Segment Reporting (Sales Information By Product) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Oct. 29, 2011	Oct. 30, 2010	Oct. 29, 2011	Oct. 30, 2010
Segment Reporting Information [Line Items]
Net sales	$ 856,875	$ 857,414	$ 1,704,297	$ 1,707,201
Consumable And Printed Products [Member]
Segment Reporting Information [Line Items]
Net sales	569,972	547,332	1,144,934	1,133,935
Equipment And Software [Member]
Segment Reporting Information [Line Items]
Net sales	214,025	243,557	413,676	435,778
Other [Member]
Segment Reporting Information [Line Items]
Net sales	$ 72,878	$ 66,525	$ 145,687	$ 137,488