Retirement Plans (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Jan. 31, 2015	Apr. 30, 2015	Apr. 30, 2014	Apr. 30, 2013	Apr. 30, 2015	Apr. 30, 2014
Supplemental retirement benefits [Abstract]
Term of supplemental retirement benefits		10 years
Decrease in pension benefit liabilities				$ 18,200
Decrease in accumulated other comprehensive loss after-tax due to decrease in pension benefit liabilities				11,300
Curtailment expense				2,700
Defined contribution plan		$ 800
Pension plan benefit	$ 600
Retirement plans with accumulated benefit obligations in excess of plan assets [Abstract]
Projected benefit obligation for plans with accumulated benefit obligations in excess of plan assets					$ 813,300	$ 711,000
Accumulated benefit obligation for plans with accumulated benefit obligations in excess of plan assets					773,400	676,900
Fair value of plan assets for plans with accumulated benefit obligations in excess of plan assets					598,900	546,300
Minimum percentage of market value of plan assets for calculating corridor method (in hundredths)		10.00%
Reduction of pension expense		$ 1,200
Amounts in Accumulated Other Comprehensive Loss to be recognized in next fiscal year [Abstract]
Actuarial Loss		4,631
Prior Service Cost		(100)
Total		4,531
CHANGE IN PLAN ASSETS [Roll Forward]
Fair Value of Plan Assets, Beginning of Year		559,078
Employer Contributions		800
Fair Value, End of Year		$ 599,542	$ 559,078
CHANGE IN PROJECTED BENEFIT OBLIGATION [Roll Forward]
Curtailment				2,700
Amendments and Other	$ 600
AMOUNTS RECOGNIZED IN THE STATEMENT OF FINANCIAL POSITION [Abstract]
Current Pension Liability					(4,594)	(4,671)
Pension plan assets/investments [Abstract]
Equity securities, target allocation percentage (in hundredths)		50.00%
Fixed income securities and cash, target allocation percentage (in hundredths)		49.00%
Real estate, target allocation percentage (in hundredths)		1.00%
Acceptable ranges within which asset allocations will fluctuate (in hundredths)		5.00%
Future employer contributions [Abstract]
Expected employer contributions to the defined benefit pension plans		$ 12,500
Minimum amounts required for the Company's non-U.S. plans					8,300
Assets, Fair Value Disclosure [Abstract]
Fair Value of Plan Assets		559,078	559,078		599,542	559,078
Expected future benefit payments [Abstract]
2016					20,700
2017					22,100
2018					23,500
2019					23,700
2020					25,500
2021 through 2025					149,200
Other postretirement benefits [Abstract]
Accumulated post-retirement benefit obligation for contributory life insurance and health care benefits					6,700	6,200
Defined contribution savings plan expense		700	900	800
Employer cash contributions in defined contribution savings plans		14,800	13,900	9,200
Expense recorded in defined contribution savings plans		15,200	15,700	9,200
Fair Value, Inputs, Level 1 [Member]
CHANGE IN PLAN ASSETS [Roll Forward]
Fair Value of Plan Assets, Beginning of Year		14,089
Fair Value, End of Year		13,471	14,089
Assets, Fair Value Disclosure [Abstract]
Fair Value of Plan Assets		14,089	14,089		13,471	14,089
Fair Value, Inputs, Level 2 [Member]
CHANGE IN PLAN ASSETS [Roll Forward]
Fair Value of Plan Assets, Beginning of Year		544,989
Fair Value, End of Year		586,071	544,989
Assets, Fair Value Disclosure [Abstract]
Fair Value of Plan Assets		544,989	544,989		586,071	544,989
U.S. Plans [Member]
Supplemental retirement benefits [Abstract]
Curtailment expense		0	0
Defined contribution plan		3,972	9,608
Pension plan benefit		3,140	0
Defined benefit plans, net periodic benefit cost [Abstract]
Service Cost		0	0	12,701
Interest Cost		13,159	12,613	12,032
Expected Return on Plan Assets		(13,782)	(14,838)	(12,927)
Net Amortization of Prior Service Cost and Transition Asset		(115)	0	854
Recognized Net Actuarial Loss		1,470	5,681	6,050
Curtailment/Settlement Loss		0	0	2,681
Net Pension Expense		$ 732	$ 3,456	$ 21,391
Weighted-average assumptions [Abstract]
Discount Rate (in hundredths)		4.70%	4.20%	4.70%
Rate of Compensation Increase (in hundredths)				3.10%
Expected Return on Plan Assets (in hundredths)		6.80%	8.00%	8.00%
Amounts in Accumulated Other Comprehensive Loss to be recognized in next fiscal year [Abstract]
Actuarial Loss		$ 2,152
Prior Service Cost		(154)
Total		1,998
CHANGE IN PLAN ASSETS [Roll Forward]
Fair Value of Plan Assets, Beginning of Year		207,986	$ 186,527
Actual Return on Plan Assets		23,166	22,101
Employer Contributions		3,972	9,608
Employee Contributions		0	0
Settlements		0	0
Benefits Paid		(12,158)	(10,250)
Foreign Currency Rate Changes		0	0
Fair Value, End of Year		222,966	207,986	$ 186,527
CHANGE IN PROJECTED BENEFIT OBLIGATION [Roll Forward]
Benefit Obligation, Beginning of Year		(285,659)	(307,659)
Service Cost		0	0	(12,701)
Interest Cost		(13,159)	(12,613)	(12,032)
Employee Contributions		0	0
Actuarial Gain (Loss)		(45,868)	24,363
Benefits Paid		12,158	10,250
Foreign Currency Rate Changes		0	0
Curtailment		0	0
Amendments and Other		3,140	0
Benefit Obligation, End of Year		(329,388)	(285,659)	(307,659)
Funded Status					(106,422)	(77,673)
AMOUNTS RECOGNIZED IN THE STATEMENT OF FINANCIAL POSITION [Abstract]
Other Noncurrent Assets					0	0
Current Pension Liability					(4,086)	(4,091)
Noncurrent Pension Liability					(102,336)	(73,582)
Net Amount Recognized in Statement of Financial Position					(106,422)	(77,673)
AMOUNTS RECOGNIZED IN ACCUMULATED OTHER COMPREHENSIVE LOSS (before tax) CONSIST OF [Abstract]
Net Actuarial Loss					(103,017)	(68,005)
Prior Service Cost					3,024	0
Total Accumulated Other Comprehensive Loss					$ (99,993)	$ (68,005)
Change in Accumulated Other Comprehensive Loss		(31,988)	37,306
WEIGHTED AVERAGE ASSUMPTIONS USED IN DETERMINING ASSETS AND LIABILITIES [Abstract]
Discount Rate (in hundredths)					4.20%	4.70%
Rate of Compensation Increase (in hundredths)
Accumulated Benefit Obligations					$ (329,389)	$ (285,661)
Assets, Fair Value Disclosure [Abstract]
Fair Value of Plan Assets		207,986	186,527	186,527	222,966	207,986
U.S. Plans [Member] | Fair Value, Inputs, Level 1 [Member]
CHANGE IN PLAN ASSETS [Roll Forward]
Fair Value of Plan Assets, Beginning of Year		0
Fair Value, End of Year		0	0
Assets, Fair Value Disclosure [Abstract]
Fair Value of Plan Assets		0	0		0	0
U.S. Plans [Member] | Fair Value, Inputs, Level 2 [Member]
CHANGE IN PLAN ASSETS [Roll Forward]
Fair Value of Plan Assets, Beginning of Year		207,986
Fair Value, End of Year		222,966	207,986
Assets, Fair Value Disclosure [Abstract]
Fair Value of Plan Assets		222,966	207,986		222,966	207,986
U.S. Plans [Member] | U.S. Commingled Funds [Member]
CHANGE IN PLAN ASSETS [Roll Forward]
Fair Value of Plan Assets, Beginning of Year		76,534
Fair Value, End of Year		68,671	76,534
Assets, Fair Value Disclosure [Abstract]
Fair Value of Plan Assets		76,534	76,534		68,671	76,534
U.S. Plans [Member] | U.S. Commingled Funds [Member] | Fair Value, Inputs, Level 1 [Member]
CHANGE IN PLAN ASSETS [Roll Forward]
Fair Value of Plan Assets, Beginning of Year		0
Fair Value, End of Year		0	0
Assets, Fair Value Disclosure [Abstract]
Fair Value of Plan Assets		0	0		0	0
U.S. Plans [Member] | U.S. Commingled Funds [Member] | Fair Value, Inputs, Level 2 [Member]
CHANGE IN PLAN ASSETS [Roll Forward]
Fair Value of Plan Assets, Beginning of Year		76,534
Fair Value, End of Year		68,671	76,534
Assets, Fair Value Disclosure [Abstract]
Fair Value of Plan Assets		76,534	76,534		68,671	76,534
U.S. Plans [Member] | Non-U.S. Commingled Funds [Member]
CHANGE IN PLAN ASSETS [Roll Forward]
Fair Value of Plan Assets, Beginning of Year		32,815
Fair Value, End of Year		38,336	32,815
Assets, Fair Value Disclosure [Abstract]
Fair Value of Plan Assets		32,815	32,815		38,336	32,815
U.S. Plans [Member] | Non-U.S. Commingled Funds [Member] | Fair Value, Inputs, Level 1 [Member]
CHANGE IN PLAN ASSETS [Roll Forward]
Fair Value of Plan Assets, Beginning of Year		0
Fair Value, End of Year		0	0
Assets, Fair Value Disclosure [Abstract]
Fair Value of Plan Assets		0	0		0	0
U.S. Plans [Member] | Non-U.S. Commingled Funds [Member] | Fair Value, Inputs, Level 2 [Member]
CHANGE IN PLAN ASSETS [Roll Forward]
Fair Value of Plan Assets, Beginning of Year		32,815
Fair Value, End of Year		38,336	32,815
Assets, Fair Value Disclosure [Abstract]
Fair Value of Plan Assets		38,336	32,815		38,336	32,815
U.S. Plans [Member] | Fixed Income Commingled Funds [Member]
CHANGE IN PLAN ASSETS [Roll Forward]
Fair Value of Plan Assets, Beginning of Year		85,335
Fair Value, End of Year		105,363	85,335
Assets, Fair Value Disclosure [Abstract]
Fair Value of Plan Assets		105,363	85,335		105,363	85,335
U.S. Plans [Member] | Fixed Income Commingled Funds [Member] | Fair Value, Inputs, Level 1 [Member]
CHANGE IN PLAN ASSETS [Roll Forward]
Fair Value of Plan Assets, Beginning of Year		0
Fair Value, End of Year		0	0
Assets, Fair Value Disclosure [Abstract]
Fair Value of Plan Assets		0	0		0	0
U.S. Plans [Member] | Fixed Income Commingled Funds [Member] | Fair Value, Inputs, Level 2 [Member]
CHANGE IN PLAN ASSETS [Roll Forward]
Fair Value of Plan Assets, Beginning of Year		85,335
Fair Value, End of Year		105,363	85,335
Assets, Fair Value Disclosure [Abstract]
Fair Value of Plan Assets		105,363	85,335		105,363	85,335
U.S. Plans [Member] | Real Estate [Member]
CHANGE IN PLAN ASSETS [Roll Forward]
Fair Value of Plan Assets, Beginning of Year		13,302
Fair Value, End of Year		10,596	13,302
Assets, Fair Value Disclosure [Abstract]
Fair Value of Plan Assets		13,302	13,302		10,596	13,302
U.S. Plans [Member] | Real Estate [Member] | Fair Value, Inputs, Level 1 [Member]
CHANGE IN PLAN ASSETS [Roll Forward]
Fair Value of Plan Assets, Beginning of Year		0
Fair Value, End of Year		0	0
Assets, Fair Value Disclosure [Abstract]
Fair Value of Plan Assets		0	0		0	0
U.S. Plans [Member] | Real Estate [Member] | Fair Value, Inputs, Level 2 [Member]
CHANGE IN PLAN ASSETS [Roll Forward]
Fair Value of Plan Assets, Beginning of Year		13,302
Fair Value, End of Year		10,596	13,302
Assets, Fair Value Disclosure [Abstract]
Fair Value of Plan Assets		10,596	13,302		10,596	13,302
Non-U.S. Plans [Member]
Supplemental retirement benefits [Abstract]
Curtailment expense		7,321	0
Defined contribution plan		9,701	10,396
Pension plan benefit		0	437
Defined benefit plans, net periodic benefit cost [Abstract]
Service Cost		5,942	8,066	6,204
Interest Cost		17,417	17,144	15,784
Expected Return on Plan Assets		(22,654)	(21,607)	(17,975)
Net Amortization of Prior Service Cost and Transition Asset		68	124	127
Recognized Net Actuarial Loss		6,299	7,490	3,905
Curtailment/Settlement Loss		(428)	79	0
Net Pension Expense		$ 6,644	$ 11,296	$ 8,045
Weighted-average assumptions [Abstract]
Discount Rate (in hundredths)		4.20%	4.20%	5.00%
Rate of Compensation Increase (in hundredths)		3.20%	3.20%	3.40%
Expected Return on Plan Assets (in hundredths)		6.70%	6.70%	6.80%
Amounts in Accumulated Other Comprehensive Loss to be recognized in next fiscal year [Abstract]
Actuarial Loss		$ 2,479
Prior Service Cost		54
Total		2,533
CHANGE IN PLAN ASSETS [Roll Forward]
Fair Value of Plan Assets, Beginning of Year		351,092	$ 306,689
Actual Return on Plan Assets		60,997	15,459
Employer Contributions		9,701	10,396
Employee Contributions		1,566	1,770
Settlements		(2,353)	(437)
Benefits Paid		(7,118)	(10,005)
Foreign Currency Rate Changes		(37,309)	27,220
Fair Value, End of Year		376,576	351,092	$ 306,689
CHANGE IN PROJECTED BENEFIT OBLIGATION [Roll Forward]
Benefit Obligation, Beginning of Year		(442,703)	(394,278)
Service Cost		(5,942)	(8,066)	(6,204)
Interest Cost		(17,417)	(17,144)	(15,784)
Employee Contributions		(1,566)	(1,770)
Actuarial Gain (Loss)		(83,782)	1,350
Benefits Paid		7,118	10,005
Foreign Currency Rate Changes		52,513	(33,237)
Curtailment		7,321	0
Amendments and Other		0	437
Benefit Obligation, End of Year		(484,458)	(442,703)	(394,278)
Funded Status					(107,882)	(91,611)
AMOUNTS RECOGNIZED IN THE STATEMENT OF FINANCIAL POSITION [Abstract]
Other Noncurrent Assets					17	21
Current Pension Liability					(508)	(580)
Noncurrent Pension Liability					(107,391)	(91,052)
Net Amount Recognized in Statement of Financial Position					(107,882)	(91,611)
AMOUNTS RECOGNIZED IN ACCUMULATED OTHER COMPREHENSIVE LOSS (before tax) CONSIST OF [Abstract]
Net Actuarial Loss					(128,280)	(107,540)
Prior Service Cost					(555)	(966)
Total Accumulated Other Comprehensive Loss					$ (128,835)	$ (108,506)
Change in Accumulated Other Comprehensive Loss		(20,329)	(5,384)
WEIGHTED AVERAGE ASSUMPTIONS USED IN DETERMINING ASSETS AND LIABILITIES [Abstract]
Discount Rate (in hundredths)					3.50%	4.20%
Rate of Compensation Increase (in hundredths)					3.00%	3.20%
Accumulated Benefit Obligations					$ (444,561)	$ (402,225)
Assets, Fair Value Disclosure [Abstract]
Fair Value of Plan Assets		351,092	306,689	$ 306,689	376,576	351,092
Non-U.S. Plans [Member] | Fair Value, Inputs, Level 1 [Member]
CHANGE IN PLAN ASSETS [Roll Forward]
Fair Value of Plan Assets, Beginning of Year		14,089
Fair Value, End of Year		13,471	14,089
Assets, Fair Value Disclosure [Abstract]
Fair Value of Plan Assets		14,089	14,089		13,471	14,089
Non-U.S. Plans [Member] | Fair Value, Inputs, Level 2 [Member]
CHANGE IN PLAN ASSETS [Roll Forward]
Fair Value of Plan Assets, Beginning of Year		337,003
Fair Value, End of Year		363,105	337,003
Assets, Fair Value Disclosure [Abstract]
Fair Value of Plan Assets		363,105	337,003		363,105	337,003
Non-U.S. Plans [Member] | U.S. Equities [Member]
CHANGE IN PLAN ASSETS [Roll Forward]
Fair Value of Plan Assets, Beginning of Year		24,384
Fair Value, End of Year		25,551	24,384
Assets, Fair Value Disclosure [Abstract]
Fair Value of Plan Assets		24,384	24,384		25,551	24,384
Non-U.S. Plans [Member] | U.S. Equities [Member] | Fair Value, Inputs, Level 1 [Member]
CHANGE IN PLAN ASSETS [Roll Forward]
Fair Value of Plan Assets, Beginning of Year		0
Fair Value, End of Year		0	0
Assets, Fair Value Disclosure [Abstract]
Fair Value of Plan Assets		0	0		0	0
Non-U.S. Plans [Member] | U.S. Equities [Member] | Fair Value, Inputs, Level 2 [Member]
CHANGE IN PLAN ASSETS [Roll Forward]
Fair Value of Plan Assets, Beginning of Year		24,384
Fair Value, End of Year		25,551	24,384
Assets, Fair Value Disclosure [Abstract]
Fair Value of Plan Assets		25,551	24,384		25,551	24,384
Non-U.S. Plans [Member] | Non-U.S. Equities [Member]
CHANGE IN PLAN ASSETS [Roll Forward]
Fair Value of Plan Assets, Beginning of Year		73,250
Fair Value, End of Year		80,014	73,250
Assets, Fair Value Disclosure [Abstract]
Fair Value of Plan Assets		80,014	73,250		80,014	73,250
Non-U.S. Plans [Member] | Non-U.S. Equities [Member] | Fair Value, Inputs, Level 1 [Member]
CHANGE IN PLAN ASSETS [Roll Forward]
Fair Value of Plan Assets, Beginning of Year		0
Fair Value, End of Year		0	0
Assets, Fair Value Disclosure [Abstract]
Fair Value of Plan Assets		0	0		0	0
Non-U.S. Plans [Member] | Non-U.S. Equities [Member] | Fair Value, Inputs, Level 2 [Member]
CHANGE IN PLAN ASSETS [Roll Forward]
Fair Value of Plan Assets, Beginning of Year		73,250
Fair Value, End of Year		80,014	73,250
Assets, Fair Value Disclosure [Abstract]
Fair Value of Plan Assets		80,014	73,250		80,014	73,250
Non-U.S. Plans [Member] | Balanced Managed Funds [Member]
CHANGE IN PLAN ASSETS [Roll Forward]
Fair Value of Plan Assets, Beginning of Year		78,250
Fair Value, End of Year		77,002	78,250
Assets, Fair Value Disclosure [Abstract]
Fair Value of Plan Assets		77,002	78,250		77,002	78,250
Non-U.S. Plans [Member] | Balanced Managed Funds [Member] | Fair Value, Inputs, Level 1 [Member]
CHANGE IN PLAN ASSETS [Roll Forward]
Fair Value of Plan Assets, Beginning of Year		11,284
Fair Value, End of Year		10,295	11,284
Assets, Fair Value Disclosure [Abstract]
Fair Value of Plan Assets		11,284	11,284		10,295	11,284
Non-U.S. Plans [Member] | Balanced Managed Funds [Member] | Fair Value, Inputs, Level 2 [Member]
CHANGE IN PLAN ASSETS [Roll Forward]
Fair Value of Plan Assets, Beginning of Year		66,966
Fair Value, End of Year		66,707	66,966
Assets, Fair Value Disclosure [Abstract]
Fair Value of Plan Assets		66,966	66,966		66,707	66,966
Non-U.S. Plans [Member] | Fixed Income Funds: [Member]
CHANGE IN PLAN ASSETS [Roll Forward]
Fair Value of Plan Assets, Beginning of Year		164,948
Fair Value, End of Year		190,344	164,948
Assets, Fair Value Disclosure [Abstract]
Fair Value of Plan Assets		190,344	164,948		190,344	164,948
Non-U.S. Plans [Member] | Fixed Income Funds: [Member] | Fair Value, Inputs, Level 1 [Member]
CHANGE IN PLAN ASSETS [Roll Forward]
Fair Value of Plan Assets, Beginning of Year		0
Fair Value, End of Year		0	0
Assets, Fair Value Disclosure [Abstract]
Fair Value of Plan Assets		0	0		0	0
Non-U.S. Plans [Member] | Fixed Income Funds: [Member] | Fair Value, Inputs, Level 2 [Member]
CHANGE IN PLAN ASSETS [Roll Forward]
Fair Value of Plan Assets, Beginning of Year		164,948
Fair Value, End of Year		190,344	164,948
Assets, Fair Value Disclosure [Abstract]
Fair Value of Plan Assets		190,344	164,948		190,344	164,948
Non-U.S. Plans [Member] | Real Estate/Other [Member]
CHANGE IN PLAN ASSETS [Roll Forward]
Fair Value of Plan Assets, Beginning of Year		7,455
Fair Value, End of Year		489	7,455
Assets, Fair Value Disclosure [Abstract]
Fair Value of Plan Assets		7,455	7,455		489	7,455
Non-U.S. Plans [Member] | Real Estate/Other [Member] | Fair Value, Inputs, Level 1 [Member]
CHANGE IN PLAN ASSETS [Roll Forward]
Fair Value of Plan Assets, Beginning of Year		0
Fair Value, End of Year		0	0
Assets, Fair Value Disclosure [Abstract]
Fair Value of Plan Assets		0	0		0	0
Non-U.S. Plans [Member] | Real Estate/Other [Member] | Fair Value, Inputs, Level 2 [Member]
CHANGE IN PLAN ASSETS [Roll Forward]
Fair Value of Plan Assets, Beginning of Year		7,455
Fair Value, End of Year		489	7,455
Assets, Fair Value Disclosure [Abstract]
Fair Value of Plan Assets		7,455	7,455		489	7,455
Non-U.S. Plans [Member] | Cash and Cash Equivalents [Member]
CHANGE IN PLAN ASSETS [Roll Forward]
Fair Value of Plan Assets, Beginning of Year		2,805
Fair Value, End of Year		3,176	2,805
Assets, Fair Value Disclosure [Abstract]
Fair Value of Plan Assets		2,805	2,805		3,176	2,805
Non-U.S. Plans [Member] | Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 1 [Member]
CHANGE IN PLAN ASSETS [Roll Forward]
Fair Value of Plan Assets, Beginning of Year		2,805
Fair Value, End of Year		3,176	2,805
Assets, Fair Value Disclosure [Abstract]
Fair Value of Plan Assets		2,805	2,805		3,176	2,805
Non-U.S. Plans [Member] | Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 2 [Member]
CHANGE IN PLAN ASSETS [Roll Forward]
Fair Value of Plan Assets, Beginning of Year		0
Fair Value, End of Year		0	0
Assets, Fair Value Disclosure [Abstract]
Fair Value of Plan Assets		$ 0	$ 0		$ 0	$ 0
Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Employee retirement age limit under retirement plans		60 years
Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Employee retirement age limit under retirement plans		65 years