Fair Value (Financal assets and liabilities not measure at fair value) (Details) - USD ($) $ in Millions	Jun. 30, 2018	Dec. 31, 2017
Assets
Mortgage loans	$ 865	$ 839
Liabilities
Short term debt	30	150
Long term debt	2,679	2,708
Carrying Amount
Assets
Mortgage loans	865	839
Note receivable	34	46
Liabilities
Short term debt	30	150
Long term debt	2,679	2,708
Estimated Fair Value
Assets
Mortgage loans	850	844
Note receivable	34	46
Liabilities
Short term debt	30	150
Long term debt	2,754	2,896
Level 1 \| Estimated Fair Value
Assets
Mortgage loans	0	0
Note receivable	0	0
Liabilities
Short term debt	0	0
Long term debt	0	0
Level 2 \| Estimated Fair Value
Assets
Mortgage loans	0	0
Note receivable	0	0
Liabilities
Short term debt	30	150
Long term debt	2,754	2,896
Level 3 \| Estimated Fair Value
Assets
Mortgage loans	850	844
Note receivable	34	46
Liabilities
Short term debt	0	0
Long term debt	$ 0	$ 0

For an unclassified balance sheet, the amount due from customers or clients for goods or services that have been delivered or sold in the normal course of business, reduced to their estimated net realizable fair value by an allowance established by the entity of the amount it deems uncertain of collection.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(9))
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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt, classified as current. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Amount after unamortized (discount) premium and debt issuance costs of long-term debt classified as noncurrent and excluding amounts to be repaid within one year or the normal operating cycle, if longer. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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The balance represents the amount of loans that are secured by real estate mortgages, offset by the reserve to cover probable credit losses on the loan portfolio.

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