REVENUE - Revenue Stream (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Disaggregation of Revenue [Line Items]
Revenue	$ 376,307	$ 313,499
Perpetual license
Disaggregation of Revenue [Line Items]
Revenue	7,440	5,452
Subscription license
Disaggregation of Revenue [Line Items]
Revenue	137,533	111,509
Subscription services
Disaggregation of Revenue [Line Items]
Revenue	170,033	143,419
Subscription
Disaggregation of Revenue [Line Items]
Revenue	307,566	254,928
Consulting
Disaggregation of Revenue [Line Items]
Revenue	61,301	53,119
Revenue recognized at a point in time
Disaggregation of Revenue [Line Items]
Revenue	144,973	116,961
Revenue recognized at a point in time | Perpetual license
Disaggregation of Revenue [Line Items]
Revenue	7,440	5,452
Revenue recognized at a point in time | Subscription license
Disaggregation of Revenue [Line Items]
Revenue	137,533	111,509
Revenue recognized over time
Disaggregation of Revenue [Line Items]
Revenue	231,334	196,538
Revenue recognized over time | Maintenance
Disaggregation of Revenue [Line Items]
Revenue	79,716	75,561
Revenue recognized over time | Pega Cloud
Disaggregation of Revenue [Line Items]
Revenue	90,317	67,858
Revenue recognized over time | Consulting
Disaggregation of Revenue [Line Items]
Revenue	$ 61,301	$ 53,119