Assets and Liabilities Measured at Fair Value - Quantitative information about Level 3 fair value measurements for fair value on recurring basis (Details) $ in Thousands	3 Months Ended
Mar. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt securities available-for-sale	$ 2,249,876	$ 2,274,581
Recurring
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Servicing rights for SBA/USDA loans	6,290	6,794
Residential mortgage servicing rights	11,059	13,565
Derivative assets	82,668	35,007
Derivative liabilities	27,349	15,516
Recurring \| Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Servicing rights for SBA/USDA loans	6,290	6,794
Residential mortgage servicing rights	11,059	13,565
Derivative assets	7,361	7,238
Derivative liabilities	2,717	8,559
Recurring \| Level 3 \| Servicing rights for SBA/USDA loans
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Servicing rights for SBA/USDA loans	$ 6,290	$ 6,794
Valuation technique	Discounted cash flow
Recurring \| Level 3 \| Servicing rights for SBA/USDA loans \| Discount Rate \| Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Servicing rights for SBA/USDA loans, measurement input	0.120	0.123
Recurring \| Level 3 \| Servicing rights for SBA/USDA loans \| Prepayment Rate \| Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Servicing rights for SBA/USDA loans, measurement input	0.171	0.165
Recurring \| Level 3 \| Residential mortgage servicing rights
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Residential mortgage servicing rights	$ 11,059	$ 13,565
Valuation technique	Discounted cash flow
Recurring \| Level 3 \| Residential mortgage servicing rights \| Discount Rate \| Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Residential mortgage servicing rights, measurement input	0.100	0.100
Recurring \| Level 3 \| Residential mortgage servicing rights \| Prepayment Rate \| Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Residential mortgage servicing rights, measurement input	0.193	0.141
Recurring \| Level 3 \| Corporate bonds
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt securities available-for-sale	$ 0	$ 998
Valuation technique	Indicative bid provided by a broker
Recurring \| Level 3 \| Derivative assets - mortgage
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	$ 7,361	$ 1,970
Valuation technique	Internal model
Recurring \| Level 3 \| Derivative assets - mortgage \| Pull Through Rate \| Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets, measurement input	0.805	0.836
Recurring \| Level 3 \| Derivative assets - other
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	$ 0	$ 5,268
Valuation technique	Dealer priced
Recurring \| Level 3 \| Derivative liabilities - risk participations
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative liabilities	$ 28	$ 12
Valuation technique	Internal model
Recurring \| Level 3 \| Derivative liabilities - risk participations \| Probable Exposure Rate \| Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative liabilities, measurement input	0.0015	0.0036
Recurring \| Level 3 \| Derivative liabilities - risk participations \| Probability of Default Rate \| Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative liabilities, measurement input	0.0180	0.0180
Recurring \| Level 3 \| Derivative liabilities - other
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative liabilities	$ 2,689	$ 8,547
Valuation technique	Dealer priced

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Residential Mortgage Servicing Asset at Fair Value, Amount

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- Definition

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

+ References

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-Publisher FASB
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Value of input used to measure derivative asset.

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Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and not elected to be offset.

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Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities not subject to a master netting arrangement and not elected to be offset.

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Value of input used to measure derivative liability.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Description of the valuation processes in place for fair value measurements categorized within Level 3 of the fair value hierarchy.

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Fair value of an asset representing net future revenue from contractually specified servicing fees, late charges, and other ancillary revenues, in excess of future costs related to servicing arrangements.

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Value of input used to measure servicing asset.

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