Defined Benefit Pension Plans Actuarial Assumptions (Details)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined benefit plan disclosure [Line Items]
Discount rate	4.35%	3.70%	4.20%
Expected long-term rate of return on plan assets	2.50%	2.50%	5.00%
Fixed income and cash [Member]
Defined benefit plan disclosure [Line Items]
Defined benefit plan, target plan asset allocations		100.00%
Fixed Income Investments [Member]
Defined benefit plan disclosure [Line Items]
Defined benefit plan, target plan asset allocations		5.00%
Minimum [Member]
Defined benefit plan disclosure [Line Items]
Defined benefit plan, risk management practices, investment evaluation period	3 years
Minimum [Member] | Equity securities [Member]
Defined benefit plan disclosure [Line Items]
Defined benefit plan, target plan asset allocations		20.00%
Minimum [Member] | Fixed income and cash [Member]
Defined benefit plan disclosure [Line Items]
Defined benefit plan, target plan asset allocations		50.00%
Minimum [Member] | Alternative investments [Member]
Defined benefit plan disclosure [Line Items]
Defined benefit plan, target plan asset allocations		0.00%
Maximum [Member]
Defined benefit plan disclosure [Line Items]
Defined benefit plan, risk management practices, investment evaluation period	5 years
Maximum [Member] | Equity securities [Member]
Defined benefit plan disclosure [Line Items]
Defined benefit plan, target plan asset allocations		40.00%
Maximum [Member] | Fixed income and cash [Member]
Defined benefit plan disclosure [Line Items]
Defined benefit plan, target plan asset allocations		70.00%
Maximum [Member] | Alternative investments [Member]
Defined benefit plan disclosure [Line Items]
Defined benefit plan, target plan asset allocations		15.00%