Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 25, 2021	Jun. 26, 2020	Jun. 25, 2021	Jun. 26, 2020
Net loss	$ (105.8)	$ (933.1)	$ (249.7)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent		0.4	0.4	$ (0.9)
Net loss	(105.8)	(933.1)	(249.7)
Other comprehensive income (loss), net of tax:
Currency translation adjustments	0.6	0.8	0.8	(0.3)
Derivatives, net of tax	0.0	0.1	0.0	0.1
Benefit plans, net of tax	(0.3)	(0.5)	(0.4)	(0.7)
Total other comprehensive income (loss), net of tax		0.4	0.4	(0.9)
Comprehensive Income (Loss), Net of Tax, Attributable to Parent, Total	(105.5)	(932.7)	(249.3)	(984.2)
Retained Earnings (Deficit)
Net loss	(105.8)	(933.1)	(249.7)	(983.3)
Net loss	(105.8)	$ (933.1)	$ (249.7)	$ (983.3)
Accumulated Other Comprehensive Loss
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	0.3
Other comprehensive income (loss), net of tax:
Total other comprehensive income (loss), net of tax	$ 0.3