SCHEDULE I - CONDENSED FINANCIAL INFORMATION OF REGISTRANT Related-party Transactions (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
ITC Holdings Corp.
Condensed Financial Statements, Captions
Equity contributions to subsidiaries		$ 263,150	$ 348,661	$ 339,770
Dividends from subsidiaries	[1]	185,303	224,167	169,973
Return of capital from subsidiaries	[1]	161,075	126,900	96,120
ITCTransmission
Condensed Financial Statements, Captions
Tax payments from subsidiary under intercompany tax sharing agreement	[2]	36,400	38,100	39,100
MTH
Condensed Financial Statements, Captions
Tax payments from subsidiary under intercompany tax sharing agreement	[2]	39,000	41,400	30,000
ITC Midwest
Condensed Financial Statements, Captions
Tax payments from subsidiary under intercompany tax sharing agreement	[2]	31,000	34,300	33,600
ITC Great Plains
Condensed Financial Statements, Captions
Tax payments from subsidiary under intercompany tax sharing agreement	[2]	$ 14,500	$ 10,600	$ 9,400

[1] Includes ITCTransmission, MTH, ITC Midwest and other subsidiaries.

[2] The income tax payments to ITC Holdings from subsidiaries were pursuant to intercompany tax sharing arrangements and the total of these tax payments is presented as a cash inflow from operating activities in the condensed parent company statements of cash flows. Other reconciling items between the parent company and the consolidated tax liabilities are presented as deferred and other income taxes in the adjustments to reconcile net income to net cash provided by operating activities.