Stock-Based Compensation - Stock Options (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share-based Payment Arrangement [Abstract]
Contractual term	10 years
Total Stock Options
Options outstanding, beginning balance (in shares)	272,224
Options granted (in shares)	2,027,744
Options exercised (in shares)	(8,868)	(67,558)	(192,550)
Options cancelled and expired (in shares)	(715,881)
Options outstanding, ending balance (in shares)	1,575,219	272,224
Exercisable (in shares)	1,271,041
Weighted- Average Exercise Price
Options outstanding, beginning balance, weighted average exercise price (in dollars per share)	$ 17.44
Options granted, weighted average exercise price (in dollars per share)	19.44
Options exercised, weighted average exercise price (in dollars per share)	8.72
Options cancelled and expired, weighted average exercise price (in dollars per share)	19.47
Options outstanding, ending balance, weighted average exercise price (in dollars per share)	19.03	$ 17.44
Exercisable, weighted average exercise price (in dollars per share)	$ 19.72
Weighted- Average Remaining Contractual Term (Years)
Options outstanding, weighted average remaining contractual term (in years)	4 years 9 months 18 days
Exercisable, weighted average remaining contractual term (in years)	3 years 9 months 18 days
Options outstanding, aggregate intrinsic value	$ 229,390
Exercisable, aggregate intrinsic value	$ 228,958
Options exercised (in shares)	8,868	67,558	192,550
Aggregate intrinsic value	$ 100	$ 600	$ 2,400
Unrecognized compensation expense	$ 1,900
Weighted-average remaining period for recognition of unrecognized compensation costs	2 years 3 months 18 days