Net Interest Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Interest income:
Interest income	$ 53,882	$ 82,081
Interest expense:
Obligations under capital lease	15	59
Interest expense	77,307	107,713
Net interest expense	(23,425)	(25,632)
PennyMac Mortgage Investment Trust
Interest income:
Interest income		387
Interest expense:
Interest expense		1,280
Non-affiliates
Interest income:
Cash and short-term investments	572	987
Loans held for sale at fair value	49,113	74,824
Placement fees relating to custodial funds	4,197	5,883
Interest income	53,882	81,694
Interest expense:
Assets sold under agreements to repurchase	23,770	52,179
Mortgage loan participation purchase and sale agreements	1,120	1,095
Obligations under capital lease	15	59
Notes payable	9,909	9,888
Unsecured senior notes	23,428	12,670
Interest shortfall on repayments of mortgage loans serviced for Agency securitizations	17,479	29,436
Interest on mortgage loan impound deposits	1,586	1,106
Interest expense	77,307	106,433
Loan Repo Facility
Interest expense:
Assets sold under agreements to repurchase	$ 23,770	$ 52,179