Consolidated Statements Changes in Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Randolph Savings Charitable Foundation	Initial Public Offering [Member]	Common Stock [Member]	Common Stock [Member] Randolph Savings Charitable Foundation	Common Stock [Member] Initial Public Offering [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Additional Paid-in Capital [Member]	Additional Paid-in Capital [Member] Randolph Savings Charitable Foundation	Additional Paid-in Capital [Member] Initial Public Offering [Member]	Unearned Compensation ESOP [Member]
Beginning balance at Dec. 31, 2014	$ 33,656						$ 32,952	$ 704
Net income (loss)	(754)						(754)
Other comprehensive loss	(443)							(443)
Ending balance at Dec. 31, 2015	32,459						32,198	261
Net income (loss)	463						463
Other comprehensive loss	(1,545)							(1,545)
Issuance of common stock for initial public offering, value		$ 1,820	$ 54,543		$ 2	$ 57				$ 1,818	$ 54,486
Issuance of common stock for initial public offering, shares					181,976	5,686,750
Stock purchased by ESOP	(4,695)											$ (4,695)
ESOP shares committed to be released	257								$ 69			188
Ending balance at Dec. 31, 2016	$ 83,302			$ 59			$ 32,661	$ (1,284)	$ 56,373			$ (4,507)
Ending balance, shares at Dec. 31, 2016				5,868,726