CONDENSED CONSOLIDATED STATEMENTS OF INCOME - UNAUDITED (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Oct. 31, 2012	Oct. 31, 2011	Oct. 31, 2012	Oct. 31, 2011
CONDENSED CONSOLIDATED STATEMENTS OF INCOME [Abstract]
Revenue	$ 431,755	$ 446,985	$ 842,489	$ 877,054
Costs and Expenses
Cost of sales	129,554	132,667	256,798	262,341
Operating and administrative expenses	223,990	233,315	453,976	464,484
Restructuring charges	0	0	4,841	0
Impairment of consumer publishing programs	15,521	0	15,521	0
Amortization of intangibles	9,578	9,016	19,246	18,090
Total Costs and Expenses	378,643	374,998	750,382	744,915
Gain on Sale of Travel Publishing Program	9,829	0	9,829	0
Operating Income	62,941	71,987	101,936	132,139
Interest Expense	(2,903)	(1,765)	(5,730)	(3,502)
Foreign Exchange Transaction Losses	(1,472)	(746)	(452)	(965)
Interest Income and Other	696	1,289	1,227	1,873
Income Before Taxes	59,262	70,765	96,981	129,545
Provision For Income Taxes	16,205	19,989	17,807	27,973
Net Income	$ 43,057	$ 50,776	$ 79,174	$ 101,572
Earnings Per Share
Diluted (in dollars per share)	$ 0.71	$ 0.83	$ 1.31	$ 1.65
Basic (in dollars per share)	$ 0.72	$ 0.84	$ 1.33	$ 1.68
Average Shares
Diluted (in shares)	60,633	61,432	60,493	61,572
Basic (in shares)	59,853	60,516	59,669	60,592
Class A Common [Member]
Cash Dividends Per Share
Common stock (in dollars per share)	$ 0.24	$ 0.20	$ 0.48	$ 0.40
Class B Common [Member]
Cash Dividends Per Share
Common stock (in dollars per share)	$ 0.24	$ 0.20	$ 0.48	$ 0.40