Derivative Instruments and Balance Sheet Offsetting - Balance Sheet Offsetting (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Offsetting derivative assets
Gross amounts recognized	$ 10,789	$ 8,215
Offsetting derivative liabilities
Gross amounts recognized	8,918	6,359
Interest rate swaps and customer-initiated derivatives
Offsetting derivative assets
Gross amounts recognized	6,355	4,405
Gross amounts offset in the statements of financial condition	0	0
Net amounts presented in the statements of financial position	6,355	4,405
Gross amounts not offset in the statements of financial position
Financial instruments	0	0
Collateral (received)/posted	(450)	0
Net Amount	5,905	4,405
Offsetting derivative liabilities
Gross amounts recognized	6,342	4,141
Gross amounts offset in the statements of financial condition	0	0
Net amounts presented in the statements of financial position	6,342	4,141
Gross amounts not offset in the statements of financial position
Financial instruments	0	0
Collateral (received)/posted	7,506	2,550
Net Amount	$ (1,164)	$ 1,591