Goodwill and Intangible Assets (Goodwill And Acquired Intangible Assets) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012 years		Sep. 30, 2011
Goodwill (not amortized), Net Book Value	$ 616,599		$ 613,394
Intangible assets with finite lives (amortized), Gross Carrying Amount	445,289	[1]	443,767	[1]
Intangible assets with finite lives (amortized), Accumulated Amortization	240,161	[1]	221,750	[1]
Intangible assets with finite lives (amortized), Net Book Value	205,128	[1]	222,017	[1]
Total goodwill and acquired intangible asset	821,727		835,411
Purchased Software [Member]
Intangible assets with finite lives (amortized), Gross Carrying Amount	178,658	[1]	178,388	[1]
Intangible assets with finite lives (amortized), Accumulated Amortization	120,584	[1]	112,555	[1]
Intangible assets with finite lives (amortized), Net Book Value	58,074	[1]	65,833	[1]
Acquired finite-lived intangible asset, weighted average useful life	8
Capitalized Software [Member]
Intangible assets with finite lives (amortized), Gross Carrying Amount	22,877	[1]	22,877	[1]
Intangible assets with finite lives (amortized), Accumulated Amortization	22,877	[1]	22,877	[1]
Intangible assets with finite lives (amortized), Net Book Value	0	[1]	0	[1]
Customer Lists and Relationships [Member]
Intangible assets with finite lives (amortized), Gross Carrying Amount	229,175	[1]	227,961	[1]
Intangible assets with finite lives (amortized), Accumulated Amortization	84,735	[1]	75,050	[1]
Intangible assets with finite lives (amortized), Net Book Value	144,440	[1]	152,911	[1]
Acquired finite-lived intangible asset, weighted average useful life	10
Trademarks And Trade Names [Member]
Intangible assets with finite lives (amortized), Gross Carrying Amount	11,079	[1]	11,035	[1]
Intangible assets with finite lives (amortized), Accumulated Amortization	8,587	[1]	7,967	[1]
Intangible assets with finite lives (amortized), Net Book Value	2,492	[1]	3,068	[1]
Acquired finite-lived intangible asset, weighted average useful life	6
Other [Member]
Intangible assets with finite lives (amortized), Gross Carrying Amount	3,500	[1]	3,506	[1]
Intangible assets with finite lives (amortized), Accumulated Amortization	3,378	[1]	3,301	[1]
Intangible assets with finite lives (amortized), Net Book Value	$ 122	[1]	$ 205	[1]
Acquired finite-lived intangible asset, weighted average useful life	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, 6 years, and 4 years, respectively.