Share Based Compensation Expense (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jul. 02, 2011	Jun. 30, 2012	Jul. 02, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	$ 1.4	$ 2.7	$ 2.2	$ 3.8
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	0.1		0.2
Director Share Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	0.7	0.7	0.7	0.7
Performance-Based RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	0.2	1.0	0.2	1.5
Time-Based RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	$ 0.4	$ 1.0	$ 1.1	$ 1.6