Segment And Related Information (Schedule Of Segment Revenues And Operations) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2010	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Segment Reporting Information [Line Items]
Software licenses									$ 33,172	$ 32,594	$ 34,913
Subscriptions									44,618	31,160	23,298
Software services									83,408	69,617	68,340
Maintenance									171,851	146,498	135,655
Appraisal services									22,543	23,228	20,554
Hardware and other									7,712	6,294	5,868
Total revenues	95,368	93,845	91,368	82,723	82,079	77,184	76,735	73,393	363,304	309,391	288,628
Depreciation and amortization expense									12,711	10,676	10,788
Segment operating income									62,744	50,973	46,458
Capital expenditures									10,716	12,278	3,620
Segment assets	338,315				295,391				338,315	295,391	264,032
Enterprise Software Solutions [Member]
Segment Reporting Information [Line Items]
Software licenses									31,304	30,194	32,757
Subscriptions									43,319	30,400	22,975
Software services									76,103	60,840	58,371
Maintenance									155,290	130,999	120,764
Hardware and other									6,053	5,199	5,727
Intercompany									2,249	2,103	1,978
Total revenues									314,318	259,735	242,572
Depreciation and amortization expense									9,929	8,516	8,903
Segment operating income									71,135	56,856	51,942
Capital expenditures									5,469	11,143	2,960
Segment assets	134,220				119,595				134,220	119,595	100,508
Appraisal And Tax Software Solutions And Services [Member]
Segment Reporting Information [Line Items]
Software licenses									1,868	2,400	2,156
Subscriptions									1,299	760	323
Software services									7,305	8,777	9,969
Maintenance									16,561	15,499	14,891
Appraisal services									22,543	23,228	20,554
Hardware and other											6
Total revenues									49,576	50,664	47,899
Depreciation and amortization expense									958	650	683
Segment operating income									8,498	9,786	8,883
Capital expenditures									3,382	137	350
Segment assets	18,464				20,535				18,464	20,535	23,929
Corporate [Member]
Segment Reporting Information [Line Items]
Hardware and other									1,659	1,095	135
Intercompany									(2,249)	(2,103)	(1,978)
Total revenues									(590)	(1,008)	(1,843)
Depreciation and amortization expense									1,824	1,510	1,202
Segment operating income									(16,889)	(15,669)	(14,367)
Capital expenditures									1,865	998	310
Segment assets	$ 185,631				$ 155,261				$ 185,631	$ 155,261	$ 139,595