Summary of Segment Information (Detail) (USD $)	3 Months Ended									12 Months Ended
	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Sep. 30, 2012		Sep. 30, 2011		Sep. 30, 2010
Segment revenues:
Transactional and maintenance										$ 466,175,000		$ 453,430,000		$ 455,487,000
Professional services										124,971,000		115,941,000		102,878,000
License										85,277,000		50,312,000		47,278,000
Total segment revenues	186,075,000	160,478,000	159,521,000	170,349,000	160,249,000	150,679,000	152,824,000	155,931,000		676,423,000		619,683,000		605,643,000
Segment operating expense										(474,767,000)		(456,714,000)		(462,471,000)
Segment operating income										201,656,000		162,969,000		143,172,000
Unallocated share-based compensation expense										(21,229,000)		(15,500,000)		(17,305,000)
Unallocated amortization expense										(6,944,000)	[1]	(7,741,000)	[1]	(10,901,000)	[1]
Unallocated restructuring and acquisition-related	(5,125,000)						(11,500,000)	(900,000)	(1,600,000)	(5,125,000)		(12,391,000)		(1,617,000)
Unallocated restructuring expense										(3,978,000)		(12,391,000)		(1,617,000)
Operating income										168,358,000		127,337,000		113,349,000
Unallocated interest income										317,000		2,192,000		1,688,000
Unallocated interest expense										(31,734,000)		(32,364,000)		(24,124,000)
Unallocated other income (expense), net										(698,000)		290,000		1,391,000
Income before income taxes										136,243,000		97,455,000		92,304,000
Depreciation expense										14,605,000		16,456,000		20,017,000
Applications
Segment revenues:
Transactional and maintenance										263,726,000		258,736,000		257,275,000
Professional services										104,637,000		100,921,000		86,097,000
License										56,241,000		23,371,000		23,886,000
Total segment revenues										424,604,000		383,028,000		367,258,000
Segment operating expense										(291,778,000)		(276,467,000)		(273,983,000)
Segment operating income										132,826,000		106,561,000		93,275,000
Depreciation expense										11,321,000		12,784,000		14,998,000
Scores
Segment revenues:
Transactional and maintenance										172,218,000		164,918,000		170,141,000
Professional services										2,382,000		2,102,000		2,042,000
License										1,023,000		1,547,000		156,000
Total segment revenues										175,623,000		168,567,000		172,339,000
Segment operating expense										(52,687,000)		(55,169,000)		(61,688,000)
Segment operating income										122,936,000		113,398,000		110,651,000
Depreciation expense										724,000		1,007,000		1,339,000
Tools
Segment revenues:
Transactional and maintenance										30,231,000		29,776,000		28,071,000
Professional services										17,952,000		12,918,000		14,739,000
License										28,013,000		25,394,000		23,236,000
Total segment revenues										76,196,000		68,088,000		66,046,000
Segment operating expense										(58,597,000)		(54,398,000)		(57,634,000)
Segment operating income										17,599,000		13,690,000		8,412,000
Depreciation expense										1,258,000		1,667,000		2,147,000
Unallocated Corporate Expenses
Segment revenues:
Segment operating expense										(71,705,000)		(70,680,000)		(69,166,000)
Segment operating income										(71,705,000)		(70,680,000)		(69,166,000)
Depreciation expense										$ 1,302,000		$ 998,000		$ 1,533,000

[1] Cost of revenues and selling, general and administrative expenses exclude the amortization of intangible assets. See Note 7 to consolidated financial statements.