Earnings (Loss) Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands		3 Months Ended
		Mar. 31, 2017	Mar. 31, 2016
Numerator [Abstract]
Net income from continuing operations attributable to Tivity Health, Inc. - numerator for earnings per share		$ 15,481	$ 19,208
Net loss from discontinued operations attributable to Tivity Health, Inc. - numerator for loss per share		(220)	(33,417)
Net income (loss) attributable to Tivity Health, Inc. - numerator for earnings (loss) per share		$ 15,261	$ (14,209)
Denominator [Abstract]
Shares used for basic income (loss) per share (in shares)		39,069	36,109
Effect of dilutive stock options and restricted stock units outstanding [Abstract]
Shares used for diluted income (loss) per share (in shares)		40,541	36,861
Earnings (loss) per share attributable to Tivity Health, Inc. - basic [Abstract]
Continuing operations (in dollars per share)		$ 0.40	$ 0.53
Discontinued operations (in dollars per share)		(0.01)	(0.93)
Net income (loss) (in dollars per share)	[1]	0.39	(0.39)
Earnings (loss) per share attributable to Tivity Health, Inc. - diluted [Abstract]
Continuing operations (in dollars per share)		0.38	0.52
Discontinued operations (in dollars per share)		(0.01)	(0.91)
Net income (loss) (in dollars per share)	[1]	$ 0.38	$ (0.39)
Non-Qualified Stock Options [Member]
Effect of dilutive stock options and restricted stock units outstanding [Abstract]
Effect of dilutive stock options and restricted stock units outstanding (in shares)		442	165
Restricted Stock Units [Member]
Effect of dilutive stock options and restricted stock units outstanding [Abstract]
Effect of dilutive stock options and restricted stock units outstanding (in shares)		611	426
Market Stock Units [Member]
Effect of dilutive stock options and restricted stock units outstanding [Abstract]
Effect of dilutive stock options and restricted stock units outstanding (in shares)		293	161
Warrants Related to Cash Convertible Notes [Member]
Effect of dilutive stock options and restricted stock units outstanding [Abstract]
Effect of dilutive stock options and restricted stock units outstanding (in shares)		126	0
Non-Qualified Stock Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Dilutive securities outstanding not included in the computation of earnings (loss) per share because their effect is anti-dilutive (in shares)		16	1,486
Restricted Stock Units [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Dilutive securities outstanding not included in the computation of earnings (loss) per share because their effect is anti-dilutive (in shares)		18	679
Warrants Related to Cash Convertible Notes [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Dilutive securities outstanding not included in the computation of earnings (loss) per share because their effect is anti-dilutive (in shares)		0	7,707
CareFirst Convertible Note [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Dilutive securities outstanding not included in the computation of earnings (loss) per share because their effect is anti-dilutive (in shares)		0	892
CareFirst Warrants [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Dilutive securities outstanding not included in the computation of earnings (loss) per share because their effect is anti-dilutive (in shares)		0	591

[1] Figures may not add due to rounding.