Income Taxes - Components of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Components of Deferred Tax Assets [Abstract]
Deferred compensation plans	$ 34,080	$ 31,520
Deferred income	14,336	752
Allowance for uncollectible receivables	1,251	1,323
Deferred liabilities	1,869	4,625
Net operating losses and credit carryforward	11,680	32,573
Deferred tax assets	63,216	70,793
Valuation allowance	(1,052)	(1,274)
Net deferred tax asset	62,164	69,519
Deferred Tax Liabilities, Gross [Abstract]
Intangible assets in excess of tax basis	142,970	151,210
Property and equipment in excess of tax basis	31,216	37,827
Other	15,861	11,485
Deferred tax liabilities	190,047	200,522
Net deferred tax liability	(127,883)	(131,003)
Net current deferred tax asset	0	18,519
Net non-current deferred tax liability	$ (127,883)	$ (149,522)