Business Segments (Schedule Of Contributions By Major Customers) (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Wal-Mart Stores Inc. [Member]
Segment Reporting Information [Line Items]
Percentage of revenue contributed by major customers	17.40%	19.00%	17.60%	19.90%
Walgreen Co. [Member]
Segment Reporting Information [Line Items]
Percentage of revenue contributed by major customers	16.00%	14.00%	15.80%	13.40%
The Kroger Company [Member]
Segment Reporting Information [Line Items]
Percentage of revenue contributed by major customers	11.40%	11.20%	11.30%	10.40%