Equity Investments (Summary Of Investment In Joint Venture, Balance Sheet Data) (Details) - WAVE [Member] - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Schedule of Equity Method Investments [Line Items]
Current assets	$ 112.9	$ 96.8
Current assets of discontinued operations	33.8	36.4
Noncurrent assets	34.9	32.6
Current liabilities	113.6	18.1
Current liabilities of discontinued operations	6.9	8.1
Other noncurrent liabilities	$ 293.6	$ 246.6