Derivative Instruments - Derivative Financial Instruments (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Designated as hedging instruments:
Derivative financial instruments
Derivative liabilities	$ 3,274	$ 2,046
Not designated as hedging instruments:
Derivative financial instruments
Derivative assets	7,386	6,519
Derivative liabilities	5,084	6,342
Other Assets | Not designated as hedging instruments: | Interest rate contracts
Derivative financial instruments
Derivative assets	2,391	2,779
Other Assets | Not designated as hedging instruments: | Interest rate lock commitments
Derivative financial instruments
Derivative assets	4,964	3,740
Other Assets | Not designated as hedging instruments: | Forward commitments
Derivative financial instruments
Derivative assets	31	0
Other Liabilities | Designated as hedging instruments: | Interest rate swaps
Derivative financial instruments
Derivative liabilities	3,274	2,046
Other Liabilities | Not designated as hedging instruments: | Interest rate contracts
Derivative financial instruments
Derivative liabilities	2,391	2,779
Other Liabilities | Not designated as hedging instruments: | Interest rate lock commitments
Derivative financial instruments
Derivative liabilities	1	0
Other Liabilities | Not designated as hedging instruments: | Forward commitments
Derivative financial instruments
Derivative liabilities	$ 2,692	$ 3,563