Investment in Life Insurance Policies - Reconciliation of Gain (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Life Settlement Contracts, Fair Value Method, Gain (Loss) [Abstract]
Change in estimated probabilistic cash flows	$ 15,349	$ 17,122	$ 33,200	$ 34,253
Unrealized gain on acquisitions	0	1,844	0	6,303
Premiums and other annual fees	(17,626)	(16,004)	(34,825)	(31,836)
Face value of matured policies	39,889	22,998	65,391	53,457
Fair value of matured policies	(22,824)	(6,030)	(34,533)	(20,751)
Gain on life insurance policies, net	$ 14,788	$ 19,930	$ 29,233	$ 41,426