Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 29, 2018	Sep. 30, 2017	Sep. 29, 2018	Sep. 30, 2017	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Income tax benefit	$ 18,827	$ (86,227)	$ (4,179)	$ (51,883)
Effective income tax rate	90.20%	(317.30%)	(2.10%)	(28.80%)
Discrete tax benefit related to fixed assets depreciation tax change					$ 4,000
Unrecognized tax benefits	$ 38,800		$ 38,800
Unrecognized tax benefits that would impact effective tax rate	$ 25,900		$ 25,900