Investment Securities, AFS and HTM Expected Maturities (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Amortized Cost
Debt Securities, Available-for-Sale, Amortized Cost, Maturity, Allocated and Single Maturity Date, Year One	$ 6,245
Debt Securities, Available-for-Sale, Amortized Cost, Maturity, Allocated and Single Maturity Date, after Year One Through Five	86,971
Debt Securities, Available-for-Sale, Amortized Cost, Maturity, Allocated and Single Maturity Date, after Year 5 Through 10	248,453
Debt Securities, Available-for-Sale, Amortized Cost, Maturity, Allocated and Single Maturity Date, after Year 10	36,465
Debt Securities, Available-for-sale, Maturity, without Single Maturity Date, Amortized Cost	378,134
Debt Securities, Available-for-Sale, Amortized Cost, Total	2,997,032	$ 4,338,671
Fair Value
Debt Securities, Available-for-Sale, Fair Value, Maturity, Allocated and Single Maturity Date, Year One	6,230
Debt Securities, Available-for-Sale, Fair Value, Maturity, Allocated and Single Maturity Date, after Year One Through Five	81,271
Debt Securities, Available-for-Sale, Fair Value, Maturity, Allocated and Single Maturity Date, after Year 5 Through 10	233,565
Debt Securities, Available-for-Sale, Fair Value, Maturity, Allocated and Single Maturity Date, after Year 10	35,480
Debt Securities, Available-for-Sale, Maturity, without Single Maturity Date, Fair Value	356,546
Total debt securities, AFS Fair Value	$ 2,742,025	4,332,015
Ratio of Fair Value to Amortized Cost, AFS	91.50%
Amortized Cost
Debt Securities, Held-to-Maturity, Amortized Cost, after Allowance for Credit Loss, Maturity, Allocated and Single Maturity Date, Year One	$ 17,660
Debt Securities, Held-to-Maturity, Amortized Cost, after Allowance for Credit Loss, Maturity, Allocated and Single Maturity Date, after Year One through Five	30,135
Debt Securities, Held-to-Maturity, Amortized Cost, after Allowance for Credit Loss, Maturity, Allocated and Single Maturity Date, after Year 5 through 10	156,937
Debt Securities, Held-to-Maturity, Amortized Cost, after Allowance for Credit Loss, Maturity, Allocated and Single Maturity Date, after Year 10	1,528,616
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Amortized Cost	1,733,349
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	3,960,451	2,239,003
Fair Value
Debt Securities, Held-to-Maturity, Fair Value, Maturity, Allocated and Single Maturity Date, Year One	17,621
Debt Securities, Held-to-Maturity, Fair Value, Maturity, Allocated and Single Maturity Date, after Year One Through Five	29,842
Debt Securities, Held-to-Maturity, Fair Value, Maturity, Allocated and Single Maturity Date, after Year 5 Through 10	154,046
Debt Securities, Held-to-Maturity, Fair Value, Maturity, Allocated and Single Maturity Date, after Year 10	1,351,075
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Fair Value	1,552,584
Debt Securities, Held-to-maturity, Fair Value	$ 3,401,018	2,348,664
Ratio of Fair Value to Amortized Cost, HTM	85.90%
Residential Related Securities \| FNMA/FHLMC [Member]
Amortized Cost
Debt Securities, Available-for-Sale, Amortized Cost, Total	$ 1,820,642	2,709,399
Fair Value
Total debt securities, AFS Fair Value	1,604,610	2,691,879
Amortized Cost
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	961,231	34,347
Fair Value
Debt Securities, Held-to-maturity, Fair Value	816,771	36,139
Residential Related Securities \| Government National Mortgage Association (GNMA)
Amortized Cost
Debt Securities, Available-for-Sale, Amortized Cost, Total	502,537	66,189
Fair Value
Total debt securities, AFS Fair Value	497,596	67,780
Amortized Cost
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	52,979	48,053
Fair Value
Debt Securities, Held-to-maturity, Fair Value	49,628	49,631
Commercial Mortgage-Backed Securities [Member] \| FNMA/FHLMC [Member]
Amortized Cost
Debt Securities, Available-for-Sale, Amortized Cost, Total	19,038	357,240
Fair Value
Total debt securities, AFS Fair Value	17,142	350,623
Amortized Cost
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	778,796	425,937
Fair Value
Debt Securities, Held-to-maturity, Fair Value	615,839	419,400
Commercial Mortgage-Backed Securities [Member] \| Government National Mortgage Association (GNMA)
Amortized Cost
Debt Securities, Available-for-Sale, Amortized Cost, Total	115,031	165,439
Fair Value
Total debt securities, AFS Fair Value	110,462	166,799
Amortized Cost
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	69,369	100,907
Fair Value
Debt Securities, Held-to-maturity, Fair Value	62,691	102,506
FFELP asset backed securities
Amortized Cost
Debt Securities, Available-for-Sale, Amortized Cost, Total	157,138	177,974
Fair Value
Total debt securities, AFS Fair Value	151,191	177,325
Amortized Cost
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	0
Fair Value
Debt Securities, Held-to-maturity, Fair Value	0
US Government-sponsored Enterprises Debt Securities [Member]
Amortized Cost
Debt Securities, Available-for-Sale, Amortized Cost, Total	4,512	6,594
Fair Value
Total debt securities, AFS Fair Value	4,477	6,580
Amortized Cost
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	0
Fair Value
Debt Securities, Held-to-maturity, Fair Value	0
Mortgage-Backed Securities, Issued by Private Enterprises [Member]
Amortized Cost
Debt Securities, Available-for-Sale, Amortized Cost, Total	0	332,028
Fair Value
Total debt securities, AFS Fair Value	0	$ 329,724
Amortized Cost
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss	364,728
Fair Value
Debt Securities, Held-to-maturity, Fair Value	$ 303,505

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