Debt and Lines of Credit - Additional Information (Details) - USD ($) |
1 Months Ended | 3 Months Ended | 9 Months Ended | |||||
---|---|---|---|---|---|---|---|---|
Aug. 31, 2015 |
May. 31, 2015 |
Apr. 30, 2015 |
Sep. 30, 2015 |
Sep. 30, 2014 |
Sep. 30, 2015 |
Sep. 30, 2014 |
Dec. 31, 2014 |
|
Debt Instrument [Line Items] | ||||||||
Commercial paper | $ 0 | $ 0 | ||||||
Long-term debt, gross | 4,125,000,000 | 4,125,000,000 | $ 4,625,000,000 | |||||
Proceeds from issuance of long-term debt | $ 498,000,000 | 498,000,000 | $ 498,000,000 | |||||
Interest and debt expense | 22,000,000 | $ 23,000,000 | 68,000,000 | $ 72,000,000 | ||||
Notes payable | ||||||||
Debt Instrument [Line Items] | ||||||||
Retirement of long-term debt | $ 750,000,000 | $ 250,000,000 | ||||||
Long-term debt, gross | 500,000,000 | |||||||
Payments of debt issuance costs | $ 3,000,000 | |||||||
Consortium of investment-grade banks | Revolving credit facility | ||||||||
Debt Instrument [Line Items] | ||||||||
Line of credit facility, maximum borrowing capacity until March 2020 | $ 2,000,000,000 | $ 2,000,000,000 |