Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	$ 9,600
Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense	(900)	$ (400)	$ 1,700
Deferred tax assets:
Deferred compensation	46,973	50,829
Deferred income	18,787	16,305
Accrued expenses	12,624	9,235
Other	55,547	27,808
Gross deferred tax assets	133,931	104,177
Valuation allowance	0	0
Total deferred tax assets	133,931	104,177
Deferred tax liabilities:
Property and equipment	126,079	128,958
Unremitted foreign earnings	296,018	238,133
Basis difference in equity investments	(7,678)	(8,947)
Other	0	1,088
Total deferred tax liabilities	295,844	272,949
Deferred Tax Liabilities, Gross	429,775	377,126
Deferred Tax Assets (Liabilities), Net [Abstract]
Deferred tax liabilities	353,181	322,758
Deferred income taxes	$ (57,337)	$ (49,809)