REVENUE - Performance Obligations (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Jun. 30, 2020
Disaggregation of Revenue [Line Items]
Revenue remaining performance obligation	$ 1,031,136	$ 817,179
Revenue remaining performance obligation, percentage	100.00%	100.00%
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01
Disaggregation of Revenue [Line Items]
Expected timing of satisfaction		2 years
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-07-01
Disaggregation of Revenue [Line Items]
Expected timing of satisfaction		1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Disaggregation of Revenue [Line Items]
Expected timing of satisfaction	2 years	3 years
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-07-01
Disaggregation of Revenue [Line Items]
Expected timing of satisfaction	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Disaggregation of Revenue [Line Items]
Expected timing of satisfaction	3 years
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Disaggregation of Revenue [Line Items]
Expected timing of satisfaction
1 year or less
Disaggregation of Revenue [Line Items]
Revenue remaining performance obligation	$ 567,154	$ 461,398
Revenue remaining performance obligation, percentage	56.00%	57.00%
1-2 years
Disaggregation of Revenue [Line Items]
Revenue remaining performance obligation	$ 272,622	$ 190,886
Revenue remaining performance obligation, percentage	26.00%	23.00%
2-3 years
Disaggregation of Revenue [Line Items]
Revenue remaining performance obligation	$ 126,602	$ 116,035
Revenue remaining performance obligation, percentage	12.00%	14.00%
Greater than 3 years
Disaggregation of Revenue [Line Items]
Revenue remaining performance obligation	$ 64,758	$ 48,860
Revenue remaining performance obligation, percentage	6.00%	6.00%
Perpetual license
Disaggregation of Revenue [Line Items]
Revenue remaining performance obligation	$ 6,941	$ 9,820
Perpetual license | 1 year or less
Disaggregation of Revenue [Line Items]
Revenue remaining performance obligation	6,707	8,120
Perpetual license | 1-2 years
Disaggregation of Revenue [Line Items]
Revenue remaining performance obligation	234	1,700
Perpetual license | 2-3 years
Disaggregation of Revenue [Line Items]
Revenue remaining performance obligation	0	0
Perpetual license | Greater than 3 years
Disaggregation of Revenue [Line Items]
Revenue remaining performance obligation	0	0
Term license
Disaggregation of Revenue [Line Items]
Revenue remaining performance obligation	63,018	66,843
Term license | 1 year or less
Disaggregation of Revenue [Line Items]
Revenue remaining performance obligation	46,146	53,550
Term license | 1-2 years
Disaggregation of Revenue [Line Items]
Revenue remaining performance obligation	15,708	6,187
Term license | 2-3 years
Disaggregation of Revenue [Line Items]
Revenue remaining performance obligation	909	6,460
Term license | Greater than 3 years
Disaggregation of Revenue [Line Items]
Revenue remaining performance obligation	255	646
Maintenance
Disaggregation of Revenue [Line Items]
Revenue remaining performance obligation	336,449	257,959
Maintenance | 1 year or less
Disaggregation of Revenue [Line Items]
Revenue remaining performance obligation	214,645	186,618
Maintenance | 1-2 years
Disaggregation of Revenue [Line Items]
Revenue remaining performance obligation	59,164	40,153
Maintenance | 2-3 years
Disaggregation of Revenue [Line Items]
Revenue remaining performance obligation	36,076	20,671
Maintenance | Greater than 3 years
Disaggregation of Revenue [Line Items]
Revenue remaining performance obligation	26,564	10,517
Pega Cloud
Disaggregation of Revenue [Line Items]
Revenue remaining performance obligation	602,735	457,391
Pega Cloud | 1 year or less
Disaggregation of Revenue [Line Items]
Revenue remaining performance obligation	281,793	191,187
Pega Cloud | 1-2 years
Disaggregation of Revenue [Line Items]
Revenue remaining performance obligation	194,841	140,860
Pega Cloud | 2-3 years
Disaggregation of Revenue [Line Items]
Revenue remaining performance obligation	88,855	88,273
Pega Cloud | Greater than 3 years
Disaggregation of Revenue [Line Items]
Revenue remaining performance obligation	37,246	37,071
Consulting
Disaggregation of Revenue [Line Items]
Revenue remaining performance obligation	21,993	25,166
Consulting | 1 year or less
Disaggregation of Revenue [Line Items]
Revenue remaining performance obligation	17,863	21,923
Consulting | 1-2 years
Disaggregation of Revenue [Line Items]
Revenue remaining performance obligation	2,675	1,986
Consulting | 2-3 years
Disaggregation of Revenue [Line Items]
Revenue remaining performance obligation	762	631
Consulting | Greater than 3 years
Disaggregation of Revenue [Line Items]
Revenue remaining performance obligation	$ 693	$ 626