Derivative Financial Instruments - Carrying Amount and Adjustment (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amortized cost, at fair value	$ 608,567	$ 546,640
Derivatives designated as hedging instruments
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amortized cost, at fair value	88,200
Loans | Derivatives designated as hedging instruments
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Carrying amount of the hedged assets	494,019	474,957
Cumulative amount of fair value hedging adjustment included in the carrying amount of the hedged assets	44,586	21,440
Securities available-for-sale | Derivatives designated as hedging instruments
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Carrying amount of the hedged assets	152,551	151,538
Cumulative amount of fair value hedging adjustment included in the carrying amount of the hedged assets	$ 6,790	$ 2,802