Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2020	Nov. 03, 2020
Cover [Abstract]
Entity Registrant Name	TIVITY HEALTH, INC.
Entity Central Index Key	0000704415
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Current Reporting Status	Yes
Entity Shell Company	false
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q3
Trading Symbol	TVTY
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2020
Entity Common Stock, Shares Outstanding		48,619,846
Entity File Number	000-19364
Entity Tax Identification Number	62-1117144
Entity Address, Address Line One	701 Cool Springs Boulevard
Entity Address, City or Town	Franklin
Entity Address, State or Province	TN
Entity Address, Postal Zip Code	37067
City Area Code	800
Local Phone Number	869-5311
Entity Interactive Data Current	Yes
Title of 12(b) Security	Common Stock - $.001 par value
Security Exchange Name	NASDAQ
Document Quarterly Report	true
Document Transition Report	false
Entity Incorporation, State or Country Code	DE