Stock Option and Stock Award Plan (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	6 Months Ended
	Aug. 30, 2014	Aug. 31, 2013
Stock options and stock award Plans
Stock-based compensation costs	$ 9,892	$ 8,077
Weighted Average Fair Value
Total (in shares)	6,417	7,549
Stock options
Fair value assumptions
Expected stock price volatility (as a percent)	74.00%	85.00%
Expected dividend yield (as a percent)	0.00%	0.00%
Risk-free interest rate (as a percent)	1.70%	1.40%
Expected option life	5 years 6 months	5 years 6 months
Shares
Granted (in shares)	3,113	4,828
Weighted Average Fair Value
Granted (in dollars per share)	$ 4.43	$ 1.91
Unrecognized pre-tax compensation costs related to unvested stock options and restricted stock grants
Unrecognized pre tax costs	23,018
Weighted average amortization period	2 years 10 months 24 days
Stock options | Maximum
Additional General Disclosures
Vesting period	4 years
Restricted stock
Unrecognized pre-tax compensation costs related to unvested stock options and restricted stock grants
Unrecognized pre tax costs	$ 33,348
Weighted average amortization period	2 years 7 months 6 days
Stock awards
Stock awards
Granted (in shares)	3,304	2,721
Weighted Average Fair Value
Granted (in dollars per share)	$ 7.01	$ 2.77
Stock awards | Maximum
Additional General Disclosures
Vesting period	3 years