Revision of Prior Period Financial Statements - Schedule of Revised Consolidated Statements of Shareholder's Equity (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019	Dec. 31, 2018
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Stock-based compensation expense	$ 305	$ 4,856
Stockholders' Equity Attributable to Parent	124,977	47,648	$ 135,409	$ 52,137
Net loss	(9,065)	(8,250)
As Reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Stockholders' Equity Attributable to Parent		49,723
Net loss		(8,019)
Adjustment
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Stockholders' Equity Attributable to Parent		(2,075)
Net loss		(231)
Additional Paid-In Capital
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Stock-based compensation expense		4,856
Stockholders' Equity Attributable to Parent	394,507	261,672	395,695	257,955
Net loss	0	0
Additional Paid-In Capital | As Reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Stock-based compensation expense		4,415
Stockholders' Equity Attributable to Parent		261,231
Additional Paid-In Capital | Adjustment
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Stock-based compensation expense		441
Stockholders' Equity Attributable to Parent		441
Accumulated Other Comprehensive Income (Loss)
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Stock-based compensation expense	0	0
Stockholders' Equity Attributable to Parent	364	27	82	(16)
Net loss	0	0
Accumulated Other Comprehensive Income (Loss) | As Reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Stockholders' Equity Attributable to Parent		2		(41)
Accumulated Other Comprehensive Income (Loss) | Adjustment
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Stockholders' Equity Attributable to Parent		25		25
Accumulated deficit:
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Stock-based compensation expense	0	0
Stockholders' Equity Attributable to Parent	(269,919)	(214,075)	$ (260,393)	(205,825)
Net loss	$ (9,065)	(8,250)
Accumulated deficit: | As Reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Stockholders' Equity Attributable to Parent		(211,534)		(203,515)
Net loss		(8,019)
Accumulated deficit: | Adjustment
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Stockholders' Equity Attributable to Parent		(2,541)		$ (2,310)
Net loss		$ (231)