Supplemental Subsidiary Guarantors (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Jan. 25, 2013	Jan. 27, 2012	Jul. 27, 2012	Oct. 26, 2012
Condensed Consolidating Statement of Income
Net sales	$ 1,149,877	$ 1,136,201
Cost of sales	773,149	772,776
Product development, selling and administrative expenses	157,281	171,356
Other income	(1,705)	(21,677)
Operating income (loss)	221,152	213,746
Income (loss) from continuing operations before income taxes and equity	205,999	197,669
Provision (benefit) for income taxes	63,860	55,150
Income from continuing operations	142,139	142,410
Income from continuing operations attributable to noncontrolling interest	0	(109)
ASSETS
Current assets	3,136,781			3,156,077
Property, plant and equipment, net	864,794			832,862
Total assets	6,176,798	6,166,536		6,142,503
LIABILITIES AND SHAREHOLDERS' EQUITY
Current liabilities of discontinued operations	11,581			13,147
Long-term debt	1,294,200			1,306,625
Accrued pension costs	292,623			335,813
Other non-current liabilities	160,966			142,059
Total liabilities	3,464,249			3,565,314
Shareholders’ equity	2,712,549			2,577,189
Total liabilities and shareholders' equity	6,176,798			6,142,503
Condensed Consolidating Statement of Cash Flows
Net cash (used) provided by operating activities of continuing operations	92,065	(14,144)
Net cash used by operating activities of discontinued operations	(1,571)	(4,363)
Net cash provided (used) by operating activities	90,494	(18,507)
Investing Activities:
Acquisition of controlling interest in International Mining Machinery, net of cash acquired	0	(513,761)
Withdrawal of cash held in escrow	0	589,686
Other, net	2,846	151
Net cash (used) provided by investing activities	(51,742)	26,641
Net cash used by financing activities	(31,210)	(11,120)
Effect of exchange rate changes on cash and cash equivalents	(1,520)	(2,089)
Increase (Decrease) in Cash and Cash Equivalents	6,022	(5,075)
Cash and Cash Equivalents at Beginning of Period	263,873	288,321	288,321
Cash and Cash Equivalents at End of Period	269,895	283,246
Parent Company Supplemental Subsidiary Guarantors [Member]
Condensed Consolidating Statement of Income
Net sales	0		0
Cost of sales	0		0
Product development, selling and administrative expenses	12,802		26,995
Other income	0		0
Operating income (loss)	(12,802)		(26,995)
Intercompany items	31,120		14,723
Interest income (expense), net	(22,570)		(16,693)
Income (loss) from continuing operations before income taxes and equity	(4,252)		(28,965)
Provision (benefit) for income taxes	(9,276)		(13,242)
Equity in income of subsidiaries	137,115		158,242
Income from continuing operations	142,139		142,519
Income from continuing operations attributable to noncontrolling interest			(109)
Income from continuing operations attributable to Joy Global Inc.			142,410
ASSETS
Current assets	136,126			97,443
Property, plant and equipment, net	13,221			12,515
Intangible assets, net	0			0
Other assets	4,223,489			4,178,760
Total assets	4,372,836			4,288,718
LIABILITIES AND SHAREHOLDERS' EQUITY
Current liabilities	111,417			106,207
Current liabilities of discontinued operations				0
Long-term debt	1,293,098			1,305,413
Accrued pension costs	279,112			322,310
Other non-current liabilities	(23,340)			(22,401)
Total liabilities	1,660,287			1,711,529
Shareholders’ equity	2,712,549			2,577,189
Total liabilities and shareholders' equity	4,372,836			4,288,718
Condensed Consolidating Statement of Cash Flows
Net cash (used) provided by operating activities of continuing operations	51,491	(19,035)
Net cash used by operating activities of discontinued operations	0	0
Net cash provided (used) by operating activities	51,491	(19,035)
Investing Activities:
Acquisition of controlling interest in International Mining Machinery, net of cash acquired		(589,686)
Withdrawal of cash held in escrow		589,686
Other, net		(1,641)
Net cash (used) provided by investing activities	(1,449)	(1,641)
Net cash used by financing activities	(26,508)	(6,799)
Effect of exchange rate changes on cash and cash equivalents	0	0
Increase (Decrease) in Cash and Cash Equivalents	23,534	(27,475)
Cash and Cash Equivalents at Beginning of Period	3,459	100,181	100,181
Cash and Cash Equivalents at End of Period	26,993	72,706
Supplemental Subsidiary Guarantors [Member]
Condensed Consolidating Statement of Income
Net sales	600,956		692,872
Cost of sales	410,643		478,418
Product development, selling and administrative expenses	74,117		80,815
Other income	9,176		7,970
Operating income (loss)	107,020		125,669
Intercompany items	(19,848)		(7,435)
Interest income (expense), net	97		110
Income (loss) from continuing operations before income taxes and equity	87,269		118,344
Provision (benefit) for income taxes	57,046		47,334
Equity in income of subsidiaries	89,958		57,563
Income from continuing operations	120,181		128,573
Income from continuing operations attributable to noncontrolling interest			0
Income from continuing operations attributable to Joy Global Inc.			128,573
ASSETS
Current assets	1,131,131			1,129,867
Property, plant and equipment, net	378,880			374,324
Intangible assets, net	816,809			818,435
Other assets	2,546,838			2,517,019
Total assets	4,873,658			4,839,645
LIABILITIES AND SHAREHOLDERS' EQUITY
Current liabilities	697,086			701,676
Current liabilities of discontinued operations				46,693
Long-term debt	1,102			1,212
Accrued pension costs	6,445			6,589
Other non-current liabilities	10,393			10,205
Total liabilities	715,026			766,375
Shareholders’ equity	4,158,632			4,073,270
Total liabilities and shareholders' equity	4,873,658			4,839,645
Condensed Consolidating Statement of Cash Flows
Net cash (used) provided by operating activities of continuing operations	13,630	24,921
Net cash used by operating activities of discontinued operations	0	0
Net cash provided (used) by operating activities	13,630	24,921
Investing Activities:
Acquisition of controlling interest in International Mining Machinery, net of cash acquired		0
Withdrawal of cash held in escrow		0
Other, net		(31,635)
Net cash (used) provided by investing activities	(16,570)	(31,635)
Net cash used by financing activities	(104)	(100)
Effect of exchange rate changes on cash and cash equivalents	0	0
Increase (Decrease) in Cash and Cash Equivalents	(3,044)	(6,814)
Cash and Cash Equivalents at Beginning of Period	6,628	16,152	16,152
Cash and Cash Equivalents at End of Period	3,584	9,338
Non-Guarantor Subsidiaries Supplemental Subsidiary Guarantors [Member]
Condensed Consolidating Statement of Income
Net sales	877,521		767,315
Cost of sales	621,120		548,820
Product development, selling and administrative expenses	70,362		63,546
Other income	(10,881)		(29,647)
Operating income (loss)	196,920		184,596
Intercompany items	(35,657)		(32,753)
Interest income (expense), net	7,320		506
Income (loss) from continuing operations before income taxes and equity	168,583		152,349
Provision (benefit) for income taxes	16,090		21,058
Equity in income of subsidiaries	0		0
Income from continuing operations	152,493		131,291
Income from continuing operations attributable to noncontrolling interest			(109)
Income from continuing operations attributable to Joy Global Inc.			131,182
ASSETS
Current assets	2,074,611			2,149,820
Property, plant and equipment, net	472,693			446,023
Intangible assets, net	1,169,100			1,153,147
Other assets	1,973,029			1,814,876
Total assets	5,689,433			5,563,866
LIABILITIES AND SHAREHOLDERS' EQUITY
Current liabilities	977,042			1,041,266
Current liabilities of discontinued operations				(33,546)
Long-term debt	0			0
Accrued pension costs	7,066			6,914
Other non-current liabilities	173,913			154,255
Total liabilities	1,158,021			1,168,889
Shareholders’ equity	4,531,412			4,394,977
Total liabilities and shareholders' equity	5,689,433			5,563,866
Condensed Consolidating Statement of Cash Flows
Net cash (used) provided by operating activities of continuing operations	26,944	(20,030)
Net cash used by operating activities of discontinued operations	(1,571)	(4,363)
Net cash provided (used) by operating activities	25,373	(24,393)
Investing Activities:
Acquisition of controlling interest in International Mining Machinery, net of cash acquired		75,925
Withdrawal of cash held in escrow		0
Other, net		(16,008)
Net cash (used) provided by investing activities	(33,723)	59,917
Net cash used by financing activities	(4,598)	(4,221)
Effect of exchange rate changes on cash and cash equivalents	(1,520)	(2,089)
Increase (Decrease) in Cash and Cash Equivalents	(14,468)	29,214
Cash and Cash Equivalents at Beginning of Period	253,786	171,988	171,988
Cash and Cash Equivalents at End of Period	239,318	201,202
Eliminations Supplemental Subsidiary Guarantors [Member]
Condensed Consolidating Statement of Income
Net sales	(328,600)		(323,986)
Cost of sales	(258,614)		(254,462)
Product development, selling and administrative expenses	0		0
Other income	0		0
Operating income (loss)	(69,986)		(69,524)
Intercompany items	24,385		25,465
Interest income (expense), net	0		0
Income (loss) from continuing operations before income taxes and equity	(45,601)		(44,059)
Provision (benefit) for income taxes	0		0
Equity in income of subsidiaries	(227,073)		(215,805)
Income from continuing operations	(272,674)		(259,864)
Income from continuing operations attributable to noncontrolling interest			109
Income from continuing operations attributable to Joy Global Inc.			(259,755)
ASSETS
Current assets	(205,087)			(221,053)
Property, plant and equipment, net	0			0
Intangible assets, net	0			0
Other assets	(8,554,042)			(8,328,673)
Total assets	(8,759,129)			(8,549,726)
LIABILITIES AND SHAREHOLDERS' EQUITY
Current liabilities	(69,085)			(81,479)
Current liabilities of discontinued operations				0
Long-term debt	0			0
Accrued pension costs	0			0
Other non-current liabilities	0			0
Total liabilities	(69,085)			(81,479)
Shareholders’ equity	(8,690,044)			(8,468,247)
Total liabilities and shareholders' equity	(8,759,129)			(8,549,726)
Consolidated Supplemental Subsidiary Guarantors [Member]
Condensed Consolidating Statement of Income
Net sales	1,149,877		1,136,201
Cost of sales	773,149		772,776
Product development, selling and administrative expenses	157,281		171,356
Other income	(1,705)		(21,677)
Operating income (loss)	221,152		213,746
Intercompany items	0		0
Interest income (expense), net	(15,153)		(16,077)
Income (loss) from continuing operations before income taxes and equity	205,999		197,669
Provision (benefit) for income taxes	63,860		55,150
Equity in income of subsidiaries	0		0
Income from continuing operations	142,139		142,519
Income from continuing operations attributable to noncontrolling interest			(109)
Income from continuing operations attributable to Joy Global Inc.			142,410
ASSETS
Current assets	3,136,781			3,156,077
Property, plant and equipment, net	864,794			832,862
Intangible assets, net	1,985,909			1,971,582
Other assets	189,314			181,982
Total assets	6,176,798			6,142,503
LIABILITIES AND SHAREHOLDERS' EQUITY
Current liabilities	1,716,460			1,767,670
Current liabilities of discontinued operations				13,147
Long-term debt	1,294,200			1,306,625
Accrued pension costs	292,623			335,813
Other non-current liabilities	160,966			142,059
Total liabilities	3,464,249			3,565,314
Shareholders’ equity	2,712,549			2,577,189
Total liabilities and shareholders' equity	6,176,798			6,142,503
Condensed Consolidating Statement of Cash Flows
Net cash (used) provided by operating activities of continuing operations	92,065	(14,144)
Net cash used by operating activities of discontinued operations	(1,571)	(4,363)
Net cash provided (used) by operating activities	90,494	(18,507)
Investing Activities:
Acquisition of controlling interest in International Mining Machinery, net of cash acquired		(513,761)
Withdrawal of cash held in escrow		589,686
Other, net		(49,284)
Net cash (used) provided by investing activities	(51,742)	26,641
Net cash used by financing activities	(31,210)	(11,120)
Effect of exchange rate changes on cash and cash equivalents	(1,520)	(2,089)
Increase (Decrease) in Cash and Cash Equivalents	6,022	(5,075)
Cash and Cash Equivalents at Beginning of Period	263,873	288,321	288,321
Cash and Cash Equivalents at End of Period	$ 269,895	$ 283,246