CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (LOSS) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2021	Mar. 31, 2020
Income Statement [Abstract]
Revenue	$ 634,832	$ 566,350	$ 1,244,123	$ 1,114,788
Cost of goods and services	464,516	414,318	903,635	812,835
Gross profit	170,316	152,032	340,488	301,953
Selling, general and administrative expenses	126,827	126,467	248,384	244,265
Income from operations	43,489	25,565	92,104	57,688
Other income (expense)
Interest expense	(15,831)	(16,871)	(31,521)	(33,082)
Interest income	304	310	349	571
Gain (adjustment) on sale of business	(949)	0	5,291	0
Loss from debt extinguishment, net	0	(6,690)	0	(6,690)
Other, net	847	615	806	1,393
Total other expense, net	(15,629)	(22,636)	(25,075)	(37,808)
Income before taxes	27,860	2,929	67,029	19,880
Provision for income taxes	10,748	2,034	20,417	8,373
Net income	$ 17,112	$ 895	$ 46,612	$ 11,507
Basic earnings per common share (in dollars per share)	$ 0.34	$ 0.02	$ 0.92	$ 0.28
Basic weighted-average shares outstanding (in shares)	50,838	41,565	50,717	41,369
Diluted earnings per common share (in dollars per share)	$ 0.32	$ 0.02	$ 0.88	$ 0.26
Diluted weighted-average shares outstanding (in shares)	53,264	43,734	53,211	43,826
Dividends paid per common share (in dollars per share)	$ 0.08	$ 0.075	$ 0.16	$ 0.15
Other comprehensive income (loss), net of taxes:
Foreign currency translation adjustments	$ 1,739	$ (16,471)	$ 13,862	$ (10,001)
Pension and other post retirement plans	1,245	669	2,951	1,341
Change in cash flow hedges	1,791	968	1,103	667
Total other comprehensive income (loss), net of taxes	4,775	(14,834)	17,916	(7,993)
Comprehensive income, net	$ 21,887	$ (13,939)	$ 64,528	$ 3,514