Schedule IV: Mortgage Loans on Real Estate - Reconciliation of Mortgage Loans (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
SEC Schedule, 12-29, Real Estate Companies, Investment in Movement in Mortgage Loans on Real Estate [Roll Forward]
Balance at beginning of year	$ 157,572	$ 161,964	$ 42,037
New mortgage loans	310,338	98,469	59,552
Draws on existing mortgage loans	9,370	19,182	60,375
Total additions	319,708	117,651	119,927
Principal repayments	(84,486)	(113,200)	0
Reserve for loan losses	(2,503)	(8,843)	0
Total deductions	(86,989)	(122,043)	0
Balance at end of year	$ 390,291	$ 157,572	$ 161,964