CONDENSED CONSOLIDATED STATEMENTS OF INCOME - UNAUDITED (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Jan. 31, 2013	Jan. 31, 2012	Jan. 31, 2013	Jan. 31, 2012
CONDENSED CONSOLIDATED STATEMENTS OF INCOME [Abstract]
Revenue	$ 472,435	$ 451,111	$ 1,314,924	$ 1,328,165
Costs and Expenses
Cost of sales	141,794	142,131	398,592	404,472
Operating and administrative expenses	235,857	221,648	689,833	686,132
Restructuring charges	0	0	4,841	0
Impairment of consumer publishing programs	0	0	15,521	0
Amortization of intangibles	11,158	8,875	30,404	26,965
Total Costs and Expenses	388,809	372,654	1,139,191	1,117,569
Gain on Sale of Travel Publishing Program	0	0	9,829	0
Operating Income	83,626	78,457	185,562	210,596
Interest Expense	(3,827)	(2,768)	(9,557)	(6,270)
Foreign Exchange Transaction Losses	(1,147)	(184)	(1,599)	(1,149)
Interest Income and Other	342	421	1,569	2,294
Income Before Taxes	78,994	75,926	175,975	205,471
Provision For Income Taxes	21,894	13,017	39,701	40,990
Net Income	$ 57,100	$ 62,909	$ 136,274	$ 164,481
Earnings Per Share
Diluted (in dollars per share)	$ 0.95	$ 1.03	$ 2.26	$ 2.69
Basic (in dollars per share)	$ 0.96	$ 1.05	$ 2.28	$ 2.72
Average Shares
Diluted (in shares)	60,254	60,845	60,349	61,255
Basic (in shares)	59,621	59,993	59,656	60,392
Class A Common [Member]
Cash Dividends Per Share
Common stock (in dollars per share)	$ 0.24	$ 0.20	$ 0.72	$ 0.60
Class B Common [Member]
Cash Dividends Per Share
Common stock (in dollars per share)	$ 0.24	$ 0.20	$ 0.72	$ 0.60