Stockholders' Equity - Additional Information (Detail) (USD $) Share data in Millions, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended		12 Months Ended	16 Months Ended					12 Months Ended	24 Months Ended	1 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013	Jun. 30, 2014	Apr. 17, 2014	May 30, 2013	Feb. 28, 2013	Nov. 30, 2006	Dec. 31, 2014 Scenario, Forecast	Dec. 31, 2014 Scenario, Forecast	Nov. 30, 2006 Sold Warrants	Mar. 17, 2014 Warrant
Dividends Payable, Amount Per Share							$ 0.12	$ 0.10
Sold warrants to acquire shares of our common stock													215
Sold warrants to acquire shares of our common stock, exercise price per share										19.55
Common stock excluded from calculation of diluted earnings per share	1	4	4	4
Warrants and Rights Outstanding														$ 109,000,000
Repurchases of Common Stock, shares authorized to repurchase									250
Total Repurchases of Common Stock, shares			39			133
Total Repurchases of Common Stock			1,000,000,000			3,400,000,000
Shares authorized for future repurchases	117		117			117
Plan to spend for the year on common stock repurchases											3,000,000,000	6,000,000,000
Payments for Repurchase of Common Stock			$ 994,000,000	$ 991,000,000	$ 3,000,000,000