Share Based Compensation - Summary of Total Unrecognized Compensation Related to Stock-Based Compensation (Detail) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized Compensation Cost	$ 35,076
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized Compensation Cost	20,496
Weighted Average Period of Expense Recognition (in Years)	1 year 10 months 24 days
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized Compensation Cost	$ 14,580
Weighted Average Period of Expense Recognition (in Years)	11 months 19 days