CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Unearned ESOP Shares	Accumulated Other Comprehensive (Loss) Income, Net of Tax
Shares, beginning balance (in shares) at Dec. 31, 2017		11,785,507
Beginning balance at Dec. 31, 2017	$ 177,045	$ 118	$ 111,106	$ 78,602	$ (11,208)	$ (1,573)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	4,975			4,975
Common stock repurchased (in shares)		(423,213)
Common stock repurchased	(6,929)	$ (4)	(4,228)	(2,697)
Restricted stock award forfeitures (in shares)		(18,600)
Restricted stock award forfeitures net of grants	0
Restricted stock awards canceled (in shares)		(18,076)
Restricted stock awards canceled	(293)	$ (1)	(292)
Other comprehensive income (loss), net of tax	(4,334)					(4,334)
Share-based compensation	788		788
ESOP shares committed to be released	651		157		494
Shares, ending balance (in shares) at Sep. 30, 2018		11,325,618
Ending balance at Sep. 30, 2018	171,903	$ 113	107,531	80,880	(10,714)	(5,907)
Shares, beginning balance (in shares) at Jun. 30, 2018		11,483,494
Beginning balance at Jun. 30, 2018	172,947	$ 115	108,780	79,767	(10,879)	(4,836)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,926			1,926
Common stock repurchased (in shares)		(126,200)
Common stock repurchased	(2,076)	$ (1)	(1,262)	(813)
Restricted stock award forfeitures (in shares)		(13,600)
Restricted stock award forfeitures net of grants	0
Restricted stock awards canceled (in shares)		(18,076)
Restricted stock awards canceled	(293)	$ (1)	(292)
Other comprehensive income (loss), net of tax	(1,071)					(1,071)
Share-based compensation	256		256
ESOP shares committed to be released	214		49		165
Shares, ending balance (in shares) at Sep. 30, 2018		11,325,618
Ending balance at Sep. 30, 2018	$ 171,903	$ 113	107,531	80,880	(10,714)	(5,907)
Shares, beginning balance (in shares) at Dec. 31, 2018	11,170,018	11,170,018
Beginning balance at Dec. 31, 2018	$ 172,264	$ 112	105,825	81,607	(10,549)	(4,731)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	6,796			6,796
Common stock repurchased (in shares)		(372,237)
Common stock repurchased	(5,997)	$ (4)	(3,719)	(2,274)
Restricted stock award forfeitures (in shares)		19,400
Restricted stock award forfeitures net of grants	0
Restricted stock awards canceled (in shares)		(16,249)
Restricted stock awards canceled	(266)		(266)
Other comprehensive income (loss), net of tax	4,059					4,059
Share-based compensation	804		804
ESOP shares committed to be released	636		142		494
Cash dividends declared and paid	$ (986)			(986)
Shares, ending balance (in shares) at Sep. 30, 2019	10,800,932	10,800,932
Ending balance at Sep. 30, 2019	$ 177,310	$ 108	102,786	85,143	(10,055)	(672)
Shares, beginning balance (in shares) at Jun. 30, 2019		10,925,181
Beginning balance at Jun. 30, 2019	176,401	$ 109	104,064	83,795	(10,220)	(1,347)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	2,510			2,510
Common stock repurchased (in shares)		(131,400)
Common stock repurchased	(2,150)	$ (1)	(1,314)	(835)
Restricted stock award forfeitures (in shares)		23,400
Restricted stock award forfeitures net of grants	0
Restricted stock awards canceled (in shares)		(16,249)
Restricted stock awards canceled	(266)		(266)
Other comprehensive income (loss), net of tax	675					675
Share-based compensation	251		251
ESOP shares committed to be released	216		51		165
Cash dividends declared and paid	$ (327)			(327)
Shares, ending balance (in shares) at Sep. 30, 2019	10,800,932	10,800,932
Ending balance at Sep. 30, 2019	$ 177,310	$ 108	$ 102,786	$ 85,143	$ (10,055)	$ (672)