Intangible Assets - Additional Information (Details) - USD ($)	3 Months Ended		12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Intangible Assets [Line Items]
Discount Rate	9.50%
In-process research and development impairment	$ 800,000,000	$ 820,000,000	$ 800,000,000	$ 820,000,000	$ 0
Cost of Goods Sold
Intangible Assets [Line Items]
Amortization of Intangible Assets			$ 1,100,000,000	1,200,000,000	$ 912,000,000
Kite 585 Program [Member]
Intangible Assets [Line Items]
Indefinite-lived Intangible Assets (Excluding Goodwill)		$ 0		$ 0