Significant Accounting Policies Fair Value Measurements (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign exchange contracts, net		$ 48,900
Debt and Capital Lease Obligations	$ 1,864,400	1,693,500
Estimate of Fair Value Measurement [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term Debt, Fair Value	1,972,800	1,769,300
Reported Value Measurement [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt and Capital Lease Obligations	1,864,400	1,693,500
Fair value, measurements, recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign exchange contracts, net		48,900
Total assets at fair value	49,500
Non-qualified deferred compensation liabilities		(48,900)
Financial and Nonfinancial Liabilities, Fair Value Disclosure	(71,500)	(57,000)
Fair value, measurements, recurring | Supplemental Employee Retirement Plans, Defined Benefit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Non-qualified deferred compensation assets	49,500	48,900
Non-qualified deferred compensation liabilities	(49,500)
Fair value, measurements, recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets at fair value	49,500
Financial and Nonfinancial Liabilities, Fair Value Disclosure	(49,500)	(48,900)
Fair value, measurements, recurring | Level 1 | Supplemental Employee Retirement Plans, Defined Benefit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Non-qualified deferred compensation assets	49,500	48,900
Non-qualified deferred compensation liabilities	(49,500)	(48,900)
Fair value, measurements, recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets at fair value	0	0
Financial and Nonfinancial Liabilities, Fair Value Disclosure	(22,000)	(8,100)
Foreign Exchange Contract | Fair value, measurements, recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign exchange contracts, net	(2,000)	(100)
Foreign Exchange Contract | Fair value, measurements, recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign exchange contracts, net		(100)
Interest rate swap | Fair value, measurements, recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign exchange contracts, net	(20,000)	(8,000)
Interest rate swap | Fair value, measurements, recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign exchange contracts, net		(8,000)
Designated as Hedging Instrument | Prepaid Expenses and Other Current Assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value— Assets	400	1,100
Designated as Hedging Instrument | Prepaid Expenses and Other Current Assets | Foreign Exchange Contract
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset	2,000
Fair Value— Assets	400	1,100
Designated as Hedging Instrument | Prepaid Expenses and Other Current Assets | Interest rate swap
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value— Assets	0	$ (8,000)
Derivative Liability, Fair Value, Gross Liability	$ 20,000