Income Taxes - Income Tax Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 28, 2015	Jun. 29, 2014	Jun. 28, 2015	Jun. 29, 2014
Income Tax Disclosure [Abstract]
Income tax expense/(benefit)	$ 11,700	$ (5,743)	$ 2,293	$ (1,979)
Effective income tax rate (percent)	41.90%		56.10%