Retirement Plans and Profit Sharing Arrangements (Weighted Average Assumptions) (Details 5)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Pension Plans [Member]
Weighted average assumptions used to determine benefit obligations for pension plans
Discount rates (as a percent)	4.01%	3.32%
Rates of increase in compensation levels (as a percent)	4.25%	4.29%
Defined benefit plan, assumptions used calculating benefit obligation, weighted average interest crediting rate	5.00%	5.00%
Weighted average assumptions used to determine net periodic benefit cost for pension plans
Discount rates (as a percent)	3.30%	3.64%	3.67%
Rates of increase in compensation levels (as a percent)	4.29%	4.39%	4.43%
Expected long term rates of return on assets (as a percent)	7.11%	7.13%	6.98%
Defined benefit plan, assumptions used calculating net periodic benefit cost, weighted average interest crediting rate	5.00%	5.00%	5.00%
Other Postretirement Benefits Plan [Member]
Weighted average assumptions used to determine benefit obligations for pension plans
Discount rates (as a percent)	4.11%	3.41%