Restructuring Programs (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended		33 Months Ended
	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2015
Restructuring Cost and Reserve [Line Items]
Total restructuring charge	$ 24,034	$ 4,256	$ 23,879	$ 27,327	$ 91,053
Activity for Restructuring and Reinvestment Program liability [Roll Forward]
Restructuring Liability, Beginning Balance			34,972
Charges	24,034	4,256	23,879	27,327
Payments			(25,473)	(20,136)
Foreign Translation & Reclassifications			(261)
Restructuring Liability, Ending Balance	33,117		33,117		33,117
Severance [Member]
Restructuring Cost and Reserve [Line Items]
Total restructuring charge	11,962	(270)	12,605	14,661	58,271
Activity for Restructuring and Reinvestment Program liability [Roll Forward]
Restructuring Liability, Beginning Balance			29,255
Charges			12,605
Payments			(21,460)
Foreign Translation & Reclassifications			(695)
Restructuring Liability, Ending Balance	19,705		19,705		19,705
Process Reengineering Consulting [Member]
Restructuring Cost and Reserve [Line Items]
Total restructuring charge	446	2,588	301	8,199	11,475
Activity for Restructuring and Reinvestment Program liability [Roll Forward]
Restructuring Liability, Beginning Balance			722
Charges			301
Payments			(1,024)
Foreign Translation & Reclassifications			46
Restructuring Liability, Ending Balance	45		45		45
Other Activities [Member]
Restructuring Cost and Reserve [Line Items]
Total restructuring charge	11,626	1,938	10,973	4,467	21,307
Activity for Restructuring and Reinvestment Program liability [Roll Forward]
Restructuring Liability, Beginning Balance			4,995
Charges			10,973
Payments			(2,989)
Foreign Translation & Reclassifications			388
Restructuring Liability, Ending Balance	13,367		13,367		13,367
Other Activities [Member] | Other Accrued Liabilities [Member]
Activity for Restructuring and Reinvestment Program liability [Roll Forward]
Restructuring Liability, Ending Balance	100		100		100
Other Activities [Member] | Other Long-Term Liabilities [Member]
Activity for Restructuring and Reinvestment Program liability [Roll Forward]
Restructuring Liability, Ending Balance	13,300		13,300		13,300
Research [Member]
Restructuring Cost and Reserve [Line Items]
Total restructuring charge	4,507	(782)	4,322	4,590	14,992
Professional Development [Member]
Restructuring Cost and Reserve [Line Items]
Total restructuring charge	3,588	(833)	3,833	4,834	21,977
Education [Member]
Restructuring Cost and Reserve [Line Items]
Total restructuring charge	1,033	117	1,084	375	3,092
Shared Services [Member]
Restructuring Cost and Reserve [Line Items]
Total restructuring charge	$ 14,906	$ 5,754	$ 14,640	$ 17,528	$ 50,992