v3.8.0.1

Acquisitions and Noncontrolling Interest - Acquisitions (Details) - USD ($) $ in Millions |  | 1 Months Ended | 12 Months Ended |  |  |  |
--- | --- | --- | --- | --- | --- | --- | ---
Oct. 01, 2017 | Oct. 31, 2017 | Aug. 31, 2017 | Dec. 31, 2017 | Sep. 30, 2017 | Dec. 31, 2016 | Jan. 31, 2016 | Dec. 31, 2015
Business Acquisition [Line Items] |  |  |  |  |  |  |  |
Percentage of voting interests acquired |  |  |  |  |  |  | 19.00% |
Goodwill |  |  |  | $ 4,749 |  | $ 4,712 |  | $ 842
Fidelis Care |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |
Definitive agreement to acquire assets, amount |  |  |  |  | $ 3,750 |  |  |
Foundation Care |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |
Percentage of voting interests acquired | 80.00% |  |  |  |  |  |  |
Acquisition consideration |  |  |  | 59 |  |  |  |
Cash consideration |  | $ 53 |  |  |  |  |  |
Consideration transfered, present value of future consideration | $ 2 |  |  |  |  |  |  |
Deferred payment, period of payments | 2 years |  |  |  |  |  |  |
Contingent liability | $ 4 |  |  |  |  |  |  |
Goodwill | 37 |  |  |  |  |  |  |
Recognized identifiable intangible assets | 16 |  |  |  |  |  |  |
National Full-Service Specialty Pharmacy |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |
Contingent consideration based upon meeting performance metrics (not to exceed) | $ 32 |  |  |  |  |  |  |
U.S. Medical Management |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |
Percentage of voting interests acquired |  |  | 32.00% |  |  |  |  |
Acquisition consideration |  |  |  | $ 86 |  |  |  |
Cash consideration |  |  | $ 33 |  |  |  |  |
Contingent liability |  |  | 33 |  |  |  |  |
Settlement of receivable from former noncontrolling interest holder |  |  | $ 20 |  |  |  |  |

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