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Investment Securities, Equity Securities with Readily Determinable Fair Values and Other Investments (Details) - USD ($)	Mar. 31, 2023	Dec. 31, 2022
Held-to-maturity securities
Amortized cost	$ 3,400,000	$ 3,400,000
Estimated fair value	3,400,000	3,400,000
Carrying Value	3,400,000	3,400,000
Available-for-sale securities
Amortized cost	5,397,131,000	5,018,996,000
Estimated fair value, Available for sale securities	4,859,818,000	4,417,796,000
Total Amortized cost	5,397,131,000	5,018,996,000
Total Gross unrealized gains	6,774,000	4,072,000
Total Gross unrealized losses	544,087,000	605,272,000
Collateral Pledged
Available-for-sale securities
Amortized cost	1,428,702,000
Estimated Fair Value
Available-for-sale securities
Available for sale debt securities and equity securities	4,859,818,000	4,417,796,000
Reported Value Measurement
Available-for-sale securities
Available for sale debt securities and equity securities	4,859,818,000	4,417,796,000
US Treasury Securities
Available-for-sale securities
Amortized cost	49,967,000	49,752,000
Gross unrealized losses	(42,000)	(359,000)
US Treasury Securities | Estimated Fair Value
Available-for-sale securities
Estimated fair value, Available for sale securities	49,925,000	49,393,000
US Treasury Securities | Reported Value Measurement
Available-for-sale securities
Estimated fair value, Available for sale securities	49,925,000	49,393,000
Residential mortgage-backed securities
Available-for-sale securities
Amortized cost	5,184,217,000	4,805,735,000
Gross unrealized gains	5,289,000	3,145,000
Gross unrealized losses	(542,277,000)	(599,668,000)
Residential mortgage-backed securities | Estimated Fair Value
Available-for-sale securities
Estimated fair value, Available for sale securities	4,647,229,000	4,209,212,000
Residential mortgage-backed securities | Reported Value Measurement
Available-for-sale securities
Estimated fair value, Available for sale securities	4,647,229,000	4,209,212,000
US Government Corporations and Agencies Securities [Member]
Available-for-sale securities
Estimated fair value, Available for sale securities	810,907,000	681,121,000
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Available-for-sale securities
Estimated fair value, Available for sale securities	3,836,322,000	3,528,091,000
States and political subdivisions
Available-for-sale securities
Amortized cost	162,947,000	163,509,000
Gross unrealized gains	1,485,000	927,000
Gross unrealized losses	(1,768,000)	(5,245,000)
States and political subdivisions | Estimated Fair Value
Available-for-sale securities
Estimated fair value, Available for sale securities	162,664,000	159,191,000
States and political subdivisions | Reported Value Measurement
Available-for-sale securities
Estimated fair value, Available for sale securities	162,664,000	159,191,000
Other Debt Obligations
Held-to-maturity securities
Amortized cost	3,400,000	3,400,000
Estimated fair value	3,400,000	3,400,000
Carrying Value	$ 3,400,000	$ 3,400,000

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Amount of debt securities categorized neither as held-to-maturity nor trading and equity securities measured at fair value with change in fair value recognized in net income (FV-NI).

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