Schedule I - Condensed Financial Information Of Registrant (Unconsolidated Statements Of Income) (Details) - USD ($) $ in Thousands		12 Months Ended
	Sep. 21, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Condensed Financial Statements, Captions [Line Items]
Interest Expense		$ (121,771)	$ (95,509)	$ (101,130)
Loss on early extinguishment of debt	$ 8,900	0	0	(8,875)
Other income / (expense), net		(10,546)	(1,852)	2,753
Total other income / (expense), net		(128,831)	(88,884)	(81,454)
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest		167,921	147,474	157,744
Less: income tax expense - net		35,528	13,449	48,951
Net income		132,393	134,025	108,793
Parent Company [Member]
Condensed Financial Statements, Captions [Line Items]
Equity in earnings of subsidiaries		154,078	154,150	133,725
Interest Expense		(32,761)	(31,038)	(35,791)
Loss on early extinguishment of debt		0	0	(8,875)
Other income / (expense), net		(46)	(443)	26
Total other income / (expense), net		121,271	122,669	89,085
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest		121,271	122,669	89,085
Less: income tax expense - net		(7,909)	(8,143)	(16,495)
Net income		$ 129,180	$ 130,812	$ 105,580