Fair Value Disclosures - Assets And Liabilities Measured At Fair Value On Recurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Assets:
Total Assets	$ 77,254	$ 67,964
Level 1
Assets:
Total Assets	2,277	8,956
Level 1 | Plan Assets
Assets:
Total Assets	2,277	8,956
Level 2
Assets:
Total Assets	74,977	59,008
Liabilities:
Total Liabilities	981,270	858,671
Level 2 | Foreign currency forward contracts
Assets:
Total Assets	1,558	1,318
Liabilities:
Total Liabilities	1,499	3,260
Level 2 | Interest rate swap contracts
Liabilities:
Total Liabilities	64,831	10,681
Level 2 | Plan Assets
Assets:
Total Assets	73,419	57,690
Level 2 | Plan Liabilities
Liabilities:
Total Liabilities	79,556	68,570
Level 2 | Debt | Senior notes
Liabilities:
Total Liabilities	$ 835,384	$ 776,160