DEBT AND OTHER FINANCING ARRANGEMENTS - Revolving Credit Facility and Term Loan (Details) - USD ($)					3 Months Ended		6 Months Ended
	Sep. 30, 2019	Mar. 29, 2019	Dec. 31, 2018	Nov. 09, 2017	Dec. 31, 2018	Mar. 31, 2018	Dec. 31, 2018	Dec. 31, 2017
Line of Credit Facility [Line Items]
Proceeds from revolving credit facility							$ 0	$ 10,000,000
Repayment of line of credit							$ 0	$ 7,111,000
Cantaloupe
Line of Credit Facility [Line Items]
Proceeds from revolving credit facility				$ 27,800,000
Revolving Credit Facility | Credit Agreement | LIBOR
Line of Credit Facility [Line Items]
Interest rate					4.00%		4.00%
Revolving Credit Facility | Heritage Bank Of Commerce | Loan And Security Agreement
Line of Credit Facility [Line Items]
Repayment of line of credit				$ 7,200,000
Revolving Credit Facility | JPMorgan Chase Bank, N.A | Credit Agreement
Line of Credit Facility [Line Items]
Debt instrument term				5 years
Proceeds from revolving credit facility				$ 35,000,000
Maximum limit of amount under line of credit				12,500,000.0
Term Loan | JPMorgan Chase Bank, N.A | Credit Agreement
Line of Credit Facility [Line Items]
Proceeds from revolving credit facility				$ 25,000,000
Revolving Credit Facility and Term Loan
Line of Credit Facility [Line Items]
Extension fee			$ 200,000
Revolving Credit Facility and Term Loan | Credit Agreement | LIBOR
Line of Credit Facility [Line Items]
Interest rate						4.00%
Subsequent Event | Revolving Credit Facility
Line of Credit Facility [Line Items]
Maximum limit of amount under line of credit	$ 10,000,000
Subsequent Event | Revolving Credit Facility and Term Loan
Line of Credit Facility [Line Items]
Repayments of debt		$ 20,000,000
Installment payment		$ 600,000
Subsequent Event | Term Loan
Line of Credit Facility [Line Items]
Repayments of debt	$ 1,500,000