Commitments and Contingencies - Reinsurance Agreements (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Insurance Loss Reserves [Roll Forward]
Reserves for claims and performance-based arrangements attributable to the Reinsurance Agreement at the beginning of the period	$ 1,243	$ 0
Reinsurance premiums assumed	83,325	3,242
Claims assumed	72,594	3,934
Claims-related administrative expenses	14,024	551
Increase in reserves for claims and performance-based arrangements attributable to the Reinsurance Agreement	(3,293)	(1,243)
Reinsurance payments	4,536	0
Payables for claims and performance-based arrangements attributable to the Reinsurance Agreement at the end of the period	$ 0	$ 1,243