Securities - Gross Unrealized Losses and Fair Value (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Debt Securities, Available-for-sale [Line Items]
Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	$ 127,335	$ 168,673
Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value	176,218	285,282
Available-for-sale, Unrealized Loss Position, Fair Value	303,553	453,955
Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Unrealized Losses	(2,571)	(2,861)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Unrealized Losses	(6,643)	(15,959)
Debt Securities, Available-for-sale, Unrealized Loss Position, Unrealized Losses	9,214	18,820
Fair Value
Held-to-maturity, Less Than 12 Months	13,977	15,838
Held-to-maturity, 12 Months or Longer	0	0
Held-to-maturity, Total	13,977	15,838
Unrealized Losses
Held-to-maturity, Less Than 12 Months	(132)	(412)
Held-to-maturity, 12 Months or Longer	0	0
Held-to-maturity, Total	(132)	(412)
U.S. Government-sponsored agencies
Debt Securities, Available-for-sale [Line Items]
Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	4,820	69,798
Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value	62,182	33,511
Available-for-sale, Unrealized Loss Position, Fair Value	67,002	103,309
Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Unrealized Losses	(61)	(893)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Unrealized Losses	(1,881)	(1,173)
Debt Securities, Available-for-sale, Unrealized Loss Position, Unrealized Losses	1,942	2,066
Municipal securities
Debt Securities, Available-for-sale [Line Items]
Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	1,279	23,747
Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value	0	59,938
Available-for-sale, Unrealized Loss Position, Fair Value	1,279	83,685
Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Unrealized Losses	(1,501)	(710)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Unrealized Losses	0	(3,964)
Debt Securities, Available-for-sale, Unrealized Loss Position, Unrealized Losses	1,501	4,674
Fair Value
Held-to-maturity, Less Than 12 Months		9,801
Held-to-maturity, 12 Months or Longer		0
Held-to-maturity, Total		9,801
Unrealized Losses
Held-to-maturity, Less Than 12 Months		(356)
Held-to-maturity, 12 Months or Longer		0
Held-to-maturity, Total		(356)
Agency mortgage-backed securities
Debt Securities, Available-for-sale [Line Items]
Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	91,159	47,000
Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value	83,212	172,442
Available-for-sale, Unrealized Loss Position, Fair Value	174,371	219,442
Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Unrealized Losses	(829)	(509)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Unrealized Losses	(3,177)	(8,212)
Debt Securities, Available-for-sale, Unrealized Loss Position, Unrealized Losses	4,006	8,721
Private label mortgage-backed securities
Debt Securities, Available-for-sale [Line Items]
Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	30,077	9,177
Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value	2,884	0
Available-for-sale, Unrealized Loss Position, Fair Value	32,961	9,177
Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Unrealized Losses	(180)	(20)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Unrealized Losses	(8)	(1)
Debt Securities, Available-for-sale, Unrealized Loss Position, Unrealized Losses	188	21
Asset-backed securities
Debt Securities, Available-for-sale [Line Items]
Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	0	4,859
Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value	4,955	0
Available-for-sale, Unrealized Loss Position, Fair Value	4,955	4,859
Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Unrealized Losses	0	(143)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Unrealized Losses	(45)	0
Debt Securities, Available-for-sale, Unrealized Loss Position, Unrealized Losses	45	143
Corporate securities
Debt Securities, Available-for-sale [Line Items]
Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	0	14,092
Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value	22,985	19,391
Available-for-sale, Unrealized Loss Position, Fair Value	22,985	33,483
Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Unrealized Losses	0	(586)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Unrealized Losses	(1,532)	(2,609)
Debt Securities, Available-for-sale, Unrealized Loss Position, Unrealized Losses	1,532	3,195
Fair Value
Held-to-maturity, Less Than 12 Months	13,977	6,037
Held-to-maturity, 12 Months or Longer	0	0
Held-to-maturity, Total	13,977	6,037
Unrealized Losses
Held-to-maturity, Less Than 12 Months	(132)	(56)
Held-to-maturity, 12 Months or Longer	0	0
Held-to-maturity, Total	$ (132)	$ (56)