Transactions with Affiliates - Financing Activities (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018	Feb. 01, 2013
Financing activities:
Issuance pursuant to recapture agreement			$ 1,327,000	$ 1,983,000
Repayments			30,901,000	35,852,000
PMT
Financing activities:
Gain (loss) recognized	$ 3,864,000	$ (1,109,000)	11,519,000	(9,026,000)
Interest expense	2,291,000	3,740,000	8,124,000	11,584,000
Excess servicing spread financing at fair value payable to affiliate	183,141,000		183,141,000		$ 216,110,000
PMT | 2/1/13 Spread Acquisition Agreement
Financing activities:
Maximum ESS recapture obligation						$ 200,000
Excess servicing spread financing
Financing activities:
Gain (loss) recognized	(3,864,000)	1,109,000	(11,519,000)	9,026,000
Excess servicing spread financing | PMT
Financing activities:
Issuance pursuant to recapture agreement	377,000	499,000	1,327,000	1,983,000
Repayments	9,819,000	11,543,000	30,901,000	35,852,000
Gain (loss) recognized	3,864,000	(1,109,000)	11,519,000	(9,026,000)
Interest expense	2,291,000	3,740,000	8,124,000	11,584,000
Excess servicing spread recapture recognized	429,000	$ 597,000	1,311,000	$ 1,951,000
Excess servicing spread financing at fair value payable to affiliate	$ 183,141,000		$ 183,141,000		$ 216,110,000