Unaudited Quarterly Results (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Feb. 22, 2019	Nov. 23, 2018	Aug. 24, 2018	May 25, 2018	Feb. 23, 2018	Nov. 24, 2017	Aug. 25, 2017	May 26, 2017	Feb. 22, 2019	Feb. 23, 2018	Feb. 24, 2017
Unaudited Quarterly Results [Abstract]
Gross profit	$ 283.1	$ 278.3	$ 288.6	$ 237.9	$ 252.0	$ 250.8	$ 257.3	$ 245.1	$ 1,087.9	$ 1,005.2	$ 1,007.6
Operating income (loss)	47.0	45.4	67.9	23.3	31.4	36.5	52.2	35.1	183.6	155.2	196.2
Net income	$ 22.6	$ 37.3	$ 49.1	$ 17.0	$ 0.0	$ 25.7	$ 36.9	$ 18.1	$ 126.0	$ 80.7	$ 124.6
Earnings per share, basic	$ 0.19	$ 0.31	$ 0.41	$ 0.14	$ 0.00	$ 0.22	$ 0.31	$ 0.15	$ 1.06	$ 0.68	$ 1.03
Earnings per share, diluted	$ 0.19	$ 0.31	$ 0.41	$ 0.14	$ 0.00	$ 0.22	$ 0.31	$ 0.15	$ 1.05	$ 0.68	$ 1.03
Revenues	$ 912.4	$ 901.0	$ 875.8	$ 754.0	$ 772.7	$ 772.1	$ 775.6	$ 735.1	$ 3,443.2	$ 3,055.5	$ 3,032.4