Quarterly Results of Operations (Unaudited) - Summary (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2021	Mar. 31, 2020
Quarterly Financial Data [Abstract]
Total revenue	$ 13,286	$ 14,474	$ 14,109	$ 14,151	$ 14,896	$ 14,973	$ 15,585	$ 16,641
Interest expense	1,320	1,442	1,569	1,649	1,843	1,886	2,298	2,488	$ 5,980	$ 8,515
Provision for credit losses	250	650	3,050	3,300	3,919	4,597	4,000	4,385	7,250	16,901
Non-interest expense	8,963	7,407	8,131	7,343	8,584	7,950	8,927	8,971
Operating income before income taxes	2,753	4,975	1,359	1,859	550	540	360	797	10,946	2,247
Income tax expense (benefit)	884	1,190	92	429	(1,746)	229	92	206	2,595	(1,219)
Net income	$ 1,869	$ 3,785	$ 1,267	$ 1,430	$ 2,296	$ 311	$ 268	$ 591	$ 8,351	$ 3,466
Earnings per share:
Basic (in dollars per share)	$ 0.24	$ 0.49	$ 0.16	$ 0.18	$ 0.31	$ 0.04	$ 0.03	$ 0.07	$ 1.09	$ 0.45
Diluted (in dollars per share)	$ 0.24	$ 0.49	$ 0.16	$ 0.18	$ 0.31	$ 0.04	$ 0.03	$ 0.07	$ 1.09	$ 0.45