| **Condensed Consolidating Guarantor and Non-Guarantor - Statement of Cash Flows (Details) (USD $)In Millions, unless otherwise specified** | 12 Months Ended |
|--------------------------------------------------------------------------------------------------------------------------------------------|-----------------|
||
| Net Cash Provided by (Used in) Operating Activities                                                                                        | $ 100           | $ 610 | $ 880 |
| Net change in restricted cash and cash equivalents                                                                                         | 70              | 165 | (147) |
| Net purchases of marketable securities                                                                                                     | (364)           | 252 | (132) |
| Capital expenditures and purchase of equipment leased to others                                                                            | (599)           | (370) | (500) |
| Other investing activities                                                                                                                 | 83              | (49) | (44) |
| Net cash used in investing activities                                                                                                      | (810)           | (2) | (823) |
| Net borrowings (repayments) of debt                                                                                                        | 116             | 69 | 38 |
| Other Financing Activities                                                                                                                 | 277             | (132) | (138) |
| Net cash provided by (used in) financing activities                                                                                        | 393             | (63) | (100) |
| Effect of exchange rate changes on cash and cash equivalents                                                                               | (15)            | 3 | (3) |
| Increase (decrease) in cash and cash equivalents                                                                                           | (332)           | 548 | (46) |
| Cash and cash equivalents at beginning of the period                                                                                       | 1,087           | 539 | 585 |
| Cash and cash equivalents at end of the period                                                                                             | 755             | 1,087 | 539 |
| Parent Company [Domain]                                                                                                                    |            |   |   |
| Net Cash Provided by (Used in) Operating Activities                                                                                        | (669)           | 350 | (44) |
| Net change in restricted cash and cash equivalents                                                                                         | 0               | (4) | 0 |
| Net purchases of marketable securities                                                                                                     | (267)           | 115 | (55) |
| Capital expenditures and purchase of equipment leased to others                                                                            | 0               | 0 | 0 |
| Other investing activities                                                                                                                 | 0               | 0 | 0 |
| Net cash used in investing activities                                                                                                      | (267)           | 111 | (55) |
| Net borrowings (repayments) of debt                                                                                                        | 540             | 171 | 91 |
| Other Financing Activities                                                                                                                 | 30              | (156) | (5) |
| Net cash provided by (used in) financing activities                                                                                        | 570             | 15 | 86 |
| Effect of exchange rate changes on cash and cash equivalents                                                                               | 0               | 0 | 0 |
| Increase (decrease) in cash and cash equivalents                                                                                           | (366)           | 476 | (13) |
| Cash and cash equivalents at beginning of the period                                                                                       | 702             | 226 | 239 |
| Cash and cash equivalents at end of the period                                                                                             | 336             | 702 | 226 |
| Guarantor Subsidiaries [Domain]                                                                                                            |            |   |   |
| Net Cash Provided by (Used in) Operating Activities                                                                                        | (355)           | (183) | (66) |
| Net change in restricted cash and cash equivalents                                                                                         | 5               | 1 | 0 |
| Net purchases of marketable securities                                                                                                     | 0               | 0 | 0 |
| Capital expenditures and purchase of equipment leased to others                                                                            | (422)           | (213) | (264) |
| Other investing activities                                                                                                                 | 87              | (157) | (12) |
| Net cash used in investing activities                                                                                                      | (330)           | (369) | (276) |
| Net borrowings (repayments) of debt                                                                                                        | 409             | 594 | 333 |
| Other Financing Activities                                                                                                                 | 293             | 0 | 0 |
| Net cash provided by (used in) financing activities                                                                                        | 702             | 594 | 333 |
| Effect of exchange rate changes on cash and cash equivalents                                                                               | 0               | 0 | 0 |
| Increase (decrease) in cash and cash equivalents                                                                                           | 17              | 42 | (9) |
| Cash and cash equivalents at beginning of the period                                                                                       | 55              | 13 | 22 |
| Cash and cash equivalents at end of the period                                                                                             | 72              | 55 | 13 |
| Non-Guarantor Subsidiaries [Domain]                                                                                                        |            |   |   |
| Net Cash Provided by (Used in) Operating Activities                                                                                        | 401             | 901 | 556 |
| Net change in restricted cash and cash equivalents                                                                                         | 65              | 168 | (147) |
| Net purchases of marketable securities                                                                                                     | (97)            | 137 | (77) |
| Capital expenditures and purchase of equipment leased to others                                                                            | (177)           | (157) | (236) |
| Other investing activities                                                                                                                 | (4)             | 108 | (32) |
| Net cash used in investing activities                                                                                                      | (213)           | 256 | (492) |
| Net borrowings (repayments) of debt                                                                                                        | (40)            | (1,245) | 48 |
| Other Financing Activities                                                                                                                 | (116)           | 115 | (133) |
| Net cash provided by (used in) financing activities                                                                                        | (156)           | (1,130) | (85) |
| Effect of exchange rate changes on cash and cash equivalents                                                                               | (15)            | 3 | (3) |
| Increase (decrease) in cash and cash equivalents                                                                                           | 17              | 30 | (24) |
| Cash and cash equivalents at beginning of the period                                                                                       | 330             | 300 | 324 |
| Cash and cash equivalents at end of the period                                                                                             | 347             | 330 | 300 |
| Consolidation, Eliminations [Domain]                                                                                                       |            |   |   |
| Net Cash Provided by (Used in) Operating Activities                                                                                        | 723             | (458) | 434 |
| Net change in restricted cash and cash equivalents                                                                                         | 0               | 0 | 0 |
| Net purchases of marketable securities                                                                                                     | 0               | 0 | 0 |
| Capital expenditures and purchase of equipment leased to others                                                                            | 0               | 0 | 0 |
| Other investing activities                                                                                                                 | 0               | 0 | 0 |
| Net cash used in investing activities                                                                                                      | 0               | 0 | 0 |
| Net borrowings (repayments) of debt                                                                                                        | (793)           | 549 | (434) |
| Other Financing Activities                                                                                                                 | 70              | (91) | 0 |
| Net cash provided by (used in) financing activities                                                                                        | (723)           | 458 | (434) |
| Effect of exchange rate changes on cash and cash equivalents                                                                               | 0               | 0 | 0 |
| Increase (decrease) in cash and cash equivalents                                                                                           | 0               | 0 | 0 |
| Cash and cash equivalents at beginning of the period                                                                                       | 0               | 0 | 0 |
| Cash and cash equivalents at end of the period                                                                                             | $ 0             | $ 0 | $ 0 |

| X                                                                                                                                                                                                                                                                                 |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Cash and cash equivalents at beginning of the period
+ References
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Cash and cash equivalents at end of the period
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|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of increase (decrease) in cash and cash equivalents. Cash and cash equivalents are the amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Includes effect from exchange rate changes.
+ References
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|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of increase (decrease) from the effect of exchange rate changes on cash and cash equivalent balances held in foreign currencies.
+ References
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|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The net cash inflow or outflow for the increase (decrease) associated with funds that are not available for withdrawal or use (such as funds held in escrow) and are associated with underlying transactions that are classified as investing activities.
+ References
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|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of cash inflow (outflow) from financing activities, including discontinued operations. Financing activity cash flows include obtaining resources from owners and providing them with a return on, and a return of, their investment; borrowing money and repaying amounts borrowed, or settling the obligation; and obtaining and paying for other resources obtained from creditors on long-term credit.
+ References
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|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of cash inflow (outflow) from investing activities, including discontinued operations. Investing activity cash flows include making and collecting loans and acquiring and disposing of debt or equity instruments and property, plant, and equipment and other productive assets.
+ References
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|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of cash inflow (outflow) from operating activities, including discontinued operations. Operating activity cash flows include transactions, adjustments, and changes in value not defined as investing or financing activities.
+ References
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The net cash paid (received) associated with the acquisition or disposal of all investments, including securities and other assets.
+ References
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The net cash outflow or inflow from other investing activities. This element is used when there is not a more specific and appropriate element in the taxonomy.
+ References
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The cash outflow for purchases of and capital improvements on property, plant and equipment (capital expenditures), software, and other intangible assets.
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The net cash inflow or outflow from other financing activities. This element is used when there is not a more specific and appropriate element in the taxonomy.
+ References
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The net cash inflow or outflow in aggregate debt due to repayments and proceeds from additional borrowings.
+ References
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