Employee Benefits (Weighted Average Assumptions Used to Calculate Net Period Benefit Costs- Retirement Plans) (Details)		12 Months Ended
	Jan. 01, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Net Periodic Benefit Costs | Retirement Income Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Expected long-term return on plan assets		7.50%	7.00%	7.00%
Rate of compensation increase		4.50%	4.50%	4.50%
Net Periodic Benefit Costs | Excess Benefit Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Rate of compensation increase		4.50%	4.50%	4.50%
Subsequent Event | Retirement Income Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Expected long-term return on plan assets	7.50%
Benefit Obligation | Net Periodic Benefit Costs | Retirement Income Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount Rate		3.77%	4.30%	4.57%
Benefit Obligation | Net Periodic Benefit Costs | Supplemental Employee Retirement Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount Rate		3.40%	3.76%	3.99%
Benefit Obligation | Net Periodic Benefit Costs | Excess Benefit Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount Rate		3.81%	4.35%	4.63%
Service cost | Net Periodic Benefit Costs | Retirement Income Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount Rate		3.86%	4.51%	4.83%
Service cost | Net Periodic Benefit Costs | Excess Benefit Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount Rate		3.89%	4.52%	4.87%
Interest cost | Net Periodic Benefit Costs | Retirement Income Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount Rate		3.40%	3.70%	3.86%
Interest cost | Net Periodic Benefit Costs | Supplemental Employee Retirement Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount Rate		2.84%	2.94%	3.04%
Interest cost | Net Periodic Benefit Costs | Excess Benefit Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount Rate		3.48%	3.78%	3.90%