Summary of Significant Accounting Policies - Significant Changes in Contract Liabilities (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Deferred revenue
Beginning Balance	$ 1,822	$ 946
Cash receipts (Payments)	75,475	12,963
Less: Impact on Revenue	64,561	13,306
Ending Balance	12,736	603
Payables to customers related to BTC
Beginning Balance	699	914
Cash receipts (Payments)	0	0
Less: Impact on Revenue	0	215
Ending Balance	699	699
Total
Beginning Balance	2,521	1,860
Cash receipts (Payments)	75,475	12,963
Less: Impact on Revenue	64,561	13,521
Ending Balance	$ 13,435	$ 1,302