Segment and Related Information - Schedule of Segment Revenues and Operations (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Segment Reporting Information [Line Items]
Software licenses and royalties	$ 19,930	$ 15,690	$ 54,331	$ 44,576
Subscriptions	36,869	29,036	104,926	81,273
Software services	44,738	36,398	133,208	101,765
Maintenance	83,000	61,018	237,775	177,829
Appraisal services	6,541	6,557	20,083	19,337
Hardware and other	3,419	2,146	12,439	7,326
Total revenues	194,497	150,845	562,762	432,106
Segment operating income	46,001	33,323	122,911	93,312
Operating segments [Member] | Enterprise Software [Member]
Segment Reporting Information [Line Items]
Software licenses and royalties	18,492	14,680	50,585	40,563
Subscriptions	35,169	27,772	99,470	77,814
Software services	40,608	33,210	121,372	94,203
Maintenance	78,292	56,451	223,802	164,457
Hardware and other	3,428	2,162	9,406	4,632
Intercompany	1,971	1,014	4,743	2,919
Total revenues	177,960	135,289	509,378	384,588
Segment operating income	52,372	37,853	139,151	104,513
Operating segments [Member] | Appraisal and Tax [Member]
Segment Reporting Information [Line Items]
Software licenses and royalties	1,438	1,010	3,746	4,013
Subscriptions	1,700	1,264	5,456	3,459
Software services	4,130	3,188	11,836	7,562
Maintenance	4,708	4,567	13,973	13,372
Appraisal services	6,541	6,557	20,083	19,337
Hardware and other			16	11
Total revenues	18,517	16,586	55,110	47,754
Segment operating income	4,713	4,420	13,534	11,391
Corporate [Member]
Segment Reporting Information [Line Items]
Hardware and other	(9)	(16)	3,017	2,683
Intercompany	(1,971)	(1,014)	(4,743)	(2,919)
Total revenues	(1,980)	(1,030)	(1,726)	(236)
Segment operating income	$ (11,084)	$ (8,950)	$ (29,774)	$ (22,592)