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		9 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Condensed Income Statements, Captions [Line Items]
Revenue	$ 516,550	$ 358,114	$ 1,432,413	$ 1,094,198
Cost of goods and services	377,758	260,130	1,051,304	800,601
Gross profit	138,792	97,984	381,109	293,597
Selling, general and administrative expenses	114,294	80,555	323,776	241,372
Restructuring and other related charges				0
Total operating expenses				241,372
Income from operations	24,498	17,429	57,333	52,225
Other income (expense)
Interest income (expense), net	(15,796)	(12,662)	(48,482)	(38,656)
Other, net	300	(220)	1,266	(422)
Total other expense, net	(15,496)	(12,882)	(47,216)	(39,078)
Income before taxes from continuing operations	9,002	4,547	10,117	13,147
Provision (benefit) for income taxes	1,560	95	(22,107)	(299)
Income (loss) before equity in net income of subsidiaries	7,442	4,452	32,224	13,446
Equity in net income (loss) of subsidiaries	0	0	0	0
Income from continuing operations	7,442	4,452	32,224	13,446
Income (loss) from operations of discontinued operations (including a gain on sale of $117,625 in 2018)	(200)	7,024	124,642	21,639
Provision for income taxes (including tax on gain on sale of $31,268 in 2018)	1,415	1,922	29,770	8,222
Income (loss) from discontinued operations (including a gain on sale, net of tax of $86,357 in 2018)	(1,615)	5,102	94,872	13,417
Net income	5,827	9,554	127,096	26,863
Comprehensive income (loss), net	(2,978)	16,710	147,050	30,640
Parent Company [Member]
Condensed Income Statements, Captions [Line Items]
Revenue	0	0	0	0
Cost of goods and services	0	0	0	0
Gross profit	0	0	0	0
Selling, general and administrative expenses	14,670	7,038	32,021	20,759
Restructuring and other related charges				0
Total operating expenses				20,759
Income from operations	(14,670)	(7,038)	(32,021)	(20,759)
Other income (expense)
Interest income (expense), net	(5,891)	(3,266)	(18,626)	(10,616)
Other, net	108	229	1,376	172
Total other expense, net	(5,783)	(3,037)	(17,250)	(10,444)
Income before taxes from continuing operations	(20,453)	(10,075)	(49,271)	(31,203)
Provision (benefit) for income taxes	(4,741)	(6,080)	(44,601)	(16,643)
Income (loss) before equity in net income of subsidiaries	(15,712)	(3,995)	(4,670)	(14,560)
Equity in net income (loss) of subsidiaries	21,539	13,549	131,766	41,423
Income from continuing operations	5,827	9,554	127,096	26,863
Income (loss) from operations of discontinued operations (including a gain on sale of $117,625 in 2018)	0	0	0	0
Provision for income taxes (including tax on gain on sale of $31,268 in 2018)	0	0		0
Income (loss) from discontinued operations (including a gain on sale, net of tax of $86,357 in 2018)	0	0	0	0
Net income	5,827	9,554	127,096	26,863
Comprehensive income (loss), net	(2,978)	16,710	147,050	30,640
Guarantor Companies [Member]
Condensed Income Statements, Captions [Line Items]
Revenue	431,997	303,167	1,181,068	922,996
Cost of goods and services	323,098	225,566	891,498	694,670
Gross profit	108,899	77,601	289,570	228,326
Selling, general and administrative expenses	77,820	57,566	216,750	171,171
Restructuring and other related charges				0
Total operating expenses				171,171
Income from operations	31,079	20,035	72,820	57,155
Other income (expense)
Interest income (expense), net	(2,282)	(6,070)	(16,497)	(18,093)
Other, net	(9,766)	262	1,157	1,263
Total other expense, net	(12,048)	(5,808)	(15,340)	(16,830)
Income before taxes from continuing operations	19,031	14,227	57,480	40,325
Provision (benefit) for income taxes	21,046	5,562	13,744	16,018
Income (loss) before equity in net income of subsidiaries	(2,015)	8,665	43,736	24,307
Equity in net income (loss) of subsidiaries	(5,307)	(4,015)	(65,666)	(12,631)
Income from continuing operations	(7,322)	4,650	(21,930)	11,676
Income (loss) from operations of discontinued operations (including a gain on sale of $117,625 in 2018)	(200)	5,033	109,028	13,826
Provision for income taxes (including tax on gain on sale of $31,268 in 2018)	1,415	1,347	31,856	3,987
Income (loss) from discontinued operations (including a gain on sale, net of tax of $86,357 in 2018)	(1,615)	3,685	77,172	9,839
Net income	(8,937)	8,335	55,242	21,515
Comprehensive income (loss), net	668	15,899	36,634	23,651
Non-Guarantor Companies [Member]
Condensed Income Statements, Captions [Line Items]
Revenue	90,285	61,676	272,714	194,985
Cost of goods and services	60,719	41,836	182,125	130,778
Gross profit	29,566	19,840	90,589	64,207
Selling, general and administrative expenses	21,896	16,044	75,282	49,720
Restructuring and other related charges				0
Total operating expenses				49,720
Income from operations	7,670	3,796	15,307	14,487
Other income (expense)
Interest income (expense), net	(7,623)	(3,326)	(13,359)	(9,947)
Other, net	10,420	(75)	119	(515)
Total other expense, net	2,797	(3,401)	(13,240)	(10,462)
Income before taxes from continuing operations	10,467	395	2,067	4,025
Provision (benefit) for income taxes	12,939	613	8,793	326
Income (loss) before equity in net income of subsidiaries	(2,472)	(218)	(6,726)	3,699
Equity in net income (loss) of subsidiaries	(2,015)	8,665	43,736	24,307
Income from continuing operations	(4,487)	8,447	37,010	28,006
Income (loss) from operations of discontinued operations (including a gain on sale of $117,625 in 2018)	0	1,991	15,614	7,813
Provision for income taxes (including tax on gain on sale of $31,268 in 2018)	0	575	(2,086)	4,235
Income (loss) from discontinued operations (including a gain on sale, net of tax of $86,357 in 2018)	0	1,417	17,700	3,578
Net income	(4,487)	9,864	54,710	31,584
Comprehensive income (loss), net	(14,092)	2,300	73,318	29,448
Elimination [Member]
Condensed Income Statements, Captions [Line Items]
Revenue	(5,732)	(6,729)	(21,369)	(23,783)
Cost of goods and services	(6,059)	(7,272)	(22,319)	(24,847)
Gross profit	327	543	950	1,064
Selling, general and administrative expenses	(92)	(93)	(277)	(278)
Restructuring and other related charges				0
Total operating expenses				(278)
Income from operations	419	636	1,227	1,342
Other income (expense)
Interest income (expense), net	0	0	0	0
Other, net	(462)	(636)	(1,386)	(1,342)
Total other expense, net	(462)	(636)	(1,386)	(1,342)
Income before taxes from continuing operations	(43)	0	(159)	0
Provision (benefit) for income taxes	(27,684)	0	(43)	0
Income (loss) before equity in net income of subsidiaries	27,641	0	(116)	0
Equity in net income (loss) of subsidiaries	(14,217)	(18,199)	(109,836)	(53,099)
Income from continuing operations	13,424	(18,199)	(109,952)	(53,099)
Income (loss) from operations of discontinued operations (including a gain on sale of $117,625 in 2018)	0	0	0	0
Provision for income taxes (including tax on gain on sale of $31,268 in 2018)	0	0	0	0
Income (loss) from discontinued operations (including a gain on sale, net of tax of $86,357 in 2018)	0	0	0	0
Net income	13,424	(18,199)	(109,952)	(53,099)
Comprehensive income (loss), net	$ 13,424	$ (18,199)	$ (109,952)	$ (53,099)