Condensed Consolidating Financial Information (Details 2) (USD $) In Millions, unless otherwise specified	Sep. 30, 2012	Jun. 30, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Dec. 31, 2010
Assets
Cash and cash equivalents	$ 6,001	$ 3,964	$ 4,017	$ 3,246	$ 3,349	$ 3,354
Other current assets	4,303		3,519
Total current assets	10,304		7,536
Property and equipment, net	20,459		20,788
Goodwill	2,987		3,217
Other assets	1,562		3,491
Total assets	35,312		35,032
Liabilities and equity
Debt due within one year	2,729		2,187
Other current liabilities	3,972		3,341
Total current liabilities	6,701		5,528
Long-term debt	11,388		11,349
Other long-term liabilities	1,967		2,412
Total long-term liabilities	13,355		13,761
Commitments and contingencies
Redeemable noncontrolling interest			116	71		41
Total equity	15,256		15,627	20,794		21,340
Total liabilities and equity	35,312		35,032
Parent Guarantor
Assets
Cash and cash equivalents	9		3	1		38
Other current assets	17		8
Total current assets	26		11
Property and equipment, net	1		1
Investment in affiliates	15,926		16,439
Total assets	15,953		16,451
Liabilities and equity
Other current liabilities	78		294
Total current liabilities	78		294
Long-term debt	568		495
Other long-term liabilities	35		25
Total long-term liabilities	603		520
Commitments and contingencies
Total equity	15,272		15,637
Total liabilities and equity	15,953		16,451
Subsidiary Issuer
Assets
Cash and cash equivalents	4,029		2,793	536		2,041
Other current assets	2,748		784
Total current assets	6,777		3,577
Investment in affiliates	26,469		27,518
Other assets	1,797		1,368
Total assets	35,043		32,463
Liabilities and equity
Debt due within one year	2,212		1,693
Other current liabilities	324		367
Total current liabilities	2,536		2,060
Long-term debt	17,192		14,308
Other long-term liabilities	392		439
Total long-term liabilities	17,584		14,747
Commitments and contingencies
Total equity	14,923		15,656
Total liabilities and equity	35,043		32,463
Other Subsidiaries
Assets
Cash and cash equivalents	1,963		1,221	2,709		1,275
Other current assets	3,377		4,476
Total current assets	5,340		5,697
Property and equipment, net	20,458		20,787
Goodwill	2,987		3,217
Other assets	19,315		20,799
Total assets	48,100		50,500
Liabilities and equity
Debt due within one year	517		494
Other current liabilities	5,409		4,429
Total current liabilities	5,926		4,923
Long-term debt	13,178		15,222
Other long-term liabilities	1,540		1,948
Total long-term liabilities	14,718		17,170
Commitments and contingencies
Redeemable noncontrolling interest			116
Total equity	27,456		28,291
Total liabilities and equity	48,100		50,500
Consolidating adjustments
Assets
Other current assets	(1,839)		(1,749)
Total current assets	(1,839)		(1,749)
Investment in affiliates	(42,395)		(43,957)
Other assets	(19,550)		(18,676)
Total assets	(63,784)		(64,382)
Liabilities and equity
Other current liabilities	(1,839)		(1,749)
Total current liabilities	(1,839)		(1,749)
Long-term debt	(19,550)		(18,676)
Total long-term liabilities	(19,550)		(18,676)
Commitments and contingencies
Total equity	(42,395)		(43,957)
Total liabilities and equity	$ (63,784)		$ (64,382)