Cover Page - shares	3 Months Ended
	Mar. 31, 2020	May 01, 2020
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2020
Document Transition Report	false
Entity File Number	001-31932
Entity Registrant Name	CATASYS, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	88-0464853
Entity Address, Address Line One	2120 Colorado Ave.
Entity Address, Address Line Two	Suite 230
Entity Address, City or Town	Santa Monica
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	90404
City Area Code	310
Local Phone Number	444-4300
Title of 12(b) Security	Common Stock, $0.0001 par value
Trading Symbol	CATS
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		16,985,292
Entity Central Index Key	0001136174
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q1
Amendment Flag	false
Current Fiscal Year End Date	--12-31