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Securities - Summary of Gross Unrealized Losses and Fair Values, Aggregated by Investment Category and Length of Individual Securities Continuous Unrealized Loss Position Available-for-sale (Details) $ in Thousands	Dec. 31, 2019 USD ($) Security	Dec. 31, 2018 USD ($) Security
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Number of Securities | Security	99	179
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	$ 343,722	$ 191,761
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Unrealized Losses	(2,377)	(2,441)
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value	257,869	427,243
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Unrealized Losses	(2,328)	(17,287)
Available-for-sale Securities, Continuous Unrealized Loss Position, Total Fair Value	601,591	619,004
Available-for-sale Securities, Continuous Unrealized Loss Position, Total Unrealized Losses	$ (4,705)	$ (19,728)
U.S. Government Agencies
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Number of Securities | Security	8	25
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	$ 49,318	$ 43,487
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Unrealized Losses	(662)	(80)
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value	20,283	50,101
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Unrealized Losses	(92)	(1,216)
Available-for-sale Securities, Continuous Unrealized Loss Position, Total Fair Value	69,601	93,588
Available-for-sale Securities, Continuous Unrealized Loss Position, Total Unrealized Losses	$ (754)	$ (1,296)
Obligations of States, Municipalities, and Political Subdivisions
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Number of Securities | Security	7	56
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	$ 13,309	$ 13,926
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Unrealized Losses	(45)	(97)
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value	1,419	18,563
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Unrealized Losses	(4)	(489)
Available-for-sale Securities, Continuous Unrealized Loss Position, Total Fair Value	14,728	32,489
Available-for-sale Securities, Continuous Unrealized Loss Position, Total Unrealized Losses	$ (49)	$ (586)
Agency, Residential Mortgage-Backed Securities
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Number of Securities | Security	50	42
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	$ 132,703	$ 4,288
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Unrealized Losses	(666)	(45)
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value	193,363	254,121
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Unrealized Losses	(1,688)	(11,131)
Available-for-sale Securities, Continuous Unrealized Loss Position, Total Fair Value	326,066	258,409
Available-for-sale Securities, Continuous Unrealized Loss Position, Total Unrealized Losses	$ (2,354)	$ (11,176)
Non-Agency, Residential Mortgage-Backed Securities
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Number of Securities | Security	9	8
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	$ 36,902	$ 59,107
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Unrealized Losses	(206)	(1,378)
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value	10,126	4,009
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Unrealized Losses	(66)	(198)
Available-for-sale Securities, Continuous Unrealized Loss Position, Total Fair Value	47,028	63,116
Available-for-sale Securities, Continuous Unrealized Loss Position, Total Unrealized Losses	$ (272)	$ (1,576)
Agency, Commercial Mortgage-Backed Securities
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Number of Securities | Security	13	9
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	$ 67,649	$ 21,356
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Unrealized Losses	(563)	(447)
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value	32,678	52,640
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Unrealized Losses	(478)	(2,717)
Available-for-sale Securities, Continuous Unrealized Loss Position, Total Fair Value	100,327	73,996
Available-for-sale Securities, Continuous Unrealized Loss Position, Total Unrealized Losses	$ (1,041)	$ (3,164)
Asset-Backed Securities
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Number of Securities | Security	8
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	$ 37,738
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Unrealized Losses	(198)
Available-for-sale Securities, Continuous Unrealized Loss Position, Total Fair Value	37,738
Available-for-sale Securities, Continuous Unrealized Loss Position, Total Unrealized Losses	$ (198)
Corporate Securities
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Number of Securities | Security	4	15
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	$ 6,103	$ 25,762
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Unrealized Losses	(37)	(342)
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value		4,642
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Unrealized Losses		(268)
Available-for-sale Securities, Continuous Unrealized Loss Position, Total Fair Value	6,103	30,404
Available-for-sale Securities, Continuous Unrealized Loss Position, Total Unrealized Losses	$ (37)	$ (610)
U.S. Treasury Notes
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Number of Securities | Security		18
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value		$ 23,835
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Unrealized Losses		(52)
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value		9,865
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Unrealized Losses		(137)
Available-for-sale Securities, Continuous Unrealized Loss Position, Total Fair Value		33,700
Available-for-sale Securities, Continuous Unrealized Loss Position, Total Unrealized Losses		$ (189)
Non-Agency, Commercial Mortgage-Backed Securities
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Number of Securities | Security		5
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value		$ 30,458
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Unrealized Losses		(1,000)
Available-for-sale Securities, Continuous Unrealized Loss Position, Total Fair Value		30,458
Available-for-sale Securities, Continuous Unrealized Loss Position, Total Unrealized Losses		$ (1,000)
Other Securities
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Number of Securities | Security		1
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value		$ 2,844
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Unrealized Losses		(131)
Available-for-sale Securities, Continuous Unrealized Loss Position, Total Fair Value		2,844
Available-for-sale Securities, Continuous Unrealized Loss Position, Total Unrealized Losses		$ (131)

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Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for more than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

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