Effective Income Tax Rate Reconciliation Percent Excluding the Catastrophe Losses within Subsidiaries

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- Definition

Amount of reported income tax expense (benefit) in excess of (less than) expected income tax expense (benefit) computed by applying domestic federal statutory income tax rate to pretax income (loss) from continuing operations, attributable to Tax Cuts and Jobs Act.

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No definition available.

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- Definition

Income Tax Reconciliation.

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- Definition

Percentage of domestic federal statutory tax rate applicable to pretax income (loss).

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- Definition

Amount of operating loss carryforward, before tax effects, available to reduce future taxable income under enacted tax laws.

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- Definition

Amount, after effects of reinsurance, of expense for claims incurred in the current reporting period and related claims settlement costs.

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Income Taxes - Narrative (Details) - USD ($) $ in Millions		3 Months Ended			9 Months Ended
Income Taxes - Narrative (Details) - USD ($) $ in Millions	Jan. 01, 2018	Sep. 30, 2018	Dec. 31, 2017	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Income Tax Reconciliation [Line Items]
Statutory rate of income taxes		21.00%		35.00%	21.00%	35.00%
Provision for losses and LAE occurring in the current period					$ 2,337	$ 2,237
Effective tax rate excluding the catastrophe losses within subsidiaries				22.00%
Operating loss carryforwards subject to SRLY tax rules will expire unutilized at December 31, 2018		$ 19			$ 19
Tax Cuts and Jobs Act of 2017
Income Tax Reconciliation [Line Items]
Statutory rate of income taxes	21.00%
Decrease in net deferred tax asset resulting from the changes in the Tax Cuts and Jobs Act of 2017			$ 83
Hurricane \| Neon Capital Limited
Income Tax Reconciliation [Line Items]
Provision for losses and LAE occurring in the current period				$ 53