Summary of Significant Accounting Policies and Other Information - Effect of Line Items on Consolidated Statement of Stockholders' Equity (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2019	Sep. 30, 2019	Dec. 31, 2019	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Dec. 31, 2018
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Equity balance	$ 20,277	$ 20,277	$ 28,497	$ 9,036	$ 10,355		$ 14,391	$ (18,578)
Additional Paid-in Capital
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Stock-based compensation expense	(1,907)	(722)	(572)
Equity balance	156,580	156,580	156,727	157,138	157,052	$ 156,891	158,530	119,724
Treasury Stock
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Stock-based compensation expense	2,080	1,823	1,820
Equity balance	(1,338)	(1,338)	(1,341)	$ (1,293)	(1,354)	(1,349)	(3,418)	(3,161)
Previously Reported | Additional Paid-in Capital
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Stock-based compensation expense	(14)	1,390	1,540
Equity balance	165,380	165,380	165,527		165,852	165,691	165,437	126,412
Previously Reported | Treasury Stock
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Stock-based compensation expense	187	(289)	(292)
Equity balance	(10,138)	(10,138)	(10,141)		(10,154)	(10,149)	(10,325)	(9,849)
Adjustment | Additional Paid-in Capital | Adjustment
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Stock-based compensation expense	(1,893)	(2,112)	(2,112)
Equity balance	(8,800)	(8,800)	(8,800)		(8,800)	(8,800)	(6,907)	(6,688)
Adjustment | Treasury Stock | Adjustment
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Stock-based compensation expense	1,893	2,112	2,112
Equity balance	$ 8,800	$ 8,800	$ 8,800		$ 8,800	$ 8,800	$ 6,907	$ 6,688