Transactions with Affiliates - Financing Activities (Details) - USD ($)	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018	Feb. 01, 2013
Financing activities:
Issuance pursuant to recapture agreement	$ 508,000	$ 904,000
Repayments	10,552,000	12,291,000
PMT
Financing activities:
Gain (loss) recognized	4,051,000	(6,921,000)
Interest expense	3,066,000	3,934,000
Excess servicing spread financing at fair value payable to affiliate	205,081,000		$ 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	(4,051,000)	6,921,000
Excess servicing spread financing | PMT
Financing activities:
Issuance pursuant to recapture agreement	508,000	904,000
Repayments	10,552,000	12,291,000
Gain (loss) recognized	4,051,000	(6,921,000)
Interest expense	3,066,000	3,934,000
Excess servicing spread recapture recognized	489,000	$ 830,000
Excess servicing spread financing at fair value payable to affiliate	$ 205,081,000		$ 216,110,000