Loans - Concentrations and Restrictions (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017
Consumer \| Consumer Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Concentration risk, percentage	23.00%
Consumer \| Residential Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Concentration risk, percentage	24.00%
Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loans	$ 20,545,198	$ 20,271,968
Loans pledged to secure potential borrowings	6,100,000
Commercial \| Finance And Insurance Companies
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loans	$ 2,800,000
Percentage of commercial & industrial loan portfolio	17.00%
Percentage contributed in total loan	10.00%
Commercial \| Loans To Mortgage Companies
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loans	$ 2,000,000
Percentage of commercial & industrial loan portfolio	12.00%
Percentage contributed in total loan	7.00%
Commercial \| Finance Insurance And Loans To Mortgage Companies
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage of commercial & industrial loan portfolio	29.00%

Bank-related and TRUPs loans divided by total loan portfolio.

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- Definition

Percentage of Commercial And Industrial Loan Portfolio

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No definition available.

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For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

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Amount, before allowance and fees, of loans and leases receivable. Excludes 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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