Debt	6 Months Ended
Jun. 30, 2015
Debt Disclosure [Abstract]
Debt	6. Debt In January 2015, the Corporation entered into a $4 billion syndicated revolving credit facility that expires in January 2020. The new facility, which replaced a $4 billion facility that was scheduled to expire in April 2016, can be used for borrowings and letters of credit. Based on the Corporation’s credit rating as of June 30, 2015, borrowings on the facility will generally bear interest at 1.075% above the London Interbank Offered Rate with the facility fee amounting to 0.175% per annum. The interest rate and facility fee are subject to adjustment if the Corporation's credit rating changes. The restrictions on the amount of total borrowings and secured debt are substantially similar to the previous facility. At June 30, 2015, there were no borrowings outstanding or letters of credit issued against the syndicated revolving credit facility.

Debt

6 Months Ended

Jun. 30, 2015

6. Debt

In January 2015, the Corporation entered into a $4 billion syndicated revolving credit facility that expires in January 2020. The new facility, which replaced a $4 billion facility that was scheduled to expire in April 2016, can be used for borrowings and letters of credit. Based on the Corporation’s credit rating as of June 30, 2015, borrowings on the facility will generally bear interest at 1.075% above the London Interbank Offered Rate with the facility fee amounting to 0.175% per annum. The interest rate and facility fee are subject to adjustment if the Corporation's credit rating changes. The restrictions on the amount of total borrowings and secured debt are substantially similar to the previous facility. At June 30, 2015, there were no borrowings outstanding or letters of credit issued against the syndicated revolving credit facility.