Consolidated Balance Sheets (Unaudited) (Parenthetical) (USD $) In Millions, except Share data, unless otherwise specified	Mar. 28, 2013	Dec. 31, 2012
Shareholders' equity
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
VIE Accounts Payable [Member]
Variable Interest Entity Classification [Line Items]
Variable Interest Entity Liabilities	$ 0.5
VIE Accrued Expenses [Member]
Variable Interest Entity Classification [Line Items]
Variable Interest Entity Liabilities	0.7
VIE Property Plant Equipment Net [Member]
Variable Interest Entity Classification [Line Items]
Variable Interest Entity Assets	$ 0.1
Class A [Member]
Shareholders' equity
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	200,000,000	200,000,000
Common stock, shares issued	119,668,567	119,671,298
Class B
Shareholders' equity
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	150,000,000	150,000,000
Common stock, shares issued	24,005,505	24,025,880