REGULATORY MATTERS Additional Information (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended
Sep. 30, 2013
Regulatory Assets
Transmission rate, applicable period	1 year
Revenue true-up amount reflected in customer bill, period of recognition	2 years
ITC Great Plains \| Start-up, Development and Pre-construction Expenses, Including Associated Carrying Charges
Regulatory Assets
Regulatory asset	$ 13.9
Amortization period	10

The amount for the individual regulatory asset as itemized in a table of regulatory assets as of the end of the period.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 980

-SubTopic 340

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6499975&loc=d3e44250-110382

Name:	us-gaap_RegulatoryAssets
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant