Stockholders' Equity - Additional Information (Detail) - USD ($)			3 Months Ended
	Mar. 17, 2017	Feb. 15, 2017	Mar. 31, 2017	Mar. 31, 2016	Jul. 31, 2015	Aug. 31, 2007
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock repurchase program, authorized amount			$ 2,200,000,000
Stock repurchase program, number of shares authorized to be repurchased						20,000,000
Number of common stock shares repurchased			0	699,345
Treasury stock value				$ 32,000,000
Dividends declared date		Feb. 15, 2017
Dividends per share on common stock		$ 0.16
Dividends declared paid date		Mar. 17, 2017
Dividends declared date of record		Mar. 03, 2017
Dividends paid on common stock	$ 31,200,000		$ 31,400,000	$ 26,200,000
Maximum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock repurchase program, authorized amount					$ 1,500,000,000
Stock repurchase program, additional authorized amount			$ 1,500,000,000