Mortgage Servicing Rights - Summary of MSRs Carried at Fair Value (Parenthetical) (Detail) $ in Billions	1 Months Ended
Jun. 30, 2026 USD ($)
Servicing Asset At Fair Value Changes In Fair Value [Abstract]
Aggregate UPB of MSRs	$ 13.0

Mortgage servicing rights aggregate of unpaid principal balance

No definition available.

Name:	pmt_MortgageServicingRightsAggregateOfUnpaidPrincipalBalance
Namespace Prefix:	pmt_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration