Schedule IV: Mortgage Loans on Real Estate - Reconciliation of Mortgage Loans (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
SEC Schedule, 12-29, Real Estate Companies, Investment in Movement in Mortgage Loans on Real Estate [Roll Forward]
Balance at beginning of year	$ 42,037	$ 188,418	$ 196,359
New mortgage loans	59,552	0	0
Construction draws	60,375	42,398	13,776
Total additions	119,927	42,398	13,776
Principal repayments	0	(188,779)	(36,708)
Total deductions	0	(188,779)	(36,708)
Change in balance due to foreign currency translation	0	0	14,991
Balance at end of year	$ 161,964	$ 42,037	$ 188,418