Condensed Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jan. 31, 2014	Jan. 31, 2013
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 15,539	$ 14,190
Adjustments to reconcile net cash provided by operating activities:
(Benefit from) provision for deferred income taxes	(7,039)	3,593
Depreciation and amortization	10,850	8,043
Loss on investment	484
Change in fair value of contingent consideration	25	(120)
Share-based compensation expense	5,839	5,954
Excess tax benefit from share-based compensation	(3,190)	(1,970)
Write-down of inventory to net realizable value	1,212	1,297
Allowance for doubtful accounts	130	186
Other		634
(Gain) loss on sale of property, plant and equipment	(12)	1
Net changes in operating assets and liabilities, exclusive of acquisition-related assets and liabilities:
Accounts receivable	19,138	10,167
Inventory	2,421	(17,674)
Refundable income taxes	(7,990)	(1,150)
Other current assets	833	(3,055)
Accounts payable	504	(795)
Accrued liabilities	(12,228)	(9,045)
Deferred revenue	(32)	(278)
Accrued income taxes	(1,964)	(2,767)
Other liabilities	649	117
NET CASH FLOWS PROVIDED BY OPERATING ACTIVITIES	25,169	7,328
CASH FLOWS FROM INVESTING ACTIVITIES:
Additions to property, plant, and equipment	(8,654)	(12,972)
Acquisition of business, net of cash acquired	(10,561)
Proceeds from the sale of property, plant, and equipment	140	58
NET CASH FLOWS USED IN INVESTING ACTIVITIES	(19,075)	(12,914)
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	4,305	4,035
Shares repurchased for taxes for vested employee restricted stock grants	(6,184)	(4,443)
Contingent consideration payment		(340)
Excess tax benefit from share-based compensation	3,190	1,970
Repurchase of common stock	(6,974)	(6,024)
Dividends paid to shareholders	(2,486)	(2,664)
NET CASH FLOWS USED IN FINANCING ACTIVITIES	(8,149)	(7,466)
EFFECT OF EXCHANGE RATE CHANGES ON CASH	49	1,166
NET DECREASE IN CASH AND CASH EQUIVALENTS	(2,006)	(11,886)
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD	113,033	187,011
CASH AND CASH EQUIVALENTS, END OF PERIOD	$ 111,027	$ 175,125