Parent Company Financial Statements - Condensed Statements of Financial Condition (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Assets
Cash and deposits with banks	$ 34,365	$ 27,690
Total cash and cash equivalents	46,880	45,887	$ 35,910	$ 32,980
Other assets	28,360	33,182
Total assets	2,649,905	2,191,345
Liabilities and Shareholders' Equity
Total liabilities	2,355,640	1,941,539
Total shareholders' equity	294,265	249,806	244,245	240,135
Total liabilities and shareholders’ equity	2,649,905	2,191,345
Parent Company [Member]
Assets
Cash and deposits with banks	4,974	25,924
Total cash and cash equivalents	4,974	25,924	$ 21,163	$ 20,764
Other assets	3,935	2,878
Total assets	294,277	250,459
Liabilities and Shareholders' Equity
Accrued expenses and other liabilities	12	653
Total liabilities	12	653
Total shareholders' equity	294,265	249,806
Total liabilities and shareholders’ equity	294,277	250,459
Parent Company [Member] | Home Savings [Member]
Assets
Investment in subsidiary	276,494	216,475
Parent Company [Member] | HSB Capital LLC [Member]
Assets
Investment in subsidiary	5,095	3,014
Parent Company [Member] | HSB Insurance LLC [Member]
Assets
Investment in subsidiary	2,463	$ 2,168
Parent Company [Member] | HSB Insurance, Inc. [Member]
Assets
Investment in subsidiary	$ 1,316