CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Net gains on loans held for sale at fair value:
Net gains on loans held for sale to non-affiliates	$ 2,515,874	$ 2,690,104	$ 542,163
Net gains on loans held for sale at fair value	2,464,401	2,740,785	725,528
Loan origination fees from non-affiliates	358,028	262,143	159,461
Loan origination fees	384,154	285,551	174,156
Loan servicing fees
From non-affiliates	875,570	814,646	730,165
Other	118,884	116,464	98,564
Loan servicing fees	1,075,112	998,291	877,526
Change in fair value of mortgage servicing rights and mortgage servicing liabilities	415,906	1,501,993	988,614
Mortgage servicing rights hedging results	(475,215)	918,180	395,497
Change in fair value of excess servicing spread payable to PennyMac Mortgage Investment Trust	(892,158)	(558,843)	(583,861)
Net loan servicing fees	182,954	439,448	293,665
Interest income:
From non-affiliates	299,782	243,701	282,398
Interest income	300,169	247,026	288,700
Interest expense:
To non-affiliates	389,419	263,133	201,688
Interest expense	390,699	271,551	211,979
Net interest (expense) income	(90,530)	(24,525)	76,721
Management fees, net:
Management fees	37,801	34,538	36,492
Result of real estate acquired in settlement of loans	1,993	1,036	557
Repricing of payable to exchanged Private National Mortgage Acceptance Company , LLC unitholders under tax receivable agreement		280	379
Other	7,325	6,737	8,880
Total net revenue	3,167,361	3,705,597	1,477,404
Expenses
Compensation	999,802	738,569	503,458
Loan origination	330,788	219,746	117,338
Technology	141,426	112,570	67,946
Servicing	109,835	256,934	164,697
Professional services	94,283	64,064	32,859
Marketing and advertising	44,806	8,658	5,165
Occupancy and equipment	35,810	33,357	28,916
Other	51,428	31,090	27,581
Total expenses	1,808,178	1,464,988	947,960
Income before provision for income taxes	1,359,183	2,240,609	529,444
Provision for income taxes	355,693	593,725	136,479
Net income attributable to PennyMac Financial Services, Inc. common stockholders	$ 1,003,490	$ 1,646,884	$ 392,965
Earnings per share
Basic (in dollars per share)	$ 15.73	$ 21.91	$ 5.02
Diluted (in dollars per share)	$ 14.87	$ 20.92	$ 4.89
Weighted-average shares outstanding
Basic (in shares)	63,799	75,161	78,206
Diluted (in shares)	67,471	78,728	80,340
PennyMac Mortgage Investment Trust
Net gains on loans held for sale at fair value:
Net gains on loans held for sale to PennyMac Mortgage Investment Trust	$ (51,473)	$ 50,681	$ 183,365
Loan origination fees from PennyMac Mortgage Investment Trust	26,126	23,408	14,695
Fulfillment fees from PennyMac Mortgage Investment Trust	178,927	222,200	160,610
Loan servicing fees
Loan servicing fees from affiliates	80,658	67,181	48,797
Changes in fair value included in income	(1,037)	24,970	9,256
Interest income:
From PennyMac Mortgage Investment Trust	387	3,325	6,302
Interest expense:
To PennyMac Mortgage Investment Trust	1,280	8,418	10,291
Management fees, net:
Management fees	37,801	34,538	36,492
Change in fair value of investment in and dividends received from affiliate	$ 336	$ (453)	$ 416