REVENUE RECOGNITION - Cumulative Effect of the Changes to Consolidated Balance Sheet for the Adoption of Topic 606 (Detail) - USD ($) $ in Thousands	Jul. 31, 2019	Aug. 01, 2018	Jul. 31, 2018	Jul. 31, 2017
Assets
Inventories, net	$ 23,674	$ 26,553	$ 47,786
Prepaid expenses and other current assets	31,445	37,456	13,415
Total current assets	213,324	267,089	264,281
Total assets	731,563	829,858	827,050
Liabilities
Other current liabilities	39,046	38,699	42,029
Total current liabilities	256,850	273,026	276,356
Total liabilities	643,685	680,900	684,230
Stockholders' equity
Accumulated deficit	(7,426,287)	(7,357,431)	(7,363,569)
Total stockholders’ equity	52,692	113,766	107,628	$ 62,971
Total liabilities, contingently redeemable preferred stock and stockholders’ equity	731,563	829,858	827,050
Calculated under Revenue Guidance in Effect before Topic 606
Assets
Inventories, net	45,853		47,786
Prepaid expenses and other current assets	9,973		13,415
Total current assets	214,031		264,281
Total assets	732,270		827,050
Liabilities
Other current liabilities	46,641		42,029
Total current liabilities	264,445		276,356
Total liabilities	651,280		684,230
Stockholders' equity
Accumulated deficit	(7,433,175)		(7,363,569)
Total stockholders’ equity	45,804		107,628
Total liabilities, contingently redeemable preferred stock and stockholders’ equity	732,270		$ 827,050
Accounting Standards Update 2014-09 | Difference between Revenue Guidance in Effect before and after Topic 606
Assets
Inventories, net	(22,179)	(21,233)
Prepaid expenses and other current assets	21,472	24,041
Total current assets	(707)	2,808
Total assets	(707)	2,808
Liabilities
Other current liabilities	(7,595)	(3,330)
Total current liabilities	(7,595)	(3,330)
Total liabilities	(7,595)	(3,330)
Stockholders' equity
Accumulated deficit	6,888	6,138
Total stockholders’ equity	6,888	6,138
Total liabilities, contingently redeemable preferred stock and stockholders’ equity	$ (707)	$ 2,808