Note 11 - Stock-based Compensation (Details Textual) - USD ($) $ / shares in Units, shares in Millions	3 Months Ended		6 Months Ended
	Aug. 26, 2017	Aug. 27, 2016	Aug. 26, 2017	Aug. 27, 2016
Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Stock Options	$ 22,600,000		$ 22,600,000
Allocated Share-based Compensation Expense	15,400,000	$ 16,800,000	36,900,000	$ 37,600,000
Allocated Share-based Compensation Expense, Net of Tax	$ 9,700,000	$ 10,700,000	$ 22,400,000	$ 23,700,000
Stock Based Compensation Expense, Impact On Diluted Earnings Per Share	$ 0.07	$ 0.07	$ 0.16	$ 0.16
Employee Service Share-based Compensation, Allocation of Recognized Period Costs, Capitalized Amount			$ 1,000,000	$ 1,100,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term			4 years 219 days
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value	$ 0		$ 0
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term			3 years 36 days
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Intrinsic Value	0		$ 0
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value			3,900,000	9,000,000
Proceeds from Stock Options Exercised			10,161,000	$ 20,258,000
Employee Service Share-based Compensation, Tax Benefit from Exercise of Stock Options			200,000
Performance Shares [Member]
Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Share-based Awards Other than Options	$ 35,300,000		$ 35,300,000
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition			2 years
Share Based Compensation Arrangement By Share Based Payment Award Target Award Percentage	150.00%		150.00%
Employee Stock Option [Member]
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition			3 years 73 days
Restricted Stock [Member]
Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Share-based Awards Other than Options	$ 159,600,000		$ 159,600,000
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition			4 years 292 days
The 2012 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized	43.2		43.2
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value			$ 9.50	$ 11.87
The 2012 Plan [Member] | Employee Stock Options and Restricted Stock [Member]
Share Based Compensation Arrangement By Share Based Payment Award Award Requisite Service Period Minimum			1 year
Share Based Compensation Arrangement By Share Based Payment Award Award Requisite Service Period Maximum			3 years
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period			5 years
The 2012 Plan [Member] | Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period			4 years
The 2012 Plan [Member] | Performance Shares [Member] | Scenario Assumption [Member]
Share Based Compensation Arrangement By Share Based Payment Award Target Award Percentage	100.00%		100.00%
The 2012 Plan [Member] | Performance Shares [Member] | One-year Performance Period Awards [Member]
Share Based Compensation Arrangement By Share Based Payment Award Award Requisite Service Period Minimum			1 year
Share Based Compensation Arrangement By Share Based Payment Award Award Requisite Service Period Maximum			3 years
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period			4 years
The 2012 Plan [Member] | Performance Shares [Member] | Minimum [Member]
Share Based Compensation Arrangement By Share Based Payment Award Target Award Percentage	0.00%		0.00%
The 2012 Plan [Member] | Employee Stock Option [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period			3 years
The 2012 Plan [Member] | Employee Stock Option [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period			5 years
The 2012 Plan [Member] | Employee Stock Option Issued Since May 10, 2010 [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period			8 years
Share Based Compensation Arrangement By Share Based Payment Award Requisite Service Period			1 year
Share Based Compensation Arrangement By Share Based Payment Award Award Requisite Service Period Minimum			1 year
Share Based Compensation Arrangement By Share Based Payment Award Award Requisite Service Period Maximum			3 years
The 2012 Plan [Member] | Restricted Stock [Member]
Share Based Compensation Arrangement By Share Based Payment Award Award Requisite Service Period Minimum			1 year
Share Based Compensation Arrangement By Share Based Payment Award Award Requisite Service Period Maximum			3 years
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period			5 years