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Acquisition Business Combination Details- Narrative (Details) - USD ($) | 1 Months Ended | 3 Months Ended | 6 Months Ended | 12 Months Ended |  |  |
--- | --- | --- | --- | --- | --- | --- | ---
Oct. 31, 2017 | May 31, 2016 | Dec. 31, 2017 | Sep. 30, 2016 | Jun. 30, 2016 | Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015 | Dec. 06, 2017 | Oct. 03, 2017 | Sep. 30, 2017
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Indefinite-Lived Intangible Assets |  |  |  |  |  |  |  |  |  | $ 8,950,000,000 |
Business Combination, Consideration Transferred | $ 11,155,000,000 |  |  |  |  |  |  |  |  |  |
Business Combination, Consideration Transferred, Equity Interests Issued and Issuable | 75,000,000 |  |  |  |  |  |  |  |  |  |
Allocated Share-based Compensation Expense |  |  |  |  |  | $ 649,000,000 | $ 380,000,000 | $ 382,000,000 |  |  |
Fair Value Inputs, Discount Rate |  |  |  |  |  | 9.50% |  |  |  |  |
Gross Carrying Amount |  |  | $ 18,154,000,000 |  |  | $ 18,154,000,000 | 11,863,000,000 |  |  |  |
Goodwill Acquired From Business Combination | 2,987,000,000 |  |  |  |  |  |  |  |  |  |
Operating Income (Loss) |  |  |  |  |  | 14,124,000,000 | 17,633,000,000 | 22,193,000,000 |  |  |
Research and development expenses |  |  |  |  |  | $ 3,734,000,000 | $ 5,098,000,000 | $ 3,014,000,000 |  |  |
Payments to Outstanding Common Stockholders [Member] |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |
Payments to Acquire Businesses, Gross | 10,420,000,000 |  |  |  |  |  |  |  |  |  |
Payments to Vested Equity Award Holders [Member] |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |
Payments to Acquire Businesses, Gross | 645,000,000 |  |  |  |  |  |  |  |  |  |
Payments to Warrant Holders [Member] |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |
Payments to Acquire Businesses, Gross | 15,000,000 |  |  |  |  |  |  |  |  |  |
Share Based Compensation Expense [Member] |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |
Business Acquisition, Equity Interest Issued or Issuable, Value Assigned |  |  |  |  |  |  |  |  |  | $ 733,000,000 |
Kite Pharma, Inc [Member] |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |
Business Acquisition, Share Price |  |  |  |  |  |  |  |  |  | $ 180 |
Allocated Share-based Compensation Expense |  |  | 238,000,000 |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award Accelerated Compensation Cost |  |  | 209,000,000 |  |  |  |  |  |  |  |
Operating Income (Loss) |  |  | 675,000,000 |  |  |  |  |  |  |  |
Acquisition Costs, Period Cost |  |  | 431,000,000 |  |  |  |  |  |  |  |
Share-based Compensation |  |  | 290,000,000 |  |  |  |  |  |  |  |
Amortization of Intangible Assets |  |  | $ 73,000,000 |  |  |  |  |  |  |  |
Business Acquisition, Transaction Costs |  |  |  |  |  |  |  |  |  | $ 48,000,000 |
Ownership Cell Design Labs, Inc. |  |  | 12.20% |  |  | 12.20% |  |  |  |  |
Research and development expenses |  |  | $ 222,000,000 |  |  |  |  |  |  |  |
2017 Senior Unsecured Notes [Member] |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |
Debt Instrument, Face Amount |  |  |  |  |  |  |  |  |  |  | $ 3,000,000,000.0
Term Loan Facilities [Member] |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |
Line of Credit Facility, Maximum Borrowing Capacity | $ 6,000,000,000 |  |  |  |  |  |  |  |  |  |
Intangible Asset - axicabtagene ciloleucel (DLBCL) [Member] |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |
Gross Carrying Amount |  |  | 6,200,000,000 |  |  | $ 6,200,000,000 |  |  |  |  |
Finite-Lived Intangible Asset, Useful Life |  |  |  |  |  | 18 years |  |  |  |  |
Intangible Asset - Daiichi Sankyo [Member] |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |
Gross Carrying Amount |  |  | 91,000,000 |  |  | $ 91,000,000 |  |  |  |  |
Finite-Lived Intangible Asset, Useful Life |  |  |  |  |  | 14 years |  |  |  |  |
Acquisition-related Costs [Member] |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost |  |  |  |  |  | $ 223,000,000 |  |  |  |  |
Proforma Adjustments Acquisition Related Transacton Expenses |  |  |  |  |  | 139,000,000 |  |  |  |  |
Cell Design Labs, Inc. [Member] |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |
Business Combination, Consideration Transferred |  |  | $ 150,000,000 |  |  |  |  |  |  |  |
Regulatory Milestone-based Payments, Maximum |  |  |  |  |  | 322,000,000 |  |  |  |  |
Carrying Value of Equity Interest Owned Prior to Acquisition |  |  |  |  |  |  |  |  | $ 30,000,000 |  |
Acquired IPR&D CDL |  |  |  |  |  | $ 172,000,000 |  |  |  |  |
Nimbus Apollo, Inc. [Member] |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |
Research and development expenses |  | $ 400,000,000 |  | $ 200,000,000 | $ 400,000,000 |  |  |  |  |  |
Regulatory Milestone-based Payments, Maximum |  | $ 800,000,000 |  |  |  |  |  |  |  |  |

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