Stockholders' Equity - Accumulated Other Comprehensive Loss (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Dec. 30, 2012	Mar. 25, 2012
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total accumulated other comprehensive loss	$ (0.7)	$ (0.8)	$ (0.2)
Reclassifications from other comprehensive income	0
Cumulative translation adjustment
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total accumulated other comprehensive loss	(0.2)		0.1
Post retirement benefit reserve adjustment net of tax expense
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total accumulated other comprehensive loss	$ (0.5)		$ (0.3)