Fair Value Hierarchy of Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Millions	Nov. 23, 2018	Feb. 23, 2018	Nov. 24, 2017	Feb. 24, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	$ 51.0	$ 283.1
Assets, Fair Value Disclosure [Abstract]
Cash and Cash Equivalents, Fair Value Disclosure	51.0	283.1
Restricted Cash		2.5	$ 2.5	$ 2.5
Restricted Cash and Cash Equivalents	3.4	2.5
Assets, Fair Value Disclosure	61.2	291.2
Liabilities, Fair Value Disclosure [Abstract]
Foreign exchange forward contracts, Liability, Fair Value Disclosure	(1.0)	(1.4)
Liabilities, Fair Value Disclosure	(1.0)	(1.4)
Foreign Exchange Contract [Member]
Assets, Fair Value Disclosure [Abstract]
Foreign Currency Contract, Asset, Fair Value Disclosure	3.2	2.1
Auction Rate Securities [Member]
Assets, Fair Value Disclosure [Abstract]
Available-for-sale Securities, Fair Value Disclosure	3.6	3.5
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Assets, Fair Value Disclosure [Abstract]
Cash and Cash Equivalents, Fair Value Disclosure		283.1
Restricted Cash	3.4
Restricted Cash and Cash Equivalents		2.5
Assets, Fair Value Disclosure	54.4	285.6
Liabilities, Fair Value Disclosure [Abstract]
Foreign exchange forward contracts, Liability, Fair Value Disclosure	0.0	0.0
Liabilities, Fair Value Disclosure	0.0	0.0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Foreign Exchange Contract [Member]
Assets, Fair Value Disclosure [Abstract]
Foreign Currency Contract, Asset, Fair Value Disclosure	0.0	0.0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Auction Rate Securities [Member]
Assets, Fair Value Disclosure [Abstract]
Available-for-sale Securities, Fair Value Disclosure	0.0	0.0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Assets, Fair Value Disclosure [Abstract]
Cash and Cash Equivalents, Fair Value Disclosure	0.0	0.0
Restricted Cash and Cash Equivalents	0.0	0.0
Assets, Fair Value Disclosure	3.2	2.1
Liabilities, Fair Value Disclosure [Abstract]
Foreign exchange forward contracts, Liability, Fair Value Disclosure	(1.0)	(1.4)
Liabilities, Fair Value Disclosure	(1.0)	(1.4)
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Foreign Exchange Contract [Member]
Assets, Fair Value Disclosure [Abstract]
Foreign Currency Contract, Asset, Fair Value Disclosure	3.2	2.1
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Auction Rate Securities [Member]
Assets, Fair Value Disclosure [Abstract]
Available-for-sale Securities, Fair Value Disclosure	0.0	0.0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Assets, Fair Value Disclosure [Abstract]
Cash and Cash Equivalents, Fair Value Disclosure	0.0	0.0
Restricted Cash and Cash Equivalents	0.0	0.0
Assets, Fair Value Disclosure	3.6	3.5
Liabilities, Fair Value Disclosure [Abstract]
Foreign exchange forward contracts, Liability, Fair Value Disclosure	0.0	0.0
Liabilities, Fair Value Disclosure	0.0	0.0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Foreign Exchange Contract [Member]
Assets, Fair Value Disclosure [Abstract]
Foreign Currency Contract, Asset, Fair Value Disclosure	0.0	0.0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Auction Rate Securities [Member]
Assets, Fair Value Disclosure [Abstract]
Available-for-sale Securities, Fair Value Disclosure	$ 3.6	$ 3.5