Business Combination Business Combinations - Acquired Markers Accretiable Yield (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
Dec. 31, 2017	Dec. 31, 2018	Oct. 06, 2017	Dec. 31, 2016
Business Combinations [Abstract]
Business Combination, Acquired Receivable, Fair Value			$ 139
Receivables, net	$ 494	$ 457		$ 167
Certain Loans Acquired in Transfer, Accretable Yield	6	3	$ 8
Accretion Expense	$ (2)	$ (3)

Fair value of acquired receivable from business combination, excluding certain loans and debt securities acquired in transfer.

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The aggregate excess of a loan's cash flows expected to be collected over the investor's initial investment in the loan. This relates to loans with deteriorating of credit quality since origination that were acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable.

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Amount of accretion recognized for the excess of a loan's cash flows expected to be collected over the investor's initial investment in acquired loans not accounted for as debt securities, with evidence of deterioration of credit quality.

+ References

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- Definition

The total amount due to the entity within one year of the balance sheet date (or one operating cycle, if longer) from outside sources, including trade accounts receivable, notes and loans receivable, as well as any other types of receivables, net of allowances established for the purpose of reducing such receivables to an amount that approximates their net realizable value.

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