Loans Receivable - Summary of Loan Activity (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Advances on loans receivable:
Net cash advances on loans receivable	$ 997,449	$ 247,543	$ 119,699
Seniors Housing Operating
Advances on loans receivable:
Investments in new loans	975,018	224,078	46,824
Draws on existing loans	22,431	23,465	72,875
Net cash advances on loans receivable	997,449	247,543	119,699
Receipts on loans receivable:
Loan payoffs	266,822	15,677	118,703
Principal payments on loans	76,438	15,871	9,003
Net cash receipts on loans receivable	343,260	31,548	127,706
Net cash advances (receipts) on loans receivable	$ 654,189	$ 215,995	$ (8,007)