Income Taxes - Deferred Taxes (Details) - USD ($) $ in Thousands	Jul. 31, 2019	Jul. 31, 2018
Deferred tax assets:
Accrued expenses	$ 4,175	$ 5,354
Inventories	5,408	3,165
Accounts receivable	593	306
Other long-term liabilities	211	103
Stock-based compensation	3,586	2,700
Capital investment	426	426
Domestic NOLs	137	0
Foreign NOLs	10,284	8,605
Subtotal	24,820	20,659
Valuation allowance	(5,701)	(6,358)
Deferred tax assets, net of valuation allowance	19,119	14,301
Deferred tax liabilities:
Property and equipment	(11,342)	(7,352)
Intangible assets	(21,156)	(21,300)
Goodwill	(11,618)	(10,362)
Deferred tax liabilities, gross	(44,116)	(39,014)
Deferred income taxes (assets)	4,281	2,911
Deferred income taxes (liabilities)	(29,278)	(27,624)
Net deferred income taxes	$ (24,997)	$ (24,713)