Contingent Consideration (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020
Business Combination, Contingent Consideration Arrangements, Change in Amount of Contingent Consideration [Abstract]
Business Combination, Contingent Consideration, Liability Beginning Balance			$ 354
Business Combination, Contingent Consideration Arrangements, Change in Amount of Contingent Consideration, Liability	$ 0	$ 10	(108)	$ (18)
Payment of contingent consideration			(38)
Business Combination, Contingent Consideration, Liability Ending Balance	208		208
Business Combination, Contingent Consideration Arrangements [Abstract]
Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, High					$ 627
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Abstract]
Business Combination, Contingent Consideration, Liability	208		208		208
Valuation Technique, Discounted Cash Flow [Member] | R&D, Regulatory and Commercialization-based Milestone [Member]
Business Combination, Contingent Consideration Arrangements, Change in Amount of Contingent Consideration [Abstract]
Business Combination, Contingent Consideration, Liability Ending Balance	97		97
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Abstract]
Business Combination, Contingent Consideration, Liability	97		97		97
Valuation Technique, Discounted Cash Flow [Member] | revenue-based payments [Member]
Business Combination, Contingent Consideration Arrangements, Change in Amount of Contingent Consideration [Abstract]
Business Combination, Contingent Consideration, Liability Ending Balance	111		111
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Abstract]
Business Combination, Contingent Consideration, Liability	$ 111		$ 111		$ 111
Minimum [Member] | Valuation Technique, Discounted Cash Flow [Member] | R&D, Regulatory and Commercialization-based Milestone [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Abstract]
contingent consideration liability, probability of payment					90.00%
Discount Rate, Fair Value Input			3.00%
Minimum [Member] | Valuation Technique, Discounted Cash Flow [Member] | revenue-based payments [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Abstract]
contingent consideration liability, probability of payment					100.00%
Discount Rate, Fair Value Input			11.00%
Maximum [Member] | Valuation Technique, Discounted Cash Flow [Member] | R&D, Regulatory and Commercialization-based Milestone [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Abstract]
contingent consideration liability, probability of payment					90.00%
Discount Rate, Fair Value Input			3.00%
Maximum [Member] | Valuation Technique, Discounted Cash Flow [Member] | revenue-based payments [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Abstract]
contingent consideration liability, probability of payment					100.00%
Discount Rate, Fair Value Input			14.00%
Weighted Average [Member] | Valuation Technique, Discounted Cash Flow [Member] | R&D, Regulatory and Commercialization-based Milestone [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Abstract]
contingent consideration liability, probability of payment					90.00%
Discount Rate, Fair Value Input			3.00%
Weighted Average [Member] | Valuation Technique, Discounted Cash Flow [Member] | revenue-based payments [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Abstract]
contingent consideration liability, probability of payment					100.00%
Discount Rate, Fair Value Input			13.00%