Fair Value Measurements Schedule of Level 3 Financial Assets and Liabilities Measured on A Recurring Basis (Details) - Level 3 - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Fair Value Measurement On Nonrecurring Basis Asset And Liabilities Value [Roll Forward]
Beginning balance	$ 6,916	$ 8,482
Loans classified as impaired during the period	3,098	2,832
Specific valuation allowance allocations	(94)	(665)
Fair Value	3,004	2,167
(Additional) reduction in specific valuation allowance allocations	(19)	0
Paydowns, payoffs, other activity	(881)	(3,733)
Ending balance	$ 9,020	$ 6,916