Income Taxes (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 29, 2015	Sep. 30, 2014	Dec. 30, 2014
Reconciliation unrecognized tax benefits
Income tax benefit	$ 3.9	$ 4.6
Income tax benefit primarily related to federal employment-related tax credits		4.6
Favorable adjustment related to the release of liabilities for uncertain tax positions		0.8
Deferred state income tax expense (benefit)		$ 1.0
Uncertain tax positions	$ 2.7		$ 2.8