Industry Segments and Geographic Area Information - Geographic Area (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Net Sales:
Net sales	$ 1,144.1	$ 1,179.7	$ 1,166.7	$ 991.2	$ 917.7	$ 950.5	$ 948.3	$ 852.3	$ 4,481.7	$ 3,668.8	$ 3,505.2
Operating Income:
Operating Income									556.9	518.8	489.8
Long-lived Assets:
Long-Lived Assets	3,217.4				2,110.2				3,217.4	2,110.2	1,963.0
United States
Net Sales:
Net sales									4,040.6	3,280.9	3,147.4
Operating Income:
Operating Income									478.0	435.8	431.1
Long-lived Assets:
Long-Lived Assets	2,972.4				1,877.4				2,972.4	1,877.4	1,762.9
International
Net Sales:
Net sales									441.1	387.9	357.8
Operating Income:
Operating Income									78.9	83.0	58.7
Long-lived Assets:
Long-Lived Assets	$ 245.0				$ 232.8				$ 245.0	$ 232.8	$ 200.1