Stockholders' Equity - Stock Options Activities (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Number
Options outstanding at the beginning of the year (in shares)	709,668
Granted (in shares)	0	0	0
Exercised (in shares)	(253,715)
Forfeited (in shares)	(1,605)
Options outstanding at the end of the period (in shares)	454,348	709,668
Options exercisable at the end of the year (in shares)	452,264
Weighted average exercise price
Options outstanding at the beginning of the year, weighted average exercise price (in dollars per share)	$ 17.941
Granted, weighted average exercise price (in dollars per share)	0
Exercised, weighted average exercise price (in dollars per share)	13.068
Forfeited, weighted average exercise price (in dollars per share)	27.512
Options outstanding at the end of the period, weighted average exercise price (in dollars per share)	20.628	$ 17.941
Options exercisable at the end of the year, weighted average exercise price (in dollars per share)	$ 20.645
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Options outstanding at the beginning of the year, aggregate intrinsic value	$ 25,935	$ 24,810
Options exercisable at the end of the year, aggregate intrinsic value	$ 25,808
Options outstanding at the beginning of the year, weighted average remaining contractual life (Year)	4 years 4 months 4 days	4 years 6 months 5 days
Options exercisable at the end of the year, weighted average remaining contractual life (Year)	4 years 4 months 1 day