CONSOLIDATED STATEMENTS OF INCOME (LOSS) (UNAUDITED) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
CONSOLIDATED STATEMENTS OF INCOME (LOSS) (UNAUDITED) [Abstract]
Revenue	$ 221,778	$ 139,979
Cost of sales	122,445	65,965
Gross profit	99,333	74,014
Operating expenses:
Research, development and technical	14,040	12,151
Selling, general and administrative	61,128	24,751
Total operating expenses	75,168	36,902
Operating income	24,165	37,112
Interest expense	6,890	1,132
Interest income	1,019	951
Other income (expense), net	(1,411)	(279)
Income before income taxes	16,883	36,652
Provision for income taxes	3,440	39,735
Net income (loss)	$ 13,443	$ (3,083)
Basic earnings (loss) per share (in dollars per share)	$ 0.50	$ (0.12)
Weighted average basic shares outstanding (in shares)	27,156,882	25,325,757
Diluted earnings (loss) per share (in dollars per share)	$ 0.48	$ (0.12)
Weighted average diluted shares outstanding (in shares)	27,761,836	25,325,757