Fair Value Measurements - Quantitative information about Level 3 measurements for fair value on a recurring basis (Details) $ in Thousands	12 Months Ended
Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt securities available-for-sale	$ 2,274,581	$ 2,628,467
Derivative assets	35,007	24,705
Derivative liabilities	15,516	26,433
Recurring
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	35,007	24,705
Derivative liabilities	15,516	26,433
Recurring \| Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	7,238	11,841
Derivative liabilities	8,559	15,732
Recurring \| Level 3 \| Corporate bonds
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt securities available-for-sale	$ 998	995
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	$ 1,970	$ 1,190
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	0.836	0.807
Recurring \| Level 3 \| Derivative assets - other
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative assets	$ 5,268	$ 10,651
Valuation technique	Dealer priced
Recurring \| Level 3 \| Derivative liabilities - risk participations
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative liabilities	$ 12	$ 8
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	0.0036	0.0044
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	$ 8,547	$ 15,724
Valuation technique	Dealer priced

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

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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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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Description of the valuation processes in place for fair value measurements categorized within Level 3 of the fair value hierarchy.

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