Segment Reporting (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	6 Months Ended
Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2015 segment	Mar. 31, 2014	Sep. 30, 2014
Segment Reporting
Number of business segments			3us-gaap_NumberOfReportableSegments
Segment revenue	$ 179,725us-gaap_Revenues	$ 156,512us-gaap_Revenues	$ 379,322us-gaap_Revenues	$ 322,127us-gaap_Revenues
Depreciation and amortization	(12,946)	(13,413)	(25,856)	(26,460)
Operating income (loss)	8,230us-gaap_OperatingIncomeLoss	549us-gaap_OperatingIncomeLoss	27,402us-gaap_OperatingIncomeLoss	8,109us-gaap_OperatingIncomeLoss
Net interest expense	(35,965)us-gaap_InterestIncomeExpenseNet	(12,234)us-gaap_InterestIncomeExpenseNet	(47,917)us-gaap_InterestIncomeExpenseNet	(22,290)us-gaap_InterestIncomeExpenseNet
Other income (expense), net	(33)us-gaap_OtherNonoperatingIncomeExpense	(32)us-gaap_OtherNonoperatingIncomeExpense	(302)us-gaap_OtherNonoperatingIncomeExpense	(20)us-gaap_OtherNonoperatingIncomeExpense
Income tax benefit	2,780us-gaap_IncomeTaxExpenseBenefit	2,210us-gaap_IncomeTaxExpenseBenefit	2,980us-gaap_IncomeTaxExpenseBenefit	2,560us-gaap_IncomeTaxExpenseBenefit
Loss from continuing operations	(24,988)	(9,507)	(17,837)	(11,641)
Income (loss) from discontinued operations, net of income taxes	(210)	(575)	(277)	125
Net loss	(25,198)us-gaap_ProfitLoss	(10,082)us-gaap_ProfitLoss	(18,114)us-gaap_ProfitLoss	(11,516)us-gaap_ProfitLoss
Capital expenditures	8,703	9,056	17,474	15,944
Segment assets	803,236us-gaap_Assets	896,306us-gaap_Assets	803,236us-gaap_Assets	896,306us-gaap_Assets	896,306us-gaap_Assets
Building Products
Segment Reporting
Segment revenue	106,406	94,139	223,940	187,151
Construction Materials
Segment Reporting
Segment revenue	67,498	59,093	148,902	130,614
Energy Technology
Segment Reporting
Segment revenue	5,821	3,280	6,480	4,362
Operating Segments \| Building Products
Segment Reporting
Segment revenue	106,406	94,139	223,940	187,151
Depreciation and amortization	(8,702)	(9,546)	(17,415)	(18,758)
Operating income (loss)	4,679	1,907	16,627	6,993
Capital expenditures	6,131	6,864	12,152	11,316
Segment assets	396,568	411,968	396,568	411,968
Operating Segments \| Construction Materials
Segment Reporting
Segment revenue	67,498	59,093	148,902	130,614
Depreciation and amortization	(3,799)	(3,319)	(7,535)	(6,605)
Operating income (loss)	8,175	5,228	21,663	15,161
Capital expenditures	1,026	1,377	2,374	2,562
Segment assets	308,750	325,140	308,750	325,140
Operating Segments \| Energy Technology
Segment Reporting
Segment revenue	5,821	3,280	6,480	4,362
Depreciation and amortization	(341)	(479)	(694)	(967)
Operating income (loss)	1,473	(821)	(138)	(3,107)
Capital expenditures	61	75	229	305
Segment assets	27,131	22,674	27,131	22,674
Corporate, Non-Segment
Segment Reporting
Segment revenue	0	0	0	0
Depreciation and amortization	(104)	(69)	(212)	(130)
Operating income (loss)	(6,097)	(5,765)	(10,750)	(10,938)
Capital expenditures	1,485	740	2,719	1,761
Segment assets	$ 70,787	$ 136,524	$ 70,787	$ 136,524

The amount of depreciation and amortization from continuing operations.

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Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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This element represents the income or loss from continuing operations attributable to the economic entity which may also be defined as revenue less expenses and taxes from ongoing operations before extraordinary items, and noncontrolling interest.

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Amount of income (loss) from a disposal group, net of income tax before extraordinary items allocable to noncontrolling interests. Includes, net of tax, income (loss) from operations during the phase-out period, gain (loss) on disposal, provision (or any reversals of earlier provisions) for loss on disposal, and adjustments of a prior period gain (loss) on disposal.

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Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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The net amount of operating interest income (expense).

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Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements.

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The cash outflow associated with the acquisition of long-lived, physical assets that are used in the normal conduct of business to produce goods and services and not intended for resale; includes cash outflows to pay for construction of self-constructed assets.

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The consolidated profit or loss for the period, net of income taxes, including the portion attributable to the noncontrolling interest.

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Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

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