Contracts Accounted for as Insurance - Net Expected Loss to be Expensed Insurance Contracts (Details) $ in Millions	Sep. 30, 2018 USD ($)
Insurance [Abstract]
2018 (October 1 – December 31)	$ 9
2019	37
2020	38
2021	42
2022	42
2023-2027	171
2028-2032	112
2033-2037	61
After 2037	13
Net expected loss to be expensed	525
Future accretion	181
Total expected future loss and LAE	$ 706

Financial Guarantee Insurance Contracts Future Expected Net Loss to be Expensed Beyond Twentieth Fiscal Year

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- Definition

Financial Guarantee Insurance Contracts Future Expected Net Loss to be Expensed During Fourth Quarter Following Balance Sheet Date

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- Definition

Financial Guarantee Insurance Contracts Future Expected Net Loss to be Expensed More than 10 and within 15 Years from Balance Sheet Date

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- Definition

Financial Guarantee Insurance Contracts Future Expected Net Loss to be Expensed More than 15 and within 20 Years from Balance Sheet Date

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- Definition

For financial guarantee insurance contracts, the amount of net loss expected to be expensed during the sixth through tenth year following the statement of financial position reporting date.

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- Definition

Financial Guarantee Insurance Contracts Future Expected Net Loss to be Expensed in Fifth Full Fiscal Year

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- Definition

For financial guarantee insurance contracts, the amount of net loss expected to be expensed within the fourth full fiscal year following the date of the latest balance sheet presented in the financial statements.

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- Definition

For financial guaranty insurance contracts, the amount of net loss expected to be expensed within the second full fiscal year following the date of the latest balance sheet presented in the financial statements.

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Financial Guarantee Insurance Contracts, Future Expected, Net Loss to be Expensed in Third Full Fiscal Year

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- Definition

Financial Guarantee Insurance Contracts, Net Loss to be Expensed, Present Value

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- Definition

Financial Guarantee Insurance Contracts, Net Loss to be Expensed, Undiscounted

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- Definition

Schedule of Insured Financial Obligations with Credit Deterioration, Reductions of Gross Claim Liability, Net of Reinsurance Recoverable, Discount

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