Income Taxes Income Tax Contingencies (Details) - USD ($) $ in Millions	12 Months Ended
	Feb. 22, 2019	Feb. 23, 2018	Feb. 24, 2017
Unrecognized Tax Benefits [Roll Forward]
Unrecognized tax benefits, beginning of period	$ 2.2	$ 2.8	$ 8.6
Gross decreases - tax positions in prior period	0.0	(1.0)	(5.3)
Lapse of statute of limitations	(0.2)	0.4	(0.5)
Unrecognized tax benefits, end of period	$ 2.0	$ 2.2	$ 2.8