Income Taxes (Narrative) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Income Tax Contingency [Line Items]
Net overall tax benefit including accrued interest	$ 710				$ 25,920				$ 710	$ 25,920
Foreign tax credits	74,253				55,026				74,253	55,026
Accrued and recognized tax expense (benefit)									957	(9,938)	1,563
Net expense (benefit) of accrued interest	1,310,762	998,117	1,019,060	1,531,189	1,006,578	956,597	922,188	1,158,462	4,927,908	4,114,569	3,559,257
Alternative Minimum Tax credits	21,438				41,693				21,438	41,693
Tax benefits related to share-based compensation	4,071				629				4,071	629
Deferred tax asset	582,393				389,841				582,393	389,841
Net operating loss carryforwards	477,397								477,397
2003 and 2004 IRS Audit [Member]
Income Tax Contingency [Line Items]
Net overall tax benefit including accrued interest	12,356								12,356
Accrued and recognized tax expense (benefit)										(10,591)
Understatement [Member]
Income Tax Contingency [Line Items]
Deferred tax asset	$ 12,232								$ 12,232