Condensed Consolidating Financial Statements of Guarantors (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2012
Condensed Consolidating Financial Statements of Guarantors
Ownership percentage in subsidiary	100.00%		100.00%
Current Assets
Other current assets	$ 79,447		$ 79,447			$ 78,579
Total current assets	1,271,920		1,271,920			1,212,399
Other assets	60,106		60,106			68,235
Total assets	5,119,383		5,119,383			5,073,316
Current liabilities:
Total current liabilities	465,138		465,138			479,202
Deferred income taxes	747,014		747,014			751,419
Total liabilities	3,436,320		3,436,320			3,448,477
Stockholder's equity:
Capital in excess of par	1,559,482		1,559,482			1,556,926
Retained earnings	123,905		123,905			81,497
Accumulated other comprehensive income (loss)	(324)	(58,697)	(324)	(58,697)	(303)	(13,584)	(18,565)	(18,594)
Total stockholder's equity	1,683,063		1,683,063			1,624,839
Total liabilities and stockholder's equity	5,119,383		5,119,383			5,073,316
Consolidated Statements of Operations and Comprehensive Income (Loss)
Selling, general and administrative	238,894	231,431	471,577	450,940
Income (loss) from operations	50,268	23,490	164,450	128,615
Total other income (expense)	(34,800)	(41,540)	(68,629)	(78,224)
Income (loss) before income taxes	15,468	(18,050)	95,821	50,391
Provision (benefit) for income taxes	5,568	(7,649)	32,100	15,621
Net income (loss)	9,900	(10,401)	63,721	34,770
Foreign currency translation adjustment, net of taxes	(706)	(41,085)	11,489	(42,364)
Change in fair value of interest rate swaps, net of taxes	684	953	1,769	2,261
Comprehensive income (loss)	9,878	(50,533)	76,979	(5,333)
Statements of cash flows
Cash (used in) provided by operating activities			(2,069)	142,087
Cash paid for acquisitions, net of cash acquired				(78,550)
Net cash used in investing activities			(47,244)	(134,694)
Dividends paid			(21,313)	(193,956)
Cash used in financing activities			(21,528)	(176,343)
Parent Company | As Reported
Current Assets
Intercompany						857,700
Total current assets						939,000
Intercompany						323,300
Investments in subsidiaries						3,211,100
Total assets						4,562,000
Current liabilities:
Total current liabilities						38,400
Deferred income taxes						721,800
Total liabilities						2,937,200
Stockholder's equity:
Capital in excess of par						1,556,900
Retained earnings						81,500
Accumulated other comprehensive income (loss)						(13,600)
Total stockholder's equity						1,624,800
Total liabilities and stockholder's equity						4,562,000
Consolidated Statements of Operations and Comprehensive Income (Loss)
Selling, general and administrative		63,900		86,700
Income (loss) from operations		(63,900)		(86,700)
Intercompany interest		2,400		4,900
Total other income (expense)		(39,500)		(74,100)
Income (loss) before income taxes		(103,400)		(160,800)
Provision (benefit) for income taxes		(34,400)		(52,300)
Equity in income of subsidiaries		58,600		143,300
Net income (loss)		(10,400)		34,800
Change in fair value of interest rate swaps, net of taxes		13,500		14,200
Comprehensive income (loss)		3,100		49,000
Statements of cash flows
Cash (used in) provided by operating activities				128,600
Cash paid for acquisitions, net of cash acquired				(78,100)
Net cash used in investing activities				(88,700)
Dividends paid				(194,000)
Cash used in financing activities				(176,300)
Guarantor Subsidiaries | As Reported
Current Assets
Other current assets						43,100
Total current assets						790,700
Other assets						68,200
Total assets						3,583,300
Current liabilities:
Intercompany						1,121,800
Total current liabilities						1,424,300
Deferred income taxes						22,000
Total liabilities						1,464,000
Stockholder's equity:
Capital in excess of par						352,000
Retained earnings						1,767,300
Total stockholder's equity						2,119,300
Total liabilities and stockholder's equity						3,583,300
Consolidated Statements of Operations and Comprehensive Income (Loss)
Selling, general and administrative		83,800		193,700
Income (loss) from operations		39,500		122,000
Total other income (expense)		800		2,900
Income (loss) before income taxes		40,200		124,800
Provision (benefit) for income taxes		14,100		43,700
Net income (loss)		26,200		81,100
Comprehensive income (loss)		26,200		81,100
Statements of cash flows
Cash (used in) provided by operating activities				18,600
Cash paid for acquisitions, net of cash acquired				(500)
Net cash used in investing activities				(30,400)
Non-Guarantor Subsidiaries | As Reported
Current Assets
Intercompany						264,100
Other current assets						35,400
Total current assets						604,400
Other assets						100
Total assets						1,584,100
Current liabilities:
Total current liabilities						135,200
Intercompany						323,300
Deferred income taxes						7,500
Total liabilities						492,300
Stockholder's equity:
Capital in excess of par						301,300
Retained earnings						789,300
Accumulated other comprehensive income (loss)						1,200
Total stockholder's equity						1,091,800
Total liabilities and stockholder's equity						1,584,100
Consolidated Statements of Operations and Comprehensive Income (Loss)
Selling, general and administrative		83,700		170,500
Income (loss) from operations		47,900		93,400
Intercompany interest		(2,400)		(4,900)
Total other income (expense)		(2,800)		(7,000)
Income (loss) before income taxes		45,100		86,400
Provision (benefit) for income taxes		12,600		24,200
Net income (loss)		32,500		62,200
Foreign currency translation adjustment, net of taxes		(53,600)		(54,300)
Comprehensive income (loss)		(21,200)		7,900
Statements of cash flows
Cash (used in) provided by operating activities				(5,100)
Net cash used in investing activities				(15,600)
Reportable Legal Entities | Parent Company
Current Assets
Intercompany	32,716		32,716			34,549
Other current assets	19,476		19,476			19,033
Total current assets	107,487		107,487			134,938
Other assets	51,368		51,368			61,218
Intercompany	2,490,442		2,490,442			2,480,760
Investments in subsidiaries	2,282,832		2,282,832			2,180,814
Total assets	5,005,847		5,005,847			4,946,342
Current liabilities:
Intercompany	67,856		67,856
Total current liabilities	104,903		104,903			38,407
Intercompany	1,021,342		1,021,342			1,091,982
Deferred income taxes	14,151		14,151			14,151
Total liabilities	3,322,784		3,322,784			3,321,503
Stockholder's equity:
Capital in excess of par	1,559,482		1,559,482			1,556,926
Retained earnings	123,905		123,905			81,497
Accumulated other comprehensive income (loss)	(324)		(324)			(13,584)
Total stockholder's equity	1,683,063		1,683,063			1,624,839
Total liabilities and stockholder's equity	5,005,847		5,005,847			4,946,342
Consolidated Statements of Operations and Comprehensive Income (Loss)
Selling, general and administrative	27,813	33,681	50,085	56,518
Income (loss) from operations	(27,813)	(33,681)	(50,085)	(56,518)
Intercompany interest	39,121	44,055	78,829	83,803
Total other income (expense)	5,012	2,170	10,832	4,768
Income (loss) before income taxes	(22,801)	(31,511)	(39,253)	(51,750)
Provision (benefit) for income taxes	51	(7,954)	(5,318)	(14,081)
Equity in income of subsidiaries	32,752	13,156	97,656	72,439
Net income (loss)	9,900	(10,401)	63,721	34,770
Foreign currency translation adjustment, net of taxes	(706)	(41,085)	11,489	(42,364)
Change in fair value of interest rate swaps, net of taxes	684	953	1,769	2,261
Comprehensive income (loss)	9,878	(50,533)	76,979	(5,333)
Statements of cash flows
Cash (used in) provided by operating activities			(11,110)	14,509
Cash paid for acquisitions, net of cash acquired				(78,089)
Net cash used in investing activities			(2,338)	(88,681)
Dividends paid			(21,313)	(193,956)
Cash used in financing activities			(12,613)	(62,276)
Reportable Legal Entities | Guarantor Subsidiaries
Current Assets
Other current assets	25,492		25,492			24,104
Total current assets	850,079		850,079			771,635
Other assets	8,648		8,648			6,938
Intercompany	1,025,750		1,025,750			1,062,900
Total assets	4,598,507		4,598,507			4,565,976
Current liabilities:
Intercompany	32,716		32,716			34,549
Total current liabilities	346,260		346,260			340,126
Intercompany	2,161,910		2,161,910			2,157,500
Deferred income taxes	633,316		633,316			637,726
Total liabilities	3,157,043		3,157,043			3,150,002
Stockholder's equity:
Capital in excess of par	1,211,581		1,211,581			1,211,581
Retained earnings	232,016		232,016			208,295
Accumulated other comprehensive income (loss)	(2,133)		(2,133)			(3,902)
Total stockholder's equity	1,441,464		1,441,464			1,415,974
Total liabilities and stockholder's equity	4,598,507		4,598,507			4,565,976
Consolidated Statements of Operations and Comprehensive Income (Loss)
Selling, general and administrative	113,790	114,024	230,670	223,906
Income (loss) from operations	22,388	9,274	105,592	91,773
Intercompany interest	(34,204)	(41,668)	(69,002)	(78,891)
Total other income (expense)	(35,252)	(40,893)	(69,098)	(76,019)
Income (loss) before income taxes	(12,864)	(31,619)	36,494	15,754
Provision (benefit) for income taxes	(5,843)	(12,343)	12,773	5,514
Net income (loss)	(7,021)	(19,276)	23,721	10,240
Change in fair value of interest rate swaps, net of taxes	684	953	1,769	2,261
Comprehensive income (loss)	(6,337)	(18,323)	25,490	12,501
Statements of cash flows
Cash (used in) provided by operating activities			9,042	184,619
Net cash used in investing activities			(29,864)	(29,983)
Dividends paid			(5,835)	(52,416)
Cash used in financing activities			(14,535)	(166,483)
Reportable Legal Entities | Non-Guarantor Subsidiaries
Current Assets
Intercompany	67,856		67,856
Other current assets	34,479		34,479			35,442
Total current assets	419,959		419,959			340,375
Other assets	90		90			79
Intercompany						29,082
Total assets	1,419,658		1,419,658			1,349,103
Current liabilities:
Total current liabilities	119,580		119,580			135,218
Intercompany	332,940		332,940			323,260
Deferred income taxes	99,547		99,547			99,542
Total liabilities	578,290		578,290			584,263
Stockholder's equity:
Capital in excess of par	733,411		733,411			733,411
Retained earnings	98,298		98,298			30,198
Accumulated other comprehensive income (loss)	9,659		9,659			1,231
Total stockholder's equity	841,368		841,368			764,840
Total liabilities and stockholder's equity	1,419,658		1,419,658			1,349,103
Consolidated Statements of Operations and Comprehensive Income (Loss)
Selling, general and administrative	97,291	83,726	190,822	170,516
Income (loss) from operations	55,693	47,897	108,943	93,360
Intercompany interest	(4,917)	(2,387)	(9,827)	(4,912)
Total other income (expense)	(4,560)	(2,817)	(10,363)	(6,973)
Income (loss) before income taxes	51,133	45,080	98,580	86,387
Provision (benefit) for income taxes	11,360	12,648	24,645	24,188
Net income (loss)	39,773	32,432	73,935	62,199
Foreign currency translation adjustment, net of taxes	(1,486)	(35,268)	8,429	(32,465)
Comprehensive income (loss)	38,287	(2,836)	82,364	29,734
Statements of cash flows
Cash (used in) provided by operating activities			16,702	47,791
Cash paid for acquisitions, net of cash acquired				(461)
Net cash used in investing activities			(15,042)	(16,030)
Dividends paid			(5,835)	(52,416)
Cash used in financing activities			(6,050)	(52,416)
Eliminations
Current Assets
Intercompany	(100,572)		(100,572)			(34,549)
Total current assets	(105,605)		(105,605)			(34,549)
Intercompany	(3,516,192)		(3,516,192)			(3,572,742)
Investments in subsidiaries	(2,282,832)		(2,282,832)			(2,180,814)
Total assets	(5,904,629)		(5,904,629)			(5,788,105)
Current liabilities:
Intercompany	(100,572)		(100,572)			(34,549)
Total current liabilities	(105,605)		(105,605)			(34,549)
Intercompany	(3,516,192)		(3,516,192)			(3,572,742)
Total liabilities	(3,621,797)		(3,621,797)			(3,607,291)
Stockholder's equity:
Capital in excess of par	(1,944,992)		(1,944,992)			(1,944,992)
Retained earnings	(330,314)		(330,314)			(238,493)
Accumulated other comprehensive income (loss)	(7,526)		(7,526)			2,671
Total stockholder's equity	(2,282,832)		(2,282,832)			(2,180,814)
Total liabilities and stockholder's equity	(5,904,629)		(5,904,629)			(5,788,105)
Consolidated Statements of Operations and Comprehensive Income (Loss)
Equity in income of subsidiaries	(32,752)	(13,156)	(97,656)	(72,439)
Net income (loss)	(32,752)	(13,156)	(97,656)	(72,439)
Foreign currency translation adjustment, net of taxes	1,486	35,268	(8,429)	32,465
Change in fair value of interest rate swaps, net of taxes	(684)	(953)	(1,769)	(2,261)
Comprehensive income (loss)	(31,950)	21,159	(107,854)	(42,235)
Statements of cash flows
Cash (used in) provided by operating activities			(16,703)	(104,832)
Dividends paid			11,670	104,832
Cash used in financing activities			11,670	104,832
Eliminations | As Reported
Current Assets
Intercompany						(1,121,800)
Total current assets						(1,121,800)
Intercompany						(323,300)
Investments in subsidiaries						(3,211,100)
Total assets						(4,656,100)
Current liabilities:
Intercompany						(1,121,800)
Total current liabilities						(1,121,800)
Intercompany						(323,300)
Total liabilities						(1,445,000)
Stockholder's equity:
Capital in excess of par						(653,300)
Retained earnings						(2,556,600)
Accumulated other comprehensive income (loss)						(1,200)
Total stockholder's equity						(3,211,100)
Total liabilities and stockholder's equity						(4,656,100)
Consolidated Statements of Operations and Comprehensive Income (Loss)
Equity in income of subsidiaries		(58,600)		(143,300)
Net income (loss)		(58,600)		(143,300)
Comprehensive income (loss)		$ (58,600)		$ (143,300)