Income Taxes (Details 4) (USD $) In Millions, unless otherwise specified	12 Months Ended				2 Months Ended	12 Months Ended
	Dec. 31, 2011 U.S. federal net operating losses [Member]	Dec. 31, 2011 U.S. state net operating losses [Member]	Dec. 31, 2011 Federal and state capital losses [Member]	Dec. 31, 2011 U.S. federal tax credits [Member]	Dec. 31, 2011 U.S. state tax credits [Member]	Dec. 31, 2011 Foreign net operating losses [Member]
Deferred tax asset attributes
Attribute amount	$ 85	$ 2,519	$ 13	$ 33	$ 12	$ 87
First year of expiration	2031	2012	2013	2012	2012	2012