Condensed Consolidating Financial Information (Details 4) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2011
Cash flows from operating activities:
Net income (loss)	$ 10,253	$ 11,016	$ (8,260)	$ (5,872)	$ (4,906)	$ (13,036)	$ (20,558)	$ (23,748)	$ 7,137	$ (62,248)	$ (229,921)
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Depreciation and amortization									52,317	51,481	64,230
Interest expense related to amortization of debt issue costs and debt discount									5,841	14,184	20,069
Stock-based compensation									1,703	1,737	3,658
Deferred income taxes									698	198	(34)
Net gain on disposition of property, plant and equipment									(649)	(538)	(329)
Gain (loss) on sale of discontinued operations, net of income taxes									55	(267)	0
Gain on convertible debt repayments									(35)	(2,479)	0
Asset impairments and non-cash restructuring costs									0	13,166	86,702
Net income (loss) of unconsolidated joint ventures									0	9,314	(3,990)
Increase in trade receivables									(5,035)	(9,792)	(1,986)
Decrease in inventories									2,221	2,954	3,233
Increase (decrease) in accounts payable and accrued liabilities									(4,218)	27,443	9,336
Other changes in operating assets and liabilities, net									(1,472)	1,016	(2,682)
Net cash provided by (used in) operating activities									58,563	46,169	(51,714)
Cash flows from investing activities:
Payments for acquisitions									(43,250)	(996)	(2,466)
Purchase of property, plant and equipment									(29,119)	(26,447)	(27,381)
Proceeds from disposition of property, plant and equipment									791	1,261	556
Proceeds from sale of discontinued operations									4,813	2,000	0
Proceeds from sale of interests in joint ventures									0	18,522	0
Net change in other assets									(1,608)	(748)	(381)
Net cash used in investing activities									(68,373)	(6,408)	(29,672)
Cash flows from financing activities:
Net proceeds from issuance of long-term debt									0	0	392,942
Proceeds from issuance of common stock									77,957	0	0
Payments on long-term debt									(47,355)	(36,334)	(352,449)
Debt issue costs									0	(1,090)	0
Employee stock purchases									742	635	719
Net cash provided by (used in) financing activities									31,344	(36,789)	41,212
Net increase (decrease) in cash and cash equivalents									21,534	2,972	(40,174)
Cash and cash equivalents, beginning of year				53,782				50,810	53,782	50,810	90,984
Cash and cash equivalents, end of year	75,316				53,782				75,316	53,782	50,810
Guarantor Subsidiaries | Reportable Legal Entities
Cash flows from operating activities:
Net income (loss)									47,117	(13,536)	(113,490)
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Depreciation and amortization									52,027	51,333	64,143
Stock-based compensation									765	673	1,875
Deferred income taxes									698	199	(9,953)
Net gain on disposition of property, plant and equipment									(649)	(538)	(329)
Gain (loss) on sale of discontinued operations, net of income taxes									55	(267)
Asset impairments and non-cash restructuring costs										13,166	86,447
Net income (loss) of unconsolidated joint ventures										9,314	(3,990)
Increase in trade receivables									(5,035)	(9,792)	(1,986)
Decrease in inventories									2,221	2,954	3,233
Increase (decrease) in accounts payable and accrued liabilities									(5,637)	9,646	11,228
Other changes in operating assets and liabilities, net									1,305	(51,803)	6,890
Net cash provided by (used in) operating activities									92,867	11,349	44,068
Cash flows from investing activities:
Payments for acquisitions									(43,250)	(996)	(2,466)
Purchase of property, plant and equipment									(26,940)	(24,419)	(27,381)
Proceeds from disposition of property, plant and equipment									791	1,261	556
Proceeds from sale of discontinued operations									4,813	2,000
Proceeds from sale of interests in joint ventures										18,522
Net change in other assets									(2,184)	(190)	(368)
Net cash used in investing activities									(66,770)	(3,822)	(29,659)
Cash flows from financing activities:
Employee stock purchases									539	462	545
Net cash provided by (used in) financing activities									539	462	545
Net increase (decrease) in cash and cash equivalents									26,636	7,989	14,954
Cash and cash equivalents, beginning of year				44,111				36,122	44,111	36,122	21,168
Cash and cash equivalents, end of year	70,747				44,111				70,747	44,111	36,122
Parent Company | Reportable Legal Entities
Cash flows from operating activities:
Net income (loss)									(39,980)	(48,712)	(116,431)
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Depreciation and amortization									290	148	87
Interest expense related to amortization of debt issue costs and debt discount									5,841	14,184	20,069
Stock-based compensation									938	1,064	1,783
Deferred income taxes										(1)	9,919
Gain on convertible debt repayments									(35)	(2,479)
Asset impairments and non-cash restructuring costs											255
Increase (decrease) in accounts payable and accrued liabilities									1,419	17,797	(1,892)
Other changes in operating assets and liabilities, net									(2,777)	52,819	(9,572)
Net cash provided by (used in) operating activities									(34,304)	34,820	(95,782)
Cash flows from investing activities:
Purchase of property, plant and equipment									(2,179)	(2,028)
Net change in other assets									576	(558)	(13)
Net cash used in investing activities									(1,603)	(2,586)	(13)
Cash flows from financing activities:
Net proceeds from issuance of long-term debt											392,942
Proceeds from issuance of common stock									77,957
Payments on long-term debt									(47,355)	(36,334)	(352,449)
Debt issue costs										(1,090)
Employee stock purchases									203	173	174
Net cash provided by (used in) financing activities									30,805	(37,251)	40,667
Net increase (decrease) in cash and cash equivalents									(5,102)	(5,017)	(55,128)
Cash and cash equivalents, beginning of year				9,671				14,688	9,671	14,688	69,816
Cash and cash equivalents, end of year	$ 4,569				$ 9,671				$ 4,569	$ 9,671	$ 14,688