Retirement Plans (Asset Allocations) (Details)	Dec. 31, 2015	Dec. 31, 2014
Asset category [Abstract]
Weighted average asset allocation (in hundreths)	100.00%	100.00%
Common Stock Securities [Member]
Asset category [Abstract]
Weighted average asset allocation (in hundreths)	47.00%	45.00%
Debt Securities [Member]
Asset category [Abstract]
Weighted average asset allocation (in hundreths)	46.00%	47.00%
Alternative Investments [Member]
Asset category [Abstract]
Weighted average asset allocation (in hundreths)	6.00%	6.00%
Cash and Cash Equivalents [Member]
Asset category [Abstract]
Weighted average asset allocation (in hundreths)	1.00%	2.00%