Related Party Transactions - Amounts due from Affiliate (Details) - PMT - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Amounts due from affiliate
Allocated expenses	$ 23,325	$ 38,142
Fulfillment fees	17,347	20,873
Correspondent production fees	12,937	13,065
Management fees	8,449	8,686
Servicing fees	6,586	6,213
Interest on assets purchased under agreements to resell		26
Total due from affiliate	68,644	87,005
Payable to affiliate
Amounts advanced by PMT	156,948	132,154
MSR Recapture Payable to PMT		296
Other expenses	7,521	7,856
Payable to affiliates	$ 164,469	$ 140,306