Securities (Amortized Cost and Fair Value of Debt Securities by Contractual Maturity) (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Investments, Debt and Equity Securities [Abstract]
Debt Securities Available for Sale, Due in one year or less, Amortized cost	$ 101,999
Debt Securities Available for Sale, Due after one year through five years, Amortized cost	814,705
Debt Securities Available for Sale, Due after five years through ten years, Amortized cost	2,344,169
Debt Securities Available for Sale, Due after ten years, Amortized cost	2,344,976
Securities Available for Sale, Gross Amortized cost	5,605,849	$ 5,496,718
Debt Securities Available for Sale, Due in one year or less, Fair value	101,229
Debt Securities Available for Sale, Due after one year through five years, Fair value	779,834
Debt Securities Available for Sale, Due after five years through ten years, Fair value	2,092,416
Debt Securities Available for Sale, Due after ten years, Fair value	1,991,735
Total available for sale debt securities, Fair value	4,965,214	4,915,195
Debt Securities Held to Maturity, Due in one year or less, Amortized cost	158,621
Debt Securities Held to Maturity, Due after one year through five years, Amortized cost	790,154
Debt Securities Held to Maturity, Due after five years through ten years, Amortized cost	569,629
Debt Securities Held to Maturity, Due after ten years, Amortized cost	1,052,218
Securities Held to Maturity, Gross Amortized cost	2,570,622	2,684,779
Debt Securities Held to Maturity, Due in one year or less, Fair value	156,501
Debt Securities Held to Maturity, Due after one year through five years, Fair value	740,272
Debt Securities Held to Maturity, Due after five years through ten years, Fair value	530,008
Debt Securities Held to Maturity, Due after ten years, Fair value	921,176
Total held to maturity debt securities, Fair value	$ 2,347,957	$ 2,485,918