Investment Securities - Analysis of the Contractual Maturities of Investment Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Amortized Cost Basis Rolling Maturity[Abstract]
Due in One Year or Less	$ 1,629
Due After One Year Through Five Years	403,241
Due After Five Years Through Ten Years	533,344
Amortized Cost, Total	938,214
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Rolling Maturities [Abstract]
Available-for-Sale: Amortized Cost	2,694,012	$ 3,172,436
Due in One Year or Less	1,608
Due After One Year Through Five Years	376,036
Due After Five Years Through Ten Years	491,553
Fair Value, Total	869,197
Available-for-Sale: Fair Value	2,408,933	2,844,823
Held-to-maturity Securities, Debt Maturities, Single Maturity Date, Amortized Cost Basis, Rolling Maturities (Abstract]
Due in One Year or Less	726
Due After One Year Through Five Years	82,259
Due After Five Years Through Ten Years	60,240
Amortized Cost, Total	143,225
Held-to-Maturity Securities, Debt Maturities, Single Maturity Date, Fair Value, Rolling Maturities [Abstract]
Held-to-Maturity: Amortized Cost	4,997,335
Due in One Year or Less	714
Due After One Year Through Five Years	74,148
Due After Five Years Through Ten Years	51,154
Fair Value, Total	126,016
Held-to-Maturity: Fair Value	4,253,637	4,615,393
Debt Securities Issued by Government Agencies
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Rolling Maturities [Abstract]
Available-for-sale Securities: Amortized Cost	66,069
Available-for-sale Securities, Debt Securities Issued by Government Agencies and Mortgage-Backed Securities: Fair Value	66,359
Residential - Government Agencies
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Rolling Maturities [Abstract]
Available-for-sale Securities: Amortized Cost	713,918
Available-for-Sale: Amortized Cost	713,918	828,798
Available-for-sale Securities, Debt Securities Issued by Government Agencies and Mortgage-Backed Securities: Fair Value	629,327
Available-for-Sale: Fair Value	629,327	732,828
Held-to-Maturity Securities, Debt Maturities, Single Maturity Date, Fair Value, Rolling Maturities [Abstract]
Held-to-Maturity: Mortgage-Backed Securities: Amortized Cost	1,674,076
Held-to-Maturity: Mortgage-Backed Securities: Fair Value	1,408,603
Held-to-Maturity: Fair Value	1,408,603	1,554,227
Residential - U.S. Government-Sponsored Enterprises
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Rolling Maturities [Abstract]
Available-for-sale Securities: Amortized Cost	818,296
Available-for-Sale: Amortized Cost	818,296	919,980
Available-for-sale Securities, Debt Securities Issued by Government Agencies and Mortgage-Backed Securities: Fair Value	709,127
Available-for-Sale: Fair Value	709,127	793,871
Held-to-Maturity Securities, Debt Maturities, Single Maturity Date, Fair Value, Rolling Maturities [Abstract]
Held-to-Maturity: Mortgage-Backed Securities: Amortized Cost	2,744,094
Held-to-Maturity: Mortgage-Backed Securities: Fair Value	2,374,138
Held-to-Maturity: Fair Value	2,374,138	2,571,275
Commercial - Government Agencies - Sponsored Agencies
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Rolling Maturities [Abstract]
Available-for-sale Securities: Amortized Cost	157,515
Available-for-Sale: Amortized Cost	157,515	168,242
Available-for-sale Securities, Debt Securities Issued by Government Agencies and Mortgage-Backed Securities: Fair Value	134,923
Available-for-Sale: Fair Value	134,923	145,667
Held-to-Maturity Securities, Debt Maturities, Single Maturity Date, Fair Value, Rolling Maturities [Abstract]
Held-to-Maturity: Mortgage-Backed Securities: Amortized Cost	435,940
Held-to-Maturity: Mortgage-Backed Securities: Fair Value	344,880
Held-to-Maturity: Fair Value	344,880	361,994
Mortgage-Backed Securities
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Rolling Maturities [Abstract]
Available-for-sale Securities: Amortized Cost	1,689,729
Available-for-Sale: Amortized Cost	1,689,729	1,917,020
Available-for-sale Securities, Debt Securities Issued by Government Agencies and Mortgage-Backed Securities: Fair Value	1,473,377
Available-for-Sale: Fair Value	1,473,377	1,672,366
Held-to-Maturity Securities, Debt Maturities, Single Maturity Date, Fair Value, Rolling Maturities [Abstract]
Held-to-Maturity: Mortgage-Backed Securities: Amortized Cost	4,854,110
Held-to-Maturity: Mortgage-Backed Securities: Fair Value	4,127,621
Held-to-Maturity: Fair Value	$ 4,127,621	$ 4,487,496