Condensed Consolidating Financial Information (Details 3) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Revenue:
Light building products	$ 97,164	$ 91,635	$ 244,809	$ 224,021
Heavy construction materials	74,728	62,435	189,105	170,746
Energy technology	3,729	6,587	8,766	14,914
Total revenue	175,621	160,657	442,680	409,681
Cost of revenue:
Light building products	66,558	66,177	176,501	171,961
Heavy construction materials	54,863	47,234	143,341	133,095
Energy technology	1,842	3,258	4,473	7,731
Total cost of revenue	123,263	116,669	324,315	312,787
Gross profit	52,358	43,988	118,365	96,894
Operating expenses:
Amortization	4,936	5,673	15,739	16,826
Research and development	2,280	1,358	5,750	4,948
Selling, general and administrative	29,212	22,999	76,186	88,305
Restructuring costs	0	393	2,145	6,192
Total operating expenses	36,428	30,423	99,820	116,271
Operating income (loss)	15,930	13,565	18,545	(19,377)
Other income (expense):
Net interest expense	(15,975)	(13,337)	(41,958)	(112,827)
Other, net	57	1,703	(4,253)	4,525
Total other income (expense), net	(15,918)	(11,634)	(46,211)	(108,302)
Income (loss) from continuing operations before income taxes	12	1,931	(27,666)	(127,679)
Income tax benefit (provision)	2,030	100	(1,800)	(2,920)
Income (loss) from continuing operations	2,042	2,031	(29,466)	(130,599)
Loss from discontinued operations, net of income taxes	(15,078)	(8,379)	(27,876)	(52,590)
Net loss	(13,036)	(6,348)	(57,342)	(183,189)
Guarantor Subsidiaries
Revenue:
Light building products	97,164	91,635	244,809	224,021
Heavy construction materials	74,728	62,435	189,105	170,746
Energy technology	3,729	6,587	8,766	14,914
Total revenue	175,621	160,657	442,680	409,681
Cost of revenue:
Light building products	66,558	66,177	176,501	171,961
Heavy construction materials	54,863	47,234	143,341	133,095
Energy technology	1,842	3,258	4,473	7,731
Total cost of revenue	123,263	116,669	324,315	312,787
Gross profit	52,358	43,988	118,365	96,894
Operating expenses:
Amortization	4,936	5,673	15,739	16,826
Research and development	2,280	1,358	5,750	4,948
Selling, general and administrative	22,539	21,446	60,330	77,956
Restructuring costs		393	2,145	5,212
Total operating expenses	29,755	28,870	83,964	104,942
Operating income (loss)	22,603	15,118	34,401	(8,048)
Other income (expense):
Net interest expense	(25)	9	(62)	15
Other, net	(268)		(711)	371
Total other income (expense), net	(293)	9	(773)	386
Income (loss) from continuing operations before income taxes	22,310	15,127	33,628	(7,662)
Income tax benefit (provision)	2,225	267	4,035	(113)
Income (loss) from continuing operations	24,535	15,394	37,663	(7,775)
Loss from discontinued operations, net of income taxes	(15,078)	(8,379)	(27,876)	(52,590)
Net loss	9,457	7,015	9,787	(60,365)
Non-Guarantor Subsidiaries
Other income (expense):
Other, net		1,703	(5,892)	4,154
Total other income (expense), net		1,703	(5,892)	4,154
Income (loss) from continuing operations before income taxes		1,703	(5,892)	4,154
Income tax benefit (provision)	236	20	(707)	61
Income (loss) from continuing operations	236	1,723	(6,599)	4,215
Net loss	236	1,723	(6,599)	4,215
Parent Company
Operating expenses:
Selling, general and administrative	6,673	1,553	15,856	10,349
Restructuring costs				980
Total operating expenses	6,673	1,553	15,856	11,329
Operating income (loss)	(6,673)	(1,553)	(15,856)	(11,329)
Other income (expense):
Net interest expense	(15,950)	(13,346)	(41,896)	(112,842)
Other, net	325		2,350
Total other income (expense), net	(15,625)	(13,346)	(39,546)	(112,842)
Income (loss) from continuing operations before income taxes	(22,298)	(14,899)	(55,402)	(124,171)
Income tax benefit (provision)	(431)	(187)	(5,128)	(2,868)
Income (loss) from continuing operations	(22,729)	(15,086)	(60,530)	(127,039)
Net loss	$ (22,729)	$ (15,086)	$ (60,530)	$ (127,039)