Fair Value Disclosures - Assets And Liabilities Measured At Fair Value On Recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Assets:
Assets measured at fair value on a recurring basis	$ 70,541	$ 67,964
Liabilities:
Liabilities measured at fair value on a recurring basis	993,410	858,671
Fair Value, Inputs, Level 1
Assets:
Assets measured at fair value on a recurring basis	8,985	8,956
Fair Value, Inputs, Level 2
Assets:
Assets measured at fair value on a recurring basis	61,556	59,008
Liabilities:
Liabilities measured at fair value on a recurring basis	993,410	858,671
Fair Value, Inputs, Level 2 | Foreign currency forward contracts
Assets:
Assets measured at fair value on a recurring basis	65	1,318
Liabilities:
Liabilities measured at fair value on a recurring basis	285	3,260
Fair Value, Inputs, Level 2 | Interest rate swap contracts
Liabilities:
Liabilities measured at fair value on a recurring basis	80,233	10,681
Fair Value, Inputs, Level 2 | Deferred compensation plan assets
Assets:
Assets measured at fair value on a recurring basis	61,491	57,690
Fair Value, Inputs, Level 2 | Deferred compensation plan liabilities
Liabilities:
Liabilities measured at fair value on a recurring basis	74,308	68,570
Senior Notes
Liabilities:
Long term debt	800,000	800,000
Senior Notes | Fair Value, Inputs, Level 2 | Senior notes
Liabilities:
Liabilities measured at fair value on a recurring basis	$ 838,584	$ 776,160