Segment Information - Summary of Segment Information (Detail) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Segment revenues:
Transactional and maintenance		$ 166,695	$ 153,886	$ 481,604	$ 451,701
Professional services		43,871	44,304	128,698	117,798
License		20,420	40,588	68,662	76,033
Total revenues		230,986	238,778	678,964	645,532
Segment operating expense		(189,557)	(183,459)	(562,567)	(520,855)
Operating income		41,429	55,319	116,397	124,677
Unallocated share-based compensation expense		(14,315)	(13,404)	(43,546)	(41,704)
Unallocated amortization expense	[1]	(3,365)	(3,486)	(9,997)	(10,573)
Restructuring and acquisition-related		(4,471)	0	(4,471)	0
Unallocated interest expense		(6,653)	(6,781)	(19,403)	(20,320)
Unallocated other income, net		555	1,752	128	1,853
Income before income taxes		35,331	50,290	97,122	106,210
Depreciation expense		5,697	4,473	17,044	12,554
Operating Segments
Segment revenues:
Segment operating expense		(167,406)	(166,569)	(504,553)	(468,578)
Operating income		63,580	72,209	174,411	176,954
Unallocated Corporate Expenses
Segment revenues:
Segment operating expense		(26,724)	(29,240)	(76,580)	(75,184)
Operating income		(26,724)	(29,240)	(76,580)	(75,184)
Depreciation expense		331	354	1,021	986
Applications | Operating Segments
Segment revenues:
Transactional and maintenance		87,443	82,925	258,337	244,659
Professional services		35,990	36,560	102,971	95,405
License		10,349	22,080	41,576	43,559
Total revenues		133,782	141,565	402,884	383,623
Segment operating expense		(95,357)	(92,532)	(294,608)	(267,924)
Operating income		38,425	49,033	108,276	115,699
Depreciation expense		3,931	2,961	11,758	8,413
Scores | Operating Segments
Segment revenues:
Transactional and maintenance		68,376	59,781	190,256	174,263
Professional services		487	822	2,002	2,682
License		651	527	2,071	1,303
Total revenues		69,514	61,130	194,329	178,248
Segment operating expense		(14,013)	(14,321)	(41,816)	(42,580)
Operating income		55,501	46,809	152,513	135,668
Depreciation expense		239	211	741	573
Decision Management Software | Operating Segments
Segment revenues:
Transactional and maintenance		10,876	11,180	33,011	32,779
Professional services		7,394	6,922	23,725	19,711
License		9,420	17,981	25,015	31,171
Total revenues		27,690	36,083	81,751	83,661
Segment operating expense		(31,312)	(30,476)	(91,549)	(82,890)
Operating income		(3,622)	5,607	(9,798)	771
Depreciation expense		$ 1,196	$ 947	$ 3,524	$ 2,582

[1] Cost of revenues and selling, general and administrative expenses exclude the amortization of intangible assets. See Note 5.