Fair Value Measurements (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	May 26, 2012 Discounted cash flow	May 26, 2012 Discounted cash flow Minimum	May 26, 2012 Discounted cash flow Maximum	May 26, 2012 Auction Rate Securities	Feb. 25, 2012 Auction Rate Securities
Fair value inputs quantitative information
Auction rate securities, temporary valuation adjustments				$ 3.1	$ 3.7
Coupon rates (as a percent)		0.14%	0.34%
Estimated redemption period	5 years
Discount rate (as a percent)	1.15%