Debt Schedule of Short Term Debt (Details) - USD ($)	Dec. 31, 2017	Dec. 31, 2016
Short-term Debt [Line Items]
Federal Home Loan Bank Overnight Advances	$ 105,000,000	$ 123,000,000
Federal Funds Purchased and Securities Sold Under Agreements to Repurchase	64,966,000	35,836,000
Short-term Borrowings	169,966,000	158,836,000
Overnight Advances from the Federal Home Loan Bank of New York [Member]
Short-term Debt [Line Items]
Maximum Borrowing Capacity	511,301,000	445,805,000
Federal Funds Purchased [Member]
Short-term Debt [Line Items]
Maximum Borrowing Capacity	35,000,000	35,000,000
Federal Reserve Bank of New York [Member]
Short-term Debt [Line Items]
Maximum Borrowing Capacity	$ 424,724,000	$ 370,136,000