Organization and Summary of Significant Accounting Policies - Schedule of Loans Receivable Held-for-sal (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Loans Receivable Held-for-sale, Net, Reconciliation to Cash Flow [Roll Forward]
Balance at beginning of year	$ 687,393	$ 680,454
Originations	1,005,165	1,079,472	$ 1,149,617
Proceeds from sale	(457,533)	(1,086,614)	(883,366)
Gain on sale of loans	29,002	75,170	78,590
Principal collections, net of deferred fees and costs	(58,683)	(23,977)
Non-cash transfers, net	(238,897)	(37,112)
Balance at end of period	$ 966,447	$ 687,393	$ 680,454