Industry Segments and Geographic Area Information - Geographic Area (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Net Sales:
Net sales	$ 1,037.9	$ 1,108.6	$ 949.2	$ 1,090.3	$ 1,103.3	$ 1,204.0	$ 1,196.4	$ 1,087.3	$ 4,186.0	$ 4,591.0	$ 4,481.7
Operating Income:
Operating Income									533.0	596.6	556.9
Long-lived Assets:
Long-Lived Assets	3,492.4				3,322.6				3,492.4	3,322.6	3,217.4
United States
Net Sales:
Net sales									3,860.4	4,190.5	4,040.6
Operating Income:
Operating Income									476.2	529.7	478.0
Long-lived Assets:
Long-Lived Assets	3,113.7				2,950.4				3,113.7	2,950.4	2,972.4
International
Net Sales:
Net sales									325.6	400.5	441.1
Operating Income:
Operating Income									56.8	66.9	78.9
Long-lived Assets:
Long-Lived Assets	$ 378.7				$ 372.2				$ 378.7	$ 372.2	$ 245.0