Loans - Secured Loan Principal Transactions (Details) - USD ($) $ in Thousands		3 Months Ended	9 Months Ended
		Sep. 30, 2019	Sep. 30, 2019	Sep. 30, 2018
Receivables [Abstract]
Principal, beginning of period		$ 96,132	$ 97,438
Loans originated		26,444	52,838	$ 23,125
Loans sold to non-affiliate		(7,740)	(7,740)
Principal collected		(28,646)	(56,346)
Principal, Ending of period	[1]	$ 86,190	$ 86,190

[1] Borrower payments are deposited into an independent bank trust account established and administered by RMC, pursuant to California regulations, and are disbursed to the partnership after an appropriate holding period to ensure the funds are collected. Borrower payments deposited into the trust account are not included in the consolidated financial statements until disbursed to the partnership. At September 30, 2019, there was $69,325 in borrower payments held in the RMC trust account, all of which was disbursed to the partnership by October 22, 2019.