Basis of Presentation and Nature of Operations - Schedule of Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Payables And Accruals [Abstract]
Deposits	$ 14,069	$ 9,881
Restricted deposits	34,404	68,138
Accrued IT and software licensing costs	1,445	2,157
Accrued taxes and insurance premiums	3,504	4,327
Accrued facilities rental and lease exit costs	1,351	780
Accrued interest	236	214
Accrued professional services	3,825	2,094
Accrued dividends	2,641	2,641
Contingent liabilities from acquisitions		683
Interest rate swap liability - current	3,584	3,693
Other accrued expenses and current liabilities	5,376	6,300
Total accrued expenses and other current liabilities	$ 70,435	$ 100,908