Securities - Summary of securities in unrealized loss position (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Debt Securities, Available-for-sale [Line Items]
Fair Value, Less than 12 Months	$ 7,375	$ 20,639
Gross Unrealized Losses, Less than 12 Months	(19)	(66)
Fair Value, 12 Months or Longer	5,302	31,824
Gross Unrealized Losses, 12 Months or Longer	(42)	(369)
Fair Value, Total	12,677	52,463
Gross Unrealized Losses, Total	(61)	(435)
Mortgage-backed securities – agency
Debt Securities, Available-for-sale [Line Items]
Fair Value, 12 Months or Longer		9,529
Gross Unrealized Losses, 12 Months or Longer		(90)
Fair Value, Total		9,529
Gross Unrealized Losses, Total		(90)
CMO's - agency
Debt Securities, Available-for-sale [Line Items]
Fair Value, Less than 12 Months	7,375	20,639
Gross Unrealized Losses, Less than 12 Months	(19)	(66)
Fair Value, 12 Months or Longer	5,302	22,295
Gross Unrealized Losses, 12 Months or Longer	(42)	(279)
Fair Value, Total	12,677	42,934
Gross Unrealized Losses, Total	$ (61)	$ (345)