v2.4.0.8

Consolidated Statements of Cash Flows (Parentheticals) (USD $) In Millions, unless otherwise specified | 9 Months Ended
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Sep. 30, 2014 | Sep. 30, 2013
Consolidated Statements of Cash Flows (Parentheticals) [Abstract] |  |
Cash Acquired from Acquisition | $ 4 | $ 38

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- Details
Name: | ace_ConsolidatedStatementsofCashFlowsParentheticalsAbstract
Namespace Prefix: | ace_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

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- Definition The cash inflow associated with the acquisition of business during the period (for example, cash that was held by the acquired business). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Investing Activities -URI http://asc.fasb.org/extlink&oid=6516133 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 12 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3179-108585 + Details
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Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration