Condensed Financial Information of Registrant (Parent Company Only) - Statements of Operations and Comprehensive Loss (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Condensed Income Statements, Captions [Line Items]
Net loss	$ (18,527)	$ (52,293)	$ (46,682)
COMPREHENSIVE LOSS	$ (19,491)	$ (49,872)	$ (45,876)
Net loss per share attributable to stockholders
Basic (in USD per share)	$ (0.21)	$ (0.59)	$ (0.53)
Diluted (in USD per share)	$ (0.21)	$ (0.59)	$ (0.53)
Weighted average number of shares outstanding
Basic (in shares)	90,218,386	88,345,312	88,154,830
Diluted (in shares)	90,218,386	88,345,312	88,154,830
Parent Company
Condensed Income Statements, Captions [Line Items]
Equity in net loss of subsidiaries	$ (18,527)	$ (52,293)	$ (46,682)
Net loss	(18,527)	(52,293)	(46,682)
Subsidiaries’ other comprehensive income	(964)	2,421	806
COMPREHENSIVE LOSS	$ (19,491)	$ (49,872)	$ (45,876)
Net loss per share attributable to stockholders
Basic (in USD per share)	$ (0.21)	$ (0.59)	$ (0.53)
Diluted (in USD per share)	$ (0.21)	$ (0.59)	$ (0.53)
Weighted average number of shares outstanding
Basic (in shares)	90,218,386	88,345,312	88,154,830
Diluted (in shares)	90,218,386	88,345,312	88,154,830