Condensed Consolidating Financial Statements of Guarantors (Details 3) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
Cash flows from operating activities:
Net income	$ (5,974)	$ 33,878	$ 10,609	$ 35,906	$ (141,140)	$ 33,267	$ 9,900	$ 53,821	$ 74,418	$ (44,152)	$ 136,910
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Impairments and disposals of assets									63,781	214,813	5,269
Depreciation of property, plant and equipment									89,850	60,530	64,883
Amortization of intangible assets									45,556	46,027	45,753
Foreign currency transaction loss (gain)									4,929	1,702	(946)
Amortization and write-off of deferred financing fees									18,791	19,033	22,504
Stock-based compensation									2,845	4,088	2,043
Allowance for doubtful accounts									619	988	(2,587)
Amortization of incremental inventory fair value											2,417
Inventory reserves									6,475	6,006	2,042
Deferred income taxes									(30,261)	(48,881)	(2,137)
Call premium on term loan											(15,075)
Changes in operating assets and liabilities, net of acquisitions:
Accounts receivable									(31,941)	(6,700)	(4,696)
Inventories									(29,093)	(123,071)	(14,350)
Other assets									4,327	372	(3,733)
Accounts payable									46,252	(30,932)	45,753
Accrued expenses and other liabilities									23,971	2,921	27,526
Cash (used in) provided by operating activities									290,519	102,744	311,576
Cash flows from investing activities:
Purchases of property, plant and equipment									(115,460)	(105,207)	(129,220)
Proceeds from sale of buildings and equipment									933	7,188	7,548
Proceeds from sale of powder facility assets									23,983
Cash paid for acquisitions, net of cash acquired											(82,473)
Net cash used in investing activities									(90,544)	(98,019)	(204,145)
Cash flows from financing activities:
Principal payments under long-term agreements									(871)	(378)	(603)
Proceeds from borrowings under the revolver											80,000
Paydowns of debt under the revolver											(80,000)
Proceeds from sale-leaseback									52,826
Payments for financing fees									(611)		(7,387)
Dividends paid									(78,398)	(60,063)	(216,926)
Net cash used in financing activities									(27,054)	(60,441)	(224,916)
Effect of exchange rate changes on cash and cash equivalents									(9,059)	(3,357)	910
Net increase (decrease) in cash and cash equivalents									163,862	(59,073)	(116,575)
Cash and cash equivalents at beginning of year				139,488				198,561	139,488	198,561	315,136
Cash and cash equivalents at end of year	303,350				139,488				303,350	139,488	198,561
Reportable Legal Entities | Parent Company
Cash flows from operating activities:
Net income									74,418	(44,152)	136,910
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Equity in earnings of subsidiaries									132,860	20,328	199,590
Depreciation of property, plant and equipment									16,796	11,956	8,213
Foreign currency transaction loss (gain)											(745)
Amortization and write-off of deferred financing fees									18,791	19,033	22,504
Stock-based compensation									2,461	3,521	1,845
Call premium on term loan											(15,075)
Changes in operating assets and liabilities, net of acquisitions:
Dividends received									63,966	126,596	62,010
Cash (used in) provided by operating activities									43,572	96,626	16,072
Cash flows from investing activities:
Purchases of property, plant and equipment									(33,420)	(22,031)	(35,186)
Proceeds from sale of buildings and equipment											7,548
Investment in subsidiary									7,000	6,500
Cash paid for acquisitions, net of cash acquired											(77,936)
Net cash used in investing activities									(40,420)	(28,531)	(105,574)
Cash flows from financing activities:
Proceeds from borrowings under the revolver											80,000
Paydowns of debt under the revolver											(80,000)
Payments for financing fees									(611)		(7,387)
Dividends paid									(78,398)	(60,063)	(216,926)
Intercompany									162,750	(11,838)	211,510
Net cash used in financing activities									83,741	(71,901)	(12,803)
Net increase (decrease) in cash and cash equivalents									86,893	(3,806)	(102,305)
Cash and cash equivalents at beginning of year				77,550				81,356	77,550	81,356	183,661
Cash and cash equivalents at end of year	164,443				77,550				164,443	77,550	81,356
Reportable Legal Entities | Guarantor Subsidiaries
Cash flows from operating activities:
Net income									11,263	(101,895)	87,010
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Equity in earnings of subsidiaries									18,870	24,086	20,010
Impairments and disposals of assets									62,239	213,314	5,014
Depreciation of property, plant and equipment									48,257	28,234	40,124
Amortization of intangible assets									42,590	42,590	42,341
Foreign currency transaction loss (gain)									4,907	1,372
Stock-based compensation									140	185	72
Allowance for doubtful accounts									598	407	(2,587)
Amortization of incremental inventory fair value											2,417
Inventory reserves									1,728	2,874	2,042
Deferred income taxes									(19,773)	(49,158)	5,293
Changes in operating assets and liabilities, net of acquisitions:
Accounts receivable									(23,422)	(3,956)	9,126
Inventories									1,115	(88,597)	(11,297)
Other assets									(885)	7,451	1,721
Accounts payable									32,774	(56,196)	42,331
Accrued expenses and other liabilities									8,405	(973)	20,544
Dividends received									8,789	25,341	27,589
Intercompany accounts									6,111	545	(44,124)
Cash (used in) provided by operating activities									153,744	(3,638)	295,854
Cash flows from investing activities:
Purchases of property, plant and equipment									(15,317)	(34,701)	(59,039)
Proceeds from sale of buildings and equipment									933	7,178
Proceeds from sale of powder facility assets									23,983
Cash paid for acquisitions, net of cash acquired											(4,537)
Net cash used in investing activities									9,599	(27,523)	(63,576)
Cash flows from financing activities:
Intercompany									(162,750)	(3,445)	(211,510)
Net cash used in financing activities									(162,750)	(3,445)	(211,510)
Net increase (decrease) in cash and cash equivalents									593	(34,606)	20,768
Cash and cash equivalents at beginning of year				751				35,357	751	35,357	14,589
Cash and cash equivalents at end of year	1,344				751				1,344	751	35,357
Reportable Legal Entities | Non-Guarantor Subsidiaries
Cash flows from operating activities:
Net income									140,467	146,309	132,590
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Impairments and disposals of assets									1,542	1,499	255
Depreciation of property, plant and equipment									24,797	20,340	16,546
Amortization of intangible assets									2,966	3,437	3,412
Foreign currency transaction loss (gain)									22	330	(201)
Stock-based compensation									244	382	126
Allowance for doubtful accounts									21	581
Inventory reserves									4,747	3,132
Deferred income taxes									(10,488)	277	(7,430)
Changes in operating assets and liabilities, net of acquisitions:
Accounts receivable									(8,519)	(2,744)	(13,822)
Inventories									(30,208)	(34,474)	(3,053)
Other assets									5,212	(7,079)	(5,454)
Accounts payable									13,478	25,264	3,422
Accrued expenses and other liabilities									15,566	3,894	6,982
Intercompany accounts									(6,111)	(545)	44,124
Cash (used in) provided by operating activities									165,958	161,693	89,249
Cash flows from investing activities:
Purchases of property, plant and equipment									(66,723)	(48,475)	(34,995)
Proceeds from sale of buildings and equipment										10
Net cash used in investing activities									(66,723)	(48,465)	(34,995)
Cash flows from financing activities:
Principal payments under long-term agreements									(871)	(378)	(603)
Proceeds from sale-leaseback									52,826
Dividends paid									(72,755)	(151,937)	(89,599)
Capital contribution									7,000	(6,500)
Intercompany										15,283
Net cash used in financing activities									(13,800)	(130,532)	(90,202)
Effect of exchange rate changes on cash and cash equivalents									(9,059)	(3,357)	910
Net increase (decrease) in cash and cash equivalents									76,376	(20,661)	(35,038)
Cash and cash equivalents at beginning of year				$ 61,187				$ 81,848	61,187	81,848	116,886
Cash and cash equivalents at end of year	$ 137,563				$ 61,187				137,563	61,187	81,848
Eliminations
Cash flows from operating activities:
Net income									(151,730)	(44,414)	(219,600)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Equity in earnings of subsidiaries									(151,730)	(44,414)	(219,600)
Changes in operating assets and liabilities, net of acquisitions:
Dividends received									(72,755)	(151,937)	(89,599)
Cash (used in) provided by operating activities									(72,755)	(151,937)	(89,599)
Cash flows from investing activities:
Investment in subsidiary									(7,000)	(6,500)
Net cash used in investing activities									7,000	6,500
Cash flows from financing activities:
Dividends paid									72,755	151,937	89,599
Capital contribution									(7,000)	6,500
Net cash used in financing activities									65,755	145,437	89,599
As Reported
Cash flows from operating activities:
Net income									74,418	(44,152)	129,480
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Amortization of intangible assets									$ 45,556	$ 46,027	45,753
Deferred income taxes											5,293
Changes in operating assets and liabilities, net of acquisitions:
Cash (used in) provided by operating activities											$ 311,576