Benefit Plans (Schedule of Allocation of Plan Assets) (Details)	Dec. 31, 2015	Dec. 31, 2014
Defined Benefit Plan Disclosure [Line Items]
Percentage of Plan Assets on Measurement Date	100.00%	100.00%
Cash and domestic money market funds
Defined Benefit Plan Disclosure [Line Items]
Percentage of Plan Assets on Measurement Date	1.95%	1.49%
U.S. Treasury obligations
Defined Benefit Plan Disclosure [Line Items]
Percentage of Plan Assets on Measurement Date	2.40%	1.97%
U.S. Government agencies
Defined Benefit Plan Disclosure [Line Items]
Percentage of Plan Assets on Measurement Date	1.08%	1.12%
Corporate bonds
Defined Benefit Plan Disclosure [Line Items]
Percentage of Plan Assets on Measurement Date	2.74%	2.79%
Common stocks
Defined Benefit Plan Disclosure [Line Items]
Percentage of Plan Assets on Measurement Date	14.30%	13.54%
Equity mutual funds
Defined Benefit Plan Disclosure [Line Items]
Percentage of Plan Assets on Measurement Date	17.61%	18.85%
Fixed income mutual funds
Defined Benefit Plan Disclosure [Line Items]
Percentage of Plan Assets on Measurement Date	49.62%	50.11%
Foreign mutual funds
Defined Benefit Plan Disclosure [Line Items]
Percentage of Plan Assets on Measurement Date	10.30%	10.13%