Commitments and Contingencies - Summary of Activity in Representations and Warranties Liability (Details) - Commitment to Purchase Loans [Member] - Originations [Member] - Representations And Warranties [Member] - USD ($) $ in Thousands	1 Months Ended	11 Months Ended	12 Months Ended
	Feb. 09, 2018	Dec. 31, 2018	Dec. 31, 2017
Loss Contingency Accrual [Roll Forward]
Balance at beginning of the period	$ 16,792	$ 16,487	$ 22,094
Provision for new sales	729	5,522	6,991
Change in estimate of existing reserves	(1,001)	(6,919)	(10,596)
Net realized losses on repurchases	(33)	(2,343)	(1,697)
Balance at end of the period	$ 16,487	$ 12,747	$ 16,792