Borrowed Funds (Borrowed funds obligations) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Schedule of Debt [Line Items]
Borrowed funds	$ 318,596		$ 318,596		$ 309,732
Borrowed funds, Rate	1.58%		1.58%		1.50%
Securities Sold under Agreements to Repurchase [Member]
Schedule of Debt [Line Items]
Short-term Debt, Maximum Month-end Outstanding Amount	$ 57,032	$ 67,599	$ 61,783	$ 84,859
Short Term Debt Weighted Average Interest Rates	0.13%	0.13%	0.13%	0.13%
Borrowed funds	$ 53,596		$ 53,596		$ 70,532
Borrowed funds, Rate	0.13%		0.13%		0.12%
Short-term Debt, Average Outstanding Amount	$ 56,010	$ 63,294	$ 58,531	$ 71,129
Federal Funds Purchased [Member]
Schedule of Debt [Line Items]
Short-term Debt, Maximum Month-end Outstanding Amount	$ 11,800	$ 12,600	$ 11,800	$ 12,600
Short Term Debt Weighted Average Interest Rates	0.69%	0.52%	0.69%	0.50%
Borrowed funds	$ 0		$ 0		$ 4,200
Borrowed funds, Rate	0.00%		0.00%		0.75%
Short-term Debt, Average Outstanding Amount	$ 12,294	$ 5,770	$ 8,495	$ 5,738
Federal Home Loan Bank Advances [Member]
Schedule of Debt [Line Items]
Borrowed funds	$ 265,000		$ 265,000		$ 235,000
Borrowed funds, Rate	1.87%		1.87%		1.93%