SEGMENTS (Summary of Segment Revenues, Operating Costs and Balance Sheet Items) (Details) $ in Thousands		3 Months Ended		9 Months Ended
		May 31, 2018 USD ($) warehouse country	May 31, 2017 USD ($)	May 31, 2018 USD ($) warehouse country	May 31, 2017 USD ($)	Mar. 31, 2018 USD ($)	Aug. 31, 2017 USD ($)
Segment Reporting Information [Line Items]
Number of stores | warehouse		41		41
Number of countries | country		13		13
Segment Reporting Information
Revenue		$ 782,201	$ 730,258	$ 2,388,836	$ 2,263,126
Depreciation and amortization		13,566	11,883	38,378	34,445
Operating income		28,429	27,626	98,859	105,407
Net income (loss) attributable to PriceSmart Inc.		18,694	18,838	55,332	70,926
Capital expenditures, net		31,068	12,016	76,702	98,419
Long-lived assets (other than deferred tax assets)		659,299	593,616	659,299	593,616		$ 616,090
Goodwill and intangibles, net		66,944	35,632	66,944	35,632	$ 32,100	35,642
Total assets		1,246,470	1,143,876	1,246,470	1,143,876		1,177,514
Net income attributable to non-controlling interest		22		22
United States Operations Segment [Member]
Segment Reporting Information
Revenue		17,802	6,455	35,087	25,381
Depreciation and amortization		2,245	1,788	5,680	4,837
Operating income		(883)	245	3,354	10,166
Net income (loss) attributable to PriceSmart Inc.		(2,792)	(1,795)	(17,182)	5,998
Capital expenditures, net		3,024	2,336	4,612	54,465
Long-lived assets (other than deferred tax assets)		72,343	69,141	72,343	69,141		70,353
Goodwill and intangibles, net		31,626		31,626
Total assets		160,793	142,643	160,793	142,643		147,650
Central American Operations Segment [Member]
Segment Reporting Information
Revenue		451,597	438,871	1,397,668	1,351,099
Depreciation and amortization		6,050	5,142	17,459	15,146
Operating income		31,257	31,444	100,463	102,410
Net income (loss) attributable to PriceSmart Inc.		25,485	25,901	82,997	81,764
Capital expenditures, net		12,803	6,895	35,364	33,112
Long-lived assets (other than deferred tax assets)		312,468	289,405	312,468	289,405		296,915
Goodwill and intangibles, net		30,770	31,113	30,770	31,113		31,118
Total assets		562,401	524,806	562,401	524,806		544,683
Caribbean Operations Segment [Member]
Segment Reporting Information
Revenue		214,506	201,007	663,317	627,544
Depreciation and amortization		2,934	2,594	8,343	7,583
Operating income		11,538	9,706	36,763	35,531
Net income (loss) attributable to PriceSmart Inc.		10,074	9,251	33,000	28,333
Capital expenditures, net		14,368	2,015	33,997	8,554
Long-lived assets (other than deferred tax assets)		148,789	107,542	148,789	107,542		122,616
Goodwill and intangibles, net		4,548	4,519	4,548	4,519		4,524
Total assets		333,985	295,431	333,985	295,431		303,234
Colombia Operations Segment [Member]
Segment Reporting Information
Revenue		98,296	83,925	292,764	259,102
Depreciation and amortization		2,337	2,359	6,896	6,879
Operating income		2,989	1,410	8,198	3,238
Net income (loss) attributable to PriceSmart Inc.		2,377	660	6,414	769
Capital expenditures, net		873	770	2,729	2,288
Long-lived assets (other than deferred tax assets)		125,699	127,528	125,699	127,528		126,206
Total assets		189,291	180,996	189,291	180,996		$ 181,947
Intersegment [Member]
Segment Reporting Information
Revenue	[1],[2]	(293,388)	(260,221)	(910,072)	(851,147)
Intersegment [Member] | United States Operations Segment [Member]
Segment Reporting Information
Revenue		(291,925)	(259,337)	(906,114)	(847,368)
Intersegment [Member] | Caribbean Operations Segment [Member]
Segment Reporting Information
Revenue		(1,087)	(853)	(3,265)	(3,726)
Intersegment [Member] | Colombia Operations Segment [Member]
Segment Reporting Information
Revenue		(376)	(31)	(693)	(53)
Reconciling Items [Member]
Segment Reporting Information
Operating income	[1],[2]	(16,472)	(15,179)	(49,919)	(45,938)
Net income (loss) attributable to PriceSmart Inc.	[1],[2]	$ (16,450)	$ (15,179)	$ (49,897)	$ (45,938)
Aeropost, Inc [Member] | Latin America [Member]
Segment Reporting Information [Line Items]
Number of countries | country		38		38

[1] The reconciling items contain a $22,000 adjustment for net income attributable to non-controlling interest.

[2] The reconciling items reflect the amount eliminated on consolidation of intersegment transactions.