Income Taxes (Income Tax Expense (Benefit)) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Current income taxes:
Current income taxes: U.S. federal	$ 247,917	$ 117,602	$ 100,826
Current income taxes: State and local	31,939	11,175	13,686
Current income taxes: Foreign	61,712	31,981	41,151
Total current income taxes	341,568	160,758	155,663
Deferred income taxes:
Deferred income taxes: U.S. federal	(16,167)	4,165	31,052
Deferred income taxes: State and local	(22,115)	(3,983)	(3,473)
Deferred income taxes: Foreign	4,273	(29,065)	(51,605)
Total deferred income taxes	(34,009)	(28,883)	(24,026)
Income tax expense (benefit)	$ 307,559	$ 131,875	$ 131,637