Income Taxes - Income Tax Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 27, 2015	Sep. 28, 2014	Sep. 27, 2015	Sep. 28, 2014
Income Tax Disclosure [Abstract]
Income tax expense/(benefit)	$ 3,611	$ (10,247)	$ 5,904	$ (12,226)
Effective income tax rate (percent)	27.80%		34.60%