Supplemental Cash Flow Information (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Supplemental Cash Flow Elements [Abstract]
Payments of interest and commitment fees	$ 33.7	$ 39.5
Interest paid, capitalized	0.5	0.7
Incurred liabilities for fixed and intangible asset additions	$ 17.2	$ 13.1