Goodwill and Other Intangible Assets - Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 04, 2017	Feb. 27, 2016	Feb. 28, 2015
Finite Lived And Indefinite Lived Intangible Assets By Major Class
Gross Carrying Amount of Finite Lived	$ 2,862,005	$ 2,819,815
Accumulated Amortization	(2,059,710)	(1,848,936)
Net	802,295	970,879
Gross Carrying Amount, Total	2,895,505	2,853,315
Net, Total	835,795	1,004,379
Unfavorable lease intangibles	38,242	46,947
Amortization expense for intangible assets and liabilities	222,150	186,816	$ 118,105
Anticipated annual amortization expense for intangible assets and liabilities
2018	180,560
2019	143,150
2020	113,607
2021	80,891
2022	51,883
Trademarks
Finite Lived And Indefinite Lived Intangible Assets By Major Class
Gross Carrying Amount of Indefinite Lived	33,500	33,500
Favorable leases and other
Finite Lived And Indefinite Lived Intangible Assets By Major Class
Gross Carrying Amount of Finite Lived	664,670	665,197
Accumulated Amortization	(531,022)	(507,776)
Net	$ 133,648	$ 157,421
Remaining Weighted Average Amortization Period	7 years	8 years
Prescription files
Finite Lived And Indefinite Lived Intangible Assets By Major Class
Gross Carrying Amount of Finite Lived	$ 1,584,240	$ 1,541,518
Accumulated Amortization	(1,390,139)	(1,285,633)
Net	$ 194,101	$ 255,885
Remaining Weighted Average Amortization Period	3 years	3 years
Customer relationships
Finite Lived And Indefinite Lived Intangible Assets By Major Class
Gross Carrying Amount of Finite Lived	$ 465,000	$ 465,000
Accumulated Amortization	(110,653)	(44,203)
Net	$ 354,347	$ 420,797
Remaining Weighted Average Amortization Period	16 years	17 years
CMS license
Finite Lived And Indefinite Lived Intangible Assets By Major Class
Gross Carrying Amount of Finite Lived	$ 57,500	$ 57,500
Accumulated Amortization	(3,872)	(1,572)
Net	$ 53,628	$ 55,928
Remaining Weighted Average Amortization Period	24 years	25 years
Claims adjudication and other developed software
Finite Lived And Indefinite Lived Intangible Assets By Major Class
Gross Carrying Amount of Finite Lived	$ 58,995	$ 59,000
Accumulated Amortization	(14,188)	(5,760)
Net	$ 44,807	$ 53,240
Remaining Weighted Average Amortization Period	6 years	7 years
Trademarks
Finite Lived And Indefinite Lived Intangible Assets By Major Class
Gross Carrying Amount of Finite Lived	$ 20,100	$ 20,100
Accumulated Amortization	(3,383)	(1,373)
Net	$ 16,717	$ 18,727
Remaining Weighted Average Amortization Period	9 years	10 years
Backlog
Finite Lived And Indefinite Lived Intangible Assets By Major Class
Gross Carrying Amount of Finite Lived	$ 11,500	$ 11,500
Accumulated Amortization	(6,453)	(2,619)
Net	$ 5,047	$ 8,881
Remaining Weighted Average Amortization Period	2 years	3 years