Esop - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Employee Stock Ownership Plan (ESOP) Disclosures [Line Items]
Total ESOP shares	600,000	600,000
ESOP common stock, per share	$ 13.14
ESOP borrowed	$ 7.9
2015 HopFed Bancorp, Inc. Employee Stock Ownership Plan ("ESOP") [Member]
Employee Stock Ownership Plan (ESOP) Disclosures [Line Items]
Employee stock ownership plan employee minimum service period	1 year
Minimum age eligibility of employee	21 years