Shareholders' Equity - Changes in Accumulated Other Comprehensive Loss by Component (Details) - USD ($)
$ in Millions |
9 Months Ended |
Sep. 30, 2020 |
Sep. 30, 2019 |
| AOCI Attributable to Parent, Net of Tax [Roll Forward] |
|
|
| Beginning balance |
$ 6,121
|
$ 5,864
|
| Other comprehensive loss before reclassifications |
(4)
|
(13)
|
| Amounts reclassified from accumulated other comprehensive loss |
2
|
1
|
| Net other comprehensive income (loss) |
(2)
|
(12)
|
| Ending balance |
6,512
|
6,190
|
| Employee Benefit Plan Funded Status |
|
|
| AOCI Attributable to Parent, Net of Tax [Roll Forward] |
|
|
| Beginning balance |
(94)
|
(102)
|
| Ending balance |
(94)
|
(102)
|
| Amortization of Prior Service Cost |
|
|
| AOCI Attributable to Parent, Net of Tax [Roll Forward] |
|
|
| Beginning balance |
1
|
1
|
| Ending balance |
1
|
1
|
| Amortization of Actuarial Loss |
|
|
| AOCI Attributable to Parent, Net of Tax [Roll Forward] |
|
|
| Beginning balance |
60
|
56
|
| Amounts reclassified from accumulated other comprehensive loss |
2
|
2
|
| Net other comprehensive income (loss) |
2
|
2
|
| Ending balance |
62
|
58
|
| Foreign Currency Translation |
|
|
| AOCI Attributable to Parent, Net of Tax [Roll Forward] |
|
|
| Beginning balance |
0
|
1
|
| Amounts reclassified from accumulated other comprehensive loss |
|
(1)
|
| Net other comprehensive income (loss) |
|
(1)
|
| Ending balance |
0
|
0
|
| Gain (Loss) on Cash Flow Hedges |
|
|
| AOCI Attributable to Parent, Net of Tax [Roll Forward] |
|
|
| Beginning balance |
(3)
|
10
|
| Other comprehensive loss before reclassifications |
(4)
|
(13)
|
| Net other comprehensive income (loss) |
(4)
|
(13)
|
| Ending balance |
(7)
|
(3)
|
| Accumulated Other Comprehensive Loss |
|
|
| AOCI Attributable to Parent, Net of Tax [Roll Forward] |
|
|
| Beginning balance |
(36)
|
(34)
|
| Ending balance |
$ (38)
|
$ (46)
|