Common Stock and Share-Based Compensation - Additional Information (Detail) - USD ($)		1 Months Ended						3 Months Ended		9 Months Ended
	Mar. 03, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Preferred stock authorized		1,000,000						1,000,000		1,000,000
Common stock authorized		250,000,000						250,000,000		250,000,000
Common stock, par value (in dollars per share)		$ 0.01						$ 0.01		$ 0.01		$ 0.01
Quarterly dividends expected (in dollars per share)	$ 0.09									0.09
Annual dividends expected (in dollars per share)										$ 0.36
Dividends paid (in dollars per share)	$ 0.07	$ 0.09	$ 0.09	$ 0.09	$ 0.07	$ 0.07	$ 0.07
Cash dividends paid										$ (24,681,000)	$ (19,784,000)
Repurchase of common stock									$ (53,000,000.0)	(25,000,000)	$ (53,010,000)
Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Authorized amount for common share repurchase threshold		$ 2,380,000,000.00						$ 2,380,000,000.00		$ 2,380,000,000.00
Repurchase of common stock (in shares)								0	(3,165,582,000)	(1,371,185)	(3,165,582)
Remaining authorized amount for common share repurchase		$ 197,100,000						$ 197,100,000		$ 197,100,000
Employees | RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)										3 years
Non-Employee Directors | RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)										3 years