Derivative Instruments and Hedging Activities - Schedule of Derivative Instruments (Details) - Not Designated as Hedging Instrument - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Derivative Asset [Abstract]
Notional Amount	$ 491,453	$ 404,928
Fair Value	23,499	12,621
Derivative Liability [Abstract]
Notional Amount	453,406	370,477
Fair Value	23,406	12,551
Customer derivatives – interest rate swaps
Derivative Asset [Abstract]
Notional Amount	452,558	369,623
Fair Value	23,405	12,550
Derivative Liability [Abstract]
Notional Amount	452,558	369,623
Fair Value	23,404	12,549
RPAs sold
Derivative Asset [Abstract]
Notional Amount	0	0
Fair Value	0	0
Derivative Liability [Abstract]
Notional Amount	848	854
Fair Value	2	2
RPAs purchased
Derivative Asset [Abstract]
Notional Amount	35,141	35,305
Fair Value	87	71
Derivative Liability [Abstract]
Notional Amount	0	0
Fair Value	$ 0	$ 0