Income Taxes (Details 4) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Reconciliation of unrecognized tax benefits
Gross balance at January 1	$ 4,949,788	$ 4,050,491	$ 1,825,447
Additions based on tax positions related to the current year	211,966	480,843	2,286,759
Additions for tax positions of prior years	332,744	871,682	697,615
Reductions for tax positions of prior years	(259,895)	(438,460)	(372,862)
Settlements	(841,528)	(10,462)	(385,321)
Lapse of statute of limitations	(5,295)	(4,306)	(1,147)
Gross balance at December 31	4,387,780	4,949,788	4,050,491
Offsets to gross unrecognized tax benefits:
Credit and loss carryovers	(3,212,397)	(3,771,301)	(3,349,589)
Cash paid to taxing authorities	(363,266)	(373,000)	(373,000)
Unrecognized tax benefits net of unused tax attributes and payments	$ 812,117	$ 805,487	$ 327,902