Goodwill and Other Intangible Assets (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended		12 Months Ended
	Nov. 29, 2014	Nov. 30, 2013	Nov. 29, 2014	Nov. 30, 2013	Mar. 01, 2014
Goodwill and Other Intangible Assets
Goodwill impairment charges			$ 0
Acquisitions:
Initial goodwill acquired			83,971
Change in purchase price allocation			(7,847)
Balance at end of period	76,124		76,124
Finite-lived intangible assets
Gross Carrying Amount	2,064,756		2,064,756		1,987,377
Accumulated Amortization	(1,644,341)		(1,644,341)		(1,556,150)
Unfavorable lease intangibles	57,305		57,305		62,687
Amortization expense for intangible assets and liabilities	29,399	28,961	87,167	89,767
Anticipated annual amortization expense for intangible assets and liabilities
2015	114,637		114,637
2016	109,355		109,355
2017	96,029		96,029
2018	58,036		58,036
2019	32,007		32,007
Favorable leases and other
Finite-lived intangible assets
Gross Carrying Amount	652,184		652,184		634,320
Accumulated Amortization	(475,460)		(475,460)		(447,608)
Remaining Weighted Average Amortization Period			8 years		9 years
Prescription files
Finite-lived intangible assets
Gross Carrying Amount	1,412,572		1,412,572		1,353,057
Accumulated Amortization	$ (1,168,881)		$ (1,168,881)		$ (1,108,542)
Remaining Weighted Average Amortization Period			3 years		4 years