Stockholders' Equity and Stock-Based Compensation - Summary of Activity of Stock Options (Details) - USD ($) $ / shares in Units, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Activity of stock option plans [Roll Forward]
Number of Shares Outstanding (Options), Beginning Balance (in shares)	440,545
Number of Shares Outstanding (Options), Exercised (in shares)	(180,629)
Number of Shares Outstanding (Options), Cancelled (in shares)	(855)
Number of Shares Outstanding (Options), Ending Balance (in shares)	259,061	440,545
Number of Shares Outstanding (Options), Exercisable (in shares)	255,665
Weighted average exercise price for stock option plans [Roll Forward]
Weighted Average Exercise Price, Beginning Balance (in dollars per share)	$ 15.06
Weighted Average Exercise Price, Exercised (in dollars per share)	13.58
Weighted Average Exercise Price, Cancelled (in dollars per share)	16.63
Weighted Average Exercise Price, Ending Balance (in dollars per share)	16.09	$ 15.06
Weighted Average Exercise Price, Exercisable (in dollars per share)	$ 16.06
Weighted Average Remaining Contractual Term, Outstanding	1 year 9 months 22 days	2 years 1 month 13 days
Weighted Average Remaining Contractual Term, Exercisable	1 year 9 months 14 days
Aggregate Intrinsic Value, Outstanding	$ 3,293	$ 4,405
Aggregate Intrinsic Value, Exercisable	$ 3,256