Estimated Fair Values (Estimated Fair Values For Certain Financial Assets And Financial Liabilities) (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and due from banks	$ 454,220	$ 376,719
Overnight investments	688,518	1,107,844
Debt Securities, Available-for-sale	7,789,034	7,059,674
Investment securities held to maturity	740,662	30,996
Investment in marketable equity securities	315,501	82,333
Loans held for sale	76,300	67,900
Loans and Leases Receivable, Net Amount	29,031,700	28,656,355
Income earned not collected	125,626	123,154
Stock issued by Federal Home Loan Bank	51,100	43,000
Deposits	35,346,711	34,431,236
Securities sold under customer repurchase agreements	540,362	442,956
FDIC shared-loss payable	14,737	112,395
Subordinated Debt	504,145	163,412
Other Borrowings	105,303	148,318
Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Federal Home Loan Bank Advances	792,684	572,185
Cash and due from banks	454,220	376,719
Overnight investments	688,518	1,107,844
Debt Securities, Available-for-sale	7,789,034	7,059,674
Investment securities held to maturity	740,662	30,996
Investment in marketable equity securities	315,501	82,333
Loans held for sale	76,347	67,869
Loans and Leases Receivable, Net Amount	29,031,700	28,656,355
Income earned not collected	125,626	123,154
Stock issued by Federal Home Loan Bank	51,087	43,039
Mortgage servicing rights	21,488	24,891
Deposits	35,346,711	34,431,236
Securities sold under customer repurchase agreements	540,362	442,956
FDIC shared-loss payable	14,737	112,395
Accrued interest payable	13,500	18,124
Subordinated Debt	504,145	163,412
Other Borrowings	105,303	148,318
Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Federal Home Loan Bank Advances	829,785	577,362
Cash and due from banks	454,220	376,719
Overnight investments	688,518	1,107,844
Debt Securities, Available-for-sale	7,789,034	7,059,674
Investment securities held to maturity	753,178	30,996
Investment in marketable equity securities	315,501	82,333
Loans held for sale	76,347	67,869
Loans and Leases Receivable, Net Amount	29,565,373	28,878,550
Income earned not collected	125,626	123,154
Stock issued by Federal Home Loan Bank	51,087	43,039
Mortgage servicing rights	22,733	26,927
Deposits	35,382,365	34,435,789
Securities sold under customer repurchase agreements	540,362	442,956
FDIC shared-loss payable	15,674	114,252
Accrued interest payable	13,500	18,124
Subordinated Debt	467,612	173,685
Other Borrowings	$ 105,460	$ 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 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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