Employee Benefit Plans - Schedule of Components of Net Pension and Post-retirement Expense (Details) - USD ($) $ in Millions	4 Months Ended
	Jun. 16, 2018	Jun. 17, 2017
Pension
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Estimated return on plan assets	$ (34.6)	$ (36.8)
Service cost	16.1	15.3
Interest cost	26.4	27.1
Amortization of prior service cost	0.0	0.1
Amortization of unrecognized loss	(1.9)	0.1
Net expense	6.0	5.8
Other post-retirement benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Estimated return on plan assets	0.0	0.0
Service cost	0.3	0.3
Interest cost	0.2	0.3
Amortization of prior service cost	1.1	1.1
Amortization of unrecognized loss	(0.1)	0.0
Net expense	$ 1.5	$ 1.7