Income Taxes (Details 3) (USD $) In Millions, unless otherwise specified	Dec. 31, 2011
Operating and capital loss carryforwards [Line Items]
Amount of operating and capital loss carryforwards due to expire in 2012	$ 26
Amount of operating and capital loss carryforwards due to expire between 2013 and 2016	258
Amount of operating and capital loss carryforwards due to expire between 2017 and 2031	1,906
Amount of operating and capital loss carryforwards which may be carried forward indefinitely	838
Total operating and capital loss carryforwards	3,028
Foreign [Member]
Operating and capital loss carryforwards [Line Items]
Amount of operating and capital loss carryforwards due to expire in 2012	4
Amount of operating and capital loss carryforwards due to expire between 2013 and 2016	66
Amount of operating and capital loss carryforwards due to expire between 2017 and 2031	136
Amount of operating and capital loss carryforwards which may be carried forward indefinitely	833
Total operating and capital loss carryforwards	1,039
U.S. federal and state [Member]
Operating and capital loss carryforwards [Line Items]
Amount of operating and capital loss carryforwards due to expire in 2012	22
Amount of operating and capital loss carryforwards due to expire between 2013 and 2016	192
Amount of operating and capital loss carryforwards due to expire between 2017 and 2031	1,770
Amount of operating and capital loss carryforwards which may be carried forward indefinitely	5
Total operating and capital loss carryforwards	$ 1,989