Securities - Equity Securities Unrealized Loss Position (Details) $ in Thousands	Dec. 31, 2017 USD ($) item
Number of securities
Unrealized loss for less than twelve months | item	1
Unrealized loss for twelve months or longer | item	1
Total | item	2
Fair Value
Unrealized loss for less than twelve months	$ 944
Unrealized loss for twelve months or longer	6,800
Total	7,744
Unrealized Losses
Unrealized loss for less than twelve months	13
Unrealized loss for twelve months or longer	103
Total	$ 116