Income Taxes - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	9 Months Ended
Sep. 30, 2013
Income Taxes Disclosure [Line Items]
Annual limitation on ownership change	$ 7.0
Additional annual limitations to NOL	1.6
Arbinet Corporation Acquisition [Member]
Income Taxes Disclosure [Line Items]
Net operating loss carryforwards subject to annual limitation	$ 2.2

Operating loss carryforwards annual change of ownership limitation.

No definition available.

Name:	ptgi_OperatingLossCarryforwardsAnnualChangeOfOwnershipLimitation
Namespace Prefix:	ptgi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration