Fair Value Measurements - Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Liabilities:
Payments Of Contingent Earn Out Consideration	$ 800
Monte Carlo Simulation Valuation Model
Liabilities:
Undiscounted maximum payment under the contingent consideration arrangements	7,900
Level 1 | Fair Value, Measurements, Recurring
Assets:
Short-term investments	42,942	$ 42,994
Total	42,942	42,994
Level 3 | Fair Value, Measurements, Recurring
Liabilities:
Contingent consideration	2,100	2,695
Total	$ 2,100	$ 2,695