Equity Incentive Plans - Summary of Activity for Options Outstanding, Options Exercisable and Intrinsic Value (Details 4) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Aggressive Intrinsic Value
Estimated stock price (in dollars per share)	$ 9.76
Stock options
Options
Options outstanding at beginning of year (in shares)	1,817,548	1,163,621
Options granted (in shares)	620,600	712,570
Options exercised (in shares)	(261,936)	(41,904)
Options cancelled/forfeited (in shares)	(11,147)	(16,739)
Options outstanding at end of year (in shares)	2,165,065	1,817,548	1,163,621
Options exercisable at end of year (in shares)	1,083,249
Vested and expected to vest, at end of year (in shares)	2,165,065
Weighted-Average Exercise Price
Options outstanding at beginning of year (in dollars per share)	$ 5.56	$ 3.44
Options granted (in dollars per share)	9.84	8.76
Options exercised (in dollars per share)	2.26	1.61
Options cancelled/forfeited (in dollars per share)	2.14	4.65
Options outstanding at end of year (in dollars per share)	7.19	$ 5.56	$ 3.44
Options exercisable at end of year (in dollars per share)	5.06
Vested and expected to vest, at end of year (in dollars per share)	$ 7.19
Weighted-Average Remaining Contractual Life (Years)
Options outstanding at end of year	7 years 9 months 18 days	7 years 10 months 24 days	7 years 10 months 24 days
Options exercisable at end of year	6 years 8 months 12 days
Vested and expected to vest, at end of year	7 years 9 months 18 days
Aggressive Intrinsic Value
Options outstanding at the end of the period (in dollars)	$ 6,459
Options exercisable at the end of the period (in dollars)	5,622
Options exercised for intrinsic value (in dollars)	$ 1,841