Securities - Continuous Unrealized Loss Position (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Available-for-sale securities, Continuous Unrealized Loss Position, Fair Value
Available-for-sale securities, Continuous Unrealized Loss Position, Fair Value, Less than 12 Months	$ 1,113	$ 95,772
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value, Total	1,113	95,772
Available-for-sale securities, Continuous Unrealized Loss Position, Gross Unrealized Losses
Available-for-sale securities, Continuous Unrealized Loss Position, Gross Unrealized Losses, Less than 12 Months	1	39
Available-for-sale securities, Continuous Unrealized Loss Position, Gross Unrealized Losses, Total	1	39
Federal agencies
Available-for-sale securities, Continuous Unrealized Loss Position, Fair Value
Available-for-sale securities, Continuous Unrealized Loss Position, Fair Value, Less than 12 Months		94,963
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value, Total		94,963
Available-for-sale securities, Continuous Unrealized Loss Position, Gross Unrealized Losses
Available-for-sale securities, Continuous Unrealized Loss Position, Gross Unrealized Losses, Less than 12 Months		37
Available-for-sale securities, Continuous Unrealized Loss Position, Gross Unrealized Losses, Total		37
Mortgage-backed - Government-sponsored entity (GSE) - residential
Available-for-sale securities, Continuous Unrealized Loss Position, Fair Value
Available-for-sale securities, Continuous Unrealized Loss Position, Fair Value, Less than 12 Months	1,113	809
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value, Total	1,113	809
Available-for-sale securities, Continuous Unrealized Loss Position, Gross Unrealized Losses
Available-for-sale securities, Continuous Unrealized Loss Position, Gross Unrealized Losses, Less than 12 Months	1	2
Available-for-sale securities, Continuous Unrealized Loss Position, Gross Unrealized Losses, Total	$ 1	$ 2