Stockholders' Equity - Additional Information (Detail) (USD $)	0 Months Ended	1 Months Ended		3 Months Ended	12 Months Ended
	Apr. 25, 2012	May 31, 2014	Feb. 28, 2013	Jun. 30, 2013	Dec. 31, 2014 Number_of_stock_repurchase	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	May 23, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Repurchase Programs authorized					2
Common stock, par value					$ 0.00001	$ 0.00001
Preferred stock, par value					$ 0.00001	$ 0.00001
Common stock, shares authorized					200,000,000	200,000,000
Preferred stock, shares authorized					25,000,000	25,000,000
Outstanding common stock repurchase program authorized amount	$ 20,000,000	$ 30,000,000.0	$ 25,000,000
Shares repurchased		1,700,000		3,000,000
Additional stock repurchase program authorized amount		22,400,000		25,000,000	22,442,000	25,000,000	19,996,000
Average cost of repurchase per share	$ 5.22
Remaining authorized repurchase amount					7,600,000
Shares repurchased by company	(3,800,000)
Tax payments, for net share settlement of share based award					1,347,000	309,000
Total intrinsic value of options exercised					20,200,000	15,700,000	3,200,000
Share based compensation arrangement by share based payment award future tax benefit					3,100,000	3,500,000
Service Based Restricted Stock Unit
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Contractual maturity of plan					10 years
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance criteria met for approximate units					432,706	257,693	97,007
Approximate units outstanding					1,226,088	1,279,123	582,212	1,096
Unrecognized stock-based compensation expense related to non-vested stock options					11,100,000
Weighted average period					2 years 6 months
Performance Based Restricted Stock Unit
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Contractual maturity of plan					10 years
Approximate units of performance restricted stock granted					100,000	300,000	200,000
Performance criteria met for approximate units					100,000
Approximate units outstanding					200,000
Incremental stock option expense					1,000,000	1,400,000	700,000
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares withheld, for net share settlement of share based award					74,000
Tax payments, for net share settlement of share based award					1,300,000
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate intrinsic value price per share					$ 26.48
New option granted							0
Aggregate intrinsic value, option outstanding					34,800,000
Aggregate intrinsic value, options exercisable					34,100,000
Number of Options Outstanding					1,641,083	3,365,692	6,321,076	7,576,493
Weighted Average Exercise Price					$ 5.26	$ 6.15	$ 6.05	5.75
Options expected to vest, end of year					4,443
Non-Vested Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Options Outstanding					0
Weighted Average Exercise Price					$ 4.74
Weighted average fair value					$ 2.51
Weighted average remaining contractual life					4 years 3 months 0 days
Aggregate intrinsic value of unvested options					800,000
Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Incremental stock option expense						100,000	100,000
Number of Options Outstanding					300,000
Unvested performance options					30,600
Unvested share, expected to vest					0
Options expected to vest, end of year					300,000
Fair value of performance-based stock options outstanding and expected to vest					800,000
Incentive Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Incremental stock option expense					0	100,000	500,000
Non Qualified Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Tax benefit recorded					$ 2,500,000	$ 6,800,000	$ 4,700,000
2013 Stock Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares reserved for future grants									1,600,000
Option available for future grants					1,700,000
Repurchase of Equity
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Average cost of repurchase per share		$ 12.99		$ 8.20
Minimum | Service Based Restricted Stock Unit
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period					3 years
Minimum | Performance Based Restricted Stock Unit
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period					1 year
Maximum | Service Based Restricted Stock Unit
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period					4 years
Maximum | Performance Based Restricted Stock Unit
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period					4 years