Goodwill and Acquired Intangible Assets (Goodwill and Acquired Intangible Assets) (Details) (USD $) In Thousands, unless otherwise specified						12 Months Ended								12 Months Ended				12 Months Ended				12 Months Ended
	Sep. 30, 2012		Sep. 30, 2011		Sep. 30, 2010	Sep. 30, 2012 Purchased Software [Member] Y		Sep. 30, 2011 Purchased Software [Member]		Sep. 30, 2012 Capitalized Software [Member]		Sep. 30, 2011 Capitalized Software [Member]		Sep. 30, 2012 Customer Lists and Relationships [Member] Y		Sep. 30, 2011 Customer Lists and Relationships [Member]		Sep. 30, 2012 Trademarks And Trade Names [Member] Y		Sep. 30, 2011 Trademarks And Trade Names [Member]		Sep. 30, 2012 Other [Member] Y		Sep. 30, 2011 Other [Member]
Goodwill (not amortized), Net Book Value	$ 610,347		$ 613,394		$ 418,509
Intangible assets with finite lives (amortized), Gross Carrying Amount	441,590	[1]	443,767	[1]		177,166	[1]	178,388	[1]	22,877	[1]	22,877	[1]	227,097	[1]	227,961	[1]	11,013	[1]	11,035	[1]	3,437	[1]	3,506	[1]
Intangible assets with finite lives (amortized), Accumulated Amortization	255,705	[1]	221,750	[1]		127,250	[1]	112,555	[1]	22,877	[1]	22,877	[1]	93,215	[1]	75,050	[1]	8,967	[1]	7,967	[1]	3,396	[1]	3,301	[1]
Intangible assets with finite lives (amortized), Net Book Value	185,885	[1]	222,017	[1]		49,916	[1]	65,833	[1]	0	[1]	0	[1]	133,882	[1]	152,911	[1]	2,046	[1]	3,068	[1]	41	[1]	205	[1]
Total goodwill and acquired intangible assets	$ 796,232		$ 835,411
Weighted average useful lives (in years)						8								10				7				4

[1] The weighted average useful lives of purchased software, customer lists and relationships, trademarks and trade names and other intangible assets with a remaining net book value are 8 years, 10 years, 7 years and 4 years, respectively.