Guarantor Financial Information (Senior Notes) (Details) - Senior Notes - USD ($) $ in Millions	Sep. 11, 2018	Sep. 30, 2018	Sep. 23, 2016	Jun. 03, 2016
Debt Instrument [Line Items]
Extinguishment of debt	$ 2,300
Senior Notes, 2.0 % due 2018
Debt Instrument [Line Items]
Debt Interest Rate (Stated Rate)				2.00%
Senior Notes, 2.875% due 2020
Debt Instrument [Line Items]
Debt Interest Rate (Stated Rate)				2.875%
Senior Notes, 3.6% due 2022
Debt Instrument [Line Items]
Debt Interest Rate (Stated Rate)				3.60%
Senior Notes, 4.0% due 2025
Debt Instrument [Line Items]
Debt Interest Rate (Stated Rate)				4.00%
Senior Notes, 5.25% due 2045
Debt Instrument [Line Items]
Debt Interest Rate (Stated Rate)				5.25%
Shire Acquisitions Investment Ireland Designated Activity Company | Fixed-rate notes due 2019
Debt Instrument [Line Items]
Debt Interest Rate (Stated Rate)		1.90%	1.90%
Shire Acquisitions Investment Ireland Designated Activity Company | Fixed-rate notes due 2021
Debt Instrument [Line Items]
Debt Interest Rate (Stated Rate)		2.40%	2.40%
Shire Acquisitions Investment Ireland Designated Activity Company | Fixed-rate notes due 2023
Debt Instrument [Line Items]
Debt Interest Rate (Stated Rate)		2.875%	2.875%
Shire Acquisitions Investment Ireland Designated Activity Company | Fixed-rate notes due 2026
Debt Instrument [Line Items]
Debt Interest Rate (Stated Rate)		3.20%	3.20%