Stock-Based Compensation - Vested Options (Details) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted non-vested options (shares)	0	4,000	479,500	304,000
Deferred Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted non-vested options (shares)	15,621	20,027	41,293	44,670
Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted non-vested options (shares)	0	16,729	515,960	328,720