Condensed Consolidated Statements of Operations (Unaudited) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Oct. 31, 2011	Oct. 31, 2010	Oct. 31, 2011	Oct. 31, 2010
Condensed Consolidated Statements of Operations [Abstract]
Net sales	$ 1,013.7	$ 905.7	$ 1,854.0	$ 1,650.6
Excise taxes	232.6	207.3	435.1	382.8
Cost of sales	279.2	239.6	496.7	430.2
Gross profit	501.9	458.8	922.2	837.6
Advertising expenses	106.7	93.5	197.5	169.8
Selling, general, and administrative expenses	146.8	132.9	285.9	264.9
Amortization expense	1.3	1.3	2.5	2.5
Other (income) expense, net	0.8	(3.9)	4.1	(7.3)
Operating income	246.3	235.0	432.2	407.7
Interest income	0.7	0.6	1.5	1.0
Interest expense	7.8	6.7	15.7	13.4
Income before income taxes	239.2	228.9	418.0	395.3
Income taxes	81.6	74.9	142.4	129.9
Net income	$ 157.6	$ 154.0	$ 275.6	$ 265.4
Earnings per share:
Basic	$ 1.10	$ 1.06	$ 1.91	$ 1.81
Diluted	$ 1.09	$ 1.05	$ 1.90	$ 1.80
Cash dividends per common share:
Declared			$ 0.64	$ 0.60
Paid	$ 0.32	$ 0.30	$ 0.64	$ 0.60