CONSOLIDATING GUARANTOR AND NON-GUARANTOR FINANCIAL INFORMATION (Details) - Summary of Condensed Consolidating Statements of Operations and Comprehensive Income (Loss) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Condensed Income Statements, Captions [Line Items]
Revenue	$ 510,522	$ 437,303
Cost of goods and services	367,476	316,524
Gross profit	143,046	120,779
Selling, general and administrative expenses	113,754	106,624
Income from operations	29,292	14,155
Other income (expense)
Interest income (expense), net	(16,331)	(16,642)
Other, net	1,004	414
Total other expense, net	(15,327)	(16,228)
Income (loss) before taxes from continuing operations	13,965	(2,073)
Provision (benefit) for income taxes	5,212	(24,904)
Income (loss) before equity in net income of subsidiaries	8,753	22,831
Equity in net income (loss) of subsidiaries	0	0
Income from continuing operations	8,753	22,831
Income from operations of discontinued operations	0	11,466
Provision for income taxes	0	3,308
Income from discontinued operations	0	8,158
Net income	8,753	30,989
Comprehensive income, net	3,303	39,347
Parent Company [Member]
Condensed Income Statements, Captions [Line Items]
Revenue	0	0
Cost of goods and services	0	0
Gross profit	0	0
Selling, general and administrative expenses	5,060	11,337
Income from operations	(5,060)	(11,337)
Other income (expense)
Interest income (expense), net	(6,307)	(6,774)
Other, net	(262)	(5)
Total other expense, net	(6,569)	(6,779)
Income (loss) before taxes from continuing operations	(11,629)	(18,116)
Provision (benefit) for income taxes	(3,535)	(29,692)
Income (loss) before equity in net income of subsidiaries	(8,094)	11,576
Equity in net income (loss) of subsidiaries	16,847	19,413
Income from continuing operations	8,753	30,989
Income from discontinued operations		0
Net income	8,753	30,989
Comprehensive income, net	3,303	39,347
Guarantor Companies [Member]
Condensed Income Statements, Captions [Line Items]
Revenue	419,244	351,312
Cost of goods and services	309,097	262,640
Gross profit	110,147	88,672
Selling, general and administrative expenses	84,976	75,330
Income from operations	25,171	13,342
Other income (expense)
Interest income (expense), net	(9,130)	(6,202)
Other, net	687	1,205
Total other expense, net	(8,443)	(4,997)
Income (loss) before taxes from continuing operations	16,728	8,345
Provision (benefit) for income taxes	5,974	2,734
Income (loss) before equity in net income of subsidiaries	10,754	5,611
Equity in net income (loss) of subsidiaries	6,050	(652)
Income from continuing operations	16,804	4,959
Income from discontinued operations		4,360
Net income	16,804	9,319
Comprehensive income, net	53,569	22,769
Non-Guarantor Companies [Member]
Condensed Income Statements, Captions [Line Items]
Revenue	98,240	92,519
Cost of goods and services	65,702	60,779
Gross profit	32,538	31,740
Selling, general and administrative expenses	23,817	20,049
Income from operations	8,721	11,691
Other income (expense)
Interest income (expense), net	(894)	(3,666)
Other, net	1,041	(324)
Total other expense, net	147	(3,990)
Income (loss) before taxes from continuing operations	8,868	7,701
Provision (benefit) for income taxes	2,775	2,057
Income (loss) before equity in net income of subsidiaries	6,093	5,644
Equity in net income (loss) of subsidiaries	10,754	5,611
Income from continuing operations	16,847	11,255
Income from discontinued operations		3,798
Net income	16,847	15,053
Comprehensive income, net	(4,551)	47,447
Elimination [Member]
Condensed Income Statements, Captions [Line Items]
Revenue	(6,962)	(6,528)
Cost of goods and services	(7,323)	(6,895)
Gross profit	361	367
Selling, general and administrative expenses	(99)	(92)
Income from operations	460	459
Other income (expense)
Interest income (expense), net	0	0
Other, net	(462)	(462)
Total other expense, net	(462)	(462)
Income (loss) before taxes from continuing operations	(2)	(3)
Provision (benefit) for income taxes	(2)	(3)
Income (loss) before equity in net income of subsidiaries	0	0
Equity in net income (loss) of subsidiaries	(33,651)	(24,372)
Income from continuing operations	(33,651)	(24,372)
Income from discontinued operations		0
Net income	(33,651)	(24,372)
Comprehensive income, net	$ (49,018)	$ (70,216)