Equity Equity (Dividends) (Details) (USD $) In Millions, except Share data, unless otherwise specified	0 Months Ended	1 Months Ended	3 Months Ended								12 Months Ended			54 Months Ended	2 Months Ended	56 Months Ended
	Dec. 12, 2014	Jul. 31, 2014	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2014	Feb. 25, 2015	Feb. 25, 2015	Feb. 20, 2015
Subsequent Event [Line Items]
Common Stock, Dividends, Per Share, Cash Paid			$ 0.05	$ 0.05	$ 0.05	$ 0.05
Dividends declared on common stock (per share amount)	$ 0.10		$ 0.15	$ 0.05	$ 0.05	$ 0	$ 0.09	$ 0	$ 0.08	$ 0	$ 0.25	$ 0.17	$ 0.08
Stock repurchase program, additional authorized amount		$ 140
Treasury Stock, Value, Acquired, Cost Method		1,300
Payments for Repurchase of Common Stock											308	322	301	1,300
Treasury Stock, Shares, Acquired											21,900,246			105,912,477
Treasury Stock Acquired, Average Cost Per Share														$ 12.37
Stock Repurchase Program, Remaining Authorized Repurchase Amount			24								24			24
Treasury stock, shares (in shares)			110,687,849				90,808,168				110,687,849	90,808,168		110,687,849
Subsequent Event
Subsequent Event [Line Items]
Payments for Repurchase of Common Stock															24	1,300
Treasury Stock, Shares, Acquired															1,892,432	107,804,909
Treasury Stock Acquired, Average Cost Per Share																$ 12.37
Stock Repurchase Program, Remaining Authorized Repurchase Amount															400	400
Stock Repurchase Program, Authorized Amount																	$ 400