Condensed Consolidating Financial Statements of Guarantors (Details 3) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2015	Mar. 31, 2014
Cash flows from operating activities:
Cash (used in) provided by operating activities			$ 204,037	$ (2,069)
Cash flows from investing activities:
Purchases of property, plant and equipment	(26,878)	(25,997)	(45,967)	(47,244)
Proceeds from sale of equipment			260
Net cash used in investing activities			(45,707)	(47,244)
Cash flows from financing activities:
Principal payments under long-term agreements			(255)	(215)
Payments for financing fees			(611)
Dividends paid			(38,750)	(21,313)
Net cash used in financing activities			(39,616)	(21,528)
Effect of exchange rate changes on cash			(7,804)	1,213
Net increase (decrease) in cash and cash equivalents			110,910	(69,628)
Cash and cash equivalents at beginning of period	250,398		139,488	198,561
Cash and cash equivalents at end of period	250,398	128,933	250,398	128,933
Reportable Legal Entities | Parent Company
Cash flows from operating activities:
Cash (used in) provided by operating activities			(20,970)	(11,110)
Cash flows from investing activities:
Purchases of property, plant and equipment			(17,373)	(2,338)
Investment in subsidiary			(7,000)
Net cash used in investing activities			(24,373)	(2,338)
Cash flows from financing activities:
Payments for financing fees			(611)
Dividends paid			(38,750)	(21,313)
Intercompany accounts			156,640	8,700
Net cash used in financing activities			117,279	(12,613)
Net increase (decrease) in cash and cash equivalents			71,936	(26,061)
Cash and cash equivalents at beginning of period			77,550	81,356
Cash and cash equivalents at end of period	149,486	55,295	149,486	55,295
Reportable Legal Entities | Guarantor Subsidiaries
Cash flows from operating activities:
Cash (used in) provided by operating activities			163,021	9,042
Cash flows from investing activities:
Purchases of property, plant and equipment			(4,660)	(29,864)
Proceeds from sale of equipment			260
Net cash used in investing activities			(4,400)	(29,864)
Cash flows from financing activities:
Dividends paid				(5,835)
Intercompany accounts			(156,640)	(8,700)
Net cash used in financing activities			(156,640)	(14,535)
Net increase (decrease) in cash and cash equivalents			1,981	(35,357)
Cash and cash equivalents at beginning of period			751	35,357
Cash and cash equivalents at end of period	2,732		2,732
Reportable Legal Entities | Non-Guarantor Subsidiaries
Cash flows from operating activities:
Cash (used in) provided by operating activities			70,775	16,702
Cash flows from investing activities:
Purchases of property, plant and equipment			(23,934)	(15,042)
Net cash used in investing activities			(23,934)	(15,042)
Cash flows from financing activities:
Principal payments under long-term agreements			(255)	(215)
Dividends paid			(8,789)	(5,835)
Capital contribution			7,000
Net cash used in financing activities			(2,044)	(6,050)
Effect of exchange rate changes on cash			(7,804)	1,213
Net increase (decrease) in cash and cash equivalents			36,993	(3,177)
Cash and cash equivalents at beginning of period			61,187	81,848
Cash and cash equivalents at end of period	98,180	78,671	98,180	78,671
Eliminations
Cash flows from operating activities:
Cash (used in) provided by operating activities			(8,789)	(16,703)
Cash flows from investing activities:
Investment in subsidiary			7,000
Net cash used in investing activities			7,000
Cash flows from financing activities:
Dividends paid			8,789	11,670
Capital contribution			(7,000)
Net cash used in financing activities			1,789	11,670
Net increase (decrease) in cash and cash equivalents				(5,033)
Cash and cash equivalents at end of period		$ (5,033)		$ (5,033)