Share-Based Compensation - Share Based Compensation Expense (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 29, 2012	Oct. 01, 2011	Sep. 29, 2012	Oct. 01, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	$ 1.3	$ (1.6)	$ 3.5	$ 2.2
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	0.1		0.3
Director Share Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense			0.7	0.7
Performance-Based RSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	0.2	(2.7)	0.4	(1.2)
Time-Based RSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	$ 1.0	$ 1.1	$ 2.1	$ 2.7