Stock Based Compensation - Exercise Price Range (Details) - $ / shares	9 Months Ended
	Sep. 30, 2021	Dec. 31, 2020	Dec. 31, 2019
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Number of Options, Outstanding (in shares)	407,500	107,500	215,345
Weighted Average Remaining Contractual Life (In Years)	7 years 6 months 3 days
Weighted Average Exercise Price, Outstanding (in dollars per share)	$ 7.57	$ 19.64	$ 12.27
Number of Options, Exercisable (in shares)	107,500	107,500	215,345
Weighted Average Exercise Price, Exercisable (in dollars per share)	$ 19.64	$ 19.64	$ 12.27
$0.00 – $10.00
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Range of price, lower range limit (in dollars per share)	0.00
Range of price, upper range limit (in dollars per share)	$ 10.00
Number of Options, Outstanding (in shares)	302,500
Weighted Average Remaining Contractual Life (In Years)	9 years 8 months 4 days
Weighted Average Exercise Price, Outstanding (in dollars per share)	$ 3.30
Number of Options, Exercisable (in shares)	2,500
Weighted Average Exercise Price, Exercisable (in dollars per share)	$ 9.00
$10.01 – $20.00
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Range of price, lower range limit (in dollars per share)	10.01
Range of price, upper range limit (in dollars per share)	$ 20.00
Number of Options, Outstanding (in shares)	97,500
Weighted Average Remaining Contractual Life (In Years)	1 year 3 months 21 days
Weighted Average Exercise Price, Outstanding (in dollars per share)	$ 19.32
Number of Options, Exercisable (in shares)	97,500
Weighted Average Exercise Price, Exercisable (in dollars per share)	$ 19.32
$20.01 – $30.00
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Range of price, lower range limit (in dollars per share)	20.01
Range of price, upper range limit (in dollars per share)	$ 30.00
Number of Options, Outstanding (in shares)	2,500
Weighted Average Remaining Contractual Life (In Years)	8 months 4 days
Weighted Average Exercise Price, Outstanding (in dollars per share)	$ 21.80
Number of Options, Exercisable (in shares)	2,500
Weighted Average Exercise Price, Exercisable (in dollars per share)	$ 21.80
$30.01 – $40.00
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Range of price, lower range limit (in dollars per share)	30.01
Range of price, upper range limit (in dollars per share)	$ 40.00
Number of Options, Outstanding (in shares)	5,000
Weighted Average Remaining Contractual Life (In Years)	5 months 12 days
Weighted Average Exercise Price, Outstanding (in dollars per share)	$ 30.20
Number of Options, Exercisable (in shares)	5,000
Weighted Average Exercise Price, Exercisable (in dollars per share)	$ 30.20