Cash and Cash Equivalents, Restricted Cash and Short-Term Investments - Summary of Cash, Cash Equivalents, Restricted Cash, and Short-Term Investments (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013	Jun. 30, 2013	Dec. 31, 2012
Cash And Cash Equivalents [Abstract]
Cash	$ 1,642	$ 930
Money market	50,924	9,084
Total cash and cash equivalents	52,566	10,014	2,210	8,896
Corporate bonds	0	6,191
Total short-term investments	0	6,191
Total restricted cash	250	375	375
Total	$ 52,816	$ 16,580