Debt (Notes)	9 Months Ended
Sep. 30, 2016
Debt Disclosure [Abstract]
Debt	Debt Revolving credit facility Effective June 28, 2016, the Company extended the maturity date by one year on its existing revolving U.S. $2.0 billion revolving credit facility, which includes a U.S. $1.0 billion five-year portion and U.S. $1.0 billion one-year plus one-year term-out portion. The maturity date on the U.S. $1.0 billion one-year plus one-year term-out portion has been extended to June 28, 2018; the maturity date on the U.S. $1.0 billion five-year portion was extended to June 28, 2021. Commercial paper program The Company has a commercial paper program which enables it to issue commercial paper up to a maximum aggregate principal amount of U.S. $1.0 billion in the form of unsecured promissory notes. The commercial paper is backed by the U.S. $1.0 billion one-year plus one-year term-out portion of the revolving credit facility. As at September 30, 2016, the Company had total commercial paper borrowings of U.S. $280 million ($367 million), presented in “Long-term debt maturing within one year” on the Interim Consolidated Balance Sheets (December 31, 2015 - $nil). The weighted-average interest rate on these borrowings was 0.75%. The Company presents issuances and repayments of commercial paper in the Interim Consolidated Statements of Cash Flows on a net basis, all of which have a maturity of less than 90 days.

Debt (Notes)

9 Months Ended

Sep. 30, 2016

Revolving credit facility

Effective June 28, 2016, the Company extended the maturity date by one year on its existing revolving U.S. $2.0 billion revolving credit facility, which includes a U.S. $1.0 billion five-year portion and U.S. $1.0 billion one-year plus one-year term-out portion. The maturity date on the U.S. $1.0 billion one-year plus one-year term-out portion has been extended to June 28, 2018; the maturity date on the U.S. $1.0 billion five-year portion was extended to June 28, 2021.

Commercial paper program

The Company has a commercial paper program which enables it to issue commercial paper up to a maximum aggregate principal amount of U.S. $1.0 billion in the form of unsecured promissory notes. The commercial paper is backed by the U.S. $1.0 billion one-year plus one-year term-out portion of the revolving credit facility. As at September 30, 2016, the Company had total commercial paper borrowings of U.S. $280 million ($367 million), presented in “Long-term debt maturing within one year” on the Interim Consolidated Balance Sheets (December 31, 2015 - $nil). The weighted-average interest rate on these borrowings was 0.75%.

The Company presents issuances and repayments of commercial paper in the Interim Consolidated Statements of Cash Flows on a net basis, all of which have a maturity of less than 90 days.