Investment Securities, HTM Credit Quality Indicators (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	$ 3,945,269	$ 2,239,003
US Treasury Securities
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	998	1,000
US States and Political Subdivisions Debt Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	1,717,627	1,628,759
Residential Related Securities | FNMA/FHLMC
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	967,421	34,347
Residential Related Securities | Government National Mortgage Association (GNMA) [Member]
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	42,248	48,053
Mortgage-backed Securities, Issued by Private Enterprises [Member]
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	375,638
Commercial mortgage-related securities | FNMA/FHLMC
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	762,086	425,937
Commercial mortgage-related securities | Government National Mortgage Association (GNMA) [Member]
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	79,250	100,907
Not Rated [Domain]
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	894	896
Not Rated [Domain] | US Treasury Securities
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	0	0
Not Rated [Domain] | US States and Political Subdivisions Debt Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	894	896
Not Rated [Domain] | Residential Related Securities | FNMA/FHLMC
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	0	0
Not Rated [Domain] | Residential Related Securities | Government National Mortgage Association (GNMA) [Member]
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	0	0
Not Rated [Domain] | Mortgage-backed Securities, Issued by Private Enterprises [Member]
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	0
Not Rated [Domain] | Commercial mortgage-related securities | FNMA/FHLMC
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	0	0
Not Rated [Domain] | Commercial mortgage-related securities | Government National Mortgage Association (GNMA) [Member]
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	0	0
AAA
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	3,027,567	1,312,642
AAA | US Treasury Securities
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	998	1,000
AAA | US States and Political Subdivisions Debt Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	799,925	702,399
AAA | Residential Related Securities | FNMA/FHLMC
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	967,421	34,347
AAA | Residential Related Securities | Government National Mortgage Association (GNMA) [Member]
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	42,248	48,053
AAA | Mortgage-backed Securities, Issued by Private Enterprises [Member]
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	375,638
AAA | Commercial mortgage-related securities | FNMA/FHLMC
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	762,086	425,937
AAA | Commercial mortgage-related securities | Government National Mortgage Association (GNMA) [Member]
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	79,250	100,907
AA
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	908,098	914,591
AA | US Treasury Securities
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	0	0
AA | US States and Political Subdivisions Debt Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	908,098	914,591
AA | Residential Related Securities | FNMA/FHLMC
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	0	0
AA | Residential Related Securities | Government National Mortgage Association (GNMA) [Member]
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	0	0
AA | Mortgage-backed Securities, Issued by Private Enterprises [Member]
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	0
AA | Commercial mortgage-related securities | FNMA/FHLMC
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	0	0
AA | Commercial mortgage-related securities | Government National Mortgage Association (GNMA) [Member]
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	0	0
A
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	8,710	10,873
A | US Treasury Securities
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	0	0
A | US States and Political Subdivisions Debt Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	8,710	10,873
A | Residential Related Securities | FNMA/FHLMC
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	0	0
A | Residential Related Securities | Government National Mortgage Association (GNMA) [Member]
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	0	0
A | Mortgage-backed Securities, Issued by Private Enterprises [Member]
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	0
A | Commercial mortgage-related securities | FNMA/FHLMC
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	0	0
A | Commercial mortgage-related securities | Government National Mortgage Association (GNMA) [Member]
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	$ 0	$ 0