Geographic Information And Major Customers (Narrative) (Details)	3 Months Ended
Mar. 31, 2012
Geographic Information And Major Customers [Abstract]
Major customer percentage	10.00%

Entity-Wide Revenue, Criteria for Major Customer, Percentage of Revenue

No definition available.

Name:	pega_EntityWideRevenueCriteriaForMajorCustomerPercentageOfRevenue
Namespace Prefix:	pega_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration