Cover Page - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2019	Feb. 20, 2020	Jun. 28, 2019
Cover page.
Document Type	10-K
Document Annual Report	true
Document Transition Report	false
Document Period End Date	Dec. 31, 2019
Document Fiscal Period Focus	FY
Amendment Flag	false
Document Fiscal Year Focus	2019
Current Fiscal Year End Date	--12-31
Entity File Number	000-33043
Entity Registrant Name	OMNICELL, INC.
Entity Central Index Key	0000926326
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	94-3166458
Entity Address, Address Line One	590 East Middlefield Road
Entity Address, City or Town	Mountain View
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94043
City Area Code	650
Local Phone Number	251-6100
Title of 12(b) Security	Common Stock, $0.001 par value
Trading Symbol	OMCL
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
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 Public Float			$ 3.5
Entity Common Stock, Shares Outstanding		42,465,814
Documents Incorporated by Reference	Portions of the registrant’s definitive Proxy Statement for the 2020 Annual Meeting of Stockholders to be filed with the Securities and Exchange Commission pursuant to Regulation 14A not later than 120 days after the end of the fiscal year covered by this Form 10-K are incorporated by reference in Part III, Items 10-14 of this Form 10-K.