Goodwill And Intangible Assets (Schedule Of Goodwill) (Details) (USD $) In Thousands, unless otherwise specified			3 Months Ended
	Jul. 31, 2012	Apr. 30, 2012	Jul. 31, 2012 Tax Services [Member]
Goodwill and Intangible Assets [Line Items]
Goodwill before impairment losses, beginning balance			$ 459,863
Accumulated impairment losses, beginning balance			(32,297)
Goodwill, beginning balance	431,101	427,566	427,566
Acquisitions			3,651
Disposals and foreign currency changes			(116)
Goodwill before impairment losses, ending balance			463,398
Accumulated impairment losses, ending balance			(32,297)
Goodwill, ending balance	$ 431,101	$ 427,566	$ 431,101