Changes in Accumulated Other Comprehensive Income (Loss) by Component (Detail) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance		$ 1,455.3	$ 1,804.9	$ 2,088.2
Other comprehensive income (loss) before reclassifications		(51.5)	(134.6)	(87.8)
Tax (provision) benefit	[1]	7.8	15.3	12.9
Other comprehensive income (loss) before reclassifications, net of taxes		(43.7)	(119.3)	(74.9)
Reclassifications		20.4	1.0	10.7
Tax provision (benefit)		(4.2)	(0.9)	(3.7)
Reclassifications, net of tax		16.2	0.1	7.0
Other comprehensive income (loss)		(27.5)	(119.2)	(67.9)
Ending Balance		1,675.1	1,455.3	1,804.9
Derivative Instruments Designated as Cash Flow Hedges
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance		(8.7)	0.9	0.0
Other comprehensive income (loss) before reclassifications		(13.3)	(2.6)	2.5
Tax (provision) benefit	[1]	2.7	0.7	(2.0)
Other comprehensive income (loss) before reclassifications, net of taxes		(10.6)	(1.9)	0.5
Reclassifications	[2]	9.8	(11.1)	0.6
Tax provision (benefit)		(0.4)	3.4	(0.2)
Reclassifications, net of tax		9.4	(7.7)	0.4
Other comprehensive income (loss)		(1.2)	(9.6)	0.9
Ending Balance		(9.9)	(8.7)	0.9
Foreign Currency Translation
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance		(94.2)	(3.1)	47.3
Other comprehensive income (loss) before reclassifications		(21.8)	(91.1)	(50.4)
Tax (provision) benefit	[1]	0.0	0.0	0.0
Other comprehensive income (loss) before reclassifications, net of taxes		(21.8)	(91.1)	(50.4)
Reclassifications		0.0	0.0	0.0
Tax provision (benefit)		0.0	0.0	0.0
Reclassifications, net of tax		0.0	0.0	0.0
Other comprehensive income (loss)		(21.8)	(91.1)	(50.4)
Ending Balance		(116.0)	(94.2)	(3.1)
Benefit Plans
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	[3]	(105.1)	(86.6)	(68.2)
Other comprehensive income (loss) before reclassifications	[3]	(16.4)	(40.9)	(39.9)
Tax (provision) benefit	[1],[3]	5.1	14.6	14.9
Other comprehensive income (loss) before reclassifications, net of taxes	[3]	(11.3)	(26.3)	(25.0)
Reclassifications	[3]	10.6	12.1	10.1
Tax provision (benefit)	[3]	(3.8)	(4.3)	(3.5)
Reclassifications, net of tax	[3]	6.8	7.8	6.6
Other comprehensive income (loss)	[3]	(4.5)	(18.5)	(18.4)
Ending Balance	[3]	(109.6)	(105.1)	(86.6)
Accumulated Other Comprehensive Loss
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance		(208.0)	(88.8)	(20.9)
Other comprehensive income (loss)		(27.5)	(119.2)	(67.9)
Ending Balance		$ (235.5)	$ (208.0)	$ (88.8)

[1] Income taxes are not provided for foreign currency translation adjustments.

[2] See Note 6 of the notes to consolidated financial statements.

[3] These components are included in the computation of net periodic pension cost. See Note 12 of the notes to consolidated financial statements.