Significant Accounting Policies - Summary of Impacts of ASU on Condensed Consolidated Financial Statements (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Revenue Initial Application Period Cumulative Effect Transition [Line Items]
Net Sales	$ 2,017.6	$ 1,972.4
Selling, general and administrative	785.1	758.2
Operating expenses	1,712.6	1,624.3
Operating Profit	305.0	348.1
Other expense, net	(3.6)	(0.5)
Accounts receivable, less allowance for doubtful accounts	1,418.5		$ 1,544.1
Inventories	2,125.9		2,068.3
Prepaid expenses and other current assets	465.5		428.0
Other current liabilities	$ 1,075.7		1,094.1
As Previously Reported [Member]
Revenue Initial Application Period Cumulative Effect Transition [Line Items]
Net Sales		1,977.3
Selling, general and administrative		760.8
Operating expenses		1,626.9
Operating Profit		350.4
Other expense, net		(2.8)
Accounts receivable, less allowance for doubtful accounts			1,494.6
Inventories			2,081.8
Prepaid expenses and other current assets			414.5
Other current liabilities			1,143.6
ASU 2014-09 [Member] | New Revenue Standard Adjustment [Member]
Revenue Initial Application Period Cumulative Effect Transition [Line Items]
Net Sales		(4.9)
Selling, general and administrative		(4.9)
Operating expenses		(4.9)
Accounts receivable, less allowance for doubtful accounts			49.5
Inventories			(13.5)
Prepaid expenses and other current assets			13.5
Other current liabilities			$ 49.5
ASU 2017-07 [Member] | New Pension Standard Adjustment [Member]
Revenue Initial Application Period Cumulative Effect Transition [Line Items]
Selling, general and administrative		2.3
Operating expenses		2.3
Operating Profit		(2.3)
Other expense, net		$ 2.3