Investment Securities - Gross unrealized losses (Details) - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
Fair Value
Less Than 12 Months	$ 98,000	$ 655,000
12 Months or More	1,648,000	3,682,000
Total fair value	1,746,000	4,337,000
Unrealized (Losses)
Less Than 12 Months	(2,000)	(4,000)
12 Months or More	(9,000)	(23,000)
Total unrealized (losses)	(11,000)	(27,000)
Declines deemed to be other-than-temporary	0	0
SBA 7a Pools
Fair Value
12 Months or More	1,648,000	1,692,000
Total fair value	1,648,000	1,692,000
Unrealized (Losses)
12 Months or More	(9,000)	(8,000)
Total unrealized (losses)	(9,000)	(8,000)
FHLMC | Mortgage-Backed Securities
Fair Value
Less Than 12 Months	98,000	655,000
12 Months or More		1,990,000
Total fair value	98,000	2,645,000
Unrealized (Losses)
Less Than 12 Months	(2,000)	(4,000)
12 Months or More		(15,000)
Total unrealized (losses)	$ (2,000)	$ (19,000)