Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Jul. 31, 2015	Jul. 31, 2014	Jul. 31, 2013
Cash flows from operating activities:
Net income	$ 23,245,000	$ 25,151,000	$ 17,808,000
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization of property, plant and equipment	6,525,000	6,721,000	7,837,000
Amortization of intangible assets with finite lives	6,211,000	6,285,000	6,328,000
Amortization of stock-based compensation	4,363,000	4,263,000	3,130,000
Deferred financing costs	65,000	1,107,000	1,419,000
Change in fair value of contingent earn-out liability	0	(239,000)	(3,267,000)
Loss on disposal of property, plant and equipment	3,000	13,000	9,000
Provision for (benefit from) allowance for doubtful accounts	764,000	120,000	(422,000)
Provision for excess and obsolete inventory	2,813,000	2,952,000	2,810,000
Excess income tax benefit from stock-based award exercises	(148,000)	(738,000)	(265,000)
Deferred income tax (benefit) expense	(2,365,000)	(404,000)	1,115,000
Changes in assets and liabilities:
Accounts receivable	(15,132,000)	(5,092,000)	6,591,000
Inventories	(3,446,000)	1,250,000	4,093,000
Prepaid expenses and other current assets	543,000	(1,879,000)	216,000
Other assets	(39,000)	46,000	79,000
Accounts payable	(3,194,000)	512,000	(2,577,000)
Accrued expenses and other current liabilities	(815,000)	(840,000)	(9,484,000)
Customer advances and deposits	1,631,000	(2,195,000)	391,000
Other liabilities	(931,000)	300,000	735,000
Interest payable	(29,000)	(1,372,000)	0
Income taxes payable	1,662,000	(1,373,000)	1,149,000
Net cash provided by operating activities	21,726,000	34,588,000	37,695,000
Cash flows from investing activities:
Purchases of property, plant and equipment	(3,362,000)	(4,937,000)	(5,347,000)
Net cash used in investing activities	(3,362,000)	(4,937,000)	(5,347,000)
Cash flows from financing activities:
Cash dividends paid	(19,426,000)	(18,677,000)	(18,879,000)
Repurchases of common stock	(4,989,000)	(70,729,000)	(26,954,000)
Proceeds from exercises of stock options	1,439,000	6,058,000	1,182,000
Proceeds from issuance of employee stock purchase plan shares	917,000	913,000	908,000
Excess income tax benefit from stock-based award exercises	148,000	738,000	265,000
Repayment of 3.0% convertible senior notes	0	(149,963,000)	0
Payment of contingent consideration related to business acquisition	0	(49,000)	(97,000)
Fees related to line of credit	0	(84,000)	(25,000)
Net cash used in financing activities	(21,911,000)	(231,793,000)	(43,600,000)
Net decrease in cash and cash equivalents	(3,547,000)	(202,142,000)	(11,252,000)
Cash and cash equivalents at beginning of period	154,500,000	356,642,000	367,894,000
Cash and cash equivalents at end of period	150,953,000	154,500,000	356,642,000
Cash paid during the period for:
Interest	117,000	6,274,000	6,350,000
Income taxes	11,441,000	15,134,000	7,420,000
Non-cash investing and financing activities:
Cash dividends declared but unpaid (including accrual of dividend equivalents)	5,164,000	4,960,000	4,531,000
Equity-classified stock awards issued	0	139,000	0
Principal amount of 3.0% convertible senior notes converted into common stock	$ 0	$ 50,037,000	$ 0