Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Jul. 31, 2016	Jul. 31, 2015	Jul. 31, 2014
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 12,127	$ 33,481	$ 34,480
Adjustments to reconcile net income to net cash provided by operating activities:
(Benefit from) provision for deferred income taxes	(457)	4,404	(5,412)
Depreciation and amortization	22,952	23,307	22,057
Share-based compensation expense	8,864	10,938	11,512
Write down of demo equipment to net realizable value	2,914	2,646	2,357
Provision for excess and obsolescence inventory	1,354	2,391	1,561
Excess tax benefit from share-based compensation	(395)	(1,134)	(3,982)
Change in fair value of contingent consideration	141	(62)	125
Provision for doubtful accounts, net of recovery	(151)	420	203
Loss on sale of other investments			484
Loss (gain) on sale of property, plant and equipment	110	(115)	17
Net changes in operating assets and liabilities, exclusive of acquisition-related assets and liabilities:
Accounts receivable	6,073	(16,050)	6,633
Inventory	(21,624)	(14,714)	(12,347)
Prepaid expenses and other assets	(2,275)	(387)	2,525
Accounts payable	(2,233)	(7,281)	3,222
Accrued liabilities	(1,367)	4,755	(9,100)
Deferred revenue	(126)	(5,433)	1,533
Customer deposits	(516)	965	(213)
Accrued income taxes and income taxes receivable	6,832	(1,895)	(8,769)
Other liabilities	764	2,474	1,045
NET CASH PROVIDED BY OPERATING ACTIVITIES	32,987	38,710	47,931
CASH FLOWS FROM INVESTING ACTIVITIES:
Additions to property, plant, and equipment	(13,121)	(9,954)	(17,517)
Acquisition of businesses, net of cash acquired	(8,424)	(1,600)	(10,561)
Purchases of marketable securities in Rabbi Trust under the Non-qualified Deferred Compensation Plan			(715)
Proceeds from the sale of property, plant, and equipment	106	559	260
NET CASH USED IN INVESTING ACTIVITIES	(21,439)	(10,995)	(28,533)
CASH FLOWS FROM FINANCING ACTIVITIES:
Issuance of stock pursuant to exercise of stock options, employee stock purchase plan, restricted stock plans, and non-employee director stock plan	4,724	7,893	5,379
Repurchase of common stock	(13,698)	(13,872)	(14,959)
Shares repurchased for taxes for vested employee restricted stock grants	(2,724)	(2,832)	(7,680)
Excess tax benefit from share-based compensation	395	1,134	3,982
Dividends paid to shareholders	(4,964)	(5,111)	(4,962)
Cash paid for financing cost	(500)
NET CASH USED IN FINANCING ACTIVITIES	(16,767)	(12,788)	(18,240)
EFFECT OF EXCHANGE RATE CHANGES ON CASH	116	(5,667)	349
NET DECREASE INCREASE IN CASH AND CASH EQUIVALENTS	(5,103)	9,260	1,507
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD	123,800	114,540	113,033
CASH AND CASH EQUIVALENTS, END OF PERIOD	118,697	123,800	114,540
Supplemental disclosures of cash flow information:
Income taxes paid, net of refunds	(1,494)	4,996	8,024
Fixed asset additions in accounts payable and accrued liabilities	$ 790	$ 596	$ 705