REVISION OF PREVIOUSLY REPORTED CONSOLIDATED FINANCIAL STATEMENTS - Consolidated Balance Sheet (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2021
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accounts receivable, net	$ 32,132				$ 35,922				$ 32,132	$ 35,922
Contract assets, current portion	18,355				7,037				18,355	7,037
Prepaid expenses	3,513				1,946				3,513	1,946
Goodwill	123,548				115,632				123,548	115,632
Deferred income tax assets	11,645				10,110				11,645	10,110
Total assets	405,375				364,479				405,375	364,479
Income tax payables	4,329				206				4,329	206
Other current liabilities	1,482				2,402				1,482	2,402
Deferred revenue, current portion	17,360				21,350				17,360	21,350
Deferred income tax liabilities	6,476				9,578				6,476	9,578
Total liabilities	200,187				193,500				200,187	193,500
Revenue	$ 37,656	$ 43,070	$ 46,123	$ 45,703	39,626	$ 39,195	$ 33,510	$ 32,473	$ 172,552	144,804	$ 119,797
As Previously Reported
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accounts receivable, net					27,874					27,874
Contract assets, current portion					6,273					6,273
Prepaid expenses					2,000					2,000
Goodwill					120,186					120,186
Deferred income tax assets					10,245					10,245
Total assets					360,410					360,410
Income tax payables					194					194
Other current liabilities					2,409					2,409
Deferred revenue, current portion					13,394					13,394
Deferred income tax liabilities					14,132					14,132
Total liabilities					190,093					190,093
Revenue										143,943
Total Adjustments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accounts receivable, net					8,048					8,048
Contract assets, current portion					764					764
Prepaid expenses					(54)					(54)
Goodwill					(4,554)					(4,554)
Deferred income tax assets					(135)					(135)
Total assets					4,069					4,069
Income tax payables					12					12
Other current liabilities					(7)					(7)
Deferred revenue, current portion					7,956					7,956
Deferred income tax liabilities					(4,554)					(4,554)
Total liabilities					$ 3,407					3,407
Revenue										$ 861