Significant Accounting Policies (Policies)

3 Months Ended

Mar. 31, 2013

Accounting Policies [Abstract]

Comprehensive Income [Policy Text Block]

Comprehensive Income

Comprehensive income is the change in common shareholders’ equity during a period from transactions and events from non-owner sources, including net income. As shown in the following table, amounts recorded to accumulated other comprehensive loss for the three months ended March 31, 2013 include unrealized gains and losses from derivatives accounted for as cash flow hedges, unrealized gains and losses on available for sale securities and the Company’s interest in comprehensive income of equity investees, which comprise the net unrealized gain/(loss) on investments, changes in benefit obligations, consisting of deferred actuarial losses, prior service costs and transition amounts related to pension and other postretirement benefit plans, and foreign currency translation adjustments.

Intangible Assets

Emission allowances and renewable energy credits are charged to expense, using average cost, as the allowances and credits are consumed in the operation of the business. The Company amortizes contract intangible assets on a straight-line basis over the expected period of benefit, ranging from 3 to 28 years.

Income Tax [Policy Text Block]

Income Taxes

The Company's effective tax rate from continuing operations for the three months ended March 31, 2013 is 31 percent as compared to 32 percent for the three months ended March 31, 2012.

The Company had $3 million of unrecognized tax benefits at March 31, 2013, that, if recognized, would favorably impact its effective tax rate. The Company believes that it is possible that there will be a decrease in the unrecognized tax benefits of up to $1 million in the next twelve months.