Parent Company Only Financial Statements - Schedule of Consolidated Statements of Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended									12 Months Ended
	Dec. 31, 2017	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Condensed Financial Statements Captions [Line Items]
Interest on ESOP loan										$ 52
Income (loss) before income taxes		$ (784)	$ (4,852)	$ 1,765	$ 908	$ 398	$ 521	$ 213	$ 1,298	(2,963)	$ 2,430	$ 3,833
Income tax (benefit)		2,081	(1,643)	641	345	159	239	117	490	1,424	1,005	1,315
Net income (loss)	$ (2,864)	$ (2,865)	$ (3,209)	$ 1,124	$ 563	$ 239	$ 282	$ 96	$ 808	(4,387)	$ 1,425	$ 2,518
Ponce Bank Mutual Holding Company
Condensed Financial Statements Captions [Line Items]
Interest on ESOP loan										53
Contribution to Ponce De Leon Foundation										6,293
Income (loss) before income taxes										(6,240)
Income tax (benefit)										(1,287)
Equity in undistributed earnings of Ponce Bank										1,523
Net income (loss)										$ (3,430)