Revenue Recognition - Summary of Revenue Disaggregated by Program (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Disaggregation Of Revenue [Line Items]
Revenue		$ 120,071	$ 81,923	$ 228,156	$ 241,615
Continuing Operations
Disaggregation Of Revenue [Line Items]
Revenue		120,071	81,923	228,156	241,615
Continuing Operations | SilverSneakers
Disaggregation Of Revenue [Line Items]
Revenue		90,742	49,157	170,568	170,764
Continuing Operations | Prime Fitness
Disaggregation Of Revenue [Line Items]
Revenue		23,357	19,047	45,951	51,858
Continuing Operations | WholeHealth Living
Disaggregation Of Revenue [Line Items]
Revenue		5,712	4,747	11,348	9,796
Continuing Operations | Other
Disaggregation Of Revenue [Line Items]
Revenue	[1]	$ 260	$ 8,972	$ 289	$ 9,197

[1]   (1) For the three and six months ended June 30, 2020, other revenue in the table above includes $6.8 million from a well-being program with a large employer as well as $2.1 million of revenue from home-delivered meals through our Wisely Well brand.