SIGNIFICANT ACCOUNTING POLICIES (Policies)	9 Months Ended
Apr. 28, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	(b) Basis of Presentation The accompanying unaudited condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All significant intercompany transactions and balances have been eliminated in consolidation. The accompanying unaudited condensed consolidated financial statements have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission (the "SEC") for interim financial information, including the instructions to Form 10-Q and Rule 10-01 of Regulation S-X. Accordingly, certain information and note disclosures normally required in complete financial statements prepared in conformity with accounting principles generally accepted in the United States have been condensed or omitted. In the Company’s opinion, these condensed consolidated financial statements include all adjustments necessary for a fair presentation of the financial position, results of operations and cash flows for the interim periods presented. However, the results of operations for interim periods may not be indicative of the results that may be expected for a full year. These condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the fiscal year ended July 29, 2017. Net sales consist primarily of sales of natural, organic and specialty products to retailers, adjusted for customer volume discounts, returns, and allowances. Net sales also include amounts charged by the Company to customers for shipping and handling and fuel surcharges. The principal components of cost of sales include the amounts paid to suppliers for product sold, plus the cost of transportation necessary to bring the product to the Company’s distribution facilities, offset by consideration received from suppliers in connection with the purchase or promotion of the suppliers' products. Cost of sales also includes amounts incurred by the Company’s manufacturing subsidiary, United Natural Trading LLC, which does business as Woodstock Farms Manufacturing, for inbound transportation costs offset by consideration received from suppliers in connection with the purchase or promotion of the suppliers’ products. Operating expenses include salaries and wages, employee benefits, warehousing and delivery, selling, occupancy, insurance, administrative, share-based compensation, amortization expense, and depreciation expense related to the wholesale and retail divisions. Other expense (income) includes interest on outstanding indebtedness, including the financing obligation related to our Aurora, Colorado distribution center and the lease for office space for our corporate headquarters in Providence, Rhode Island, interest income and miscellaneous income and expenses. As noted above, the Company includes shipping and handling fees billed to customers in net sales. Shipping and handling costs associated with inbound freight are generally recorded in cost of sales, whereas shipping and handling costs for selecting, quality assurance, and outbound transportation are recorded in operating expenses. Outbound shipping and handling costs, including allocated employee benefit expenses, totaled $148.4 million and $129.2 million for the third quarter of fiscal 2018 and 2017, respectively. Outbound shipping and handling costs, including allocated employee benefit expenses, totaled $432.8 million and $385.1 million for the first 39 weeks of fiscal 2018 and 2017, respectively. (c) Change in Accounting Estimate The preparation of condensed consolidated financial statements in conformity with U.S. generally accepted accounting principles (U.S. GAAP) requires the Company to make estimates and judgments that affect the amounts reported in its condensed consolidated financial statements and the accompanying notes. Actual results may differ materially from the Company's estimates. The Company has experienced growth in customer demand since the start of fiscal 2018 and for the 13 and 39-week periods ended April 28, 2018, net sales increased approximately 11.8% and 10.1%, respectively, when compared to the comparable periods in fiscal 2017. Additionally, inventories have increased approximately 15.9% since July 29, 2017. During the first quarter of fiscal 2018, the Company opened its shared services center which established a centralized processing function for certain of its legal entities. As a result of the aforementioned growth in net sales and inventory and the changes in processing and the resulting increase in the Company’s estimate of its accrual for inventory purchases the Company initiated a review of its vendor invoicing processes and undertook a review of its estimate of its accrual for inventory purchases. The Company typically generates purchase orders to initiate the procurement process for the products it sells, and orders are subsequently fulfilled by suppliers and delivered to the Company. In certain situations, inventory purchased by the Company may be delivered to the Company prior to the supplier sending the Company an associated invoice. When the Company receives inventory from a supplier before the supplier invoice is received, the Company customarily accrues for liabilities associated with this received but not invoiced inventory as its accrual for inventory purchases. During the 13 and 39-week periods ended April 28, 2018 the Company experienced an increased volume in its accrual for inventory purchases. When the Company receives a vendor invoice subsequent to a period end, the invoice is reconciled to the accrual for inventory purchases account. Due to the large volumes of orders and SKUs, and pricing and quantity differences between the vendor invoice and the Company’s records, at times only a portion of the accrual for inventory purchases is able to be matched to the vendor invoice. Historically, the Company relieved any unresolved and partially matched amounts in its accrual for inventory purchases following when such amounts were substantially matched or aged past twelve months as it was determined that a liability was no longer considered probable at that point. In the third quarter of fiscal 2018, the Company finalized its analysis and review of its accrual for inventory purchases, including a historical data analysis of unmatched and partially matched amounts that were aged greater than twelve months and the ultimate resolution of such aged accruals. Based on its analysis, the Company determined that it could reasonably estimate the outcome of its partially matched vendor invoices upon receipt of such invoice rather than when the amount was aged greater than twelve months and a liability was no longer considered probable. As a result of this change in estimate, accounts payable was reduced by $20.9 million, resulting in an increase to net income of $13.9 million, or $0.27 per diluted share, for both the 13 and 39-weeks ended April 28, 2018.

(b) Basis of Presentation

The accompanying unaudited condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All significant intercompany transactions and balances have been eliminated in consolidation.

The accompanying unaudited condensed consolidated financial statements have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission (the "SEC") for interim financial information, including the instructions to Form 10-Q and Rule 10-01 of Regulation S-X. Accordingly, certain information and note disclosures normally required in complete financial statements prepared in conformity with accounting principles generally accepted in the United States have been condensed or omitted. In the Company’s opinion, these condensed consolidated financial statements include all adjustments necessary for a fair presentation of the financial position, results of operations and cash flows for the interim periods presented. However, the results of operations for interim periods may not be indicative of the results that may be expected for a full year. These condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the fiscal year ended July 29, 2017.

Net sales consist primarily of sales of natural, organic and specialty products to retailers, adjusted for customer volume discounts, returns, and allowances. Net sales also include amounts charged by the Company to customers for shipping and handling and fuel surcharges. The principal components of cost of sales include the amounts paid to suppliers for product sold, plus the cost of transportation necessary to bring the product to the Company’s distribution facilities, offset by consideration received from suppliers in connection with the purchase or promotion of the suppliers' products. Cost of sales also includes amounts incurred by the Company’s manufacturing subsidiary, United Natural Trading LLC, which does business as Woodstock Farms Manufacturing, for inbound transportation costs offset by consideration received from suppliers in connection with the purchase or promotion of the suppliers’ products. Operating expenses include salaries and wages, employee benefits, warehousing and delivery, selling, occupancy, insurance, administrative, share-based compensation, amortization expense, and depreciation expense related to the wholesale and retail divisions. Other expense (income) includes interest on outstanding indebtedness, including the financing obligation related to our Aurora, Colorado distribution center and the lease for office space for our corporate headquarters in Providence, Rhode Island, interest income and miscellaneous income and expenses.

As noted above, the Company includes shipping and handling fees billed to customers in net sales. Shipping and handling costs associated with inbound freight are generally recorded in cost of sales, whereas shipping and handling costs for selecting, quality assurance, and outbound transportation are recorded in operating expenses. Outbound shipping and handling costs, including allocated employee benefit expenses, totaled $148.4 million and $129.2 million for the third quarter of fiscal 2018 and 2017, respectively. Outbound shipping and handling costs, including allocated employee benefit expenses, totaled $432.8 million and $385.1 million for the first 39 weeks of fiscal 2018 and 2017, respectively.

The preparation of condensed consolidated financial statements in conformity with U.S. generally accepted accounting principles (U.S. GAAP) requires the Company to make estimates and judgments that affect the amounts reported in its condensed consolidated financial statements and the accompanying notes. Actual results may differ materially from the Company's estimates.

The Company has experienced growth in customer demand since the start of fiscal 2018 and for the 13 and 39-week periods ended April 28, 2018, net sales increased approximately 11.8% and 10.1%, respectively, when compared to the comparable periods in fiscal 2017. Additionally, inventories have increased approximately 15.9% since July 29, 2017. During the first quarter of fiscal 2018, the Company opened its shared services center which established a centralized processing function for certain of its legal entities. As a result of the aforementioned growth in net sales and inventory and the changes in processing and the resulting increase in the Company’s estimate of its accrual for inventory purchases the Company initiated a review of its vendor invoicing processes and undertook a review of its estimate of its accrual for inventory purchases.

The Company typically generates purchase orders to initiate the procurement process for the products it sells, and orders are subsequently fulfilled by suppliers and delivered to the Company. In certain situations, inventory purchased by the Company may be delivered to the Company prior to the supplier sending the Company an associated invoice. When the Company receives inventory from a supplier before the supplier invoice is received, the Company customarily accrues for liabilities associated with this received but not invoiced inventory as its accrual for inventory purchases. During the 13 and 39-week periods ended April 28, 2018 the Company experienced an increased volume in its accrual for inventory purchases. When the Company receives a vendor invoice subsequent to a period end, the invoice is reconciled to the accrual for inventory purchases account. Due to the large volumes of orders and SKUs, and pricing and quantity differences between the vendor invoice and the Company’s records, at times only a portion of the accrual for inventory purchases is able to be matched to the vendor invoice. Historically, the Company relieved any unresolved and partially matched amounts in its accrual for inventory purchases following when such amounts were substantially matched or aged past twelve months as it was determined that a liability was no longer considered probable at that point.

In the third quarter of fiscal 2018, the Company finalized its analysis and review of its accrual for inventory purchases, including a historical data analysis of unmatched and partially matched amounts that were aged greater than twelve months and the ultimate resolution of such aged accruals. Based on its analysis, the Company determined that it could reasonably estimate the outcome of its partially matched vendor invoices upon receipt of such invoice rather than when the amount was aged greater than twelve months and a liability was no longer considered probable. As a result of this change in estimate, accounts payable was reduced by $20.9 million, resulting in an increase to net income of $13.9 million, or $0.27 per diluted share, for both the 13 and 39-weeks ended April 28, 2018.