Segment Information - Revenues, operating profit, total assets, and long-lived assets for Mexico operations $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2017 USD ($)	Sep. 30, 2017 USD ($)	Jun. 30, 2017 USD ($)	Mar. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Sep. 30, 2016 USD ($)	Jun. 30, 2016 USD ($)	Mar. 31, 2016 USD ($)	Dec. 31, 2017 USD ($) segment	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Segment Reporting [Abstract]
Number of principal business segments of Company | segment									5
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	$ 906.4	$ 973.6	$ 905.5	$ 877.3	$ 1,103.8	$ 1,111.7	$ 1,184.9	$ 1,187.9	$ 3,662.8	$ 4,588.3	$ 6,392.7
Total Assets	9,543.2				9,125.3				9,543.2	9,125.3	8,885.9
Operating profit	144.3	$ 153.0	$ 135.2	$ 116.6	163.6	$ 183.6	$ 191.6	$ 203.4	549.1	742.2	1,438.9
Mexico:
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									263.1	317.9	336.6
Total Assets	287.5				319.0				287.5	319.0
Long-Lived Assets	$ 183.2				$ 195.5				183.2	195.5
Operating profit									0.7	59.0	77.1
Mexico: | External
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									111.5	118.9	106.0
Mexico: | Intercompany
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									$ 151.6	$ 199.0	$ 230.6