Retirement Plans (Weighted-Average Asset Allocation for the Defined Benefit Cash Balance Plan) (Details)
Dec. 31, 2015
Dec. 31, 2014
Defined Benefit Plan Disclosure [Line Items]    
Defined benefit plan, actual plan asset allocations 100.00% 100.00%
Debt Securities [Member]    
Defined Benefit Plan Disclosure [Line Items]    
Defined benefit plan, actual plan asset allocations 33.00% 33.00%
Equity Securities [Member]    
Defined Benefit Plan Disclosure [Line Items]    
Defined benefit plan, actual plan asset allocations 64.00% 64.00%
Other Liabilities [Member]    
Defined Benefit Plan Disclosure [Line Items]    
Defined benefit plan, actual plan asset allocations 3.00% 3.00%