Income Tax (Provision for Income Tax Expense) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Income Tax Disclosure [Abstract]
Effective Income Tax Rate Reconciliation at Federal Statutory Income Tax Rate, Amount	$ 119,057	$ 100,660	$ 310,562	$ 261,941
Effective Income Tax Rate Reconciliation, Foreign Income Tax Rate Differential, Amount	(3,635)	(2,335)	(14,049)	(14,617)
Income Tax Reconciliation Foreign Income Tax Basis Differential	2,126	(7,078)	(14,633)	(21,567)
Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Amount	(2,501)	4,411	11,627	13,698
Effective Income Tax Rate Reconciliation, Tax Contingency, Domestic, Amount	299	(3,979)	(873)	(175)
Income Tax Reconciliation Change In Foreign Enacted Tax Rate	(1,139)	0	(2,332)	0
Income Tax Reconciliation SubpartF	64	1,779	1,390	3,212
Effective Income Tax Rate Reconciliation, Tax Credit, Foreign, Amount	1,230	(1,934)	(834)	(2,655)
Effective Income Tax Rate Reconciliation, Equity in Earnings (Losses) of Unconsolidated Subsidiary, Amount	2,762	0	7,226	0
Effective Income Tax Rate Reconciliation, Prior Year Income Taxes, Amount	452	(1,996)	133	(2,227)
Effective Income Tax Rate Reconciliation, Other Adjustments, Amount	(620)	(647)	(1,737)	(501)
Income Tax Expense (Benefit)	$ 112,571	$ 88,881	$ 282,028	$ 237,109
Effective Income Tax Rate Reconciliation, Percent	33.10%	30.90%	31.80%	31.70%