Stock-Based Compensation - Summary of Stock Option Activity (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Shares, Outstanding, Beginning Balance	1,948,259
Number of Shares, Cancelled/forfeited	(61,332)
Number of Shares, Exercised	(753,755)
Number of Shares, Outstanding, Ending Balance	1,133,172
Number of Shares, Exercisable, Ending Balance	987,843
Weighted Average Exercise Price, Outstanding, Beginning Balance	$ 15.38
Weighted Average Exercise Price, Cancelled/forfeited	$ 23.03
Weighted Average Exercise Price, Exercised	$ 15.56
Weighted Average Exercise Price, Outstanding, Ending Balance	$ 14.84
Weighted Average Exercise Price, Exercisable, Ending Balance	$ 13.71
Aggregate Intrinsic Value, Outstanding at December 31, 2013	$ 40,138
Aggregate Intrinsic Value, Exercisable at December 31, 2013	$ 36,103
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Option Price Per Share, Outstanding, Beginning Balance	$ 2.89
Option Price Per Share, Cancelled/forfeited	$ 22.17
Option Price Per Share, Exercised	$ 2.89
Option Price Per Share, Outstanding, Ending Balance	$ 2.89
Option Price Per Share, Exercisable, Ending Balance	$ 2.89
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Option Price Per Share, Outstanding, Beginning Balance	$ 24.65
Option Price Per Share, Cancelled/forfeited	$ 24.65
Option Price Per Share, Exercised	$ 24.65
Option Price Per Share, Outstanding, Ending Balance	$ 24.65
Option Price Per Share, Exercisable, Ending Balance	$ 24.65