Employee Benefit Plans (Actuarial Assumptions) (Details)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Retirement Benefits [Abstract]
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	3.69%	4.28%
Discount rate (percent)	4.28%	4.54%	3.81%
Effective rate for interest on benefit obligation (percent)	3.49%	3.77%	3.81%
Expected return on plan assets (percent)	8.00%	8.00%	8.00%
Cumulative Gains and Losses Amortization Period Limit	12 years