Derivative Instruments - Gain (loss) recognized on derivatives instruments (Details) - Not designated as hedging - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Gain (loss) recognized on derivative instruments
Gain (loss) recognized on derivatives instruments	$ 224	$ 17	$ 2,374	$ 13
Interest rate lock commitments | Mortgage banking
Gain (loss) recognized on derivative instruments
Gain (loss) recognized on derivatives instruments	(257)	(29)	2,024	(11)
Forward loan sales commitments | Mortgage banking
Gain (loss) recognized on derivative instruments
Gain (loss) recognized on derivatives instruments	(199)	$ 46	454	$ 24
TBA mortgage backed securities | Mortgage banking
Gain (loss) recognized on derivative instruments
Gain (loss) recognized on derivatives instruments	$ 680		$ (104)