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Stock-based Compensation - Additional Information (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2013	Dec. 31, 2012
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share based compensation expense	$ 167,000	$ 249,000	$ 403,000	$ 965,000
2005 Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation shares authorized under stock option plans (in shares)	770,000		770,000
Percent of the fair value options granted			100.00%
Shares available for future grant (in shares)	0		0
Weighted average remaining contractual term stock options outstanding			1 year 11 months 23 days
Number of options outstanding, Granted (in shares)			0
2005 Plan \| Employee Stock Option
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period			5 years
Stock options, when granted, expiration period			10 years
2010 Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation shares authorized under stock option plans (in shares)	0		0		2,500,000	1,350,000
Percent of the fair value options granted			100.00%
Weighted average remaining contractual term stock options outstanding			2 years 6 months
Unrecognized compensation costs related to unvested restricted stock awards	$ 69,000		$ 69,000
Unrecognized compensation costs weighted average period			2 years 5 months 4 days
Number of options outstanding, Granted (in shares)			0
2010 Plan \| Employee Stock Option
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period			5 years
Stock options, when granted, expiration period			10 years
2010 Plan \| Restricted Stock Awards
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Tax benefits or expenses realized from awards	$ 0	$ 24,000	$ (85,000)	$ 21,000
2021 Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares available for future grant (in shares)	1,323,207		1,323,207
Unrecognized compensation costs related to unvested restricted stock awards	$ 1,600,000		$ 1,600,000
Unrecognized compensation costs weighted average period			3 years 6 months
2021 Plan \| Restricted Stock Awards
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation shares authorized under stock option plans (in shares)	1,500,000		1,500,000
Percent of the fair value options granted			100.00%
Number of options outstanding, Granted (in shares)			0
Tax benefits or expenses realized from awards			$ 0