Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Jul. 31, 2018	Jul. 31, 2017	Jul. 31, 2016
Cash flows from operating activities:
Net income (loss)	$ 29,769,000	$ 15,827,000	$ (7,738,000)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization of property, plant and equipment	13,655,000	14,354,000	9,830,000
Amortization of intangible assets with finite lives	21,075,000	22,823,000	13,415,000
Amortization of stock-based compensation	8,569,000	8,506,000	4,117,000
Amortization of deferred financing costs	2,196,000	1,977,000	795,000
Loss (gain) on disposal of property, plant and equipment	79,000	(126,000)	(21,000)
Provision for allowance for doubtful accounts	573,000	497,000	907,000
Provision for excess and obsolete inventory	5,628,000	2,900,000	2,780,000
Deferred income tax (benefit) expense	(6,379,000)	9,056,000	(3,241,000)
Settlement of intellectual property litigation	0	(12,020,000)	0
Change in fair value of contingent liability	0	0	(359,000)
Excess income tax benefit from stock-based award exercises	0	(82,000)	(28,000)
Changes in assets and liabilities, net of effects of business acquisition:
Accounts receivable	(24,578,000)	25,508,000	5,806,000
Inventories	(20,065,000)	7,812,000	8,280,000
Prepaid expenses and other current assets	787,000	(956,000)	2,112,000
Other assets	(140,000)	666,000	(86,000)
Accounts payable	13,728,000	(4,472,000)	(1,255,000)
Accrued expenses and other current liabilities	(3,374,000)	(21,796,000)	(13,360,000)
Customer advances and deposits	9,143,000	(2,431,000)	(6,397,000)
Other liabilities, non-current	(682,000)	(1,442,000)	(882,000)
Interest payable	234,000	(1,039,000)	1,292,000
Income taxes payable	126,000	1,355,000	(892,000)
Net cash provided by operating activities	50,344,000	66,917,000	15,075,000
Cash flows from investing activities:
Purchases of property, plant and equipment	(8,642,000)	(8,150,000)	(5,667,000)
Payments for business acquisition, net of cash acquired	0	0	(280,535,000)
Net cash used in investing activities	(8,642,000)	(8,150,000)	(286,202,000)
Cash flows from financing activities:
Repayment of long-term debt under Term Loan Facility	(18,960,000)	(33,567,000)	(77,353,000)
Cash dividends paid	(9,538,000)	(18,872,000)	(19,406,000)
Net (payments) borrowings under Revolving Loan Facility	(8,800,000)	(26,500,000)	83,904,000
Repayment of principal amounts under capital lease and other obligations	(2,802,000)	(3,592,000)	(1,753,000)
Remittance of employees' statutory tax withholdings for stock awards	(1,143,000)	(262,000)	(105,000)
Proceeds from issuance of employee stock purchase plan shares	855,000	694,000	676,000
Proceeds from exercises of stock options	326,000	0	0
Payment of deferred financing costs	0	(1,085,000)	(9,464,000)
Payment of issuance costs related to equity offering	0	(626,000)	(476,000)
Excess income tax benefit from stock-based award exercises	0	82,000	28,000
Borrowings of long-term debt under Term Loan Facility	0	0	250,000,000
Proceeds received from equity offering	0	0	95,029,000
Required payments for debt assumed for business acquisition	0	0	(134,101,000)
Net cash (used in) provided by financing activities	(40,062,000)	(83,728,000)	186,979,000
Net increase (decrease) in cash and cash equivalents	1,640,000	(24,961,000)	(84,148,000)
Cash and cash equivalents at beginning of year	41,844,000	66,805,000	150,953,000
Cash and cash equivalents at end of year	43,484,000	41,844,000	66,805,000
Cash paid (received) during the year for:
Interest	7,291,000	10,424,000	5,307,000
Income taxes, net	1,112,000	(758,000)	3,678,000
Non-cash investing and financing activities:
Accrued remittance of employees' statutory tax withholdings for fully-vested share units	2,963,000	0	0
Cash dividends declared but unpaid (including accrual of dividend equivalents)	2,656,000	2,616,000	7,462,000
Capital lease and other obligations incurred (excluding the effect of business acquisition)	1,306,000	68,000	373,000
Accrued fixed asset additions	719,000	1,221,000	346,000
(Forfeiture) issuance of restricted stock	(1,000)	14,000	0
Accrued issuance costs related to equity offering	0	0	636,000
Accrued deferred financing costs	$ 0	$ 0	$ 155,000