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Claim and Claim Adjustment Expense Reserves - Schedule of Impact of Loss Portfolio Transfer on the Consolidated Statement of Operations (Detail) - CNA Financial [Member] - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2017 | Sep. 30, 2016 | Sep. 30, 2017 | Sep. 30, 2016
Claim And Claim Adjustment Expense Reserves [Line Items] |  |  |  |
Net A&EP adverse development before consideration of LPT |  |  | $ 60 | $ 200
Retroactive reinsurance benefit recognized | $ (17) | $ (12) | $ (60) | (94)
Pretax impact of A&EP reserve development and the LPT | $ (17) | $ (12) |  | $ 106

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- Definition Benefit Recognized Under Retroactive Reinsurance Accounting + References No definition available. + Details
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- Definition Claim And Claim Adjustment Expense Reserves [Line Items] + References No definition available. + Details
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- Definition Net Asbestos And Environmental Pollution Adverse Development Before Consideration Of Loss Portfolio Transfer + References No definition available. + Details
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- Definition Pretax impact of unrecognized deferred retroactive insurance benefit. + References No definition available. + Details
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- Details
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