Real Estate Loans Receivable - Summary of Real Estate Loans Receivable (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Less allowance for losses on loans receivable	$ (68,372)	$ (68,372)
Totals	361,530	330,339	[1]
Mortgage loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Real estate loans receivable	320,989	317,443
Other real estate loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Real estate loans receivable	$ 108,913	$ 81,268

[1] The consolidated balance sheet at December 31, 2018 has been derived from the audited financial statements at that date but does not include all of the information and footnotes required by U.S. generally accepted accounting principles for complete financial statements.