Schedule I - Condensed Financial Information of the Registrant - Condensed Balance Sheets (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash and cash equivalents	$ 13,162	$ 70,726
Prepaid expenses	2,983	3,566
Total current assets	115,596	150,743
Other long-term assets	9,176	12,347
Total assets	762,378	731,342
Total current liabilities	56,476	47,439
Total liabilities	628,594	595,538
Common stock	355	353
Additional paid-in capital	371,311	361,628
Retained earnings	(235,474)	(222,403)
Accumulated other comprehensive loss	(2,408)	(3,774)
Total stockholders’ equity	133,784	135,804	$ (27,935)	$ 16,428
Total liabilities and stockholders’ equity	762,378	731,342
Parent Company [Member]
Cash and cash equivalents	282	13,549
Intercompany Receivables	8
Prepaid expenses	26	49
Total current assets	316	13,598
Investment in subsidiaries	134,811	122,972
Other long-term assets	8
Total assets	135,135	136,570
Intercompany payables	1,351	766
Total current liabilities	1,351	766
Total liabilities	1,351	766
Common stock	355	353
Additional paid-in capital	371,311	361,628
Retained earnings	(235,474)	(222,403)
Accumulated other comprehensive loss	(2,408)	(3,774)
Total stockholders’ equity	133,784	135,804
Total liabilities and stockholders’ equity	$ 135,135	$ 136,570