Goodwill and other intangible assets Changes in Deferred Tax Liabilities due to Intangible Asset Amortization For the Next Five Years (Details) - The Chubb Corporation [Member] $ in Millions	Jun. 30, 2016 USD ($)
Changes in Deferred Tax Liabilities due to Intangible Asset Amortization [Line Items]
Unearned Premium Reserves Amortization, Next Three to Six Months	$ 320
Unearned Premium Reserves Amortization, Next Six to Nine Months	144
Unearned Premium Reserves Amortization, Total	$ 464

[Line Items] for Changes in Deferred Tax Liabilities due to Intangible Asset Amortization [Table]

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