Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenues:
Total revenues	$ 1,086,427	$ 935,282	$ 840,899
Cost of revenues:
Total cost of revenues	569,527	495,704	441,522
Gross profit	516,900	439,578	399,377
Selling, general and administrative expenses	257,746	207,605	175,914
Research and development expense	81,342	63,264	47,324
Amortization of customer and trade name intangibles	21,445	16,217	13,381
Operating income	156,367	152,492	162,758
Other income, net	3,471	3,378	698
Income before income taxes	159,838	155,870	163,456
Income tax provision (benefit)	13,311	8,408	(6,115)
Net income	$ 146,527	$ 147,462	$ 169,571
Earnings per common share:
Basic (USD per share)	$ 3.79	$ 3.84	$ 4.55
Diluted (USD per share)	$ 3.65	$ 3.68	$ 4.32
Software licenses and royalties
Revenues:
Total revenues	$ 100,205	$ 93,441	$ 86,242
Cost of revenues:
Total cost of revenues	3,938	3,802	3,321
Subscriptions
Revenues:
Total revenues	296,352	220,547	172,176
Software services
Revenues:
Total revenues	213,061	191,269	180,460
Maintenance
Revenues:
Total revenues	430,318	384,521	359,319
Acquired software
Cost of revenues:
Total cost of revenues	30,642	22,972	21,686
Software services, maintenance and subscriptions
Cost of revenues:
Total cost of revenues	502,138	438,923	387,634
Appraisal services
Revenues:
Total revenues	23,479	21,846	25,023
Cost of revenues:
Total cost of revenues	15,337	14,299	16,286
Hardware and other
Revenues:
Total revenues	23,012	23,658	17,679
Cost of revenues:
Total cost of revenues	$ 17,472	$ 15,708	$ 12,595