Business Combinations - Additional Information (Details) $ / shares in Units, $ in Thousands			3 Months Ended	9 Months Ended
	Mar. 08, 2019 USD ($) $ / shares	Dec. 09, 2018	Jun. 30, 2019 USD ($)	Sep. 30, 2019 USD ($)	Sep. 30, 2018 USD ($)
Business Acquisition [Line Items]
Increase (decrease) in acquisition, integration, and restructuring costs				$ (33,400)	$ 38,700
Increase (decrease) in income tax expense				$ (2,700)	2,700
Increase in cost of revenue					$ 2,800
Nutrisystem, Inc.
Business Acquisition [Line Items]
Business acquisition, cash received in conversion | $ / shares	$ 38.75
Business acquisition, common stock exchange ratio	0.2141
Merger consideration	$ 1,286,108
Decreased estimated fair value of intangible assets due to change in timing of projected revenue			$ (15,000)
Increase to goodwill			11,400
Decrease in deferred liabilities			$ 3,600
Nutrisystem, Inc. | Merger Agreement
Business Acquisition [Line Items]
Business acquisition, agreement date		Dec. 09, 2018
Business acquisition, effective date of acquisition	Mar. 08, 2019
Business acquisition, cash received in conversion | $ / shares	$ 38.75
Business acquisition, common stock exchange ratio	0.2141