Debt (Corporate Revolving Facility and other Letters of Credit Facilities) (Details) - USD ($) $ in Millions |
Jun. 27, 2018 |
Dec. 31, 2015 |
Dec. 31, 2014 |
|---|---|---|---|
| Line of Credit Facility [Line Items] | |||
| Letters of Credit Outstanding, Amount | $ 755 | $ 644 | |
| Corporate Revolving Facility [Member] | |||
| Line of Credit Facility [Line Items] | |||
| Letters of Credit Outstanding, Amount | 316 | 223 | |
| CDH [Member] | |||
| Line of Credit Facility [Line Items] | |||
| Letters of Credit Outstanding, Amount | 241 | 214 | |
| Various Project Financing Facilities [Member] | |||
| Line of Credit Facility [Line Items] | |||
| Letters of Credit Outstanding, Amount | $ 198 | $ 207 | |
| Subsequent Event [Member] | Corporate Revolving Facility [Member] | |||
| Line of Credit Facility [Line Items] | |||
| Future line of credit facility maximum borrowing capacity | $ 1,520 |