Summary of Segment Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2013		Sep. 30, 2012		Sep. 30, 2011
Segment revenues:
Transactional and maintenance									$ 514,304		$ 466,175		$ 453,430
Professional services									135,194		124,971		115,941
License									93,946		85,277		50,312
Total segment revenues	190,327	183,772	179,325	190,020	186,075	160,478	159,521	170,349	743,444		676,423		619,683
Segment operating expense									(581,851)		(508,065)		(492,346)
Unallocated share-based compensation expense									(25,850)		(21,229)		(15,500)
Unallocated amortization expense	(1,700)	(1,700)	(1,700)	(1,500)	(500)	(100)	(100)	(600)	(13,535)	[1]	(6,944)	[1]	(7,741)	[1]
Unallocated restructuring and acquisition-related									(3,486)		(5,125)		(12,391)
Unallocated restructuring and acquisition-related									(2,719)		(3,978)		(12,391)
Operating income									161,593		168,358		127,337
Unallocated interest income									54		317		2,192
Unallocated interest expense									(30,281)		(31,734)		(32,364)
Unallocated other expense, net									618		(698)		290
Income before income taxes									131,984		136,243		97,455
Depreciation expense									19,679		14,605		16,456
Applications
Segment revenues:
Transactional and maintenance									306,738		263,726		258,736
Professional services									110,081		104,637		100,921
License									59,265		56,241		23,371
Total segment revenues									476,084		424,604		383,028
Depreciation expense									14,171		11,321		12,784
Scores
Segment revenues:
Transactional and maintenance									175,281		172,218		164,918
Professional services									4,012		2,382		2,102
License									1,520		1,023		1,547
Total segment revenues									180,813		175,623		168,567
Depreciation expense									867		724		1,007
Tools
Segment revenues:
Transactional and maintenance									32,285		30,231		29,776
Professional services									21,101		17,952		12,918
License									33,161		28,013		25,394
Total segment revenues									86,547		76,196		68,088
Depreciation expense									1,998		1,258		1,667
Unallocated Corporate Expenses
Segment revenues:
Depreciation expense									2,643		1,302		998
Operating Segments
Segment revenues:
Segment operating expense									(538,980)		(474,767)		(456,714)
Operating income									204,464		201,656		162,969
Operating Segments | Applications
Segment revenues:
Segment operating expense									(346,222)		(291,778)		(276,467)
Operating income									129,862		132,826		106,561
Operating Segments | Scores
Segment revenues:
Segment operating expense									(51,781)		(52,687)		(55,169)
Operating income									129,032		122,936		113,398
Operating Segments | Tools
Segment revenues:
Segment operating expense									(70,011)		(58,597)		(54,398)
Operating income									16,536		17,599		13,690
Operating Segments | Unallocated Corporate Expenses
Segment revenues:
Segment operating expense									(70,966)		(71,705)		(70,680)
Operating income									$ (70,966)		$ (71,705)		$ (70,680)

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