Condensed Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	9 Months Ended		12 Months Ended
	Apr. 30, 2013	Apr. 30, 2012	Jul. 31, 2012	Jul. 31, 2011
OPERATING ACTIVITIES:
Net income	$ 19,414	$ 30,971
Adjustments to reconcile net income to net cash provided by operating activities
Provision for deferred income taxes	3,761	846
Depreciation and amortization	12,537	13,729
Share-based compensation expense	7,957	7,716
Excess tax benefit from share-based compensation	(1,992)	26
Other	779	222
Gain on sale of other investments		(2,500)
Net changes in operating assets and liabilities:
Accounts receivable	15,885	9,648
Inventory	(22,292)	(9,013)
Refundable income taxes	(4,226)
Other current assets	(940)	1,598
Accounts payable	(12,011)	5,849
Accrued liabilities	(4,286)	(4,930)
Advance payments and deferred revenue	(1,346)	4,060
Accrued income taxes	(3,709)	773
Other liabilities	1,594	271
Total net changes in operating assets and liabilities:	(31,331)	8,256
NET CASH PROVIDED BY OPERATING ACTIVITIES	11,125	59,266
INVESTING ACTIVITIES:
Additions to property, plant, and equipment	(19,802)	(22,491)
Acquisition of business, net of cash acquired	(79,273)
Proceeds from the sale of other investments		2,500
NET CASH USED FOR INVESTING ACTIVITIES	(99,075)	(19,991)
FINANCING ACTIVITIES:
Issuance of stock pursuant to exercise of stock options, employee stock purchase plan, restricted stock plans, and non-employee director stock plan	5,086	1,124
Shares repurchased for taxes for vested employee restricted stock awards	(4,498)
Borrowings of other credit facilities	2,230
Repayments of other credit facilities	(3,014)
Contingent consideration payment	(340)
Excess tax benefit from share-based compensation	1,992	(26)
Purchase of common stock	(6,020)	(15,795)
Dividends paid to shareholders	(3,889)	(3,763)
NET CASH USED FOR FINANCING ACTIVITIES	(8,453)	(18,460)
EFFECT OF EXCHANGE RATE CHANGES ON CASH	739	(926)
NET (DECREASE) INCREASE IN CASH AND CASH EQUIVALENTS	(95,664)	19,889
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD	187,011	169,656	169,656
CASH AND CASH EQUIVALENTS, END OF PERIOD	91,347	189,545	187,011	169,656
Supplemental disclosure of non-cash investing activities from continuing operations were as follows
Accounts payable amounts due on the construction of a manufacturing facilities	663	1,560	1,755	1,785
Estimated amount to be paid for former stockholders of Ultrasonix	659
Other property, plant, and equipment that was included in accounts payable	$ 250