Income Taxes (Effective Income Tax Rates) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Taxes [Abstract]
Income tax expense (benefit) based on the U.S. statutory tax rate	$ (1,148,792)	$ 438,295	$ 515,440
Foreign income (loss) subject to foreign tax rates different than the U.S. statutory rate	49,739	20,562	31,752
State income taxes, net of federal benefit	(3,441)	5,746	4,642
U.S. tax benefit on certain foreign upstream investments	(16,939)	(95,838)	(133,526)
Current tax in distribution of foreign earnings		52,724
Deferred tax on distribution of foreign earnings	188,461
Tax effects on sale of Malaysian assets	(122,559)	(227,241)
Increase in deferred tax asset valuation allowance related to other foreign exploration expenditures	40,788	37,712	129,588
Impairment or abandonment of Azurite field with no tax benefit			35,475
Other, net	(13,747)	(4,663)	1,179
Total income tax expense (benefit)	$ (1,026,490)	$ 227,297	$ 584,550