Parent Company Information - Condensed Statements of Cash Flows (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Cash flow from operating activities
Net income	$ 1,003,490	$ 1,646,884	$ 392,965
Amortization of debt issuance cost (premiums), net	24,321	19,048	(4,100)
Repricing of payable to exchanged Private National Mortgage Acceptance Company, LLC unitholders under tax receivable agreement		(280)	(379)
Increase in accounts payable and accrued expenses	34,666	135,314	38,551
Net cash provided by (used in) operating activities	2,563,061	(6,198,938)	(2,245,123)
Cash flow from investing activities
Net cash (used in) provided by investing activities	(304,369)	783,034	148,782
Cash flow from financing activities
Issuance of unsecured senior notes	1,150,000	650,000
Payment of debt issuance costs	(37,567)	(30,112)	(6,603)
Issuance of common stock pursuant to exercise of stock options	7,536	9,389	5,145
Repurchase of common stock and Class A common stock	(958,194)	(337,479)	(1,056)
Payment of withholding taxes relating to stock-based compensation	(8,993)	(5,265)	(4,634)
Net cash (used in) provided by financing activities	(2,451,380)	5,760,107	2,128,995
Non-cash financing activity:
Restricted Cash	24	65	287
PennyMac Financial Services, Inc.
Non-cash financing activity:
Issuance of common stock in settlement of directors' fees	200	194	233
PennyMac Financial Services, Inc. | Parent Company [Member]
Cash flow from operating activities
Net income	1,003,490	1,646,884	392,965
Equity in undistributed earnings of subsidiaries	(261,084)	(1,435,328)	(448,033)
Amortization of debt issuance cost (premiums), net	2,321	225
Increase in receivable from PennyMac Mortgage Investment Trust	(27)
(Increase) decrease in intercompany receivable	(897,063)	(574,518)	8,962
Increase in accounts payable and accrued expenses	13,545	14,590
Increase in payable to subsidiaries	(22,289)	18,211
Increase in income taxes payable	35,839	65,406	58,609
Net cash provided by (used in) operating activities	(125,268)	(264,530)	12,503
Cash flow from financing activities
Issuance of unsecured senior notes	1,150,000	650,000
Payment of debt issuance costs	(21,922)	(4,405)
Payment of dividend to common stock and Class A common stockholders	(52,896)	(30,947)	(9,708)
Issuance of common stock pursuant to exercise of stock options	7,536	9,389	5,145
Repurchase of common stock and Class A common stock	(958,194)	(337,479)	(1,056)
Payment of withholding taxes relating to stock-based compensation	(8,993)	(5,265)	(4,634)
Net cash (used in) provided by financing activities	115,531	281,293	(10,253)
Net increase (decrease) in cash	(9,737)	16,763	2,250
Cash at beginning of year	19,013	2,250
Cash at end of year	9,276	19,013	2,250
Non-cash financing activity:
Restricted Cash	$ 0	$ 0	$ 0