Stock-Based Compensation - Summary of Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Stock option activity
Balance at the beginning of the period (in shares)	572,629	568,727	754,624
Granted (in shares)	35,800	89,575	31,000
Exercised (in shares)	(97,855)	(79,974)	(211,747)
Forfeited (in shares)	0	(5,699)	(5,150)
Balance at the end of the period (in shares)	510,574	572,629	568,727
Vested and Expected to Vest (in shares)	494,881
Exercisable at the end of the period(in shares)	384,810
Weighted average exercise price
Balance at the beginning of the period (in dollars per share)	$ 24.42	$ 16.62	$ 15.01
Granted (in dollars per share)	85.99	69.93	47.50
Exercised (in dollars per share)	14.75	18.79	14.85
Forfeited (in dollars per share)	0.00	39.83	28.28
Balance at the end of the period (in dollars per share)	30.60	$ 24.42	$ 16.62
Vested and Expected to Vest (in dollars per share)	29.20
Exercisable at the end of the period (in dollars per share)	$ 17.82
Weighted average remaining contractual life
Outstanding at the beginning of period	4 years 9 months 11 days
Vested and Expected to Vest	4 years 7 months 24 days
Exercisable at the end of period	3 years 7 months 13 days
Aggregate intrinsic value
Outstanding at the end of the period	$ 24,129
Vested and Expected to Vest at the end of the period	24,038
Exercisable at the end of the period	$ 22,865