Condensed Consolidated Statements of Cash Flows (USD $)	3 Months Ended
	Oct. 31, 2011	Oct. 31, 2010
Cash flows from operating activities:
Net income	$ 12,601,000	$ 25,656,000
Adjustments to reconcile net income to net cash (used in) provided by operating activities:
Depreciation and amortization of property, plant and equipment	2,420,000	2,938,000
Amortization of intangible assets with finite lives	1,719,000	1,887,000
Amortization of stock-based compensation	873,000	1,508,000
Deferred financing costs	366,000	353,000
Loss on disposal of property, plant and equipment		1,000
(Benefit from) provision for allowance for doubtful accounts	(55,000)	410,000
Provision for excess and obsolete inventory	565,000	372,000
Excess income tax (benefit) shortfall from stock-based award exercises	(19,000)	3,000
Deferred income tax (benefit) expense	(476,000)	170,000
Changes in assets and liabilities, net of effects of acquisition:
Accounts receivable	(3,616,000)	45,080,000
Inventories	(3,380,000)	(11,699,000)
Prepaid expenses and other current assets	407,000	735,000
Other assets	(18,000)	5,000
Accounts payable	(4,870,000)	(49,452,000)
Accrued expenses and other current liabilities	(6,466,000)	(13,780,000)
Customer advances and deposits	(2,074,000)	6,104,000
Other liabilities	225,000	137,000
Interest payable	1,500,000	1,516,000
Income taxes payable	(474,000)	7,353,000
Net cash (used in) provided by operating activities	(772,000)	19,297,000
Cash flows from investing activities:
Purchases of property, plant and equipment	(1,443,000)	(2,000,000)
Payments for business acquisitions	0	(2,400,000)
Net cash used in investing activities	(1,443,000)	(4,400,000)
Cash flows from financing activities:
Repurchases of common stock	(78,651,000)	(20,152,000)
Cash dividends paid	(6,100,000)
Proceeds from exercises of stock options	2,241,000	613,000
Proceeds from issuance of employee stock purchase plan shares	287,000	286,000
Excess income tax benefit (shortfall) from stock-based award exercises	19,000	(3,000)
Payment of contingent consideration related to business acquisition	(63,000)
Origination fees related to line of credit	0	(537,000)
Net cash used in financing activities	(82,267,000)	(19,793,000)
Net decrease in cash and cash equivalents	(84,482,000)	(4,896,000)
Cash and cash equivalents at beginning of period	558,804,000	607,594,000
Cash and cash equivalents at end of period	474,322,000	602,698,000
Cash paid during the period for:
Interest	95,000	114,000
Income taxes	2,459,000	5,692,000
Non-cash investing and financing activities:
Business acquisition liabilities		4,103,000
Cash dividends declared	6,102,000	6,915,000
Accrued repurchases of common stock	$ 4,502,000	$ 46,000