Investment in Life Insurance Policies - Reconciliation of Gain (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Life Settlement Contracts, Fair Value Method, Gain (Loss) [Abstract]
Change in estimated probabilistic cash flows	$ 14,723	$ 17,908	$ 47,923	$ 52,161
Unrealized gain on acquisitions	0	472	0	6,775
Premiums and other annual fees	(18,235)	(17,219)	(53,060)	(49,055)
Face value of matured policies	39,803	27,470	105,194	80,927
Fair value of matured policies	(22,169)	(10,839)	(56,702)	(31,590)
Gain on life insurance policies, net	$ 14,122	$ 17,792	$ 43,355	$ 59,218