Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Summary Of Significant Accounting Policies [Line Items]
Stock based compensation expenses	$ 7,997	$ 4,743	$ 3,507
Weighted average fair value of stock option granted	$ 10.47	$ 3.58	$ 2.51
Stock Options
Summary Of Significant Accounting Policies [Line Items]
Stock based compensation expenses	$ 5,300	$ 3,700	$ 2,300
Restricted Stock
Summary Of Significant Accounting Policies [Line Items]
Stock based compensation expenses	2,700	1,000	1,200
Employee and Director Awards
Summary Of Significant Accounting Policies [Line Items]
Stock based compensation expenses	8,000	$ 4,700	$ 3,500
Other Noncurrent Assets | Lease Obligations
Summary Of Significant Accounting Policies [Line Items]
Restricted cash	388
Other Noncurrent Assets | Line of Credit
Summary Of Significant Accounting Policies [Line Items]
Restricted cash	$ 104
Minimum
Summary Of Significant Accounting Policies [Line Items]
Property and equipment useful life	3 years
Maximum
Summary Of Significant Accounting Policies [Line Items]
Property and equipment useful life	5 years