Cover Page - shares	9 Months Ended
	Sep. 30, 2021	Oct. 28, 2021
Entity Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2021
Document Transition Report	false
Entity File Number	001-37702
Entity Registrant Name	Amgen Inc.
Entity Central Index Key	0000318154
Amendment Flag	false
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q3
Current Fiscal Year End Date	--12-31
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	95-3540776
Entity Address, Address Line One	One Amgen Center Drive
Entity Address, City or Town	Thousand Oaks
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	91320-1799
City Area Code	805
Local Phone Number	447-1000
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		563,265,902
The NASDAQ Global Select Market [Member] | Common Stock [Member]
Entity Information [Line Items]
Title of 12(b) Security	Common stock, $0.0001 par value
Trading Symbol	AMGN
Security Exchange Name	NASDAQ
The NASDAQ Global Select Market [Member] | 1.250% Senior Notes Due 2022 [Member]
Entity Information [Line Items]
Title of 12(b) Security	1.250% Senior Notes due 2022
Trading Symbol	AMGN22
Security Exchange Name	NASDAQ
The NASDAQ Global Select Market [Member] | 2.00% Senior Notes Due 2026 [Member]
Entity Information [Line Items]
Title of 12(b) Security	2.00% Senior Notes due 2026
Trading Symbol	AMGN26
Security Exchange Name	NASDAQ