CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Thousands	Common Stock. Common Stock	Common Stock.	Additional paid-in capital	Retained earnings	Noncontrolling interest in Private National Mortgage Acceptance Company, LLC	Total
Changes in stockholders' equity
Cumulative effect of change in accounting principle - accounting for all existing classes of mortgage servicing rights at fair value				$ 189	$ 587	$ 776
Balance after adjustment	$ 2		$ 204,103	265,495	1,250,850	1,720,450
Balance after adjustment (in shares)	23,530
Balance at Dec. 31, 2017	$ 2		204,103	265,306	1,250,263	1,719,674
Balance (in shares) at Dec. 31, 2017	23,530
Changes in stockholders' equity
Net income				16,619	50,307	66,926
Stock and unit-based compensation			5,191		4,235	9,426
Issuance of Class A common stock in settlement of director fees			24		55	79
Exchange of Class A units of Private National Mortgage Acceptance Company, LLC to Class A common stock of PennyMac Financial Services, Inc.			14,859		(14,859)	$ 14,859
Exchange of Class A units of Private National Mortgage Acceptance Company, LLC to Class A common stock of PennyMac Financial Services, Inc. (in shares)	748					748
Tax effect of exchange of Class A units of Private National Mortgage Acceptance Company, LLC to Class A common stock of PennyMac Financial Services, Inc.			(2,682)			$ (2,682)
Balance at Mar. 31, 2018	$ 2		221,495	282,114	$ 1,290,588	1,794,199
Balance (in shares) at Mar. 31, 2018	24,278
Balance at Dec. 31, 2018		$ 8	1,310,648	343,135		1,653,791
Balance (in shares) at Dec. 31, 2018		77,494
Changes in stockholders' equity
Net income				46,135		46,135
Stock and unit-based compensation			1,180			1,180
Stock and unit-based compensation (in shares)		820
Issuance of common stock in settlement of directors' fees			86			86
Issuance of common stock in settlement of directors' fees (in shares)		4
Balance at Mar. 31, 2019		$ 8	$ 1,311,914	$ 389,270		$ 1,701,192
Balance (in shares) at Mar. 31, 2019		78,318