Revenue Recognition - Additional Information (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2019 USD ($)	Sep. 30, 2018 USD ($)	Sep. 30, 2019 USD ($) Segment Program Obligation Source	Sep. 30, 2018 USD ($)
Disaggregation Of Revenue [Line Items]
Number of reportable segments | Segment			2
Revenue, Practical Expedient, Initial Application and Transition, Qualitative Assessment			true
Revenues	$ 303,897,000	$ 151,467,000	$ 858,369,000	$ 453,261,000
Healthcare
Disaggregation Of Revenue [Line Items]
Number of programs | Program			3
Number of performance obligations | Obligation			1
Number of performance obligation unsatisfied | Obligation			0
Revenue recognized from performance obligations satisfied in prior period	0		$ 0
Period of billing in arrears once timing of services to customers is known			1 month
Number of days for customer to make payment after being invoiced			30 days
Capitalized costs	300,000		$ 300,000
Number of reportable segments | Segment			2
Revenues	159,979,000	$ 151,467,000	$ 473,987,000	$ 453,261,000
Nutrition
Disaggregation Of Revenue [Line Items]
Number of sources for revenue recognition | Source			4
Description of return of obligation			Direct to consumer customers may return unopened ready-to-go Nutrisystem products within 30 days after purchase in order to receive a refund or credit.
Return of purchase order to refund or credit, period			30 days
Purchase order canceled of delivery, period			14 days
Revenues	143,918,000		$ 384,382,000
Provision for estimated returns	3,900,000		11,000,000.0
Nutrition | Accrued Liabilities
Disaggregation Of Revenue [Line Items]
Reserve for estimated returns	1,300,000		1,300,000
Nutrition | Shipping and Handling Charges
Disaggregation Of Revenue [Line Items]
Revenues	$ 5,300,000		$ 13,400,000