Loans Receivable - Narrative (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended		9 Months Ended
	Mar. 31, 2019	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Financing Receivable, Troubled Debt Restructuring [Line Items]
Interest receivable		$ 12,039		$ 12,039		$ 6,897
Non-real estate loans		460,411		460,411		362,850
Allowance for credit losses on non-real estate loans receivable		78,262		78,262		$ 25,996
Provision for loan losses	$ 18,690	2,857	$ 0	11,351	$ 18,690
Non-real estate loans receivable
Financing Receivable, Troubled Debt Restructuring [Line Items]
Non-real estate loans		86,411		86,411
Allowance for credit losses on non-real estate loans receivable		$ 42,376		42,376
Provision for loan losses				6,898
Real estate loan receivable
Financing Receivable, Troubled Debt Restructuring [Line Items]
Provision for loan losses				$ 1,303