Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Mar. 30, 2013	Dec. 29, 2012
Assets:
Property, plant and equipment, accumulated depreciation	$ 336,637	$ 326,201
Intangible assets, accumulated amortization	$ 80,034	$ 73,021
Stockholders' equity:
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	150,000,000	150,000,000
Common stock, shares issued	119,148,005	118,622,650
Treasury stock, shares	955,397	807,659