Consolidated Statements of Changes in Stockholders’ Equity - USD ($) $ in Thousands	Common Stock	Additional Paid in Capital.	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	ESOP – Owned Shares	Total
Adjustment for adoption of ASU 2016‑01			$ (71)	$ 71
Beginning balance at Dec. 31, 2017	$ 13,699	$ 26,040	140,986	(1,131)	$ (31,491)	$ 148,103
Net Income			19,833			19,833
Other comprehensive income (loss)				(4,579)		(4,579)
Common stock repurchased	(11)	(39)	(212)			(262)
Common stock dividends			(5,486)			(5,486)
Net change in fair value of ESOP shares					(3,003)	(3,003)
Stock‑based compensation expense	11	971				982
Vesting of restricted stock	77	(77)
Ending balance at Sep. 30, 2018	13,776	26,895	155,050	(5,639)	(34,494)	155,588
Beginning balance at Jun. 30, 2018	13,778	26,664	149,541	(4,617)	(31,491)	153,875
Net Income			7,370			7,370
Other comprehensive income (loss)				(1,022)		(1,022)
Common stock repurchased	(2)	(6)	(32)			(40)
Common stock dividends			(1,829)			(1,829)
Net change in fair value of ESOP shares					(3,003)	(3,003)
Stock‑based compensation expense		237				237
Ending balance at Sep. 30, 2018	13,776	26,895	155,050	(5,639)	(34,494)	155,588
Beginning balance at Dec. 31, 2018	13,775	27,743	159,037	(3,601)	(34,494)	162,460
Net Income			21,888			21,888
Other comprehensive income (loss)				6,686		6,686
Common stock repurchased	(82)	(291)	(1,574)			(1,947)
Common stock dividends			(6,312)			(6,312)
ESOP repurchase obligation termination					34,494	34,494
Initial public offering of 3,289,000 shares of common stock net of issuance costs	3,289	59,515				62,804
Stock‑based compensation expense	13	1,317				1,330
Vesting of restricted stock	54	(54)
Ending balance at Sep. 30, 2019	17,049	88,230	173,039	3,085		281,403
Beginning balance at Jun. 30, 2019	13,816	28,676	169,788	1,485	(34,494)	179,271
Net Income			7,104			7,104
Other comprehensive income (loss)				1,600		1,600
Common stock repurchased	(77)	(275)	(1,489)			(1,841)
Common stock dividends			(2,364)			(2,364)
ESOP repurchase obligation termination					$ 34,494	34,494
Initial public offering of 3,289,000 shares of common stock net of issuance costs	3,289	59,515				62,804
Stock‑based compensation expense		335				335
Vesting of restricted stock	21	(21)
Ending balance at Sep. 30, 2019	$ 17,049	$ 88,230	$ 173,039	$ 3,085		$ 281,403