Valuation and Qualifying Accounts - Allowance for Uncollectible Accounts Receivable (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of period	$ 54.2	$ 59.5	$ 64.9
Charges to costs and expenses	16.7	11.4	7.4
Deductions:
Dispositions	(2.5)	(2.8)	0.1
Uncollectible accounts written off	(9.4)	(9.8)	(8.1)
Foreign currency translation adjustment	(3.3)	(4.1)	(4.8)
Balance at end of period	$ 55.7	$ 54.2	$ 59.5