Business Combinations - Summary of Component of Merger Consideration (Details) - Nutrisystem, Inc. $ in Thousands	Mar. 08, 2019 USD ($)
Business Acquisition [Line Items]
Cash paid for outstanding Nutrisystem shares	$ 1,138,143	[1]
Value of Tivity Health Common Stock issued in the merger	132,838	[2]
Value of Nutrisystem stock options	6,020	[3]
Value of Tivity Health replacement awards attributable to pre-combination service	9,107	[4]
Total Merger Consideration	$ 1,286,108

[1] Represents the total cash paid to former Nutrisystem stockholders as cash consideration. This amount is based on the 29,370,594 shares of Nutrisystem common stock issued and outstanding as of Closing and cash consideration of $38.75 per share, plus cash payable in lieu of fractional shares.

[2] Represents the fair value of 6.3 million shares of Tivity Health Common Stock issued for outstanding Nutrisystem shares as stock consideration. This amount is based on (a) 29,370,594 Nutrisystem common shares issued and outstanding as of Closing, times (b) the Exchange Ratio of 0.2141, times (c) $21.12, which is equal to the volume-weighted averages of the trading price per share of our Common Stock for the five consecutive trading days up to and including March 6, 2019.

[3] Represents the fair value of the cash consideration paid for the net settlement of approximately 204,000 Nutrisystem stock options vested and outstanding as of the closing date. In accordance with the Merger Agreement, each vested and outstanding Nutrisystem stock option was cancelled, and the holder received a cash payment per option equal to approximately $43.27 minus the applicable exercise price of the stock option.

[4] Unvested restricted stock awards and performance stock units held by Nutrisystem employees were assumed by Tivity Health and converted into time-vesting restricted stock awards and time-vesting restricted stock units, respectively (“Replacement Awards”). The value in the table represents the portion of the fair value of the Replacement Awards that relates to pre-combination services.