STOCKHOLDERS' EQUITY (Schedule of Components of Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended		12 Months Ended
		May 31, 2018	May 31, 2017	May 31, 2018	May 31, 2017	Aug. 31, 2017
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance, Attributable to PriceSmart				$ 708,767
Balance, Attributable to PriceSmart		$ 750,107		750,107		$ 708,767
Balance				708,767	$ 638,071	638,071
Other comprehensive income (loss)		(2,340)	$ (3,447)	1,491	(4,307)
Balance		750,699	689,387	750,699	689,387	708,767
Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance, Attributable to PriceSmart				(110,059)	(103,951)	(103,951)
Balance, Attributable to PriceSmart		(108,576)	(108,258)	(108,576)	(108,258)	(110,059)
Balance				(110,059)	(103,951)	(103,951)
Other comprehensive income (loss)				1,483	(4,307)
Balance		(108,576)	(108,258)	(108,576)	(108,258)	(110,059)
Foreign Currency Translation Adjustments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss), Attributable to PriceSmart				(134)	(4,700)	(6,297)
Defined Benefit Pension Plans [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss), Attributable to PriceSmart				101		(166)
Derivative Instruments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss), Attributable to PriceSmart	[1]			1,516	364	316
Reclassification From Other Comprehensive Income (Loss) To Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amount reclassified from accumulated other comprehensive income (loss), Attributable to PriceSmart	[2]				29	39
AOCI Attributable to Noncontrolling Interest [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance
Balance		8		8
Accumulated Foreign Currency Adjustment Attributable to Noncontrolling Interest [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss)				8
Accumulated Defined Benefit Plans Adjustment Attributable to Noncontrolling Interest [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss)
Accumulated Derivative Instruments Attributable to Noncontrolling Interest [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss)
Reclassification From Other Comprehensive Income (Loss) Attributable To Noncontrolling Interest [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amounts reclassified from accumulated other comprehensive income (loss)
AOCI Including Portion Attributable to Noncontrolling Interest [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance				(110,059)	(103,951)	(103,951)
Balance		$ (108,568)	$ (108,258)	(108,568)	(108,258)	(110,059)
Accumulated Foreign Currency Adjustment Including Portion Attributable to Noncontrolling Interest [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss)				(126)	(4,700)	(6,297)
Accumulated Defined Benefit Plans Adjustment Including Portion Attributable to Noncontrolling Interest [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss)				101		(166)
Accumulated Net Investment Gain (Loss) Including Portion Attributable to Noncontrolling Interest [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss)				$ 1,516	364	316
Reclassification From Other Comprehensive Income (Loss) Including Portion Attributable To Noncontrolling Interest [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amounts reclassified from accumulated other comprehensive income (loss)					$ 29	$ 39

[1] See Note 7 - Derivative Instruments and Hedging Activities.

[2] Amounts reclassified from accumulated other comprehensive income (loss) related to the minimum pension liability are included in warehouse club operations in the Company's Consolidated Statements of Income.