TDR's that have subsequent default (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017 USD ($) contract	Dec. 31, 2016 USD ($) contract	Dec. 31, 2015 USD ($) contract
TROUBLED DEBT RESTRUCTURINGS THAT SUBSEQUENTLY DEFAULTED:
Recorded Investment | $	$ 122	$ 249	$ 1,267
Financing Receivable, Modifications, Subsequent Default, Number of Contracts | contract	1	1	7
Commercial And Industrial [Member]
TROUBLED DEBT RESTRUCTURINGS THAT SUBSEQUENTLY DEFAULTED:
Recorded Investment | $	$ 122	$ 0	$ 339
Financing Receivable, Modifications, Subsequent Default, Number of Contracts | contract	1	0	3
Commercial Real Estate [Member]
TROUBLED DEBT RESTRUCTURINGS THAT SUBSEQUENTLY DEFAULTED:
Recorded Investment | $	$ 0	$ 249	$ 502
Financing Receivable, Modifications, Subsequent Default, Number of Contracts | contract	0	1	1
Residential Real Estate [Member]
TROUBLED DEBT RESTRUCTURINGS THAT SUBSEQUENTLY DEFAULTED:
Recorded Investment | $	$ 0		$ 326
Financing Receivable, Modifications, Subsequent Default, Number of Contracts | contract	0		2
Home Equity Line of Credit [Member]
TROUBLED DEBT RESTRUCTURINGS THAT SUBSEQUENTLY DEFAULTED:
Recorded Investment | $	$ 0	$ 0	$ 100
Financing Receivable, Modifications, Subsequent Default, Number of Contracts | contract	0	0	1