Stock Based Compensation - Expense Table (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated Share-based Compensation Expense	$ 1,625	$ 1,484	$ 3,423	$ 3,169
Stock Options Compensation Expense [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated Share-based Compensation Expense	216	199	417	384
Nonvested Stock Awards and Restricted Stock Unit Compensation Expense [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated Share-based Compensation Expense	745	759	1,593	1,511
Employee Stock Purchase Plan Compensation Expense [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated Share-based Compensation Expense	20	19	43	37
401 (k) Matching Stock Contribution Plan Compensation Expense [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated Share-based Compensation Expense	587	476	1,276	1,175
Directors Stock Ownership Plan Compensation Expense [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated Share-based Compensation Expense	$ 57	$ 31	$ 94	$ 62