Debt (Notes)	6 Months Ended
Jun. 30, 2016
Debt Disclosure [Abstract]
Debt	Debt Revolving Credit Facility As of June 30, 2016, we had no borrowings against our revolving credit facility (the "Credit Facility"), as described below. In March 2016, we increased our $3.0 billion unsecured Credit Facility by $300 million to a total of $3.3 billion. The Credit Facility includes a covenant requiring that our ratio of total debt to total capitalization not exceed 65% as of the last day of each fiscal quarter. If an event of default occurs, the lenders holding more than half of the commitments may terminate the commitments under the Credit Facility and require the immediate repayment of all outstanding borrowings and the cash collateralization of all outstanding letters of credit under the Credit Facility. As of June 30, 2016, we were in compliance with this covenant with a debt-to-capitalization ratio of 28%. Debt Issuance In the second quarter of 2015, we issued $2 billion aggregate principal amount of unsecured senior notes and used the aggregate net proceeds to repay our $1 billion 0.90% senior notes November 1, 2015, and for general corporate purposes.

Debt (Notes)

6 Months Ended

Jun. 30, 2016

Revolving Credit Facility

As of June 30, 2016, we had no borrowings against our revolving credit facility (the "Credit Facility"), as described below.

In March 2016, we increased our $3.0 billion unsecured Credit Facility by $300 million to a total of $3.3 billion.

The Credit Facility includes a covenant requiring that our ratio of total debt to total capitalization not exceed 65% as of the last day of each fiscal quarter. If an event of default occurs, the lenders holding more than half of the commitments may terminate the commitments under the Credit Facility and require the immediate repayment of all outstanding borrowings and the cash collateralization of all outstanding letters of credit under the Credit Facility. As of June 30, 2016, we were in compliance with this covenant with a debt-to-capitalization ratio of 28%.

Debt Issuance

In the second quarter of 2015, we issued $2 billion aggregate principal amount of unsecured senior notes and used the aggregate net proceeds to repay our $1 billion 0.90% senior notes November 1, 2015, and for general corporate purposes.