ACQUISITION - Pro forma results (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2018	Mar. 31, 2017
Business Acquisition [Line Items]
Basic (in dollars per share)	$ 0.02	$ 0.00	$ (0.24)	$ (0.07)
Diluted (in dollars per share)	$ 0.02	$ 0.00	$ (0.24)	$ (0.07)
Basic (in shares)	53,637,085	40,327,697	51,101,813	39,703,690
Diluted (in shares)	54,234,566	40,327,697	51,101,813	39,703,690
Excluded from unaudited pro forma earnings
Business Acquisition [Line Items]
Integration and acquisition costs	$ 1,700		$ 5,800	$ 5,800
Cantaloupe
Business Acquisition [Line Items]
Revenues	35,832	$ 32,265	103,474	86,969
Net loss attributable to USAT	2,488	(339)	(8,064)	(6,898)
Net loss attributable to USAT common shares	$ 2,154	$ (673)	$ (8,732)	$ (7,566)
Basic (in dollars per share)	$ 0.04	$ (0.01)	$ (0.16)	$ (0.14)
Diluted (in dollars per share)	$ 0.04	$ (0.01)	$ (0.16)	$ (0.14)
Basic (in shares)	53,637,085	53,334,396	53,601,684	52,686,654
Diluted (in shares)	54,234,566	53,334,396	53,601,684	52,686,654