SEGMENT AND GEOGRAPHIC INFORMATION - Operating Segments Revenue and Operating Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
SEGMENT INFORMATION
Revenue	$ 135,501	$ 122,754
Operating Income (Loss)	(9,371)	(90,578)
Interest expense	(11,364)	(10,450)
Other income (expense)	1,413	(1,878)
Loss before income taxes	(19,322)	(102,906)
Depreciation and amortization	14,250	13,263
Capital expenditures	5,572	8,369
Unallocated Corporate
SEGMENT INFORMATION
Operating Income (Loss)	(16,042)	(21,678)
Depreciation and amortization	104	0
Service
SEGMENT INFORMATION
Revenue	53,863	50,048
Product
SEGMENT INFORMATION
Revenue	81,638	72,706
Discovery and Safety Assessment Segment
SEGMENT INFORMATION
Capital expenditures	2,275	3,294
Discovery and Safety Assessment Segment | Operating Segments
SEGMENT INFORMATION
Operating Income (Loss)	1,593	2,372
Depreciation and amortization	4,409	3,980
Discovery and Safety Assessment Segment | Service
SEGMENT INFORMATION
Revenue	43,563	39,971
Discovery and Safety Assessment Segment | Product
SEGMENT INFORMATION
Revenue	1,135	1,122
Research Models And Services Segment
SEGMENT INFORMATION
Capital expenditures	3,297	5,075
Research Models And Services Segment | Operating Segments
SEGMENT INFORMATION
Operating Income (Loss)	5,078	(71,272)
Depreciation and amortization	9,737	9,283
Research Models And Services Segment | Service
SEGMENT INFORMATION
Revenue	10,300	10,077
Research Models And Services Segment | Product
SEGMENT INFORMATION
Revenue	$ 80,503	$ 71,584