Income Taxes (Schedule of Deferred Tax Asset (Liability)) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Components of Deferred Tax Assets and Liabilities [Abstract]
NOLs and tax credit carry forwards	$ 123,487	$ 69,771
Compensation and benefit plans	29,294	30,880
Allowance for doubtful accounts	981	370
Fixed assets and intangible assets	24,150	24,737
Interest rate swap contracts	0	1,893
Accrued interest expense	8,832	13,049
Other liabilities	24,594	12,562
Deferred tax asset	211,338	153,262
Valuation allowance	(95,185)	(57,121)
Net deferred tax asset, noncurrent	116,153	96,141
Prepaid liabilities	(514)	(501)
Fixed assets and intangible assets	(90,960)	(61,127)
Investments in partnerships	(121,156)	(103,474)
Other assets	(29,694)	(20,657)
Deferred tax liability, noncurrent	242,324	185,759
Total net deferred tax liability	$ (126,171)	$ (89,618)