Pension Plans (Other Plans) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Actual return on pension plan assets	22.10%
Maximize return	43.50%
Liquidity	56.50%
Defined contribution, maximum contribution limit	5.00%
Qualified Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Expected return on plan assets	7.50%	7.50%
Managers’ securities holdings percentage maximum limit of total market value	7.50%
Continuing Operations [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined contribution plan, employer contributions	$ 7.1	$ 6.8	$ 6.5
Discontinued Operations, Disposed of by Sale [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined contribution plan, employer contributions	4.5	$ 6.3	$ 6.1
Pension Costs [Member]
Payment for Pension and Other Postretirement Benefits [Abstract]
Accrual for payments due to customer under agreement	$ 0.3