Segment Reporting (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Dec. 31, 2012 segment	Dec. 31, 2011	Sep. 30, 2012
Segment Reporting
Number of business segments	3
Segment reporting
Segment revenue	$ 149,573	$ 137,427
Depreciation and amortization	(12,436)	(13,182)
Operating income (loss)	6,032	4,413
Net interest expense	(10,472)	(12,456)
Other income (expense), net	36	(4,137)
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)
Capital expenditures	6,553	6,619
Segment assets	716,730	678,455	680,937
Light Building Products
Segment reporting
Segment revenue	76,688	73,334
Depreciation and amortization	(8,675)	(9,064)
Operating income (loss)	3,127	773
Capital expenditures	5,045	4,601
Segment assets	295,712	272,152
Heavy Construction Materials
Segment reporting
Segment revenue	68,158	63,138
Depreciation and amortization	(3,140)	(3,531)
Operating income (loss)	7,607	8,754
Capital expenditures	683	784
Segment assets	269,904	308,969
Energy Technology
Segment reporting
Segment revenue	4,727	955
Depreciation and amortization	(566)	(572)
Operating income (loss)	82	(2,001)
Capital expenditures	152	1,216
Segment assets	75,520	65,559
Corporate
Segment reporting
Segment revenue	0	0
Depreciation and amortization	(55)	(15)
Operating income (loss)	(4,784)	(3,113)
Capital expenditures	673	18
Segment assets	$ 75,594	$ 31,775