Estimated Fair Values (Estimated Fair Values For Certain Financial Assets And Financial Liabilities) (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and due from banks	$ 389,233	$ 376,719
Overnight investments	3,107,575	1,107,844
Debt Securities, Available-for-sale	8,619,282	7,059,674
Investment securities held to maturity at cost	774,878	30,996
Investment in marketable equity securities	114,316	82,333
Loans held for sale	107,900	67,900
Loans and Leases Receivable, Net Amount	32,195,975	28,656,355
Income earned not collected	175,496	123,154
Stock issued by Federal Home Loan Bank	45,400	43,000
Deposits	41,479,245	34,431,236
Securities sold under customer repurchase agreements	740,276	442,956
FDIC shared-loss payable	15,025	112,395
Subordinated Debt	504,246	163,412
Other Borrowings	96,791	148,318
Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Federal Home Loan Bank Advances	657,682	572,185
Cash and due from banks	389,233	376,719
Overnight investments	3,107,575	1,107,844
Debt Securities, Available-for-sale	8,619,282	7,059,674
Investment securities held to maturity at cost	774,878	30,996
Investment in marketable equity securities	114,316	82,333
Loans held for sale	107,881	67,869
Loans and Leases Receivable, Net Amount	32,195,975	28,656,355
Income earned not collected	175,496	123,154
Stock issued by Federal Home Loan Bank	45,392	43,039
Mortgage servicing rights	20,167	24,891
Deposits	38,202,609	30,593,627
Time deposits	3,276,636	3,837,609
Securities sold under customer repurchase agreements	740,276	442,956
FDIC shared-loss payable	15,025	112,395
Accrued interest payable	14,085	18,124
Subordinated Debt	504,246	163,412
Other Borrowings	96,791	148,318
Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Federal Home Loan Bank Advances	679,993	577,362
Cash and due from banks	389,233	376,719
Overnight investments	3,107,575	1,107,844
Debt Securities, Available-for-sale	8,619,282	7,059,674
Investment securities held to maturity at cost	791,325	30,996
Investment in marketable equity securities	114,316	82,333
Loans held for sale	107,881	67,869
Loans and Leases Receivable, Net Amount	32,604,388	28,878,550
Income earned not collected	175,496	123,154
Stock issued by Federal Home Loan Bank	45,392	43,039
Mortgage servicing rights	21,163	26,927
Deposits	38,202,609	30,593,627
Time deposits	3,303,841	3,842,162
Securities sold under customer repurchase agreements	740,276	442,956
FDIC shared-loss payable	15,730	114,252
Accrued interest payable	14,085	18,124
Subordinated Debt	506,089	173,685
Other Borrowings	$ 95,861	$ 149,232

Payable to FDIC for Loss Share Agreements

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Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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For banks and other depository institutions: Includes cash on hand (currency and coin), cash items in process of collection, noninterest bearing deposits due from other financial institutions (including corporate credit unions), and noninterest bearing balances with the Federal Reserve Banks, Federal Home Loan Banks and central banks.

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Amount of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

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Amount of Federal Home Loan Bank (FHLBank) advances to member financial institutions.

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Federal Home Loan Bank (FHLB) stock represents an equity interest in a FHLB. It does not have a readily determinable fair value because its ownership is restricted and it lacks a market (liquidity).

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Amount of investment in debt security measured at amortized cost (held-to-maturity).

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Amount after allowance and deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements and loans held for sale.

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Amount, after the effects of master netting arrangements, of funds outstanding borrowed in the form of a security repurchase agreement between the entity and another party for the sale and repurchase of identical or substantially the same securities at a date certain for a specified price. Includes liabilities not subject to a master netting arrangement and not elected to be offset.

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