Share Based Compensation - Summary of Total Unrecognized Compensation Cost Related to Stock-Based Compensation (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized Compensation Cost	$ 44,804
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized Compensation Cost	22,492
Weighted Average Period of Expense Recognition (in Years)	1 year 8 months 16 days
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized Compensation Cost	$ 22,312
Weighted Average Period of Expense Recognition (in Years)	1 year 15 days