Fair Value of Financial Assets and Liabilities - Schedule of Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Assets:
Convertible note receivable	$ 1,909	$ 4,715
Total assets	73,309	49,715
Liabilities:
Contingent consideration obligations	255,522	273,367
Preferred stock warrants		76,640
Warrant liability - Sponsor Warrants	20,655
Warrant liability - Public Warrants	16,531
Total liabilities	292,708	350,007
Money Market Funds
Assets:
Cash equivalents - money market funds	71,400	45,000
Level 1
Assets:
Total assets	71,400	45,000
Liabilities:
Warrant liability - Public Warrants	16,531
Total liabilities	16,531
Level 1 | Money Market Funds
Assets:
Cash equivalents - money market funds	71,400	45,000
Level 3
Assets:
Convertible note receivable	1,909	4,715
Total assets	1,909	4,715
Liabilities:
Contingent consideration obligations	255,522	273,367
Preferred stock warrants		76,640
Warrant liability - Sponsor Warrants	20,655
Total liabilities	$ 276,177	$ 350,007