RECEIVABLES, CONTRACT ASSETS, AND DEFERRED REVENUE RECEIVABLES, CONTRACT ASSETS, AND DEFERRED REVENUE - Additional Information (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Receivables [Abstract]
Accounts receivable and unbilled receivable	$ 501,675	$ 504,765
Accounts receivable and unbilled receivable percentage	10.00%

Accounts Receivable And Unbilled Receivable Percentage

No definition available.

Name:	pega_AccountsReceivableAndUnbilledReceivablePercentage
Namespace Prefix:	pega_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant