Condensed Consolidating Financial Information (Details 4) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2010
Cash flows from operating activities:
Net loss	$ (4,906)	$ (13,036)	$ (20,558)	$ (23,748)	$ (46,732)	$ (6,348)	$ (156,154)	$ (20,687)	$ (62,248)	$ (229,921)	$ (49,482)
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Depreciation and amortization									51,481	64,230	60,398
Asset impairments and non-cash restructuring costs									13,166	86,702	37,962
Interest expense related to amortization of debt issue costs and debt discount									14,184	20,069	16,027
Stock-based compensation									1,737	3,658	5,015
Deferred income taxes									198	(34)	(17,260)
Net gain of unconsolidated joint ventures									9,314	(3,990)	(17,523)
Net gain on disposition of property, plant and equipment									(805)	(329)	(683)
Gain on convertible debt repayments									(2,479)	0	0
Increase in trade receivables									(9,792)	(1,986)	(868)
Decrease in inventories									2,954	3,233	52
Increase (decrease) in accounts payable and accrued liabilities									27,443	9,336	10,000
Other changes in operating assets and liabilities, net									3,016	(2,682)	19,112
Net cash provided by (used in) operating activities									48,169	(51,714)	62,750
Cash flows from investing activities:
Purchase of property, plant and equipment and payments for acquisitions									(27,443)	(29,847)	(26,907)
Proceeds from disposition of property, plant and equipment									1,261	556	3,802
Proceeds from sale of interests in unconsolidated joint ventures and other cash payments from unconsolidated joint venture									18,522	0	17,844
Net decrease (increase) in long-term receivables and deposits									(42)	816	(7,613)
Net change in other assets									(706)	(1,197)	(514)
Net cash used in investing activities									(8,408)	(29,672)	(13,388)
Cash flows from financing activities:
Net proceeds from issuance of long-term debt									0	392,942	316,187
Payments on long-term debt									(36,334)	(352,449)	(288,795)
Other debt issue costs									(1,090)	0	(2,456)
Employee stock purchases									635	719	752
Net cash provided by (used in) financing activities									(36,789)	41,212	25,688
Net increase (decrease) in cash and cash equivalents									2,972	(40,174)	75,050
Cash and cash equivalents, beginning of year				50,810				90,984	50,810	90,984	15,934
Cash and cash equivalents, end of year	53,782				50,810				53,782	50,810	90,984
Guarantor Subsidiaries
Cash flows from operating activities:
Net loss									(13,536)	(113,490)	(19,011)
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Depreciation and amortization									51,333	64,143	60,265
Asset impairments and non-cash restructuring costs									13,166	86,447	37,962
Stock-based compensation									673	1,875	3,083
Deferred income taxes									199	(9,953)	(3,795)
Net gain of unconsolidated joint ventures									9,314	(3,990)	(17,523)
Net gain on disposition of property, plant and equipment									(805)	(329)	(683)
Increase in trade receivables									(9,792)	(1,986)	(868)
Decrease in inventories									2,954	3,233	52
Increase (decrease) in accounts payable and accrued liabilities									9,646	11,228	(7,165)
Other changes in operating assets and liabilities, net									(49,803)	6,890	(14,694)
Net cash provided by (used in) operating activities									13,349	44,068	37,623
Cash flows from investing activities:
Purchase of property, plant and equipment and payments for acquisitions									(25,415)	(29,847)	(26,880)
Proceeds from disposition of property, plant and equipment									1,261	556	3,802
Proceeds from sale of interests in unconsolidated joint ventures and other cash payments from unconsolidated joint venture									18,522		17,844
Net decrease (increase) in long-term receivables and deposits									24	816	(8,613)
Net change in other assets									(214)	(1,184)	(290)
Net cash used in investing activities									(5,822)	(29,659)	(14,137)
Cash flows from financing activities:
Employee stock purchases									462	545	629
Net cash provided by (used in) financing activities									462	545	629
Net increase (decrease) in cash and cash equivalents									7,989	14,954	24,115
Cash and cash equivalents, beginning of year				36,122				21,168	36,122	21,168	(2,947)
Cash and cash equivalents, end of year	44,111				36,122				44,111	36,122	21,168
Parent Company
Cash flows from operating activities:
Net loss									(48,712)	(116,431)	(30,471)
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Depreciation and amortization									148	87	133
Asset impairments and non-cash restructuring costs										255
Interest expense related to amortization of debt issue costs and debt discount									14,184	20,069	16,027
Stock-based compensation									1,064	1,783	1,932
Deferred income taxes									(1)	9,919	(13,465)
Gain on convertible debt repayments									(2,479)
Increase (decrease) in accounts payable and accrued liabilities									17,797	(1,892)	17,165
Other changes in operating assets and liabilities, net									52,819	(9,572)	33,806
Net cash provided by (used in) operating activities									34,820	(95,782)	25,127
Cash flows from investing activities:
Purchase of property, plant and equipment and payments for acquisitions									(2,028)		(27)
Net decrease (increase) in long-term receivables and deposits									(66)		1,000
Net change in other assets									(492)	(13)	(224)
Net cash used in investing activities									(2,586)	(13)	749
Cash flows from financing activities:
Net proceeds from issuance of long-term debt										392,942	316,187
Payments on long-term debt									(36,334)	(352,449)	(288,795)
Other debt issue costs									(1,090)		(2,456)
Employee stock purchases									173	174	123
Net cash provided by (used in) financing activities									(37,251)	40,667	25,059
Net increase (decrease) in cash and cash equivalents									(5,017)	(55,128)	50,935
Cash and cash equivalents, beginning of year				14,688				69,816	14,688	69,816	18,881
Cash and cash equivalents, end of year	$ 9,671				$ 14,688				$ 9,671	$ 14,688	$ 69,816