Employee Benefit Plans (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended		12 Months Ended
	Jul. 01, 2012	Jul. 03, 2011	Jul. 01, 2012	Jul. 03, 2011	Dec. 31, 2011
Employee Benefit Plans
Curtailment charges recorded to write-off previously unrecognized prior service costs					$ 1.5
Curtailment adjustment					12.5
Components of net periodic benefit cost
Service cost-benefits earned and administrative costs	0.2	1.3	0.4	2.6
Interest costs on benefits obligation	1.4	1.5	2.8	3.0
Expected return on assets	(1.7)	(1.8)	(3.5)	(3.6)
Prior service costs and net actuarial loss amortization	0.1	0.8	0.3	1.6
Net periodic benefit cost		1.8		3.6
Information related to the Company's pension funds cash flow
Employer contributions			0.4	5.1
Expected employer contributions in next fiscal year	$ 0.3		$ 0.3