Fair Value Level 3 Inputs - (Details)	3 Months Ended
	Jul. 28, 2012
Fair Value Inputs Assets Quantitative Information [Line Items]
Comparitive Bond Discount Rate	0.20%
Discounted Cash Flow Analysis | Level 3
Fair Value Inputs Assets Quantitative Information [Line Items]
Total Term	10 years 4 months 24 days
Auction Rate Securities (ARS) | Discounted Cash Flow Analysis | Level 3
Fair Value Inputs Assets Quantitative Information [Line Items]
ARS Yield	0.28%