Investment Securities Schedule of Amortized Cost and Fair Values of Debt Securities by Contractual Maturities (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Amortized Cost
Due in one year or less	$ 9,727
Due from one year to five years	87,566
Due from five years to ten years	340,494
Due after ten years	843,982
Amortized cost, before securities without debt maturities	1,281,769
Amortized Cost	3,544,186
Estimated Fair Value
Due in one year or less	9,548
Due from one year to five years	84,556
Due from five years to ten years	319,163
Due after ten years	734,646
Available for sale securities, debt maturities, before securities without single maturities	1,147,913
Estimated Fair Value	3,313,296	$ 2,398,352
Amortized Cost
Due in one year or less	0
Due from one year to five years	0
Due from five years to ten years	0
Due after ten years	0
Debt securities, held-to-maturity, maturity, allocated and single maturity date, amortized cost, total	0
Amortized Cost, Held to Maturity	1,231,982	1,267,922
Estimated Fair Value
Due in one year or less	0
Due from one year to five years	0
Due from five years to ten years	0
Due after ten years	0
Debt securities, held-to-maturity, maturity, Allocated and single maturity date, fair value	0
Estimated Fair Value, Held to Maturity	1,064,304	1,072,207
Mortgage-Backed Securities [Member]
Amortized Cost
Available-for-sale securities, amortized cost without single maturity date	911,713
Amortized Cost	911,713	223,273
Estimated Fair Value
Available-for-sale securities, debt maturities, without single maturity date, fair value	895,635
Estimated Fair Value	895,635	196,795
Amortized Cost
Debt securities, held-to-maturity, maturity, without single maturity date, amortized cost	373,313
Amortized Cost, Held to Maturity	373,313	407,075
Estimated Fair Value
Debt securities, held-to-maturity, maturity, without single maturity date, fair value	328,926
Estimated Fair Value, Held to Maturity	328,926	355,270
Commercial Mortgage Backed Securities [Member]
Amortized Cost
Available-for-sale securities, amortized cost without single maturity date	604,376
Amortized Cost	604,376	627,364
Estimated Fair Value
Available-for-sale securities, debt maturities, without single maturity date, fair value	520,280
Estimated Fair Value	520,280	534,388
Amortized Cost
Debt securities, held-to-maturity, maturity, without single maturity date, amortized cost	858,669
Amortized Cost, Held to Maturity	858,669	860,847
Estimated Fair Value
Debt securities, held-to-maturity, maturity, without single maturity date, fair value	735,378
Estimated Fair Value, Held to Maturity	735,378	716,937
Collateralized Mortgage Obligations [Member]
Amortized Cost
Available-for-sale securities, amortized cost without single maturity date	746,328
Amortized Cost	746,328	122,824
Estimated Fair Value
Available-for-sale securities, debt maturities, without single maturity date, fair value	749,468
Estimated Fair Value	749,468	$ 111,434
Amortized Cost
Debt securities, held-to-maturity, maturity, without single maturity date, amortized cost	0
Estimated Fair Value
Debt securities, held-to-maturity, maturity, without single maturity date, fair value	$ 0