Loans (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018
Loans [Line Items]
Net deferred loan fees and costs and fair value purchase accounting adjustments	$ 9,100	$ 4,500
Outstanding borrowings from FHLB	674,870	426,326
Accretion to interest income	18,226	16,711
Federal Agency Borrowings
Loans [Line Items]
Loans pledged as collateral	6,800,000	6,100,000
Federal Home Loan Bank Advances
Loans [Line Items]
Loans pledged as collateral	6,400,000
Federal Reserve Bank Advances
Loans [Line Items]
Loans pledged as collateral	359,300
Premium finance receivables
Loans [Line Items]
Unearned income portions of premium finance receivables	$ 118,400	$ 112,900

Amount of accretion recognized for the excess of a loan's cash flows expected to be collected over the investor's initial investment in acquired loans not accounted for as debt securities, with evidence of deterioration of credit quality.

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Including both current and noncurrent portions, Federal Home Loan Bank borrowings initially due beyond one year or beyond the normal operating cycle if longer.

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Amount of deferred interest and fee income, unamortized costs incurred to originate loans and leases, unamortized loan commitments and loan syndication fees, and premiums over or discounts from face amounts of acquired loans. Excludes amounts for loans and leases covered under loss sharing agreements.

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Carrying amount as of the balance sheet date of loans that have been pledged as collateral for borrowings. If the secured party has the right by contract or custom to sell or re-pledge the collateral, then the debtor reclassifies that asset and report that asset in its statement of financial position separately from other assets not so encumbered.

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Loans [Line Items]

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