SEGMENT AND RELATED INFORMATION - Schedule of Segment Revenues and Operations (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Segment Reporting Information
Total revenues	$ 1,951,751	$ 1,850,204	$ 1,592,287
Depreciation and amortization expense	154,079	159,072	135,624
Segment operating income	218,537	214,249	180,735
Software development expenditures	32,490	27,622	21,693
Capital expenditures	20,519	22,529	33,919
Total assets	4,676,663	4,687,417	4,732,161
Operating segments | Enterprise Software
Segment Reporting Information
Total revenues	1,373,221	1,278,822	1,165,576
Depreciation and amortization expense	25,445	55,389	54,011
Segment operating income	443,756	418,776	401,382
Software development expenditures	6,619	3,790	3,504
Capital expenditures	16,788	8,972	19,213
Total assets	631,117	636,377	601,390
Operating segments | Platform Technologies
Segment Reporting Information
Total revenues	594,766	587,196	445,717
Depreciation and amortization expense	110,354	84,609	55,539
Segment operating income	124,446	123,291	92,582
Software development expenditures	15,840	14,581	12,332
Capital expenditures	2,380	6,845	3,696
Total assets	426,064	362,610	359,919
Intercompany
Segment Reporting Information
Total revenues	(23,566)	(21,636)	(22,033)
Intercompany | Enterprise Software
Segment Reporting Information
Total revenues	23,566	21,636	22,033
Intercompany | Platform Technologies
Segment Reporting Information
Total revenues	0	0	0
Corporate
Segment Reporting Information
Total revenues	(16,236)	(15,814)	(19,006)
Depreciation and amortization expense	18,280	19,074	26,074
Segment operating income	(238,971)	(214,263)	(222,779)
Software development expenditures	10,031	9,251	5,857
Capital expenditures	1,351	6,712	11,010
Total assets	3,619,482	3,688,430	3,770,852
Operating segment and corporate non-segment
Segment Reporting Information
Segment operating income	329,231	327,804	271,185
SaaS
Segment Reporting Information
Total revenues	527,977	428,526	342,118
SaaS | Operating segments | Enterprise Software
Segment Reporting Information
Total revenues	459,544	378,953	310,416
SaaS | Operating segments | Platform Technologies
Segment Reporting Information
Total revenues	68,433	49,573	31,702
SaaS | Corporate
Segment Reporting Information
Total revenues	0	0	0
Transaction-based fees
Segment Reporting Information
Total revenues	631,535	583,778	442,317
Transaction-based fees | Operating segments | Enterprise Software
Segment Reporting Information
Total revenues	174,718	147,370	114,662
Transaction-based fees | Operating segments | Platform Technologies
Segment Reporting Information
Total revenues	456,817	436,408	327,655
Transaction-based fees | Corporate
Segment Reporting Information
Total revenues	0	0	0
Maintenance
Segment Reporting Information
Total revenues	466,661	468,455	474,287
Maintenance | Operating segments | Enterprise Software
Segment Reporting Information
Total revenues	442,781	444,143	439,589
Maintenance | Operating segments | Platform Technologies
Segment Reporting Information
Total revenues	23,880	24,312	34,698
Maintenance | Corporate
Segment Reporting Information
Total revenues	0	0	0
Professional services
Segment Reporting Information
Total revenues	249,976	277,625	237,179
Professional services | Operating segments | Enterprise Software
Segment Reporting Information
Total revenues	209,727	204,970	193,184
Professional services | Operating segments | Platform Technologies
Segment Reporting Information
Total revenues	40,249	72,655	43,995
Professional services | Corporate
Segment Reporting Information
Total revenues	0	0	0
Software licenses and royalties
Segment Reporting Information
Total revenues	38,096	59,406	74,452
Software licenses and royalties | Operating segments | Enterprise Software
Segment Reporting Information
Total revenues	32,709	55,158	66,816
Software licenses and royalties | Operating segments | Platform Technologies
Segment Reporting Information
Total revenues	5,387	4,248	7,636
Software licenses and royalties | Corporate
Segment Reporting Information
Total revenues	0	0	0
Hardware and other
Segment Reporting Information
Total revenues	37,506	32,414	21,934
Hardware and other | Operating segments | Enterprise Software
Segment Reporting Information
Total revenues	30,176	26,592	18,876
Hardware and other | Operating segments | Platform Technologies
Segment Reporting Information
Total revenues	0	0	31
Hardware and other | Corporate
Segment Reporting Information
Total revenues	$ 7,330	$ 5,822	$ 3,027