Derivative Financial Instruments (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Non-hedging derivative financial instruments
Derivative Financial Instruments
Notional or contractual amount	$ 1,081,073	$ 875,806
Asset derivatives, Fair value	29,128	7,236
Liability derivatives, Fair value	29,451	7,385
Interest rate swap contracts
Derivative Financial Instruments
Asset derivatives, Fair value	28,930	7,128
Interest rate swap contracts \| Non-hedging derivative financial instruments
Derivative Financial Instruments
Notional or contractual amount	1,024,739	855,848
Asset derivatives, Fair value	28,930	7,124
Liability derivatives, Fair value	29,434	7,250
Loan commitments \| Non-hedging derivative financial instruments
Derivative Financial Instruments
Notional or contractual amount	18,059	5,871
Asset derivatives, Fair value	198	112
Liability derivatives, Fair value	0	0
Forward contracts - mortgage loan \| Non-hedging derivative financial instruments
Derivative Financial Instruments
Notional or contractual amount	38,275	14,087
Asset derivatives, Fair value	0	0
Liability derivatives, Fair value	$ 17	$ 135

Fair value, before 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 elected not to be offset. Excludes assets not subject to a master netting arrangement.

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Fair value, before 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 elected not to be offset. Excludes liabilities not subject to a master netting arrangement.

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Nominal or face amount used to calculate payment on derivative.

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