Benefit Plans (Narrative) (Details) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Jan. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Defined Benefit Plan Disclosure [Line Items]
Term of service completed before eligible for coverage		1 year 1000 hours
Employer Matching Contribution, Percent of Match		100.00%
Maximum Annual Contributions Per Employee, Percent		4.00%
Additional Employer Matching Contribution Percent Of Deferral Match From Eligible Compensation		50.00%
Maximum Additional Annual Contributions Per Employee Deferral Percent		2.00%
Employer Discretionary Contribution Percent		100.00%
Maximum Discretionary Profit Sharing Percent Of Eligible Compensation		2.00%
Related plan expense		$ 494	$ 606	$ 556
Defined Benefit Plan General Guidelines Plan Asset Allocations		25.00%
Defined Benefit Plan, Individual Stock Cap Guildlines Percentage		5.00%
Subsequent Event [Member]
Defined Benefit Plan Disclosure [Line Items]
Term of service completed before eligible for coverage	4 months
Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Plan Asset Allocations Range Minimum		60.00%
Defined Benefit Plan, Target Plan Asset Allocations Range Maximum		90.00%
Equities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Plan Asset Allocations Range Minimum		10.00%
Defined Benefit Plan, Target Plan Asset Allocations Range Maximum		30.00%