Segment Reporting (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Dec. 31, 2011 segment	Dec. 31, 2010	Sep. 30, 2011
Segment Reporting
Number of business segments	3
Segment reporting
Segment revenue	$ 137,427	$ 135,820
Depreciation and amortization	(13,182)	(12,570)
Operating income (loss)	4,413	(1,037)
Net interest expense	(12,456)	(16,895)
Other income (expense), net	(4,137)	974
Income tax provision	(1,100)	(1,800)
Loss from continuing operations	(13,280)	(18,758)
Loss from discontinued operations, net of income taxes	(10,468)	(1,929)
Net loss	(23,748)	(20,687)
Capital expenditures	6,619	5,203
Segment assets	678,455	838,384	728,237
Light Building Products
Segment reporting
Segment revenue	73,334	69,709
Depreciation and amortization	(9,064)	(8,540)
Operating income (loss)	773	(2,248)
Capital expenditures	4,601	3,610
Segment assets	272,152	304,869
Heavy Construction Materials
Segment reporting
Segment revenue	63,138	63,215
Depreciation and amortization	(3,531)	(3,441)
Operating income (loss)	8,754	7,830
Capital expenditures	784	298
Segment assets	308,969	292,234
Energy Technology
Segment reporting
Segment revenue	955	2,896
Depreciation and amortization	(572)	(560)
Operating income (loss)	(2,001)	(1,341)
Capital expenditures	1,216	1,295
Capital expenditures related to discontinued operations	1,116	1,255
Segment assets	65,559	172,691
Segment assets related to discontinued operations	31,854
Corporate
Segment reporting
Segment revenue	0	0
Depreciation and amortization	(15)	(29)
Operating income (loss)	(3,113)	(5,278)
Capital expenditures	18	0
Segment assets	$ 31,775	$ 68,590