Fair Value Measurements - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Cash and cash equivalents
Total cash and cash equivalents	$ 105,703	$ 88,509	$ 89,955	$ 90,697
Short-term investments	0
Decrease in restricted cash	1,400
Fair Value, Inputs, Level 1
Cash and cash equivalents
Cash	49,495	33,764
Money market funds	56,208	54,745
Total cash and cash equivalents	105,703	88,509
Short-term investments	63
Long-term restricted cash	1,181	2,598
Total cash and cash equivalents and investments	$ 106,947	$ 91,107