Accumulated Other Comprehensive Loss (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Beginning Balance	$ (200.9)		$ (150.3)		$ (157.9)
Unrealized gains (losses)	(1.5)		(8.3)		7.4
Reclassifications into net income					1.7	[1]
Amortization of pension related costs	9.4	[2],[3],[4]	3.6	[2],[3]	5.4	[2],[3]
Pension re-measurement	(15.4)	[5]	(45.9)	[5]	(8.4)	[5]
Pension curtailment gain	0.2	[6]			1.5	[7]
Ending Balance	(208.2)		(200.9)		(150.3)
Actuarial (Loss) Gain on Post-Retirement Benefits [Member]
Beginning Balance	(225.6)		(183.2)		(181.6)
Unrealized gains (losses)
Reclassifications into net income						[1]
Amortization of pension related costs	9.4	[3],[4]	3.5	[3]	5.3	[3]
Pension re-measurement	(15.4)		(45.9)		(8.4)
Pension curtailment gain	0.1	[6]			1.5	[7]
Ending Balance	(231.5)		(225.6)		(183.2)
Foreign Currency Translation [Member]
Beginning Balance	24.8		33.1		25.7
Unrealized gains (losses)	(1.5)		(8.3)		7.4
Reclassifications into net income						[1]
Amortization of pension related costs		[3],[4]		[3]		[3]
Pension re-measurement
Pension curtailment gain		[6]				[7]
Ending Balance	23.3		24.8		33.1
Prior Service Cost on Post-Retirement Benefits [Member]
Beginning Balance	(0.1)		(0.2)		(0.3)
Unrealized gains (losses)
Reclassifications into net income						[1]
Amortization of pension related costs		[3],[4]	0.1	[3]	0.1	[3]
Pension re-measurement
Pension curtailment gain	0.1	[6]				[7]
Ending Balance			(0.1)		(0.2)
Designated as Hedging Instrument [Member]
Beginning Balance					(1.7)
Unrealized gains (losses)
Reclassifications into net income					1.7	[1]
Amortization of pension related costs		[3],[4]		[3]		[3]
Pension re-measurement
Pension curtailment gain		[6]				[7]
Ending Balance

[1] Amounts related to "Deferred Loss - Hedging" in 2010 represent (1) the reclassification of an unrecognized loss of $0.8 million on the 2008 Interest Rate Swap prior to its expiration in April 2010 from Accumulated Other Comprehensive Loss into earnings due to the discontinuance of hedge accounting as a result of the 2010 refinancing of the 2006 bank term loan facility (see Note 12, "Financial Instruments") and (2) the reversal of amounts recorded in Accumulated Other Comprehensive Loss pertaining to the net settlement payment of $0.9 million on the 2008 Interest Rate Swap.

[2] Net of tax of $(1.0) million, $(2.0) million and nil for the years ended December 31, 2012, 2011 and 2010, respectively.

[3] Amounts represent the change in Accumulated Other Comprehensive Loss as a result of the amortization of unrecognized prior service costs and actuarial losses (gains) arising during each year related to the Company's pension and other post-retirement plans. (See Note 15, "Savings Plan, Pension and Post-retirement Benefits").

[4] Included in this amount is a $2.0 million reclassification adjustment recorded in the first quarter of 2012 related to deferred taxes on the amortization of actuarial losses.

[5] Net of tax of $7.2 million, $30.1 million and nil for the years ended December 31, 2012, 2011 and 2010, respectively.

[6] As a result of the September 2012 Program, the Company recognized a curtailment gain of $1.7 million, partially offset by $0.1 million of accumulated actuarial losses and $0.1 million of prior service costs previously reported within Accumulated Other Comprehensive Loss, for a net gain of $1.5 million, which was recorded within restructuring charges for the year ended December 31, 2012. (See Note 15, "Savings Plan, Pension and Post-retirement Benefits").

[7] The Company recognized a $1.5 million curtailment gain in 2010, primarily in connection with the amendments to its Canadian defined benefit pension plan in 2010, which reduced pension liability and was recorded as an offset against the net actuarial losses previously reported within Accumulated Other Comprehensive Loss. (See Note 15, "Savings Plan, Pension and Post-retirement Benefits").