Income Tax (Provision for Income Tax Expense Computed from Statutory Rate to Pre-tax Income) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Effective Income Tax Rate Reconciliation, Equity in Earnings (Losses) of Unconsolidated Subsidiary, Amount	$ (10,532)	$ 0	$ 0
Effective Income Tax Rate Reconciliation at Federal Statutory Income Tax Rate, Amount	399,985	365,381	260,678
Tax Adjustments, Settlements, and Unusual Provisions	(1,033,755)	0	0
Effective Income Tax Rate Reconciliation, Foreign Income Tax Rate Differential, Amount	(21,867)	(13,974)	(9,950)
Income Tax Reconciliation Foreign Income Tax Basis Differential	(23,324)	(17,770)	(32,472)
Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Amount	29,458	10,963	19,157
Effective Income Tax Rate Reconciliation, Tax Contingency, Domestic, Amount	(7,184)	111	88
Income Tax Reconciliation Change In Foreign Enacted Tax Rate	(6,065)	0	0
Income Tax Reconciliation Subpart F	1,528	1,783	3,473
Effective Income Tax Rate Reconciliation, Tax Credit, Foreign, Amount	(1,681)	(1,683)	(1,936)
Effective Income Tax Rate Reconciliation, Prior Year Income Taxes, Amount	(4,674)	(1,473)	1,482
Effective Income Tax Rate Reconciliation, Other Adjustments, Amount	(1,255)	(835)	2,109
Income Tax Expense (Benefit)	$ (679,366)	$ 342,503	$ 242,629
Effective Income Tax Rate Reconciliation, Percent	(59.40%)	32.80%	32.60%