Quarterly Financial Data (Unaudited) Quarterly Financial Data (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2016
Quarterly Financial Information Disclosure [Abstract]
Total interest income	$ 5,796	$ 6,053	$ 6,339	$ 6,171	$ 6,733	$ 6,147	$ 6,326	$ 6,920	$ 24,359	$ 26,126
Total interest expense	1,446	1,364	1,252	1,218	1,151	1,282	1,223	1,262	5,280	4,918
Net interest income	4,350	4,689	5,087	4,953	5,582	4,865	5,103	5,658	19,079	21,208
Provision for loan losses	5	6	4	120	521	(128)	(160)	(204)	135	29
Total non-interest income	10,665	1,346	1,139	1,209	1,150	1,071	1,257	1,140	14,359	4,618
Total non-interest expense	7,601	6,942	6,786	6,653	8,163	6,957	6,771	6,640	27,982	28,531
Income tax (benefit) expense	(124)	31	30	30	82	0	0	37	(33)	119
Net income (loss)	$ 7,533	$ (944)	$ (594)	$ (641)	$ (2,034)	$ (893)	$ (251)	$ 325	$ 5,354	$ (2,853)	$ (2,853)
Earnings (Loss) Per Share, Basic (in dollars per share)	$ 0.82	$ (0.26)	$ (0.16)	$ (0.17)	$ (0.55)	$ (0.24)	$ (0.07)	$ 0.04	$ 0.58	$ (0.77)
Earnings (Loss) Per Share, Diluted (in dollars per share)	$ 0.82	$ (0.26)	$ (0.16)	$ (0.17)	$ (0.55)	$ (0.24)	$ (0.07)	$ 0.04	$ 0.58	$ (0.77)