Securities - Additional Information (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017 USD ($) item security	Dec. 31, 2016 USD ($)
Additional Information
The number of holdings of securities of any one issuer other than the U.S. Government and its sponsored entities | security	0
Holdings of securities as percentage of shareholders' equity, considered as threshold for disclosure purpose	10.00%
Number of securities held | security	504
Number of available for sale securities held | item	179
Number of held to maturity securities held | item	325
Number of securities with fair values below amortized cost | security	296
Total unrealized loss for securities 12 months or more | $	$ 6,220
12 Months or More | $	149,999	$ 2,658
Municipals - exempt from Federal tax
Additional Information
12 Months or More | $	$ 19,240	$ 2,046