QUARTERLY FINANCIAL INFORMATION (UNAUDITED) (Details) - Schedule of quarterly financial information - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018
Quarterly Financial Information Disclosure [Abstract]
Revenue	$ 660,673	$ 632,061	$ 566,350	$ 548,438	$ 574,164	$ 574,970	$ 549,633	$ 510,522	$ 2,407,522	$ 2,209,289	$ 1,977,918
Gross Profit	174,470	165,003	152,032	149,921	158,458	151,699	133,537	139,780	641,426	583,474	511,318
Income from continuing operations	$ 20,091	$ 21,831	$ 895	$ 10,612	$ 16,251	$ 14,128	$ 6,490	$ 8,753	$ 53,429	$ 45,622	$ 33,255
Per Share - Basic (in usd per share)	$ 0.44	$ 0.52	$ 0.02	$ 0.26	$ 0.40	$ 0.34	$ 0.16	$ 0.21	$ 1.25	$ 1.11	$ 0.81
Per Share - Diluted (in usd per share)	$ 0.41	$ 0.50	$ 0.02	$ 0.24	$ 0.37	$ 0.33	$ 0.15	$ 0.21	$ 1.19	$ 1.06	$ 0.78