Basis of Presentation and Summary of Significant Accounting Policies - Schedule of Revision of Balance Sheet (Detail) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Receivables, less allowance for doubtful accounts	$ 1,417.6	$ 1,331.3
Inventories	416.8	386.8
Accounts payable	$ 1,094.7	985.3
As Reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Receivables, less allowance for doubtful accounts		1,354.4
Inventories		379.6
Accounts payable		1,001.2
Adjustments
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Receivables, less allowance for doubtful accounts		(23.1)
Inventories		7.2
Accounts payable		$ (15.9)