Securities - Carrying Value (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Amortized Cost
Within one year	$ 15
One to five years	19,032
Five to ten years	81,662
After ten years	109,037
Amortized Cost	209,746
Amortized cost	608,567	$ 546,640
Held-to-maturity securities, One to five years	1,505
Held-to-maturity securities, Five to ten years	52,301
Held-to-maturity securities, After ten years	12,525
Held-to-maturity securities, Amortized Cost	66,331
Fair Value
Within one year	15
One to five years	15,068
Five to ten years	80,465
After ten years	110,765
Fair Value	206,313
Fair Value	608,682	540,852
Held-to-maturity securities, One to five years	1,584
Held-to-maturity securities, Five to ten years	54,610
Held-to-maturity securities, After ten years	13,274
Held-to-maturity securities, Fair Value	69,468
Agency mortgage-backed securities
Amortized Cost
Amortized cost	279,458	264,142
Fair Value
Fair Value	282,632	261,440
Private label mortgage-backed securities
Amortized Cost
Amortized cost	114,363	63,704
Fair Value
Fair Value	115,024	63,613
Asset-backed securities
Amortized Cost
Amortized cost	5,000	5,000
Fair Value
Fair Value	$ 4,713	$ 4,955