Retirement Benefit Plans (Schedule of Assumptions Used) (Details)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Defined Benefit Plan Disclosure [Line Items]
Net periodic pension expense, rate of compensation increase	3.00%	3.00%
Supplemental Employee Retirement Plans, Defined Benefit
Defined Benefit Plan Disclosure [Line Items]
Discount rate	4.05%	3.70%
Composite rate of compensation increase	3.00%	3.00%
Net periodic pension expense, discount rate	3.70%	4.60%
Hourly Employees’ Pension Plan | Pension Plans, Defined Benefit
Defined Benefit Plan Disclosure [Line Items]
Discount rate	4.30%	4.00%
Net periodic pension expense, discount rate	4.00%	4.60%
Net periodic pension expense, Long-term rate of return on plan assets	7.25%	7.25%
Employees’ Retirement Plan | Pension Plans, Defined Benefit
Defined Benefit Plan Disclosure [Line Items]
Discount rate	4.40%	4.10%
Net periodic pension expense, discount rate	4.10%	4.75%
Net periodic pension expense, Long-term rate of return on plan assets	7.25%	7.25%