Fair Value Reconciliation of Changes in Level 3 Balances (Details) - Auction Rate Securities [Member] $ in Millions	3 Months Ended
	May 24, 2019 USD ($)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance at the beginning of the period	$ 3.9
Balance at the end of period	4.0
Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance at the beginning of the period	3.9
Unrealized gain on investments	0.1
Balance at the end of period	$ 4.0