Securities - Gross Unrealized Losses and Fair Value (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Less Than 12 Months, Fair Value	$ 93,145	$ 127,335
Less Than 12 Months, Unrealized Losses	(4,610)	(2,571)
12 Months or Longer, Fair Value	92,086	176,218
12 Months or Longer, Unrealized Losses	(6,317)	(6,643)
Total, Fair Value	185,231	303,553
Total, Unrealized Losses	(10,927)	(9,214)
Held-to-maturity securities, Less Than 12 Months, Fair Value	21,200	13,977
Held-to-maturity securities, Less Than 12 Months, Unrealized Losses	(375)	(132)
Held-to-maturity securities, 12 Months or Longer, Fair Value	0	0
Held-to-maturity securities, 12 Months or Longer, Unrealized Losses	0	0
Held-to-maturity securities, Total, Fair Value	21,200	13,977
Held-to-maturity securities, Total, Unrealized Losses	(375)	(132)
U.S. Government-sponsored agencies
Less Than 12 Months, Fair Value	0	4,820
Less Than 12 Months, Unrealized Losses	0	(61)
12 Months or Longer, Fair Value	55,382	62,182
12 Months or Longer, Unrealized Losses	(1,814)	(1,881)
Total, Fair Value	55,382	67,002
Total, Unrealized Losses	(1,814)	(1,942)
Municipal securities
Less Than 12 Months, Fair Value	61,269	1,279
Less Than 12 Months, Unrealized Losses	(4,240)	(1,501)
12 Months or Longer, Fair Value	0	0
12 Months or Longer, Unrealized Losses	0	0
Total, Fair Value	61,269	1,279
Total, Unrealized Losses	(4,240)	(1,501)
Agency mortgage-backed securities
Less Than 12 Months, Fair Value	29,466	91,159
Less Than 12 Months, Unrealized Losses	(361)	(829)
12 Months or Longer, Fair Value	10,294	83,212
12 Months or Longer, Unrealized Losses	(2,875)	(3,177)
Total, Fair Value	39,760	174,371
Total, Unrealized Losses	(3,236)	(4,006)
Private label mortgage-backed securities
Less Than 12 Months, Fair Value	2,410	30,077
Less Than 12 Months, Unrealized Losses	(9)	(180)
12 Months or Longer, Fair Value	1,026	2,884
12 Months or Longer, Unrealized Losses	(12)	(8)
Total, Fair Value	3,436	32,961
Total, Unrealized Losses	(21)	(188)
Asset-backed securities
Less Than 12 Months, Fair Value	0	0
Less Than 12 Months, Unrealized Losses	0	0
12 Months or Longer, Fair Value	4,921	4,955
12 Months or Longer, Unrealized Losses	(79)	(45)
Total, Fair Value	4,921	4,955
Total, Unrealized Losses	(79)	(45)
Corporate securities
Less Than 12 Months, Fair Value	0	0
Less Than 12 Months, Unrealized Losses	0	0
12 Months or Longer, Fair Value	20,463	22,985
12 Months or Longer, Unrealized Losses	(1,537)	(1,532)
Total, Fair Value	20,463	22,985
Total, Unrealized Losses	(1,537)	(1,532)
Held-to-maturity securities, Less Than 12 Months, Fair Value	21,200	13,977
Held-to-maturity securities, Less Than 12 Months, Unrealized Losses	(375)	(132)
Held-to-maturity securities, 12 Months or Longer, Fair Value	0	0
Held-to-maturity securities, 12 Months or Longer, Unrealized Losses	0	0
Held-to-maturity securities, Total, Fair Value	21,200	13,977
Held-to-maturity securities, Total, Unrealized Losses	$ (375)	$ (132)