Condensed Consolidating Financial Information (Details 3) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Revenue:
Light building products	$ 76,688	$ 73,334
Heavy construction materials	68,158	63,138
Energy technology	4,727	955
Total revenue	149,573	137,427
Cost of revenue:
Light building products	56,501	55,330
Heavy construction materials	53,584	47,098
Energy technology	2,243	557
Total cost of revenue	112,328	102,985
Gross profit	37,245	34,442
Operating expenses:
Amortization	4,936	5,505
Research and development	1,606	1,854
Selling, general and administrative	24,671	21,282
Restructuring costs	0	1,388
Total operating expenses	31,213	30,029
Operating income (loss)	6,032	4,413
Other income (expense):
Net interest expense	(10,472)	(12,456)
Other, net	36	(4,137)
Total other income (expense), net	(10,436)	(16,593)
Income (loss) from continuing operations before income taxes	(4,404)	(12,180)
Income tax benefit (provision)	530	(1,100)
Loss from continuing operations	(3,874)	(13,280)
Loss from discontinued operations, net of income taxes	(1,998)	(10,468)
Net loss	(5,872)	(23,748)
Guarantor Subsidiaries
Revenue:
Light building products	76,688	73,334
Heavy construction materials	68,158	63,138
Energy technology	4,727	955
Total revenue	149,573	137,427
Cost of revenue:
Light building products	56,501	55,330
Heavy construction materials	53,584	47,098
Energy technology	2,243	557
Total cost of revenue	112,328	102,985
Gross profit	37,245	34,442
Operating expenses:
Amortization	4,936	5,505
Research and development	1,606	1,854
Selling, general and administrative	19,887	18,169
Restructuring costs		1,388
Total operating expenses	26,429	26,916
Operating income (loss)	10,816	7,526
Other income (expense):
Net interest expense	(14)	(19)
Other, net	36	(6,162)
Total other income (expense), net	22	(6,181)
Income (loss) from continuing operations before income taxes	10,838	1,345
Income tax benefit (provision)	(1,300)	189
Loss from continuing operations	9,538	1,534
Loss from discontinued operations, net of income taxes	(1,998)	(10,468)
Net loss	7,540	(8,934)
Parent Company
Operating expenses:
Selling, general and administrative	4,784	3,113
Total operating expenses	4,784	3,113
Operating income (loss)	(4,784)	(3,113)
Other income (expense):
Net interest expense	(10,458)	(12,437)
Other, net		2,025
Total other income (expense), net	(10,458)	(10,412)
Income (loss) from continuing operations before income taxes	(15,242)	(13,525)
Income tax benefit (provision)	1,830	(1,289)
Loss from continuing operations	(13,412)	(14,814)
Net loss	$ (13,412)	$ (14,814)