Parent Company Information - Condensed Balance Sheets (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016
ASSETS
Cash	$ 155,289				$ 37,725				$ 99,367
Total assets	7,478,573	$ 6,992,530	$ 6,841,706	$ 6,902,891	7,368,093	$ 6,388,369	$ 6,404,738	$ 5,251,377
LIABILITIES AND STOCKHOLDERS' EQUITY
Income taxes payable	400,546				52,160
Total liabilities	5,824,782	5,075,820	4,979,762	5,108,692	5,648,419	4,798,078	4,893,486	3,793,782
Stockholders' equity	1,653,791				469,411
Total liabilities and stockholders' equity	7,478,573	6,992,530	6,841,706	6,902,891	7,368,093	6,388,369	6,404,738	5,251,377
Long-term debt	1,648,973	$ 1,566,672	$ 1,473,188	$ 1,380,358	1,135,401	$ 1,151,545	$ 671,789	$ 690,476
PENNYMAC FINANCIAL SERVICES, INC. | Parent Company
ASSETS
Cash					2,605
Investment in subsidiaries	1,975,231				556,439
Due from subsidiaries	582				6,538
Total assets	1,975,813				565,582
LIABILITIES AND STOCKHOLDERS' EQUITY
Payable to exchanged Private National Mortgage Acceptance Company, LLC unitholders under tax receivable agreement					44,011
Income taxes payable	321,447				52,160
Payables to subsidiaries	575
Total liabilities	322,022				96,171
Stockholders' equity	1,653,791				469,411
Total liabilities and stockholders' equity	$ 1,975,813				$ 565,582