Common Shareholder's Equity Regulatory Restrictions on Common Stock Dividends (Details) (USD $) In Billions, unless otherwise specified	12 Months Ended
Dec. 31, 2014
Regulatory Restrictions on Common Stock Dividends [Abstract]
Minimum common equity to capitalization percentage	44.00%
Percentage of preferred stock to be treated as common equity for common equity percentage calculation	50.00%
Actual common equity percentage as calculated in accordance with acquisition commitment	53.00%
Amount available for dividend distribution without prior approval from regulatory agency	$ 2.3

Actual common equity percentage as calculated in accordance with the terms of the state regulatory orders that authorized the acquisition of the reporting entity.

No definition available.

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- Definition

Represents the minimum common equity to total capitalization percentage, excluding short-term debt and current maturities of long-term debt, allowed under acquisition commitments without prior regulatory approval of dividends.

+ References

No definition available.

+ Details

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- Definition

The percentage of preferred stock in existence prior to acquisition to be treated as common equity when calculating common equity to defined capitalization percentage according to the terms of the state regulatory orders.

+ References

No definition available.

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- Details

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- Definition

Amount of dividends that can be declared or paid without approval of regulatory agency.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.4-08.(e))

-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 08

-Paragraph e

-Article 4

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