Debt Schedule of Interest Charges (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Debt Disclosure [Abstract]
Interest incurred	$ 289.2	$ 311.7	$ 351.8
Interest capitalized	(8.3)	(5.5)	(2.5)
Interest expense	$ 280.9	$ 306.2	$ 349.3