Income Taxes (Schedule of Deferred Tax Asset (Liability)) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Components of Deferred Tax Assets and Liabilities [Abstract]
NOLs and tax credit carry forwards	$ 82,636	$ 83,361
Compensation and benefit plans	49,710	45,312
Allowance for doubtful accounts	421	261
Fixed assets and intangible assets	46,595	35,781
Interest rate swap contracts	2,884	2,412
Accrued interest expense	11,567	11,692
Other liabilities	20,811	17,423
Deferred tax asset	214,624	196,242
Valuation allowance	(71,563)	(54,336)
Net deferred tax asset, noncurrent	143,061	141,906
Prepaid liabilities	(819)	(820)
Fixed assets and intangible assets	(78,616)	(70,337)
Investments in partnerships	(177,376)	(154,215)
Other assets	(23,444)	(28,750)
Deferred tax liability, noncurrent	280,255	254,122
Total net deferred tax liability	$ (137,194)	$ (112,216)