Derivative Instruments and Balance Sheet Offsetting (Balance Sheet Offsetting) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Offsetting derivative assets
Gross amounts recognized	$ 8,215	$ 2,018
Offsetting derivative liabilities
Gross amounts recognized	6,359	$ 1,979
Interest rate swaps and customer-initiated derivatives
Offsetting derivative assets
Gross amounts recognized	4,405
Gross amounts offset in the statements of financial condition	0
Net amounts presented in the statements of financial position	4,405
Gross amounts of assets not offset in the statement of financial position
Financial instruments	0
Collateral (received)/posted	0
Net Amount	4,405
Offsetting derivative liabilities
Gross amounts recognized	4,141
Gross amounts offset in the statements of financial condition	0
Net amounts presented in the statements of financial position	4,141
Gross amounts of liabilities not offset in the statement of financial position
Financial instruments	0
Collateral (received)/posted	2,550
Net Amount	$ 1,591