Earnings (Loss) Per Common Share - Computation of Diluted Earnings Loss Per Share (Details) - shares shares in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total (in shares)	26,455	28,018
Warrants
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total (in shares)	1,100	900
Options and RSUs
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total (in shares)	22,931	25,172
Series A Preferred Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total (in shares)	933	933
Contingent shares
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total (in shares)	1,491	1,013