Stock-Based Compensation - Options (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Aggregate Intrinsic Value [Abstract]
Closing price (in dollars per share)	$ 4.76		$ 4.76
Options
Number of Options Outstanding [Roll Forward]
Options outstanding, beginning of period (in shares)			2,953,000
Granted (in shares)	0	0	0	0
Exercised (in shares)			(216,000)
Options outstanding, end of period (in shares)	2,737,000		2,737,000		2,953,000
Options vested and unvested options expected to vest, net of forfeitures, end of period (in shares)	2,715,000		2,715,000
Options exercisable, end of period (in shares)	2,057,000		2,057,000
Weighted-average Exercise Price [Roll Forward]
Options outstanding, beginning of period (in dollars per share)			$ 4.00
Exercised (in dollars per share)			2.38
Options outstanding, end of period (in dollars per share)	$ 4.13		4.13		$ 4.00
Options vested and unvested options expected to vest, net of forfeitures (in dollars per share)	4.13		4.13
Options exercisable, end of period (in dollars per share)	$ 4.08		$ 4.08
Weighted average Remaining Contractual Life [Abstract]
Options outstanding			5 years 6 months 29 days		5 years 11 months 12 days
Options vested and unvested options expected to vest, net of forfeitures, end of period			5 years 6 months 21 days
Option exercisable, end of period			4 years 6 months 14 days
Aggregate Intrinsic Value [Abstract]
Options outstanding, beginning of period			$ 3,040
Options outstanding, end of period	$ 3,214		3,214		$ 3,040
Options vested and expected to vest, end of period	3,182		3,182
Options exercisable, end of period	$ 2,483		$ 2,483