Segment Reporting (Schedule Of Segment Reporting) (Details) (USD $) In Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010	Sep. 30, 2010
Segment revenue	$ 172,257	$ 192,181	$ 454,093	$ 459,981
Depreciation and amortization	(16,816)	(15,345)	(48,031)	(44,501)
Operating income (loss)	8,879	13,447	(65,307)	2,810
Net interest expense	(13,427)	(18,447)	(113,110)	(51,886)
Other income (expense), net	0	(102)	328	1,076
Income tax benefit (provision)	(1,800)	6,610	(5,100)	22,580
Net income (loss)	(6,348)	1,508	(183,189)	(25,420)
Capital expenditures	5,179	5,959	17,322	19,660
Segment assets	769,283	932,361	769,283	932,361	888,974
Light Building Products [Member]
Segment revenue	91,635	95,052	224,021	227,538
Depreciation and amortization	(9,746)	(8,216)	(28,109)	(23,783)
Operating income (loss)	6,246	10,571	(8,991)	9,769
Capital expenditures	3,501	4,634	11,476	14,205
Segment assets	309,628	335,652	309,628	335,652
Heavy Construction Materials [Member]
Segment revenue	62,435	70,383	170,746	173,530
Depreciation and amortization	(3,455)	(3,455)	(10,359)	(10,232)
Operating income (loss)	7,672	8,536	15,803	16,567
Capital expenditures	458	1,273	1,585	3,587
Segment assets	303,252	304,007	303,252	304,007
Energy Technology [Member]
Segment revenue	18,187	26,746	59,326	58,913
Depreciation and amortization	(3,599)	(3,642)	(9,491)	(10,382)
Operating income (loss)	(3,486)	(572)	(60,790)	(8,424)
Capital expenditures	1,220	52	4,261	1,841
Segment assets	107,014	208,339	107,014	208,339
Corporate [Member]
Segment revenue	0	0	0	0
Depreciation and amortization	(16)	(32)	(72)	(104)
Operating income (loss)	(1,553)	(5,088)	(11,329)	(15,102)
Capital expenditures	0	0	0	27
Segment assets	$ 49,389	$ 84,363	$ 49,389	$ 84,363