Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Disaggregation of Revenue [Line Items]
Revenues	$ 1,429,801	$ 1,387,778
Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Revenues	1,342,825	1,306,717
Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Revenues	86,976	81,061
Domestic Segment
Disaggregation of Revenue [Line Items]
Revenues	1,258,456	1,221,992
Domestic Segment | Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Revenues	1,182,210	1,152,849
Domestic Segment | Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Revenues	76,246	69,143
International Segment [Member]
Disaggregation of Revenue [Line Items]
Revenues	171,345	165,786
International Segment [Member] | Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Revenues	160,615	153,868
International Segment [Member] | Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Revenues	10,730	11,918
Revenue, Licensed Software, Net [Member]
Disaggregation of Revenue [Line Items]
Revenues	189,421	161,661
Revenue, Licensed Software, Net [Member] | Domestic Segment
Disaggregation of Revenue [Line Items]
Revenues	178,913	148,833
Revenue, Licensed Software, Net [Member] | International Segment [Member]
Disaggregation of Revenue [Line Items]
Revenues	10,508	12,828
Revenue, Technology Resale, Net [Member]
Disaggregation of Revenue [Line Items]
Revenues	47,483	45,672
Revenue, Technology Resale, Net [Member] | Domestic Segment
Disaggregation of Revenue [Line Items]
Revenues	42,764	37,891
Revenue, Technology Resale, Net [Member] | International Segment [Member]
Disaggregation of Revenue [Line Items]
Revenues	4,719	7,781
Revenue, Subscriptions, Net [Member]
Disaggregation of Revenue [Line Items]
Revenues	94,423	99,812
Revenue, Subscriptions, Net [Member] | Domestic Segment
Disaggregation of Revenue [Line Items]
Revenues	90,553	95,383
Revenue, Subscriptions, Net [Member] | International Segment [Member]
Disaggregation of Revenue [Line Items]
Revenues	3,870	4,429
Revenue, Professional Services, Net [Member]
Disaggregation of Revenue [Line Items]
Revenues	525,260	494,422
Revenue, Professional Services, Net [Member] | Domestic Segment
Disaggregation of Revenue [Line Items]
Revenues	452,238	434,162
Revenue, Professional Services, Net [Member] | International Segment [Member]
Disaggregation of Revenue [Line Items]
Revenues	73,022	60,260
Revenue, Managed Services, Net [Member]
Disaggregation of Revenue [Line Items]
Revenues	324,626	317,376
Revenue, Managed Services, Net [Member] | Domestic Segment
Disaggregation of Revenue [Line Items]
Revenues	287,975	282,076
Revenue, Managed Services, Net [Member] | International Segment [Member]
Disaggregation of Revenue [Line Items]
Revenues	36,651	35,300
Revenue, Support and Maintenance Services, Net [Member]
Disaggregation of Revenue [Line Items]
Revenues	242,880	263,324
Revenue, Support and Maintenance Services, Net [Member] | Domestic Segment
Disaggregation of Revenue [Line Items]
Revenues	200,667	217,499
Revenue, Support and Maintenance Services, Net [Member] | International Segment [Member]
Disaggregation of Revenue [Line Items]
Revenues	42,213	45,825
Revenue, Reimbursement Revenue [Member]
Disaggregation of Revenue [Line Items]
Revenues	5,708	5,511
Revenue, Reimbursement Revenue [Member] | Domestic Segment
Disaggregation of Revenue [Line Items]
Revenues	5,346	6,148
Revenue, Reimbursement Revenue [Member] | International Segment [Member]
Disaggregation of Revenue [Line Items]
Revenues	$ 362	$ (637)