Property And Equipment (Details) (USD $)	12 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2009
Property And Equipment [Abstract]
Computer hardware and software	$ 213,362,000	$ 189,987,000
Furniture and fixtures	20,608,000	18,557,000
Leasehold improvements	42,453,000	38,694,000
Gross property and equipment	276,423,000	247,238,000
Accumulated depreciation and amortization	(213,854,000)	(189,174,000)
Net property and equipment	62,569,000	58,064,000	58,105,000
Depreciation expense	$ 28,700,000	$ 28,200,000	$ 26,300,000