Other Comprehensive Income (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Allocation of other comprehensive income (loss)
Unrecognized components of net periodic benefit costs	$ (204)	$ (8)	$ 37
Unrecognized gain (loss) on derivative instruments	(13)	(29)	(2)
Unrecognized loss on marketable securities	(13)
Recognized components of net periodic benefit costs	25	16	24
Recognized (gain) loss on derivative instruments	11	12	6
Recognized loss on marketable security	13		1
Other comprehensive income (loss) before income taxes	(181)	(9)	66
Income taxes related to other comprehensive income (loss)	13	(9)	24
Other comprehensive income (loss), net of income taxes	(168)	(18)	90
Components of accumulated comprehensive income (loss), net of tax
Accumulated other comprehensive income (loss)	(496)	(332)
Tax effect of changes in accumulated other comprehensive income	49	36
Controlling interest
Allocation of other comprehensive income (loss)
Unrecognized components of net periodic benefit costs	(204)	(8)	37
Unrecognized gain (loss) on derivative instruments	3	(10)	(4)
Unrecognized loss on marketable securities	(13)
Recognized components of net periodic benefit costs	25	16	24
Recognized (gain) loss on derivative instruments	(1)	14	3
Recognized loss on marketable security	13		1
Other comprehensive income (loss) before income taxes	(177)	12	61
Income taxes related to other comprehensive income (loss)	13	(9)	24
Other comprehensive income (loss), net of income taxes	(164)	3	85
Components of accumulated comprehensive income (loss), net of tax
Unrecognized components of net periodic benefit costs	(501)	(335)
Unrecognized gain (loss) on derivative investments	7	5
Unrecognized loss on marketable securities	(2)	(2)
Accumulated other comprehensive income (loss)	(496)	(332)
Non-controlling interest and Redeemable non-controlling interest
Allocation of other comprehensive income (loss)
Unrecognized gain (loss) on derivative instruments	(16)	(19)	2
Recognized (gain) loss on derivative instruments	12	(2)	3
Other comprehensive income (loss) before income taxes	(4)	(21)	5
Other comprehensive income (loss), net of income taxes	(4)	(21)	5
Non-controlling interest
Components of accumulated comprehensive income (loss), net of tax
Unrecognized gain (loss) on derivative investments	(3)	(3)
Accumulated other comprehensive income (loss)	(3)	(3)
Redeemable non-controlling interest
Components of accumulated comprehensive income (loss), net of tax
Unrecognized gain (loss) on derivative investments	(17)	(13)
Accumulated other comprehensive income (loss)	$ (17)	$ (13)