Taxation (Narrative) (Details) - USD ($) $ in Millions |
12 Months Ended | ||
---|---|---|---|
Dec. 31, 2016 |
Dec. 31, 2015 |
Dec. 31, 2014 |
|
Income Tax Examination [Line Items] | |||
Valuation allowance | $ 78 | $ 38 | |
Unrecognized tax benefits that would affect the effective tax rate | 17 | 16 | |
Tax-related interest and penalties reported in the consolidated statements of operations | 1 | $ 1 | $ (1) |
Liabilities recorded for tax-related interest and penalties | 4 | ||
Domestic Tax Authority [Member] | |||
Income Tax Examination [Line Items] | |||
Net operating loss carry-forwards | $ 356 | ||
Switzerland | |||
Income Tax Examination [Line Items] | |||
Applicable income tax rates | 7.83% | ||
Foreign Tax Authority [Member] | |||
Income Tax Examination [Line Items] | |||
Foreign tax credit carry-forward | $ 114 | ||
Bermuda | |||
Income Tax Examination [Line Items] | |||
Applicable income tax rates | 0.00% | ||
UNITED STATES | |||
Income Tax Examination [Line Items] | |||
Applicable income tax rates | 35.00% | ||
U.K. | |||
Income Tax Examination [Line Items] | |||
Applicable income tax rates | 20.00% |