Investment Securities - Schedule of AFS Debt Securities in an Unrealized Loss Position (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Schedule Of Available For Sale Securities [Line Items]
Less Than 12 Months, Fair Value	$ 8,113	$ 238,023
Less Than 12 Months, Gross Unrealized Losses	(39)	(4,044)
12 Months or Longer, Fair Value	2,192,746	2,089,545
12 Months or Longer, Gross Unrealized Losses	(288,405)	(281,739)
Total Fair Value	2,200,859	2,327,568
Total Gross Unrealized Losses	(288,444)	(285,783)
Debt Securities Issued by the U.S. Treasury and Government Agencies
Schedule Of Available For Sale Securities [Line Items]
Less Than 12 Months, Fair Value	5,468	7,171
Less Than 12 Months, Gross Unrealized Losses	(38)	(16)
12 Months or Longer, Fair Value	154,437	155,341
12 Months or Longer, Gross Unrealized Losses	(10,941)	(11,080)
Total Fair Value	159,905	162,512
Total Gross Unrealized Losses	(10,979)	(11,096)
Debt Securities Issued by States and Political Subdivisions
Schedule Of Available For Sale Securities [Line Items]
Less Than 12 Months, Fair Value		237
Less Than 12 Months, Gross Unrealized Losses		(2)
12 Months or Longer, Fair Value	63,096	63,509
12 Months or Longer, Gross Unrealized Losses	(10,146)	(9,609)
Total Fair Value	63,096	63,746
Total Gross Unrealized Losses	(10,146)	(9,611)
Debt Securities Issued by Government-Sponsored Enterprises
Schedule Of Available For Sale Securities [Line Items]
12 Months or Longer, Fair Value	1,432	1,476
12 Months or Longer, Gross Unrealized Losses	(74)	(80)
Total Fair Value	1,432	1,476
Total Gross Unrealized Losses	(74)	(80)
Debt Securities Issued by Corporations
Schedule Of Available For Sale Securities [Line Items]
Less Than 12 Months, Fair Value	0	220,987
Less Than 12 Months, Gross Unrealized Losses	0	(4,013)
12 Months or Longer, Fair Value	612,417	411,573
12 Months or Longer, Gross Unrealized Losses	(42,193)	(44,430)
Total Fair Value	612,417	632,560
Total Gross Unrealized Losses	(42,193)	(48,443)
Residential - Government Agencies
Schedule Of Available For Sale Securities [Line Items]
Less Than 12 Months, Fair Value	2,645	9,628
Less Than 12 Months, Gross Unrealized Losses	(1)	(13)
12 Months or Longer, Fair Value	571,858	613,926
12 Months or Longer, Gross Unrealized Losses	(87,535)	(84,772)
Total Fair Value	574,503	623,554
Total Gross Unrealized Losses	(87,536)	(84,785)
Residential - U.S. Government-Sponsored Enterprises
Schedule Of Available For Sale Securities [Line Items]
12 Months or Longer, Fair Value	659,245	708,797
12 Months or Longer, Gross Unrealized Losses	(113,153)	(109,176)
Total Fair Value	659,245	708,797
Total Gross Unrealized Losses	(113,153)	(109,176)
Commercial - Government Agencies or Sponsored Agencies
Schedule Of Available For Sale Securities [Line Items]
12 Months or Longer, Fair Value	130,261	134,923
12 Months or Longer, Gross Unrealized Losses	(24,363)	(22,592)
Total Fair Value	130,261	134,923
Total Gross Unrealized Losses	(24,363)	(22,592)
Mortgage-Backed Securities
Schedule Of Available For Sale Securities [Line Items]
Less Than 12 Months, Fair Value	2,645	9,628
Less Than 12 Months, Gross Unrealized Losses	(1)	(13)
12 Months or Longer, Fair Value	1,361,364	1,457,646
12 Months or Longer, Gross Unrealized Losses	(225,051)	(216,540)
Total Fair Value	1,364,009	1,467,274
Total Gross Unrealized Losses	$ (225,052)	$ (216,553)