GOODWILL AND INTANGIBLE ASSETS - Impairments (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	12 Months Ended
	Sep. 30, 2018	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016
Impairments
Goodwill	$ 64,777	$ 64,777	$ 51,705	$ 4,718
Goodwill impairment loss		4,719
Impairment of intangible assets excluding goodwill	900
Impairment of intangible assets excluding goodwill, net of tax	$ 700
Diluted earnings per share, intangible assets excluding goodwill (in dollars per share)	$ 0.01
TerraVici
Impairments
Goodwill	$ 4,700	$ 4,700
Goodwill impairment loss	4,700
Goodwill impairment loss, net of tax	$ 3,500
Diluted earnings per share related to goodwill impairment (in dollars per share)	$ 0.03