v3.4.0.3

Investment in American Transmission Company - Related Party Transactions (Details) - ATC - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Investment in ATC
Charges to ATC for services and construction	$ 4.1	$ 2.5
Charges from ATC for network transmission services	100.8	$ 59.6
Accounts receivable for services provided to ATC	2.0		$ 1.0
Accounts payable for services received from ATC	$ 30.4		$ 28.3

X

- Definition

Amount for accounts payable to related parties.

+ References

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-Name Accounting Standards Codification
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- Definition

Amount of receivables arising from transactions with related parties due within one year or the normal operating cycle, if longer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Section S99
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Expenses recognized resulting from transactions (excluding transactions that are eliminated in consolidated or combined financial statements) with related party.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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