Goodwill and Other Intangibles - Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Feb. 27, 2016	Feb. 28, 2015	Mar. 01, 2014
Finite Lived And Indefinite Lived Intangible Assets By Major Class
Gross Carrying Amount of Finite Lived	$ 2,819,815	$ 2,093,531
Accumulated Amortization	(1,848,936)	(1,672,051)
Net	970,879	421,480
Gross Carrying Amount, Total	2,853,315	2,093,531
Net, Total	1,004,379	421,480
Unfavorable lease intangibles	46,947	55,571
Amortization expense for intangible assets and liabilities	186,816	118,105	$ 119,138
Anticipated annual amortization expense for intangible assets and liabilities
2017	211,622
2018	168,788
2019	131,417
2020	101,961
2021	69,252
Trademarks
Finite Lived And Indefinite Lived Intangible Assets By Major Class
Gross Carrying Amount of Indefinite Lived	33,500
Favorable leases and other
Finite Lived And Indefinite Lived Intangible Assets By Major Class
Gross Carrying Amount of Finite Lived	665,197	653,377
Accumulated Amortization	(507,776)	(481,041)
Net	$ 157,421	$ 172,336
Remaining Weighted Average Amortization Period	8 years	8 years
Prescription files
Finite Lived And Indefinite Lived Intangible Assets By Major Class
Gross Carrying Amount of Finite Lived	$ 1,541,518	$ 1,440,154
Accumulated Amortization	(1,285,633)	(1,191,010)
Net	$ 255,885	$ 249,144
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
Accumulated Amortization	(44,203)
Net	$ 420,797
Remaining Weighted Average Amortization Period	17 years
CMS license
Finite Lived And Indefinite Lived Intangible Assets By Major Class
Gross Carrying Amount of Finite Lived	$ 57,500
Accumulated Amortization	(1,572)
Net	$ 55,928
Remaining Weighted Average Amortization Period	25 years
Claims adjudication and other developed software
Finite Lived And Indefinite Lived Intangible Assets By Major Class
Gross Carrying Amount of Finite Lived	$ 59,000
Accumulated Amortization	(5,760)
Net	$ 53,240
Remaining Weighted Average Amortization Period	7 years
Trademarks
Finite Lived And Indefinite Lived Intangible Assets By Major Class
Gross Carrying Amount of Finite Lived	$ 20,100
Accumulated Amortization	(1,373)
Net	$ 18,727
Remaining Weighted Average Amortization Period	10 years
Backlog
Finite Lived And Indefinite Lived Intangible Assets By Major Class
Gross Carrying Amount of Finite Lived	$ 11,500
Accumulated Amortization	(2,619)
Net	$ 8,881
Remaining Weighted Average Amortization Period	3 years