Condensed Consolidated Statements of Cash Flows - USD ($)	6 Months Ended
	Jan. 31, 2016	Jan. 31, 2015
Cash flows from operating activities:
Net income	$ 3,915,000	$ 12,810,000
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation and amortization of property, plant and equipment	2,996,000	3,230,000
Amortization of intangible assets with finite lives	2,572,000	3,121,000
Amortization of stock-based compensation	2,125,000	2,398,000
Amortization of deferred financing costs	0	65,000
(Gain) loss on disposal of property, plant and equipment	(2,000)	3,000
Provision for allowance for doubtful accounts	520,000	74,000
Provision for excess and obsolete inventory	1,294,000	1,324,000
Excess income tax benefit from stock-based award exercises	(5,000)	(138,000)
Deferred income tax benefit	(2,479,000)	(548,000)
Changes in assets and liabilities:
Accounts receivable	14,986,000	(14,083,000)
Inventories	2,369,000	(7,391,000)
Prepaid expenses and other current assets	1,836,000	475,000
Other assets	11,000	(37,000)
Accounts payable	2,555,000	(1,006,000)
Accrued expenses and other current liabilities	(484,000)	(2,634,000)
Customer advances and deposits	(8,112,000)	(4,086,000)
Other liabilities	(269,000)	(290,000)
Interest payable	0	(29,000)
Income taxes payable	(436,000)	(1,498,000)
Net cash provided by (used in) operating activities	23,392,000	(8,240,000)
Cash flows from investing activities:
Purchases of property, plant and equipment	(1,463,000)	(2,145,000)
Net cash used in investing activities	(1,463,000)	(2,145,000)
Cash flows from financing activities:
Cash dividends paid	(9,691,000)	(9,712,000)
Payment of shelf registration costs	(78,000)	0
Proceeds from exercises of stock options	0	119,000
Proceeds from issuance of employee stock purchase plan shares	348,000	479,000
Excess income tax benefit from stock-based award exercises	5,000	138,000
Net cash used in financing activities	(9,416,000)	(8,976,000)
Net increase (decrease) in cash and cash equivalents	12,513,000	(19,361,000)
Cash and cash equivalents at beginning of period	150,953,000	154,500,000
Cash and cash equivalents at end of period	163,466,000	135,139,000
Cash paid during the period for:
Interest	0	117,000
Income taxes	4,431,000	7,919,000
Non-cash investing and financing activities:
Cash dividends declared but unpaid (including accrual of dividend equivalents)	5,206,000	5,093,000
Accrued deferred financing costs	759,000	0
Accrued shelf registration costs	$ 235,000	$ 0