Transactions with Affiliates - Financing Activities (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 19, 2016
PMT
Financing activities:
Issuance pursuant to recapture agreement	$ 2,688,000	$ 5,244,000	$ 6,603,000
Repayments	46,750,000	54,980,000	69,992,000
Interest expense	15,138,000	16,951,000	22,601,000
Excess servicing spread financing at fair value payable to affiliate	216,110,000	236,534,000
PMT | 2/1/13 Spread Acquisition Agreement
Financing activities:
Maximum ESS recapture obligation				$ 200,000
Excess servicing spread financing
Financing activities:
Changes in fair value included in income	8,500,000	(19,350,000)	(23,923,000)
Excess servicing spread financing | PMT
Financing activities:
Issuance pursuant to recapture agreement	2,688,000	5,244,000	6,603,000
Repayments	46,750,000	54,980,000	69,992,000
Settlement			59,045,000
Changes in fair value included in income	8,500,000	(19,350,000)	(23,923,000)
Interest expense	15,138,000	16,951,000	22,601,000
Excess servicing spread recapture recognized	2,584,000	4,820,000	$ 6,529,000
Excess servicing spread financing at fair value payable to affiliate	$ 216,110,000	$ 236,534,000