Condensed Consolidating Financial Information (Details 4) (USD $) In Thousands, unless otherwise specified	3 Months Ended			6 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2014	Mar. 31, 2013
Cash flows from operating activities:
Net income (loss)	$ (10,082)	$ (8,260)		$ (11,516)	$ (14,132)
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Depreciation and amortization				26,460	25,582
Interest expense related to amortization of debt issue costs and debt discount	600	1,900		1,153	3,165
Stock-based compensation	500	400		1,016	821
Deferred income taxes				214	55
Net gain on disposition of property, plant and equipment				373	(673)
Gain on sale of discontinued operations, net of income taxes				(3,117)	(3,110)
Net loss of unconsolidated joint ventures				133	0
Decrease in trade receivables				30,911	31,676
Decrease (increase) in inventories				(9,754)	(5,960)
Decrease in accounts payable and accrued liabilities				(23,598)	(28,334)
Other changes in operating assets and liabilities, net				(5,530)	(8,133)
Net cash provided by operating activities				6,745	957
Cash flows from investing activities:
Payments for acquisitions				(60,619)	(43,250)
Payments for investments in unconsolidated joint ventures				(1,000)	0
Purchase of property, plant and equipment	(9,056)	(7,854)		(15,944)	(14,407)
Proceeds from disposition of property, plant and equipment				358	789
Proceeds from sale of discontinued operations				4,666	3,813
Net decrease (increase) in long-term receivables and deposits				5,825	(799)
Net change in other assets				24	(466)
Net cash used in investing activities				(66,690)	(54,320)
Cash flows from financing activities:
Net proceeds from issuance of common stock			78,000	0	77,957
Net proceeds from issuance of long-term debt				146,200	0
Payments on long-term debt				(7,792)	(15,217)
Employee stock purchases				454	454
Net cash provided by financing activities				138,862	63,194
Net increase in cash and cash equivalents				78,917	9,831
Cash and cash equivalents, beginning of period			53,782	75,316	53,782
Cash and cash equivalents, end of period	154,233	63,613		154,233	63,613
Eliminations
Cash flows from operating activities:
Net income (loss)	(3,574)	(5,172)		(15,225)	(12,712)
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Equity in earnings of subsidiaries	3,574	5,172		15,225	12,712
Guarantor Subsidiaries
Cash flows from operating activities:
Net income (loss)	2,894	5,172		14,619	12,712
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Depreciation and amortization				25,582	25,449
Stock-based compensation				404	381
Deferred income taxes				214	55
Net gain on disposition of property, plant and equipment				328	(673)
Gain on sale of discontinued operations, net of income taxes				(3,117)	(3,110)
Decrease in trade receivables				30,264	31,676
Decrease (increase) in inventories				(11,139)	(5,960)
Decrease in accounts payable and accrued liabilities				(21,882)	(20,707)
Other changes in operating assets and liabilities, net				(15,224)	22,303
Net cash provided by operating activities				20,049	62,126
Cash flows from investing activities:
Payments for acquisitions				(3,100)	(43,250)
Purchase of property, plant and equipment				(13,505)	(13,220)
Proceeds from disposition of property, plant and equipment				358	789
Proceeds from sale of discontinued operations				4,666	3,813
Net decrease (increase) in long-term receivables and deposits				5,527	(1,490)
Net change in other assets				(192)	(295)
Net cash used in investing activities				(6,246)	(53,653)
Cash flows from financing activities:
Employee stock purchases				344	319
Net cash provided by financing activities				344	319
Net increase in cash and cash equivalents				14,147	8,792
Cash and cash equivalents, beginning of period			44,111	70,713	44,111
Cash and cash equivalents, end of period	84,860	52,903		84,860	52,903
Non-Guarantor Subsidiaries
Cash flows from operating activities:
Net income (loss)	916			836
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Depreciation and amortization				748
Net loss of unconsolidated joint ventures				133
Decrease in trade receivables				647
Decrease (increase) in inventories				1,385
Decrease in accounts payable and accrued liabilities				(331)
Other changes in operating assets and liabilities, net				1,320
Net cash provided by operating activities				4,738
Cash flows from investing activities:
Payments for investments in unconsolidated joint ventures				(1,000)
Purchase of property, plant and equipment				(678)
Net cash used in investing activities				(1,678)
Cash flows from financing activities:
Net increase in cash and cash equivalents				3,060
Cash and cash equivalents, beginning of period				34
Cash and cash equivalents, end of period	3,094			3,094
Parent Company
Cash flows from operating activities:
Net income (loss)	(10,318)	(8,260)		(11,746)	(14,132)
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Depreciation and amortization				130	133
Interest expense related to amortization of debt issue costs and debt discount				1,153	3,165
Stock-based compensation				612	440
Net gain on disposition of property, plant and equipment				45
Equity in earnings of subsidiaries	(3,574)	(5,172)		(15,225)	(12,712)
Decrease in accounts payable and accrued liabilities				(1,385)	(7,627)
Other changes in operating assets and liabilities, net				8,374	(30,436)
Net cash provided by operating activities				(18,042)	(61,169)
Cash flows from investing activities:
Payments for acquisitions				(57,519)
Purchase of property, plant and equipment				(1,761)	(1,187)
Net decrease (increase) in long-term receivables and deposits				298	691
Net change in other assets				216	(171)
Net cash used in investing activities				(58,766)	(667)
Cash flows from financing activities:
Net proceeds from issuance of common stock					77,957
Net proceeds from issuance of long-term debt				146,200
Payments on long-term debt				(7,792)	(15,217)
Employee stock purchases				110	135
Net cash provided by financing activities				138,518	62,875
Net increase in cash and cash equivalents				61,710	1,039
Cash and cash equivalents, beginning of period			9,671	4,569	9,671
Cash and cash equivalents, end of period	$ 66,279	$ 10,710		$ 66,279	$ 10,710