Stockholders' Equity - Additional Information (Detail) (USD $) Share data in Millions, unless otherwise specified	1 Months Ended	3 Months Ended		60 Months Ended				3 Months Ended	1 Months Ended
	Feb. 27, 2013	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2013	Dec. 31, 2012	Dec. 31, 2008	Nov. 30, 2006	Mar. 31, 2013 Scenario, Forecast	Nov. 30, 2006 Sold Warrants
Accumulated Other Comprehensive Income (Loss), Net of Tax		$ (241,971,000)		$ (241,971,000)	$ (208,273,000)
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		3.1	4.6
Repurchases of Common Stock, shares authorized to repurchase						250.0
Total Repurchases of Common Stock, shares		12.6		235.5
Total Repurchases of Common Stock		308,000,000		4,700,000,000
Shares authorized for future repurchases		14.5		14.5
Stock Repurchase Program, Additional Number of Shares Authorized to be Repurchased	250.0
Plan to spend for the year on common stock repurchases								$ 1,000,000,000