Other (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended
Sep. 30, 2014
Other Income and Expenses [Abstract]
Capitalization of project feasibility costs previously expensed	$ 3.5

Capitalization of project feasibility costs previously expensed

No definition available.

Name:	tgpl_Capitalizationofprojectfeasibilitycostspreviouslyexpensed
Namespace Prefix:	tgpl_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration