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Long-Term Borrowings and Subordinated Debt - Additional Information (Details)	Dec. 31, 2020 USD ($) numberOfPrivatePlacements	Dec. 31, 2019 USD ($)
Debt Disclosure [Abstract]
Long-term borrowings at FHLB	$ 22,300,000	$ 49,300,000
Loans pledged as collateral at FHLB	4,100,000,000
Maximum eligible borrowing based on qualifying collateral at FHLB	2,500,000,000
Maximum borrowing capacity at FHLB	$ 2,900,000,000
Number of completed private placements of trust preferred securities | numberOfPrivatePlacements	3
Percentage of equity owned	100.00%

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Number Of Completed Private Placements Of Trust Preferred Securities

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The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

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Amount of the collateral pledged in support of federal home loan bank advances outstanding.

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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 current borrowing capacity under the credit facility considering any current restrictions on the amount that could be borrowed (for example, borrowings may be limited by the amount of current assets), but without considering any amounts currently outstanding under the facility.

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Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

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