NOTES PAYABLE (Details) (USD $)	0 Months Ended
	May 31, 2012 quarter option	Aug. 02, 2014
Notes payable
Letter of credit commitments		$ 33,600,000
Amended and restated revolving credit facility
Notes payable
Maximum borrowing base	600,000,000
Options granted to Company to increase borrowing base	1
Additional increase in borrowing base	150,000,000
Real estate term backed loan	200,000,000
Borrowing base, based on eligible accounts receivable and inventory levels		587,400,000
Amount outstanding		415,700,000
Letter of credit commitments		33,600,000
Reserves		2,800,000
Remaining availability of credit facility		135,300,000
Minimum fixed charge coverage ratio, numerator	1
Minimum fixed charge coverage ratio, denominator	1.0
Number of quarters used to calculate fixed charge coverage ratio	4
Percentage of maximum aggregate availability of the aggregate borrowing base (as a percent)	10.00%
Amended and restated revolving credit facility | Minimum
Notes payable
Line of Credit Facility, Maximum Aggregate Availability of the Aggregate Borrowing Base		35,000,000.0
Amended and restated revolving credit facility | Maximum
Notes payable
Line of Credit Facility, Maximum Aggregate Availability of the Aggregate Borrowing Base		50,000,000.0
Amended and restated revolving credit facility | U.S. Borrowers
Notes payable
Maximum borrowing base	550,000,000.0
Amended and restated revolving credit facility | UNFI Canada
Notes payable
Maximum borrowing base	$ 50,000,000.0
Amended and restated revolving credit facility | UNFI Canada | Minimum
Notes payable
Annual commitment fee, percentage (as a percent)	0.25%
Average daily balance of amounts actually used for annual commitments fee, percentage (as a percent)	40.00%
Amended and restated revolving credit facility | UNFI Canada | Maximum
Notes payable
Annual commitment fee, percentage (as a percent)	0.30%
Average daily balance of amounts actually used for annual commitments fee, percentage (as a percent)	40.00%
Amended and restated revolving credit facility | Federal funds effective rate | U.S. Borrowers
Notes payable
Reference rate	federal funds effective rate
Spread on reference rate (as a percent)	0.50%
Amended and restated revolving credit facility | One-month LIBOR | U.S. Borrowers
Notes payable
Reference rate	one-month London Interbank Offering Rate ("LIBOR")
Spread on reference rate (as a percent)	1.00%
Initial applicable margin	0.50%
Amended and restated revolving credit facility | LIBOR | U.S. Borrowers
Notes payable
Reference rate	LIBOR for one, two, three or six months
Amended and restated revolving credit facility | Nine month LIBOR | U.S. Borrowers
Notes payable
Reference rate	nine months LIBOR
Initial applicable margin	1.50%
Amended and restated revolving credit facility | Reuters Canadian Deposit Offering Rate | UNFI Canada
Notes payable
Reference rate	30-day Reuters Canadian Deposit Offering Rate
Spread on reference rate (as a percent)	0.50%
Amended and restated revolving credit facility | Prime rate of Bank of America N.A.'s Canada branch | UNFI Canada
Notes payable
Reference rate	Bankers' acceptance equivalent rate for a one month interest period
Spread on reference rate (as a percent)	1.00%
Initial applicable margin	0.50%
Amended and restated revolving credit facility | Annual rates applicable to Canadian Dollar bankers' acceptances | UNFI Canada
Notes payable
Reference rate	annual rates applicable to CanadianDollar bankers' acceptances
Spread on reference rate (as a percent)	0.05%
Initial applicable margin	1.50%