Condensed Consolidating Financial Information (Condensed Consolidating Statement Of Operations) (Details) (USD $) In Thousands	3 Months Ended			9 Months Ended
	Jun. 30, 2011	Mar. 31, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Revenue:
Light building products	$ 91,635		$ 95,052	$ 224,021	$ 227,538
Heavy construction materials	62,435		70,383	170,746	173,530
Energy technology	18,187		26,746	59,326	58,913
Total revenue	172,257		192,181	454,093	459,981
Cost of revenue:
Light building products	66,177		65,131	173,857	164,467
Heavy construction materials	47,234		51,251	133,095	133,040
Energy technology	18,386		20,835	56,324	50,599
Total cost of revenue	131,797		137,217	363,276	348,106
Gross profit	40,460		54,964	90,817	111,875
Operating expenses:
Amortization	5,673		5,516	16,826	16,705
Research and development	1,358		2,178	6,138	5,951
Selling, general and administrative	24,550		30,361	95,160	82,947
Asset impairment	0	38,000	3,462	38,000	3,462
Total operating expenses	31,581		41,517	156,124	109,065
Operating income (loss)	8,879		13,447	(65,307)	2,810
Other income (expense):
Net interest expense	(13,427)		(18,447)	(113,110)	(51,886)
Other, net	0		(102)	328	1,076
Total other income (expense), net	(13,427)		(18,549)	(112,782)	(50,810)
Income (loss) before income taxes	(4,548)		(5,102)	(178,089)	(48,000)
Income tax benefit (provision)	(1,800)		6,610	(5,100)	22,580
Net income (loss)	(6,348)		1,508	(183,189)	(25,420)
Guarantor Subsidiaries [Member]
Revenue:
Light building products	91,635		95,052	224,021	227,538
Heavy construction materials	62,435		70,383	170,746	173,530
Energy technology	18,187		26,746	59,326	58,913
Total revenue	172,257		192,181	454,093	459,981
Cost of revenue:
Light building products	66,177		65,131	173,857	164,467
Heavy construction materials	47,234		51,251	133,095	133,040
Energy technology	18,386		20,835	56,324	50,599
Total cost of revenue	131,797		137,217	363,276	348,106
Gross profit	40,460		54,964	90,817	111,875
Operating expenses:
Amortization	5,673		5,516	16,826	16,705
Research and development	1,358		2,178	6,138	5,951
Selling, general and administrative	22,997		25,273	83,831	67,845
Asset impairment			3,462	38,000	3,462
Total operating expenses	30,028		36,429	144,795	93,963
Operating income (loss)	10,432		18,535	(53,978)	17,912
Other income (expense):
Net interest expense	(81)		(129)	(268)	(431)
Other, net	0		(102)	328	1,076
Total other income (expense), net	(81)		(231)	60	645
Income (loss) before income taxes	10,351		18,304	(53,918)	18,557
Income tax benefit (provision)	166		(1,859)	(575)	(1,563)
Net income (loss)	10,517		16,445	(54,493)	16,994
Parent Company [Member]
Operating expenses:
Selling, general and administrative	1,553		5,088	11,329	15,102
Total operating expenses	1,553		5,088	11,329	15,102
Operating income (loss)	(1,553)		(5,088)	(11,329)	(15,102)
Other income (expense):
Net interest expense	(13,346)		(18,318)	(112,842)	(51,455)
Total other income (expense), net	(13,346)		(18,318)	(112,842)	(51,455)
Income (loss) before income taxes	(14,899)		(23,406)	(124,171)	(66,557)
Income tax benefit (provision)	(1,966)		8,469	(4,525)	24,143
Net income (loss)	$ (16,865)		$ (14,937)	$ (128,696)	$ (42,414)