DEBT - Net Carrying Value of the Notes (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Jan. 31, 2021	Jan. 31, 2020	Jan. 31, 2021	Jan. 31, 2020	Jul. 31, 2020	Feb. 28, 2019
Debt Instrument [Line Items]
Carrying amount of equity component	$ 8,200,000		$ 8,200,000		$ 8,200,000
Total debt, net	376,879,000		376,879,000		379,049,000
Interest expense	600,000	$ 701,000	1,178,000	$ 1,390,000
SPHG Holdings | Interest expense related to contractual interest coupon
Debt Instrument [Line Items]
Interest expense	287,000	280,000	573,000	560,000
SPHG Holdings | Interest expense related to accretion of the discount
Debt Instrument [Line Items]
Interest expense	313,000	$ 421,000	605,000	$ 830,000
SPHG Holdings | 7.50% Convertible Senior Note due March 1, 2024
Debt Instrument [Line Items]
Principal amount of note	14,940,000		14,940,000		14,940,000	$ 14,900,000
Debt Instrument, Unamortized Discount	(6,281,000)		(6,281,000)		(6,886,000)
Total debt, net	$ 8,659,000		$ 8,659,000		$ 8,054,000