Business Segments (Tables)

6 Months Ended

Mar. 31, 2018

Segment Reporting [Abstract]

Schedule of segment reporting information, by segment

	Three Months Ended March 31,						Six Months Ended March 31,
	2017			2018			2017			2018
Total sales
Industrial	$	161,505		$	183,949		$	308,510		$	352,217
Municipal	68,694			73,498			138,080			142,811
Products	87,939			98,237			166,906			180,007
Total sales	318,138			355,684			613,496			675,035
Intersegment sales
Industrial	1,048			2,690			2,347			5,764
Municipal	5,140			9,214			11,895			16,621
Products	12,048			10,091			19,480			21,909
Total intersegment sales	18,236			21,995			33,722			44,294
Sales to external customers
Industrial	160,457			181,259			306,163			346,453
Municipal	63,554			64,284			126,185			126,190
Products	75,890			88,147			147,425			158,097
Total sales	299,901			333,690			579,773			630,740
Earnings before interest, taxes, depreciation and amortization (EBITDA)
Industrial	35,373			41,713			67,374			81,840
Municipal	8,526			9,758			17,088			16,350
Products	16,956			22,972			31,855			33,646
Corporate	(30,001		)	(28,155		)	(72,358		)	(55,838		)
Total EBITDA	30,854			46,288			43,959			75,998
Depreciation and amortization
Industrial	9,528			10,709			18,440			20,854
Municipal	2,050			1,777			4,125			3,577
Products	3,105			3,087			6,639			6,076
Corporate	4,190			4,907			8,316			9,856
Total depreciation and amortization	18,873			20,480			37,520			40,363
Income (loss) from operations
Industrial	25,845			31,004			48,934			60,986
Municipal	6,476			7,981			12,963			12,773
Products	13,851			19,885			25,216			27,570
Corporate	(34,191		)	(33,062		)	(80,674		)	(65,694		)
Total income from operations	11,981			25,808			6,439			35,635
Interest expense	(11,898		)	(10,810		)	(26,651		)	(28,053		)
Income (loss) before income taxes	83			14,998			(20,212		)	7,582
Income tax benefit (expense)	4,812			(2,018		)	11,907			2,393
Net income (loss)	$	4,895		$	12,980		$	(8,305	)	$	9,975
Capital expenditures
Industrial	$	10,765		$	11,554		$	21,764		$	20,502
Products	1,596			1,139			2,581			2,321
Municipal	838			1,225			1,434			2,972
Corporate	367			2,495			1,450			5,875
Total capital expenditures	$	13,566		$	16,413		$	27,229		$	31,670

	September 30, 2017		March 31, 2018
Assets
Industrial	$	461,471	$	480,435
Municipal	155,698		139,195
Products	513,941		535,792
Corporate	342,199		344,437
Total assets	$	1,473,309	$	1,499,859
Goodwill
Industrial	$	128,190	$	130,186
Municipal	9,865		9,961
Products	183,858		189,751
Total goodwill	$	321,913	$	329,898