Debt Summary of Long-term Debt (Details) - USD ($) $ in Millions |
12 Months Ended |
Dec. 31, 2015 |
Dec. 31, 2014 |
| Debt Instrument [Line Items] |
|
|
| Long-term Debt and Capital Lease Obligations, Including Current Maturities |
$ 8,023
|
$ 9,032
|
| Current portion of long-term debt |
(242)
|
(1,008)
|
| Long-term Debt and Capital Lease Obligations |
7,781
|
8,024
|
| Notes [Member] | Notes due 2015 [Member] |
|
|
| Debt Instrument [Line Items] |
|
|
| Notes |
$ 0
|
|
| Long term debt debentures |
|
$ 100
|
| Debt Instrument, Interest Rate, Stated Percentage |
4.65%
|
4.65%
|
| Debt Instrument, Maturity Date |
Jun. 15, 2015
|
Jun. 15, 2015
|
| Notes [Member] | Notes due 2017 [Member] |
|
|
| Debt Instrument [Line Items] |
|
|
| Notes |
$ 250
|
$ 250
|
| Debt Instrument, Interest Rate, Stated Percentage |
5.30%
|
5.30%
|
| Debt Instrument, Maturity Date |
Mar. 15, 2017
|
Mar. 15, 2017
|
| Related long term debt converted to floating interest rates by interest rate swaps |
$ 150
|
|
| Notes [Member] | Notes due 2018 [Member] |
|
|
| Debt Instrument [Line Items] |
|
|
| Notes |
$ 450
|
$ 450
|
| Debt Instrument, Interest Rate, Stated Percentage |
5.60%
|
5.60%
|
| Debt Instrument, Maturity Date |
May 15, 2018
|
May 15, 2018
|
| Related long term debt converted to floating interest rates by interest rate swaps |
$ 415
|
|
| Notes [Member] | Notes due 2019 [Member] |
|
|
| Debt Instrument [Line Items] |
|
|
| Notes |
$ 300
|
$ 300
|
| Debt Instrument, Interest Rate, Stated Percentage |
6.95%
|
6.95%
|
| Debt Instrument, Maturity Date |
Mar. 20, 2019
|
Mar. 20, 2019
|
| Related long term debt converted to floating interest rates by interest rate swaps |
$ 300
|
|
| Notes [Member] | Notes due 2021 [Member] |
|
|
| Debt Instrument [Line Items] |
|
|
| Notes |
$ 300
|
$ 300
|
| Debt Instrument, Interest Rate, Stated Percentage |
3.47%
|
3.47%
|
| Debt Instrument, Maturity Date |
Jun. 28, 2021
|
Jun. 28, 2021
|
| Related long term debt converted to floating interest rates by interest rate swaps |
$ 275
|
|
| Notes [Member] | Notes due 2023 [Member] |
|
|
| Debt Instrument [Line Items] |
|
|
| Notes |
$ 300
|
$ 300
|
| Debt Instrument, Interest Rate, Stated Percentage |
3.68%
|
3.68%
|
| Debt Instrument, Maturity Date |
Jun. 28, 2023
|
Jun. 28, 2023
|
| Related long term debt converted to floating interest rates by interest rate swaps |
$ 200
|
|
| Notes [Member] | Notes due 2037 [Member] |
|
|
| Debt Instrument [Line Items] |
|
|
| Notes |
$ 240
|
$ 240
|
| Debt Instrument, Interest Rate, Stated Percentage |
5.80%
|
5.80%
|
| Debt Instrument, Maturity Date |
Mar. 15, 2037
|
Mar. 15, 2037
|
| Notes [Member] | Notes due from 2018 to 2035 [Member] |
|
|
| Debt Instrument [Line Items] |
|
|
| Notes |
$ 239
|
|
| Related long term debt converted to floating interest rates by interest rate swaps |
$ 50
|
|
| Notes ranging from 5.25% to 8.875%, Interest Rate, Stated Percentage Rate Range, Minimum |
5.25%
|
|
| Notes ranging from 5.25% to 8.875%, Interest Rate, Stated Percentage Rate Range, Maximum |
8.875%
|
|
| Notes maturing from 2014 to 2035, Maturity Date Range, Start |
Mar. 20, 2014
|
|
| Notes maturing from 2014 to 2035, Maturity Date Range, End |
Jun. 15, 2035
|
|
| Notes [Member] | Notes due from 2012 to 2035 [Member] |
|
|
| Debt Instrument [Line Items] |
|
|
| Notes |
|
$ 239
|
| Related long term debt converted to floating interest rates by interest rate swaps |
|
$ 50
|
| Notes ranging from 5.25% to 8.875%, Interest Rate, Stated Percentage Rate Range, Minimum |
|
5.25%
|
| Notes ranging from 5.25% to 8.875%, Interest Rate, Stated Percentage Rate Range, Maximum |
|
12.50%
|
| Notes maturing from 2014 to 2035, Maturity Date Range, Start |
|
Mar. 20, 2014
|
| Notes maturing from 2014 to 2035, Maturity Date Range, End |
|
Jun. 15, 2035
|
| Japanese Yen notes payable [Member] | Japanese Yen notes due 2018 [Member] |
|
|
| Debt Instrument [Line Items] |
|
|
| Notes |
$ 83
|
$ 84
|
| Debt Instrument, Interest Rate, Stated Percentage |
4.215%
|
4.215%
|
| Debt Instrument, Maturity Date |
Dec. 17, 2018
|
Dec. 17, 2018
|
| Senior Notes [Member] | Senior notes due 2015 [Member] |
|
|
| Debt Instrument [Line Items] |
|
|
| Long term debt debentures |
|
$ 600
|
| Senior Notes |
$ 0
|
|
| Debt Instrument, Interest Rate, Stated Percentage |
0.95%
|
0.95%
|
| Debt Instrument, Maturity Date |
Nov. 02, 2015
|
Nov. 02, 2015
|
| Senior Notes [Member] | Senior notes due 2017 [Member] |
|
|
| Debt Instrument [Line Items] |
|
|
| Senior Notes |
$ 1,000
|
$ 1,000
|
| Debt Instrument, Interest Rate, Stated Percentage |
1.50%
|
1.50%
|
| Debt Instrument, Maturity Date |
Nov. 02, 2017
|
Nov. 02, 2017
|
| Related long term debt converted to floating interest rates by interest rate swaps |
$ 750
|
|
| Senior Notes [Member] | Senior notes due 2022 [Member] |
|
|
| Debt Instrument [Line Items] |
|
|
| Senior Notes |
$ 1,600
|
$ 1,600
|
| Debt Instrument, Interest Rate, Stated Percentage |
2.75%
|
2.75%
|
| Debt Instrument, Maturity Date |
Nov. 02, 2022
|
Nov. 02, 2022
|
| Related long term debt converted to floating interest rates by interest rate swaps |
$ 1,350
|
|
| Senior Notes [Member] | Senior notes due 2032 [Member] |
|
|
| Debt Instrument [Line Items] |
|
|
| Senior Notes |
$ 700
|
$ 700
|
| Debt Instrument, Interest Rate, Stated Percentage |
4.00%
|
4.00%
|
| Debt Instrument, Maturity Date |
Nov. 02, 2032
|
Nov. 02, 2032
|
| Senior Notes [Member] | Senior notes due 2042 [Member] |
|
|
| Debt Instrument [Line Items] |
|
|
| Senior Notes |
$ 1,000
|
$ 1,000
|
| Debt Instrument, Interest Rate, Stated Percentage |
4.15%
|
4.15%
|
| Debt Instrument, Maturity Date |
Nov. 02, 2042
|
Nov. 02, 2042
|
| Debenture [Member] | Debenture due 2015 [Member] |
|
|
| Debt Instrument [Line Items] |
|
|
| Long term debt debentures |
$ 0
|
$ 300
|
| Debt Instrument, Interest Rate, Stated Percentage |
5.45%
|
5.45%
|
| Debt Instrument, Maturity Date |
Apr. 01, 2015
|
Apr. 01, 2015
|
| Debenture [Member] | Debentures due 2016 [Member] |
|
|
| Debt Instrument [Line Items] |
|
|
| Long term debt debentures |
$ 240
|
$ 240
|
| Debt Instrument, Interest Rate, Stated Percentage |
2.375%
|
2.375%
|
| Debt Instrument, Maturity Date |
Jan. 15, 2016
|
Jan. 15, 2016
|
| Debenture [Member] | Debentures due 2017 [Member] |
|
|
| Debt Instrument [Line Items] |
|
|
| Long term debt debentures |
$ 289
|
$ 289
|
| Debt Instrument, Interest Rate, Stated Percentage |
6.10%
|
6.10%
|
| Debt Instrument, Maturity Date |
Jul. 01, 2017
|
Jul. 01, 2017
|
| Debenture [Member] | Debentures due 2020 [Member] |
|
|
| Debt Instrument [Line Items] |
|
|
| Long term debt debentures |
$ 239
|
$ 239
|
| Debt Instrument, Interest Rate, Stated Percentage |
3.875%
|
3.875%
|
| Debt Instrument, Maturity Date |
Dec. 15, 2020
|
Dec. 15, 2020
|
| Related long term debt converted to floating interest rates by interest rate swaps |
$ 150
|
|
| Debenture [Member] | Debentures due 2022 [Member] |
|
|
| Debt Instrument [Line Items] |
|
|
| Long term debt debentures |
$ 100
|
$ 100
|
| Debt Instrument, Interest Rate, Stated Percentage |
8.10%
|
8.10%
|
| Debt Instrument, Maturity Date |
Aug. 15, 2022
|
Aug. 15, 2022
|
| Debenture [Member] | Debentures due 2025 [Member] |
|
|
| Debt Instrument [Line Items] |
|
|
| Long term debt debentures |
$ 145
|
$ 145
|
| Debt Instrument, Interest Rate, Stated Percentage |
6.50%
|
6.50%
|
| Debt Instrument, Maturity Date |
Jun. 01, 2025
|
Jun. 01, 2025
|
| Debenture [Member] | Debentures due 2029 [Member] |
|
|
| Debt Instrument [Line Items] |
|
|
| Long term debt debentures |
$ 200
|
$ 200
|
| Debt Instrument, Interest Rate, Stated Percentage |
7.65%
|
7.65%
|
| Debt Instrument, Maturity Date |
Nov. 15, 2029
|
Nov. 15, 2029
|
| Related long term debt converted to floating interest rates by interest rate swaps |
$ 50
|
|
| Debenture [Member] | Debentures due 2034 [Member] |
|
|
| Debt Instrument [Line Items] |
|
|
| Long term debt debentures |
$ 136
|
$ 136
|
| Debt Instrument, Interest Rate, Stated Percentage |
5.45%
|
5.45%
|
| Debt Instrument, Maturity Date |
Oct. 15, 2034
|
Oct. 15, 2034
|
| Related long term debt converted to floating interest rates by interest rate swaps |
$ 25
|
|
| Other long-term debt [Member] |
|
|
| Debt Instrument [Line Items] |
|
|
| Other |
$ 212
|
$ 220
|