Income Taxes (Schedule of Deferred Tax Asset (Liability)) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Deferred Tax Assets, Operating Loss Carryforwards	$ 41,000
Deferred tax asset, net	16,198	$ 24,822
Deferred Tax Liabilities, Net, Noncurrent	(137,233)	(128,066)
Current [Member]
Deferred Tax Assets, Operating Loss Carryforwards	7,076	9,003
Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits	17,296	15,213
Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Allowance for Doubtful Accounts	261	286
Deferred Tax Assets, Gross, Current	30,016	30,039
Deferred Tax Assets, Valuation Allowance, Current	(1,236)	(596)
Deferred Tax Assets, Net of Valuation Allowance, Current	28,780	29,443
Deferred Tax Liabilities, Gross, Current	(12,636)	(4,662)
Deferred tax asset, net	16,144	24,781
Deferred Tax Assets, Other	5,383	5,537
Noncurrent [Member]
Deferred Tax Assets, Operating Loss Carryforwards	76,285	68,042
Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits	28,016	20,705
Deferred Tax Liabilities, Other	(16,114)	(13,803)
Deferred tax asset, fixed assets and intangible assets	35,781	43,751
Deferred Tax Assets Interest Rate Swap Contracts Noncurrent	2,412	2,857
Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Accrued Liabilities	11,692	10,522
Deferred Tax Assets, Other	12,040	9,171
Deferred Tax Assets, Gross, Noncurrent	166,226	155,048
Deferred Tax Assets, Valuation Allowance, Noncurrent	(53,100)	(50,434)
Deferred Tax Assets, Net of Valuation Allowance, Noncurrent	113,126	104,614
Deferred Tax Liabilities, Prepaid Expenses	(820)	(781)
Deferred tax liability, fixed assets and intangible assets	(70,337)	(64,762)
Deferred Tax Liabilities, Investment in Noncontrolled Affiliates	(154,215)	(138,790)
Deferred Tax Liabilities, Gross, Noncurrent	241,486	218,136
Deferred Tax Liabilities, Net, Noncurrent	(128,360)	(113,522)
Deferred Tax Liabilities, Net	$ (112,216)	$ (88,741)