us-gaap	Gain Loss On Sale Of Property Plant Equipment GainLossOnSaleOfPropertyPlantEquipment	0	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
CY2018	us-gaap	Business Combination Bargain Purchase Gain Recognized Amount BusinessCombinationBargainPurchaseGainRecognizedAmount	0	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
CY2018	us-gaap	Other Operating Activities Cash Flow Statement OtherOperatingActivitiesCashFlowStatement	2023000	USD
CY2020	us-gaap	Increase Decrease In Accounts Receivable IncreaseDecreaseInAccountsReceivable	-16920000	USD
CY2019	us-gaap	Increase Decrease In Accounts Receivable IncreaseDecreaseInAccountsReceivable	-6026000	USD
CY2018	us-gaap	Increase Decrease In Accounts Receivable IncreaseDecreaseInAccountsReceivable	44419000	USD
CY2020	us-gaap	Increase Decrease In Inventories IncreaseDecreaseInInventories	-24642000	USD
CY2019	us-gaap	Increase Decrease In Inventories IncreaseDecreaseInInventories	-9002000	USD
CY2018	us-gaap	Increase Decrease In Inventories IncreaseDecreaseInInventories	36528000	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
CY2018	us-gaap	Increase Decrease In Prepaid Deferred Expense And Other Assets IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets	1762000	USD
CY2020	us-gaap	Increase Decrease In Accounts Payable IncreaseDecreaseInAccountsPayable	-5835000	USD
CY2019	us-gaap	Increase Decrease In Accounts Payable IncreaseDecreaseInAccountsPayable	-21981000	USD
CY2018	us-gaap	Increase Decrease In Accounts Payable IncreaseDecreaseInAccountsPayable	31667000	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
CY2018	us-gaap	Increase Decrease In Accrued Income Taxes Payable IncreaseDecreaseInAccruedIncomeTaxesPayable	-3179000	USD
CY2020	us-gaap	Increase Decrease In Accrued Liabilities IncreaseDecreaseInAccruedLiabilities	-32942000	USD
CY2019	us-gaap	Increase Decrease In Accrued Liabilities IncreaseDecreaseInAccruedLiabilities	-2782000	USD
CY2018	us-gaap	Increase Decrease In Accrued Liabilities IncreaseDecreaseInAccruedLiabilities	7243000	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
CY2018	us-gaap	Increase Decrease In Other Operating Capital Net IncreaseDecreaseInOtherOperatingCapitalNet	-259000	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
CY2018	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	145703000	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
CY2018	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	38501000	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
CY2018	us-gaap	Proceeds From Insurance Settlement Investing Activities ProceedsFromInsuranceSettlementInvestingActivities	0	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
CY2018	us-gaap	Proceeds From Sale Of Property Plant And Equipment ProceedsFromSaleOfPropertyPlantAndEquipment	349000	USD
CY2020	us-gaap	Proceeds From Divestiture Of Businesses ProceedsFromDivestitureOfBusinesses	0	USD
CY2019	us-gaap	Proceeds From Divestiture Of Businesses ProceedsFromDivestitureOfBusinesses	0	USD
CY2018	us-gaap	Proceeds From Divestiture Of Businesses ProceedsFromDivestitureOfBusinesses	42631000	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
CY2018	us-gaap	Payments To Acquire Businesses Net Of Cash Acquired PaymentsToAcquireBusinessesNetOfCashAcquired	3467000	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
CY2018	us-gaap	Payments For Proceeds From Other Investing Activities PaymentsForProceedsFromOtherInvestingActivities	-1502000	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
CY2018	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	2514000	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
CY2020	us-gaap	Repayments Of Secured Debt RepaymentsOfSecuredDebt	40000000	USD
CY2019	us-gaap	Repayments Of Secured Debt RepaymentsOfSecuredDebt	40000000	USD
CY2018	us-gaap	Repayments Of Secured Debt RepaymentsOfSecuredDebt	1217000	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
CY2018	atkr	Proceeds From Issuance Of Common Stock Net Of Taxes Withhold ProceedsFromIssuanceOfCommonStockNetOfTaxesWithhold	20110000	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
CY2018	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	411775000	USD
CY2020	us-gaap	Payments Of Debt Issuance Costs PaymentsOfDebtIssuanceCosts	3204000	USD
CY2019	us-gaap	Payments Of Debt Issuance Costs PaymentsOfDebtIssuanceCosts	0	USD
CY2018	us-gaap	Payments Of Debt Issuance Costs PaymentsOfDebtIssuanceCosts	5955000	USD
CY2018	us-gaap	Proceeds From Long Term Lines Of Credit ProceedsFromLongTermLinesOfCredit	358000000	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
CY2018	us-gaap	Repayments Of Long Term Lines Of Credit RepaymentsOfLongTermLinesOfCredit	443000000	USD
CY2020	us-gaap	Repayments Of Short Term Debt RepaymentsOfShortTermDebt	0	USD
CY2019	us-gaap	Repayments Of Short Term Debt RepaymentsOfShortTermDebt	20980000	USD
CY2018	us-gaap	Repayments Of Short Term Debt RepaymentsOfShortTermDebt	8150000	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
CY2018	us-gaap	Proceeds From Issuance Of Secured Debt ProceedsFromIssuanceOfSecuredDebt	426217000	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
CY2018	us-gaap	Proceeds From Payments For Other Financing Activities ProceedsFromPaymentsForOtherFinancingActivities	-161000	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
CY2018	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-65931000	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
CY2018	us-gaap	Effect Of Exchange Rate On Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	-1342000	USD
CY2020	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	161056000	USD
CY2019	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	-3247000	USD
CY2018	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	80944000	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
CY2017Q3	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	45718000	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
CY2020	us-gaap	Interest Paid Net InterestPaidNet	38791000	USD
CY2019	us-gaap	Interest Paid Net InterestPaidNet	49879000	USD
CY2018	us-gaap	Interest Paid Net InterestPaidNet	39898000	USD
CY2019	us-gaap	Tax Cuts And Jobs Act Of2017 Reclassification From Aoci To Retained Earnings Tax Effect TaxCutsAndJobsActOf2017ReclassificationFromAociToRetainedEarningsTaxEffect	0	USD
CY2020	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	50993000	USD
CY2019	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	38698000	USD
CY2018	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	41601000	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
CY2018	us-gaap	Capital Expenditures Incurred But Not Yet Paid CapitalExpendituresIncurredButNotYetPaid	916000	USD
CY2017Q3	us-gaap	Stockholders Equity StockholdersEquity	360871000	USD
CY2018	us-gaap	Net Income Loss NetIncomeLoss	136645000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	1544000	USD
CY2018	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	14664000	USD
CY2018	us-gaap	Stock Issued During Period Value New Issues StockIssuedDuringPeriodValueNewIssues	20110000	USD
CY2018	us-gaap	Treasury Stock Value Acquired Cost Method TreasuryStockValueAcquiredCostMethod	411775000	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	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
CY2020	us-gaap	Treasury Stock Value Acquired Cost Method TreasuryStockValueAcquiredCostMethod	15011000	USD
CY2020Q3	us-gaap	Stockholders Equity StockholdersEquity	378410000	USD
CY2020Q3	atkr	Common Stock Voting Rights Number Of Vote For Each Share CommonStockVotingRightsNumberOfVoteForEachShare	1	vote
CY2017Q3	us-gaap	Stock Repurchase Program Authorized Amount1 StockRepurchaseProgramAuthorizedAmount1	75000000.0	USD
CY2018Q4	us-gaap	Stock Repurchase Program Remaining Authorized Repurchase Amount1 StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1	0	USD
CY2019Q1	us-gaap	Stock Repurchase Program Authorized Amount1 StockRepurchaseProgramAuthorizedAmount1	50000000.0	USD
CY2020Q3	us-gaap	Stock Repurchase Program Remaining Authorized Repurchase Amount1 StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1	35000000.0	USD
CY2020	us-gaap	Fiscal Period FiscalPeriod	<div style="line-height:120%;text-align:left;text-indent:48px;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;font-style:italic;">Fiscal Periods </span><span style="font-family:inherit;font-size:10pt;">— 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. </span></div><div style="line-height:120%;text-align:left;text-indent:48px;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><br/></span></div>
CY2020	us-gaap	Use Of Estimates UseOfEstimates	<div style="line-height:120%;text-align:left;text-indent:48px;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;font-style:italic;">Use of Estimates </span><span style="font-family:inherit;font-size:10pt;">— 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. </span></div>
CY2020	us-gaap	Goodwill Impairment Loss GoodwillImpairmentLoss	0	USD
CY2020	us-gaap	Impairment Of Intangible Assets Indefinitelived Excluding Goodwill ImpairmentOfIntangibleAssetsIndefinitelivedExcludingGoodwill	0	USD
CY2020Q3	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	37666000	USD
CY2020Q3	us-gaap	Finance Lease Right Of Use Asset FinanceLeaseRightOfUseAsset	2999000	USD
CY2020Q3	atkr	Operating And Finance Lease Rightof Use Asset Gross OperatingAndFinanceLeaseRightofUseAssetGross	40665000	USD
CY2020Q3	atkr	Operating And Finance Lease Rightof Use Asset Accumulated Amortization OperatingAndFinanceLeaseRightofUseAssetAccumulatedAmortization	1973000	USD
CY2020Q3	atkr	Operating And Finance Lease Rightof Use Asset Net OperatingAndFinanceLeaseRightofUseAssetNet	38692000	USD
CY2020Q3	us-gaap	Operating Lease Liability Current OperatingLeaseLiabilityCurrent	15356000	USD
CY2020Q3	us-gaap	Finance Lease Liability Current FinanceLeaseLiabilityCurrent	430000	USD
CY2020Q3	atkr	Operating And Finance Lease Liability Current OperatingAndFinanceLeaseLiabilityCurrent	15786000	USD
CY2020Q3	us-gaap	Operating Lease Liability Noncurrent OperatingLeaseLiabilityNoncurrent	23354000	USD
CY2020Q3	us-gaap	Finance Lease Liability Noncurrent FinanceLeaseLiabilityNoncurrent	789000	USD
CY2020Q3	atkr	Operating And Finance Lease Liability Noncurrent OperatingAndFinanceLeaseLiabilityNoncurrent	24143000	USD
CY2020Q3	atkr	Operating And Finance Lease Liability OperatingAndFinanceLeaseLiability	39929000	USD
CY2020	us-gaap	Finance Lease Right Of Use Asset Amortization FinanceLeaseRightOfUseAssetAmortization	14803000	USD
CY2020	us-gaap	Finance Lease Interest Expense FinanceLeaseInterestExpense	41000	USD
CY2020	us-gaap	Variable Lease Cost VariableLeaseCost	714000	USD
CY2020	us-gaap	Short Term Lease Cost ShortTermLeaseCost	1451000	USD
CY2020	us-gaap	Lease Cost LeaseCost	17009000	USD
CY2020Q3	us-gaap	Finance Lease Liability Payments Due Next Twelve Months FinanceLeaseLiabilityPaymentsDueNextTwelveMonths	422000	USD
CY2020Q3	us-gaap	Lessee Operating Lease Liability Payments Due Next Twelve Months LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths	12902000	USD
CY2020Q3	us-gaap	Finance Lease Liability Payments Due Year Two FinanceLeaseLiabilityPaymentsDueYearTwo	406000	USD
CY2020Q3	us-gaap	Lessee Operating Lease Liability Payments Due Year Two LesseeOperatingLeaseLiabilityPaymentsDueYearTwo	10097000	USD
CY2020Q3	us-gaap	Finance Lease Liability Payments Due Year Three FinanceLeaseLiabilityPaymentsDueYearThree	332000	USD
CY2020Q3	us-gaap	Lessee Operating Lease Liability Payments Due Year Three LesseeOperatingLeaseLiabilityPaymentsDueYearThree	7228000	USD
CY2020Q3	us-gaap	Finance Lease Liability Payments Due Year Four FinanceLeaseLiabilityPaymentsDueYearFour	89000	USD
CY2020Q3	us-gaap	Lessee Operating Lease Liability Payments Due Year Four LesseeOperatingLeaseLiabilityPaymentsDueYearFour	5789000	USD
CY2020Q3	us-gaap	Finance Lease Liability Payments Due Year Five FinanceLeaseLiabilityPaymentsDueYearFive	3000	USD
CY2020Q3	us-gaap	Lessee Operating Lease Liability Payments Due Year Five LesseeOperatingLeaseLiabilityPaymentsDueYearFive	3451000	USD
CY2020Q3	us-gaap	Finance Lease Liability Payments Due After Year Five FinanceLeaseLiabilityPaymentsDueAfterYearFive	0	USD
CY2020Q3	us-gaap	Lessee Operating Lease Liability Payments Due After Year Five LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive	3535000	USD
CY2020Q3	us-gaap	Finance Lease Liability Payments Due FinanceLeaseLiabilityPaymentsDue	1252000	USD
CY2020Q3	us-gaap	Lessee Operating Lease Liability Payments Due LesseeOperatingLeaseLiabilityPaymentsDue	43002000	USD
CY2020Q3	us-gaap	Finance Lease Liability Undiscounted Excess Amount FinanceLeaseLiabilityUndiscountedExcessAmount	33000	USD
CY2020Q3	us-gaap	Lessee Operating Lease Liability Undiscounted Excess Amount LesseeOperatingLeaseLiabilityUndiscountedExcessAmount	4292000	USD
CY2020Q3	us-gaap	Finance Lease Liability FinanceLeaseLiability	1219000	USD
CY2020Q3	us-gaap	Operating Lease Liability OperatingLeaseLiability	38710000	USD
CY2020	us-gaap	Lease And Rental Expense LeaseAndRentalExpense	17077000	USD
CY2019	us-gaap	Lease And Rental Expense LeaseAndRentalExpense	17403000	USD
CY2020Q3	us-gaap	Operating Leases Future Minimum Payments Due Current OperatingLeasesFutureMinimumPaymentsDueCurrent	13526000	USD
CY2020Q3	us-gaap	Operating Leases Future Minimum Payments Due In Two Years OperatingLeasesFutureMinimumPaymentsDueInTwoYears	11592000	USD
CY2020Q3	us-gaap	Operating Leases Future Minimum Payments Due In Three Years OperatingLeasesFutureMinimumPaymentsDueInThreeYears	8666000	USD
CY2020Q3	us-gaap	Operating Leases Future Minimum Payments Due In Four Years OperatingLeasesFutureMinimumPaymentsDueInFourYears	6362000	USD
CY2020Q3	us-gaap	Operating Leases Future Minimum Payments Due In Five Years OperatingLeasesFutureMinimumPaymentsDueInFiveYears	5097000	USD
CY2020Q3	us-gaap	Operating Leases Future Minimum Payments Due Thereafter OperatingLeasesFutureMinimumPaymentsDueThereafter	6938000	USD
CY2020Q3	us-gaap	Operating Leases Future Minimum Payments Due OperatingLeasesFutureMinimumPaymentsDue	52181000	USD
CY2020Q3	us-gaap	Operating Lease Weighted Average Remaining Lease Term1 OperatingLeaseWeightedAverageRemainingLeaseTerm1	P4Y4M24D
CY2020Q3	us-gaap	Finance Lease Weighted Average Remaining Lease Term1 FinanceLeaseWeightedAverageRemainingLeaseTerm1	P3Y2M12D
CY2020Q3	us-gaap	Operating Lease Weighted Average Discount Rate Percent OperatingLeaseWeightedAverageDiscountRatePercent	0.036
CY2020Q3	us-gaap	Finance Lease Weighted Average Discount Rate Percent FinanceLeaseWeightedAverageDiscountRatePercent	0.031
CY2020	us-gaap	Operating Lease Payments OperatingLeasePayments	12939000	USD
CY2020	us-gaap	Finance Lease Interest Payment On Liability FinanceLeaseInterestPaymentOnLiability	26000	USD
CY2020	us-gaap	Finance Lease Principal Payments FinanceLeasePrincipalPayments	500000	USD
CY2020	atkr	Business Acquisition Goodwill Expected Tax Deductible Amount Amortization Period BusinessAcquisitionGoodwillExpectedTaxDeductibleAmountAmortizationPeriod	P15Y
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
CY2018	us-gaap	Defined Benefit Plan Assumptions Used Calculating Net Periodic Benefit Cost Discount Rate DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRate	0.037
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
CY2018	us-gaap	Defined Benefit Plan Assumptions Used Calculating Net Periodic Benefit Cost Expected Long Term Return On Assets DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostExpectedLongTermReturnOnAssets	0.064
CY2020	us-gaap	Proceeds From Stock Options Exercised ProceedsFromStockOptionsExercised	4347000	USD
CY2019	us-gaap	Proceeds From Issuance Of Common Stock ProceedsFromIssuanceOfCommonStock	7374000	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
CY2019Q3	us-gaap	Defined Benefit Plan Pension Plans With Accumulated Benefit Obligations In Excess Of Plan Assets Aggregate Accumulated Benefit Obligation DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateAccumulatedBenefitObligation	137960000	USD
CY2020Q3	us-gaap	Defined Benefit Plan Pension Plan With Projected Benefit Obligation In Excess Of Plan Assets Plan Assets DefinedBenefitPlanPensionPlanWithProjectedBenefitObligationInExcessOfPlanAssetsPlanAssets	106736000	USD
CY2019Q3	us-gaap	Defined Benefit Plan Pension Plan With Projected Benefit Obligation In Excess Of Plan Assets Plan Assets DefinedBenefitPlanPensionPlanWithProjectedBenefitObligationInExcessOfPlanAssetsPlanAssets	103451000	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
CY2019Q3	us-gaap	Defined Benefit Plan Pension Plans With Accumulated Benefit Obligations In Excess Of Plan Assets Aggregate Projected Benefit Obligation DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateProjectedBenefitObligation	137960000	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
CY2019Q3	us-gaap	Defined Benefit Plan Pension Plans With Accumulated Benefit Obligations In Excess Of Plan Assets Aggregate Fair Value Of Plan Assets DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateFairValueOfPlanAssets	103451000	USD
CY2020Q3	us-gaap	Defined Benefit Plan Expected Future Benefit Payments Next Twelve Months DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths	6155000	USD
CY2020Q3	us-gaap	Defined Benefit Plan Expected Future Benefit Payments Year Two DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo	6436000	USD
CY2020Q3	us-gaap	Defined Benefit Plan Expected Future Benefit Payments Year Three DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree	6667000	USD
CY2020Q3	us-gaap	Defined Benefit Plan Expected Future Benefit Payments Year Four DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour	6879000	USD
CY2020Q3	us-gaap	Defined Benefit Plan Expected Future Benefit Payments Year Five DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive	7125000	USD
CY2020Q3	us-gaap	Defined Benefit Plan Expected Future Benefit Payments Five Fiscal Years Thereafter DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter	37448000	USD
CY2020	us-gaap	Defined Contribution Plan Cost Recognized DefinedContributionPlanCostRecognized	3718000	USD
CY2019	us-gaap	Defined Contribution Plan Cost Recognized DefinedContributionPlanCostRecognized	3572000	USD
CY2018	us-gaap	Defined Contribution Plan Cost Recognized DefinedContributionPlanCostRecognized	3600000	USD
CY2020	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	13064000	USD
CY2019	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	11798000	USD
CY2018	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	14664000	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
CY2018	us-gaap	Employee Service Share Based Compensation Tax Benefit From Compensation Expense EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense	3681000	USD
CY2020	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Vested In Period Fair Value1 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedInPeriodFairValue1	1894000	USD
CY2018	atkr	Proceeds From Issuance Of Common Stock Net Of Taxes Withhold ProceedsFromIssuanceOfCommonStockNetOfTaxesWithhold	20110000	USD
CY2020Q3	us-gaap	Sale Of Stock Price Per Share SaleOfStockPricePerShare	37.24
CY2019Q3	us-gaap	Sale Of Stock Price Per Share SaleOfStockPricePerShare	17.90
CY2018Q3	us-gaap	Sale Of Stock Price Per Share SaleOfStockPricePerShare	20.01
CY2017Q3	us-gaap	Restructuring Reserve RestructuringReserve	737000	USD
CY2018	us-gaap	Restructuring Charges RestructuringCharges	2040000	USD
CY2018	us-gaap	Payments For Restructuring PaymentsForRestructuring	2043000	USD
CY2018	us-gaap	Restructuring Reserve Translation And Other Adjustment RestructuringReserveTranslationAndOtherAdjustment	-191000	USD
CY2018	us-gaap	Restructuring Reserve Translation Adjustment RestructuringReserveTranslationAdjustment	-8000	USD
CY2018Q3	us-gaap	Restructuring Reserve RestructuringReserve	551000	USD
CY2019	us-gaap	Restructuring Charges RestructuringCharges	3804000	USD
CY2019	us-gaap	Payments For Restructuring PaymentsForRestructuring	3818000	USD
CY2019Q3	us-gaap	Restructuring Reserve RestructuringReserve	537000	USD
CY2020	us-gaap	Restructuring Charges RestructuringCharges	3715000	USD
CY2020	us-gaap	Payments For Restructuring PaymentsForRestructuring	3548000	USD
CY2020	us-gaap	Restructuring Reserve Translation And Other Adjustment RestructuringReserveTranslationAndOtherAdjustment	-431000	USD
CY2020	us-gaap	Restructuring Reserve Translation Adjustment RestructuringReserveTranslationAdjustment	-18000	USD
CY2020Q3	us-gaap	Restructuring Reserve RestructuringReserve	291000	USD
CY2020	atkr	Restructuring Charges Net RestructuringChargesNet	3284000	USD
CY2019	atkr	Restructuring Charges Net RestructuringChargesNet	3804000	USD
CY2018	atkr	Restructuring Charges Net RestructuringChargesNet	1849000	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
CY2018	us-gaap	Business Combination Bargain Purchase Gain Recognized Amount BusinessCombinationBargainPurchaseGainRecognizedAmount	0	USD
CY2020	us-gaap	Gain Loss On Sale Of Investments GainLossOnSaleOfInvestments	0	USD
CY2019	us-gaap	Gain Loss On Sale Of Investments GainLossOnSaleOfInvestments	0	USD
CY2018	us-gaap	Gain Loss On Sale Of Investments GainLossOnSaleOfInvestments	27575000	USD
CY2020	atkr	Undesignated Foreign Currency Derivative Instruments UndesignatedForeignCurrencyDerivativeInstruments	1269000	USD
CY2019	atkr	Undesignated Foreign Currency Derivative Instruments UndesignatedForeignCurrencyDerivativeInstruments	-5384000	USD
CY2018	atkr	Undesignated Foreign Currency Derivative Instruments UndesignatedForeignCurrencyDerivativeInstruments	-121000	USD
CY2020	atkr	Foreign Exchange Gain Losson Intercompany Loans ForeignExchangeGainLossonIntercompanyLoans	2342000	USD
CY2019	atkr	Foreign Exchange Gain Losson Intercompany Loans ForeignExchangeGainLossonIntercompanyLoans	-2975000	USD
CY2018	atkr	Foreign Exchange Gain Losson Intercompany Loans ForeignExchangeGainLossonIntercompanyLoans	-1500000	USD
CY2020	us-gaap	Gains Losses On Restructuring Of Debt GainsLossesOnRestructuringOfDebt	0	USD
CY2019	us-gaap	Gains Losses On Restructuring Of Debt GainsLossesOnRestructuringOfDebt	0	USD
CY2018	us-gaap	Gains Losses On Restructuring Of Debt GainsLossesOnRestructuringOfDebt	-892000	USD
CY2020	us-gaap	Pension Contributions PensionContributions	1704000	USD
CY2019	us-gaap	Pension Contributions PensionContributions	1606000	USD
CY2018	us-gaap	Pension Contributions PensionContributions	1975000	USD
CY2020	us-gaap	Other Nonoperating Income OtherNonoperatingIncome	0	USD
CY2019	us-gaap	Other Nonoperating Income OtherNonoperatingIncome	79000	USD
CY2018	us-gaap	Other Nonoperating Income OtherNonoperatingIncome	69000	USD
CY2020	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	2777000	USD
CY2019	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	11478000	USD
CY2018	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	27348000	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
CY2018	us-gaap	Income Loss From Continuing Operations Before Income Taxes Domestic IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic	155453000	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
CY2018	us-gaap	Income Loss From Continuing Operations Before Income Taxes Foreign IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign	10899000	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
CY2018	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	166352000	USD
CY2020	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	32335000	USD
CY2019	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	31431000	USD
CY2018	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	26586000	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
CY2018	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	8662000	USD
CY2020	us-gaap	Current Foreign Tax Expense Benefit CurrentForeignTaxExpenseBenefit	3210000	USD
CY2019	us-gaap	Current Foreign Tax Expense Benefit CurrentForeignTaxExpenseBenefit	5183000	USD
CY2018	us-gaap	Current Foreign Tax Expense Benefit CurrentForeignTaxExpenseBenefit	3467000	USD
CY2020	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	45213000	USD
CY2019	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	46414000	USD
CY2018	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	38715000	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
CY2018	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	-7149000	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
CY2018	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	-1793000	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
CY2018	us-gaap	Deferred Foreign Income Tax Expense Benefit DeferredForeignIncomeTaxExpenseBenefit	-66000	USD
CY2020	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	4483000	USD
CY2019	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-796000	USD
CY2018	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-9008000	USD
CY2020	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	49696000	USD
CY2019	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	45618000	USD
CY2018	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	29707000	USD
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
CY2018	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.25
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
CY2018	us-gaap	Effective Income Tax Rate Reconciliation State And Local Income Taxes EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes	0.03
CY2020	us-gaap	Effective Income Tax Rate Reconciliation Deductions EffectiveIncomeTaxRateReconciliationDeductions	0
CY2019	us-gaap	Effective Income Tax Rate Reconciliation Deductions EffectiveIncomeTaxRateReconciliationDeductions	0
CY2018	us-gaap	Effective Income Tax Rate Reconciliation Deductions EffectiveIncomeTaxRateReconciliationDeductions	0.03
CY2020	us-gaap	Effective Income Tax Rate Reconciliation Deductions Qualified Production Activities EffectiveIncomeTaxRateReconciliationDeductionsQualifiedProductionActivities	0
CY2019	us-gaap	Effective Income Tax Rate Reconciliation Deductions Qualified Production Activities EffectiveIncomeTaxRateReconciliationDeductionsQualifiedProductionActivities	0
CY2018	us-gaap	Effective Income Tax Rate Reconciliation Deductions Qualified Production Activities EffectiveIncomeTaxRateReconciliationDeductionsQualifiedProductionActivities	0.02
CY2020	atkr	Effective Income Tax Rate Reconciliation Indemnified Uncertain Tax Benefits Percent EffectiveIncomeTaxRateReconciliationIndemnifiedUncertainTaxBenefitsPercent	0
CY2019	atkr	Effective Income Tax Rate Reconciliation Indemnified Uncertain Tax Benefits Percent EffectiveIncomeTaxRateReconciliationIndemnifiedUncertainTaxBenefitsPercent	0
CY2018	atkr	Effective Income Tax Rate Reconciliation Indemnified Uncertain Tax Benefits Percent EffectiveIncomeTaxRateReconciliationIndemnifiedUncertainTaxBenefitsPercent	0.02
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
CY2018	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense Share Based Compensation Cost EffectiveIncomeTaxRateReconciliationNondeductibleExpenseShareBasedCompensationCost	0.03
CY2019	atkr	Effective Income Tax Rate Reconciliation Gilti Withholding Taxes Amount EffectiveIncomeTaxRateReconciliationGILTIWithholdingTaxesAmount	635000	USD
CY2020	us-gaap	Effective Income Tax Rate Reconciliation Other Adjustments EffectiveIncomeTaxRateReconciliationOtherAdjustments	0.02
CY2019	us-gaap	Effective Income Tax Rate Reconciliation Other Adjustments EffectiveIncomeTaxRateReconciliationOtherAdjustments	0.01
CY2018	us-gaap	Effective Income Tax Rate Reconciliation Other Adjustments EffectiveIncomeTaxRateReconciliationOtherAdjustments	0
CY2020	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.25
CY2019	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.25
CY2018	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.18
CY2020	us-gaap	Income Tax Reconciliation State And Local Income Taxes IncomeTaxReconciliationStateAndLocalIncomeTaxes	7690000	USD
CY2020	us-gaap	Income Tax Reconciliation Change In Deferred Tax Assets Valuation Allowance IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance	2099000	USD
CY2020	atkr	Effective Income Tax Reconciliation Limitations On Executive Compensation Amount EffectiveIncomeTaxReconciliationLimitationsOnExecutiveCompensationAmount	1243000	USD
CY2020	atkr	Effective Income Tax Reconciliation Excess Tax Benefit Stock Option On Exercise Of Stock Option Amount EffectiveIncomeTaxReconciliationExcessTaxBenefitStockOptionOnExerciseOfStockOptionAmount	4203000	USD
CY2019	us-gaap	Income Tax Reconciliation State And Local Income Taxes IncomeTaxReconciliationStateAndLocalIncomeTaxes	7566000	USD
CY2019	atkr	Effective Income Tax Rate Reconciliation Gilti Provisions Amount EffectiveIncomeTaxRateReconciliationGILTIProvisionsAmount	953000	USD
CY2018	us-gaap	Tax Cuts And Jobs Act Of2017 Change In Tax Rate Deferred Tax Liability Income Tax Benefit TaxCutsAndJobsActOf2017ChangeInTaxRateDeferredTaxLiabilityIncomeTaxBenefit	5466000	USD
CY2019	atkr	Effective Income Tax Rate Reconciliation Acquisition Of Business Amount EffectiveIncomeTaxRateReconciliationAcquisitionOfBusinessAmount	1551000	USD
CY2019	atkr	Effective Income Tax Reconciliation Excess Tax Benefit Stock Option On Exercise Of Stock Option Amount EffectiveIncomeTaxReconciliationExcessTaxBenefitStockOptionOnExerciseOfStockOptionAmount	1537000	USD
CY2018	atkr	Effective Income Tax Reconciliation Excess Tax Benefit Stock Option On Exercise Of Stock Option Amount EffectiveIncomeTaxReconciliationExcessTaxBenefitStockOptionOnExerciseOfStockOptionAmount	4091000	USD
CY2018	atkr	Effective Income Tax Rate Reconciliation Releaseof Indemnified Tax Positions EffectiveIncomeTaxRateReconciliationReleaseofIndemnifiedTaxPositions	3977000	USD
CY2018	us-gaap	Income Tax Reconciliation Deductions Qualified Production Activities IncomeTaxReconciliationDeductionsQualifiedProductionActivities	3309000	USD
CY2018	us-gaap	Income Tax Reconciliation State And Local Income Taxes IncomeTaxReconciliationStateAndLocalIncomeTaxes	5675000	USD
CY2020Q3	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals DeferredTaxAssetsTaxDeferredExpenseReservesAndAccruals	26783000	USD
CY2019Q3	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals DeferredTaxAssetsTaxDeferredExpenseReservesAndAccruals	32664000	USD
CY2020Q3	atkr	Deferred Tax Assets Operating Loss And Tax Credit Carryforwards DeferredTaxAssetsOperatingLossAndTaxCreditCarryforwards	15637000	USD
CY2019Q3	atkr	Deferred Tax Assets Operating Loss And Tax Credit Carryforwards DeferredTaxAssetsOperatingLossAndTaxCreditCarryforwards	13296000	USD
CY2020Q3	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Postretirement Benefits DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsPostretirementBenefits	11751000	USD
CY2019Q3	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Postretirement Benefits DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsPostretirementBenefits	10315000	USD
CY2020Q3	us-gaap	Deferred Tax Assets Inventory DeferredTaxAssetsInventory	5240000	USD
CY2019Q3	us-gaap	Deferred Tax Assets Inventory DeferredTaxAssetsInventory	8813000	USD
CY2020Q3	atkr	Deferred Tax Assets Lease Obligations DeferredTaxAssetsLeaseObligations	9966000	USD
CY2020Q3	us-gaap	Deferred Tax Assets Other DeferredTaxAssetsOther	174000	USD
CY2019Q3	us-gaap	Deferred Tax Assets Other DeferredTaxAssetsOther	916000	USD
CY2020Q3	us-gaap	Deferred Tax Assets Gross DeferredTaxAssetsGross	69551000	USD
CY2019Q3	us-gaap	Deferred Tax Assets Gross DeferredTaxAssetsGross	66004000	USD
CY2020Q3	us-gaap	Deferred Tax Liabilities Property Plant And Equipment DeferredTaxLiabilitiesPropertyPlantAndEquipment	17648000	USD
CY2019Q3	us-gaap	Deferred Tax Liabilities Property Plant And Equipment DeferredTaxLiabilitiesPropertyPlantAndEquipment	21312000	USD
CY2020Q3	us-gaap	Deferred Tax Liabilities Goodwill And Intangible Assets Intangible Assets DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets	44774000	USD
CY2019Q3	us-gaap	Deferred Tax Liabilities Goodwill And Intangible Assets Intangible Assets DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets	47887000	USD
CY2020Q3	us-gaap	Deferred Tax Liabilities Investments DeferredTaxLiabilitiesInvestments	5153000	USD
CY2019Q3	us-gaap	Deferred Tax Liabilities Investments DeferredTaxLiabilitiesInvestments	4790000	USD
CY2020Q3	atkr	Deferred Tax Assets Rou Asset Net DeferredTaxAssetsROUAssetNet	9546000	USD
CY2020Q3	us-gaap	Deferred Tax Liabilities Other DeferredTaxLiabilitiesOther	4065000	USD
CY2019Q3	us-gaap	Deferred Tax Liabilities Other DeferredTaxLiabilitiesOther	3660000	USD
CY2020Q3	us-gaap	Deferred Income Tax Liabilities DeferredIncomeTaxLiabilities	81186000	USD
CY2019Q3	us-gaap	Deferred Income Tax Liabilities DeferredIncomeTaxLiabilities	77649000	USD
CY2020Q3	atkr	Deferred Tax Assets Netof Deferred Tax Liabilities Before Valuation Allowance DeferredTaxAssetsNetofDeferredTaxLiabilitiesBeforeValuationAllowance	11635000	USD
CY2019Q3	atkr	Deferred Tax Assets Netof Deferred Tax Liabilities Before Valuation Allowance DeferredTaxAssetsNetofDeferredTaxLiabilitiesBeforeValuationAllowance	11645000	USD
CY2020Q3	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	10203000	USD
CY2019Q3	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	7764000	USD
CY2020Q3	us-gaap	Deferred Tax Liabilities DeferredTaxLiabilities	21838000	USD
CY2019Q3	us-gaap	Deferred Tax Liabilities DeferredTaxLiabilities	19409000	USD
CY2020	atkr	Operating Loss Carryforwards Expiration Term OperatingLossCarryforwardsExpirationTerm	P5Y
CY2020Q3	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	1614000	USD
CY2020Q3	us-gaap	Unrecognized Tax Benefits Income Tax Penalties And Interest Accrued UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued	188000	USD
CY2019Q3	us-gaap	Unrecognized Tax Benefits Income Tax Penalties And Interest Accrued UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued	54000	USD
CY2017Q3	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	3578000	USD
CY2018	us-gaap	Unrecognized Tax Benefits Increases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions	893000	USD
CY2018	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Settlements With Taxing Authorities UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities	3107000	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
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
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
CY2019	atkr	Unrecognized Tax Benefits Income Tax Penalties And Interest Period Increase Decrease UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestPeriodIncreaseDecrease	-25000	USD
CY2018	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Settlements With Taxing Authorities UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities	3107000	USD
CY2018	us-gaap	Unrecognized Tax Benefits Increases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions	893000	USD
CY2018	atkr	Unrecognized Tax Benefits Income Tax Penalties And Interest Period Increase Decrease UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestPeriodIncreaseDecrease	-3139000	USD
CY2019	atkr	Effective Income Tax Rate Reconciliation Gilti Withholding Taxes Amount EffectiveIncomeTaxRateReconciliationGILTIWithholdingTaxesAmount	635000	USD
CY2020Q3	us-gaap	Undistributed Earnings Of Foreign Subsidiaries UndistributedEarningsOfForeignSubsidiaries	59719000	USD
CY2020	us-gaap	Net Income Loss NetIncomeLoss	152302000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	139051000	USD
CY2018	us-gaap	Net Income Loss NetIncomeLoss	136645000	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
CY2018	us-gaap	Undistributed Earnings Loss Allocated To Participating Securities Basic UndistributedEarningsLossAllocatedToParticipatingSecuritiesBasic	2456000	USD
CY2020	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	148946000	USD
CY2019	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	135325000	USD
CY2018	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	134189000	USD
CY2020	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	47265000	shares
CY2019	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	46577000	shares
CY2018	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	51791000	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
CY2018	us-gaap	Incremental Common Shares Attributable To Share Based Payment Arrangements IncrementalCommonSharesAttributableToShareBasedPaymentArrangements	2298000	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
CY2018	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	54089000	shares
CY2020	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	3.15
CY2019	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	2.91
CY2018	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	2.59
CY2020	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	3.10
CY2019	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	2.83
CY2018	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	2.48
CY2019	us-gaap	Oci Before Reclassifications Net Of Tax Attributable To Parent OciBeforeReclassificationsNetOfTaxAttributableToParent	-23003000	USD
CY2019	us-gaap	Reclassification From Aoci Current Period Net Of Tax Attributable To Parent ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent	-76000	USD
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
CY2020Q3	us-gaap	Percentage Of Lifo Inventory PercentageOfLIFOInventory	0.73
CY2019Q3	us-gaap	Percentage Of Lifo Inventory PercentageOfLIFOInventory	0.72
CY2020Q3	atkr	Inventory Raw Materialsand Purchased Parts Netof Valuation Reserves InventoryRawMaterialsandPurchasedPartsNetofValuationReserves	49192000	USD
CY2019Q3	atkr	Inventory Raw Materialsand Purchased Parts Netof Valuation Reserves InventoryRawMaterialsandPurchasedPartsNetofValuationReserves	52742000	USD
CY2019Q3	us-gaap	Inventory Work In Process Net Of Reserves InventoryWorkInProcessNetOfReserves	21424000	USD
CY2020Q3	us-gaap	Inventory Finished Goods Net Of Reserves InventoryFinishedGoodsNetOfReserves	125790000	USD
CY2019Q3	us-gaap	Inventory Finished Goods Net Of Reserves InventoryFinishedGoodsNetOfReserves	151924000	USD
CY2020Q3	us-gaap	Inventory Net InventoryNet	199095000	USD
CY2019Q3	us-gaap	Inventory Net InventoryNet	226090000	USD
CY2020Q3	us-gaap	Inventory Lifo Reserve InventoryLIFOReserve	4418000	USD
CY2020Q3	us-gaap	Inventory Work In Process Net Of Reserves InventoryWorkInProcessNetOfReserves	24113000	USD
CY2019Q3	us-gaap	Inventory Lifo Reserve InventoryLIFOReserve	-3138000	USD
CY2020	us-gaap	Effect Of Lifo Inventory Liquidation On Income EffectOfLIFOInventoryLiquidationOnIncome	1837000	USD
CY2020Q3	us-gaap	Inventory Valuation Reserves InventoryValuationReserves	14533000	USD
CY2019Q3	us-gaap	Inventory Valuation Reserves InventoryValuationReserves	14295000	USD
CY2020Q3	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	541884000	USD
CY2019Q3	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	520533000	USD
CY2020Q3	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	297993000	USD
CY2019Q3	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	259830000	USD
CY2020Q3	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	243891000	USD
CY2019Q3	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	260703000	USD
CY2020	us-gaap	Depreciation Depreciation	42208000	USD
CY2019	us-gaap	Depreciation Depreciation	39471000	USD
CY2018	us-gaap	Depreciation Depreciation	34786000	USD
CY2019	us-gaap	Goodwill Foreign Currency Translation Gain Loss GoodwillForeignCurrencyTranslationGainLoss	-2022000	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
CY2018Q3	us-gaap	Goodwill Goodwill	170129000	USD
CY2019	us-gaap	Goodwill Acquired During Period GoodwillAcquiredDuringPeriod	18124000	USD
CY2020Q3	us-gaap	Finite Lived Intangible Assets Gross FiniteLivedIntangibleAssetsGross	374821000	USD
CY2020Q3	us-gaap	Finite Lived Intangible Assets Accumulated Amortization FiniteLivedIntangibleAssetsAccumulatedAmortization	212352000	USD
CY2020Q3	us-gaap	Finite Lived Intangible Assets Net FiniteLivedIntangibleAssetsNet	162469000	USD
CY2019Q3	us-gaap	Finite Lived Intangible Assets Gross FiniteLivedIntangibleAssetsGross	372342000	USD
CY2019Q3	us-gaap	Finite Lived Intangible Assets Accumulated Amortization FiniteLivedIntangibleAssetsAccumulatedAmortization	179538000	USD
CY2019Q3	us-gaap	Finite Lived Intangible Assets Net FiniteLivedIntangibleAssetsNet	192804000	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
CY2019Q3	us-gaap	Intangible Assets Gross Excluding Goodwill IntangibleAssetsGrossExcludingGoodwill	465222000	USD
CY2019Q3	us-gaap	Finite Lived Intangible Assets Accumulated Amortization FiniteLivedIntangibleAssetsAccumulatedAmortization	179538000	USD
CY2019Q3	us-gaap	Intangible Assets Net Excluding Goodwill IntangibleAssetsNetExcludingGoodwill	285684000	USD
CY2020	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	32262000	USD
CY2019	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	32876000	USD
CY2018	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	32104000	USD
CY2020Q3	us-gaap	Finite Lived Intangible Assets Amortization Expense Next Twelve Months FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths	32267000	USD
CY2020Q3	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Two FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo	30859000	USD
CY2020Q3	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Three FiniteLivedIntangibleAssetsAmortizationExpenseYearThree	30806000	USD
CY2020Q3	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Four FiniteLivedIntangibleAssetsAmortizationExpenseYearFour	26287000	USD
CY2020Q3	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Five FiniteLivedIntangibleAssetsAmortizationExpenseYearFive	13681000	USD
CY2020Q3	us-gaap	Finite Lived Intangible Assets Amortization Expense After Year Five FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive	28569000	USD
CY2020Q3	us-gaap	Deferred Finance Costs Net DeferredFinanceCostsNet	7804000	USD
CY2019Q3	us-gaap	Deferred Finance Costs Net DeferredFinanceCostsNet	6569000	USD
CY2020Q3	us-gaap	Debt Longterm And Shortterm Combined Amount DebtLongtermAndShorttermCombinedAmount	803736000	USD
CY2019Q3	us-gaap	Debt Longterm And Shortterm Combined Amount DebtLongtermAndShorttermCombinedAmount	845317000	USD
CY2020Q3	us-gaap	Debt Current DebtCurrent	0	USD
CY2019Q3	us-gaap	Debt Current DebtCurrent	0	USD
CY2020Q3	us-gaap	Long Term Debt Noncurrent LongTermDebtNoncurrent	803736000	USD
CY2019Q3	us-gaap	Long Term Debt Noncurrent LongTermDebtNoncurrent	845317000	USD
CY2020Q3	us-gaap	Contractual Obligation Due In Next Twelve Months ContractualObligationDueInNextTwelveMonths	0	USD
CY2020Q3	us-gaap	Contractual Obligation Due In Second Year ContractualObligationDueInSecondYear	0	USD
CY2020Q3	us-gaap	Contractual Obligation Due In Third Year ContractualObligationDueInThirdYear	0	USD
CY2020Q3	us-gaap	Contractual Obligation Due In Fourth Year ContractualObligationDueInFourthYear	812120000	USD
CY2020Q3	us-gaap	Contractual Obligation Due In Fifth Year ContractualObligationDueInFifthYear	0	USD
CY2020Q3	us-gaap	Contractual Obligation Due After Fifth Year ContractualObligationDueAfterFifthYear	0	USD
CY2018	us-gaap	Gains Losses On Restructuring Of Debt GainsLossesOnRestructuringOfDebt	-892000	USD
CY2020	us-gaap	Gains Losses On Extinguishment Of Debt GainsLossesOnExtinguishmentOfDebt	-273000	USD
CY2020Q3	us-gaap	Purchase Obligation Due In Next Twelve Months PurchaseObligationDueInNextTwelveMonths	130932000	USD
CY2020Q3	us-gaap	Purchase Obligation Due In Second Year PurchaseObligationDueInSecondYear	1828000	USD
CY2020Q3	us-gaap	Purchase Obligation Due In Third Year PurchaseObligationDueInThirdYear	13000	USD
CY2019Q3	atkr	Total Settlementfor Prior Cap Agreement Deductible TotalSettlementforPriorCapAgreementDeductible	13000000	USD
CY2018	us-gaap	Related Party Transaction Other Revenues From Transactions With Related Party RelatedPartyTransactionOtherRevenuesFromTransactionsWithRelatedParty	6000000	USD
CY2020	us-gaap	Number Of Operating Segments NumberOfOperatingSegments	2	segment
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
CY2018	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	38501000	USD
CY2020Q3	us-gaap	Assets Assets	1558525000	USD
CY2019Q3	us-gaap	Assets Assets	1436995000	USD
CY2018Q3	us-gaap	Assets Assets	1324060000	USD
CY2020	atkr	Selling Generaland Administrative Expense Unallocated SellingGeneralandAdministrativeExpenseUnallocated	34002000	USD
CY2019	atkr	Selling Generaland Administrative Expense Unallocated SellingGeneralandAdministrativeExpenseUnallocated	38217000	USD
CY2018	atkr	Selling Generaland Administrative Expense Unallocated SellingGeneralandAdministrativeExpenseUnallocated	35050000	USD
CY2020	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	74470000	USD
CY2019	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	72347000	USD
CY2018	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	66890000	USD
CY2020	us-gaap	Interest Income Expense Nonoperating Net InterestIncomeExpenseNonoperatingNet	-40062000	USD
CY2019	us-gaap	Interest Income Expense Nonoperating Net InterestIncomeExpenseNonoperatingNet	-50473000	USD
CY2018	us-gaap	Interest Income Expense Nonoperating Net InterestIncomeExpenseNonoperatingNet	-40694000	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
CY2018	us-gaap	Gains Losses On Extinguishment Of Debt GainsLossesOnExtinguishmentOfDebt	0	USD
CY2020	us-gaap	Restructuring Settlement And Impairment Provisions RestructuringSettlementAndImpairmentProvisions	3284000	USD
CY2019	us-gaap	Restructuring Settlement And Impairment Provisions RestructuringSettlementAndImpairmentProvisions	3804000	USD
CY2018	us-gaap	Restructuring Settlement And Impairment Provisions RestructuringSettlementAndImpairmentProvisions	1849000	USD
CY2020	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	13064000	USD
CY2019	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	11798000	USD
CY2018	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	14664000	USD
CY2020	us-gaap	Gain Loss Related To Litigation Settlement GainLossRelatedToLitigationSettlement	0	USD
CY2019	us-gaap	Gain Loss Related To Litigation Settlement GainLossRelatedToLitigationSettlement	0	USD
CY2018	us-gaap	Gain Loss Related To Litigation Settlement GainLossRelatedToLitigationSettlement	4833000	USD
CY2020	atkr	Transaction Costs TransactionCosts	196000	USD
CY2019	atkr	Transaction Costs TransactionCosts	1200000	USD
CY2018	atkr	Transaction Costs TransactionCosts	9314000	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
CY2018	us-gaap	Business Combination Bargain Purchase Gain Recognized Amount BusinessCombinationBargainPurchaseGainRecognizedAmount	0	USD
CY2020	us-gaap	Gain Loss On Sale Of Investments GainLossOnSaleOfInvestments	0	USD
CY2019	us-gaap	Gain Loss On Sale Of Investments GainLossOnSaleOfInvestments	0	USD
CY2018	us-gaap	Gain Loss On Sale Of Investments GainLossOnSaleOfInvestments	27575000	USD
CY2020	us-gaap	Other Operating Income Expense Net OtherOperatingIncomeExpenseNet	6712000	USD
CY2019	us-gaap	Other Operating Income Expense Net OtherOperatingIncomeExpenseNet	-7501000	USD
CY2018	us-gaap	Other Operating Income Expense Net OtherOperatingIncomeExpenseNet	-4194000	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
CY2018	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	166352000	USD
CY2020Q3	us-gaap	Noncurrent Assets NoncurrentAssets	246882000	USD
CY2019Q3	us-gaap	Noncurrent Assets NoncurrentAssets	264966000	USD
CY2018Q3	us-gaap	Noncurrent Assets NoncurrentAssets	214715000	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
CY2018	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	1835139000	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
CY2018	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	1835139000	USD
CY2020Q3	atkr	Employees Covered By Collective Bargaining Arrangement Percentage EmployeesCoveredByCollectiveBargainingArrangementPercentage	0.24
CY2019Q4	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	447448000	USD
CY2020Q1	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	455654000	USD
CY2020Q2	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	384899000	USD
	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	477420000	USD
CY2018Q4	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	452028000	USD
CY2019Q1	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	469309000	USD
CY2019Q2	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	493491000	USD
CY2019Q3	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	501710000	USD
CY2019Q4	us-gaap	Gross Profit GrossProfit	116844000	USD
CY2020Q1	us-gaap	Gross Profit GrossProfit	131603000	USD
CY2020Q2	us-gaap	Gross Profit GrossProfit	95813000	USD
	us-gaap	Gross Profit GrossProfit	147054000	USD
CY2018Q4	us-gaap	Gross Profit GrossProfit	110256000	USD
CY2019Q1	us-gaap	Gross Profit GrossProfit	117088000	USD
CY2019Q2	us-gaap	Gross Profit GrossProfit	126134000	USD
CY2019Q3	us-gaap	Gross Profit GrossProfit	143722000	USD
CY2019Q4	us-gaap	Net Income Loss NetIncomeLoss	34790000	USD
CY2020Q1	us-gaap	Net Income Loss NetIncomeLoss	39193000	USD
CY2020Q2	us-gaap	Net Income Loss NetIncomeLoss	24078000	USD
	us-gaap	Net Income Loss NetIncomeLoss	54241000	USD
CY2018Q4	us-gaap	Net Income Loss NetIncomeLoss	26949000	USD
CY2019Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.96
CY2019Q4	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.71
CY2019Q1	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.62
CY2019Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.77
CY2019Q1	us-gaap	Net Income Loss NetIncomeLoss	29555000	USD
CY2019Q2	us-gaap	Net Income Loss NetIncomeLoss	36550000	USD
CY2019Q3	us-gaap	Net Income Loss NetIncomeLoss	45997000	USD
CY2019Q4	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.72
CY2020Q1	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.81
CY2020Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.50
	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.12
CY2018Q4	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.56
CY2020Q1	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.80
CY2020Q2	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.49
	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.11
CY2018Q4	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.54
CY2019Q1	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.61
CY2019Q2	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.75
CY2019Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.94
CY2020Q4	dei	Entity Common Stock Shares Outstanding EntityCommonStockSharesOutstanding	47409886	shares
CY2020Q3	us-gaap	Common Stock Value CommonStockValue	475000	USD
CY2019Q3	us-gaap	Common Stock Value CommonStockValue	471000	USD
CY2020Q3	us-gaap	Treasury Stock Value TreasuryStockValue	2580000	USD
CY2019Q3	us-gaap	Treasury Stock Value TreasuryStockValue	2580000	USD
CY2020Q3	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	-64154000	USD
CY2019Q3	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	-200396000	USD
CY2020Q3	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-42554000	USD
CY2019Q3	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-41698000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	-22927000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	1544000	USD
CY2020	atkr	Proceeds From Issuance Of Common Stock Net Of Taxes Withhold ProceedsFromIssuanceOfCommonStockNetOfTaxesWithhold	-2972000	USD
CY2014Q2	atkr	Paymentsfor Repurchaseof Common Stock Excluding Related Expense PaymentsforRepurchaseofCommonStockExcludingRelatedExpense	250000000	USD

Files In Submission

Name	View Source	Status
0001666138-20-000123-index-headers.html	Edgar Link	pending
0001666138-20-000123-index.html	Edgar Link	pending
0001666138-20-000123.txt	Edgar Link	pending
0001666138-20-000123-xbrl.zip	Edgar Link	pending
a4q20exhibit211.htm	Edgar Link	pending
a4q20exhibit231.htm	Edgar Link	pending
a4q20exhibit311.htm	Edgar Link	pending
a4q20exhibit312.htm	Edgar Link	pending
a4q20exhibit321.htm	Edgar Link	pending
a4q20exhibit322.htm	Edgar Link	pending
armoredcfa01.jpg	Edgar Link	pending
atk24194brandlogohorizontalc.jpg	Edgar Link	pending
atkr-20200930.xsd	Edgar Link	pending
atkr-20200930_cal.xml	Edgar Link	unprocessable
atkr-20200930_def.xml	Edgar Link	unprocessable
atkr-20200930_lab.xml	Edgar Link	unprocessable
atkr-20200930_pre.xml	Edgar Link	unprocessable
atkr2020annualreport.htm	Edgar Link	pending
atkr2020annualreport_htm.xml	Edgar Link	completed
chart-7eeb34e361865398ac9.jpg	Edgar Link	pending
emtcleana02.jpg	Edgar Link	pending
FilingSummary.xml	Edgar Link	unprocessable
Financial_Report.xlsx	Edgar Link	pending
flexcfa01.jpg	Edgar Link	pending
laddera01.jpg	Edgar Link	pending
mechpipea01.jpg	Edgar Link	pending
metalcf2a01.jpg	Edgar Link	pending
metalcfa01.jpg	Edgar Link	pending
metaleleccfa01.jpg	Edgar Link	pending
MetaLinks.json	Edgar Link	pending
pvccfa01.jpg	Edgar Link	pending
R1.htm	Edgar Link	pending
R10.htm	Edgar Link	pending
R100.htm	Edgar Link	pending
R101.htm	Edgar Link	pending
R102.htm	Edgar Link	pending
R103.htm	Edgar Link	pending
R104.htm	Edgar Link	pending
R105.htm	Edgar Link	pending
R106.htm	Edgar Link	pending
R107.htm	Edgar Link	pending
R108.htm	Edgar Link	pending
R109.htm	Edgar Link	pending
R11.htm	Edgar Link	pending
R110.htm	Edgar Link	pending
R111.htm	Edgar Link	pending
R112.htm	Edgar Link	pending
R113.htm	Edgar Link	pending
R114.htm	Edgar Link	pending
R115.htm	Edgar Link	pending
R116.htm	Edgar Link	pending
R117.htm	Edgar Link	pending
R118.htm	Edgar Link	pending
R119.htm	Edgar Link	pending
R12.htm	Edgar Link	pending
R120.htm	Edgar Link	pending
R121.htm	Edgar Link	pending
R122.htm	Edgar Link	pending
R123.htm	Edgar Link	pending
R124.htm	Edgar Link	pending
R13.htm	Edgar Link	pending
R14.htm	Edgar Link	pending
R15.htm	Edgar Link	pending
R16.htm	Edgar Link	pending
R17.htm	Edgar Link	pending
R18.htm	Edgar Link	pending
R19.htm	Edgar Link	pending
R2.htm	Edgar Link	pending
R20.htm	Edgar Link	pending
R21.htm	Edgar Link	pending
R22.htm	Edgar Link	pending
R23.htm	Edgar Link	pending
R24.htm	Edgar Link	pending
R25.htm	Edgar Link	pending
R26.htm	Edgar Link	pending
R27.htm	Edgar Link	pending
R28.htm	Edgar Link	pending
R29.htm	Edgar Link	pending
R3.htm	Edgar Link	pending
R30.htm	Edgar Link	pending
R31.htm	Edgar Link	pending
R32.htm	Edgar Link	pending
R33.htm	Edgar Link	pending
R34.htm	Edgar Link	pending
R35.htm	Edgar Link	pending
R36.htm	Edgar Link	pending
R37.htm	Edgar Link	pending
R38.htm	Edgar Link	pending
R39.htm	Edgar Link	pending
R4.htm	Edgar Link	pending
R40.htm	Edgar Link	pending
R41.htm	Edgar Link	pending
R42.htm	Edgar Link	pending
R43.htm	Edgar Link	pending
R44.htm	Edgar Link	pending
R45.htm	Edgar Link	pending
R46.htm	Edgar Link	pending
R47.htm	Edgar Link	pending
R48.htm	Edgar Link	pending
R49.htm	Edgar Link	pending
R5.htm	Edgar Link	pending
R50.htm	Edgar Link	pending
R51.htm	Edgar Link	pending
R52.htm	Edgar Link	pending
R53.htm	Edgar Link	pending
R54.htm	Edgar Link	pending
R55.htm	Edgar Link	pending
R56.htm	Edgar Link	pending
R57.htm	Edgar Link	pending
R58.htm	Edgar Link	pending
R59.htm	Edgar Link	pending
R6.htm	Edgar Link	pending
R60.htm	Edgar Link	pending
R61.htm	Edgar Link	pending
R62.htm	Edgar Link	pending
R63.htm	Edgar Link	pending
R64.htm	Edgar Link	pending
R65.htm	Edgar Link	pending
R66.htm	Edgar Link	pending
R67.htm	Edgar Link	pending
R68.htm	Edgar Link	pending
R69.htm	Edgar Link	pending
R7.htm	Edgar Link	pending
R70.htm	Edgar Link	pending
R71.htm	Edgar Link	pending
R72.htm	Edgar Link	pending
R73.htm	Edgar Link	pending
R74.htm	Edgar Link	pending
R75.htm	Edgar Link	pending
R76.htm	Edgar Link	pending
R77.htm	Edgar Link	pending
R78.htm	Edgar Link	pending
R79.htm	Edgar Link	pending
R8.htm	Edgar Link	pending
R80.htm	Edgar Link	pending
R81.htm	Edgar Link	pending
R82.htm	Edgar Link	pending
R83.htm	Edgar Link	pending
R84.htm	Edgar Link	pending
R85.htm	Edgar Link	pending
R86.htm	Edgar Link	pending
R87.htm	Edgar Link	pending
R88.htm	Edgar Link	pending
R89.htm	Edgar Link	pending
R9.htm	Edgar Link	pending
R90.htm	Edgar Link	pending
R91.htm	Edgar Link	pending
R92.htm	Edgar Link	pending
R93.htm	Edgar Link	pending
R94.htm	Edgar Link	pending
R95.htm	Edgar Link	pending
R96.htm	Edgar Link	pending
R97.htm	Edgar Link	pending
R98.htm	Edgar Link	pending
R99.htm	Edgar Link	pending
report.css	Edgar Link	pending
rrproducta01.jpg	Edgar Link	pending
Show.js	Edgar Link	pending
uniconproducta01.jpg	Edgar Link	pending
unistrutproducta01.jpg	Edgar Link	pending

Create your account

Find Stocks Worth Researching

Deeply Understand Businesses

Value Businesses Intelligently

$ATKR
Atkore Inc. Stock $atkr

2019 Q3 Form 10-K Financial Statement

#000166613820000123 Filed on November 19, 2020

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$ATKR Atkore Inc. Stock $atkr

2019 Q3 Form 10-K Financial Statement

#000166613820000123 Filed on November 19, 2020

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$ATKR
Atkore Inc. Stock $atkr