Summary Adoption of New Accounting Standard Impact on Balance Sheet (Detail) - USD ($) $ in Millions		Sep. 30, 2018	Jan. 01, 2018		Dec. 31, 2017
Assets
Inventories, net		$ 758.7			$ 704.3
Other current assets		258.3			197.0
Equity
Retained Earnings		2,189.7			4,079.2
ASU 2014-09
Assets
Inventories, net		758.7	$ 841.8	[1]	859.1	[1]
Other current assets		271.2	250.9	[1]	228.9	[1]
Equity
Retained Earnings		2,189.7	4,082.5	[1]	$ 4,079.2	[1]
ASU 2014-09 | Balances without adoption of ASC 606
Assets
Inventories, net		774.1
Other current assets		251.9
Equity
Retained Earnings		2,187.0
ASU 2014-09 | Effect of Changes
Assets
Inventories, net		(15.4)
Other current assets		19.3
Equity
Retained Earnings		$ 2.7
ASU 2014-09 | Adjustments due to ASC 606
Assets
Inventories, net	[1]		(17.3)
Other current assets	[1]		22.0
Equity
Retained Earnings	[1]		$ 3.3

[1] Impact at adoption which included both continuing and discontinued operations.