Summary of Significant Accounting Policies - Additional Information (Details)				3 Months Ended	10 Months Ended	12 Months Ended
		Mar. 07, 2019 Segment	Jan. 01, 2017 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2019 USD ($) Segment	Dec. 31, 2019 USD ($) Segment		Dec. 31, 2018 USD ($)		Dec. 31, 2017 USD ($)	Mar. 31, 2019 USD ($)	Mar. 08, 2019 USD ($)
Accounting Policies [Line Items]
Allowance for doubtful accounts				$ 200,000	$ 200,000	$ 200,000		$ 0
Unbilled receivables				29,100,000	29,100,000	29,100,000		23,200,000
Reserve for excess and obsolete inventory				1,800,000	1,800,000	1,800,000		0
Depreciation						18,400,000		4,700,000		$ 3,400,000
Carrying value of adjustable convertible equity right				10,800,000	10,800,000	10,800,000
Intangible assets not subject to amortization				589,000,000.0	589,000,000.0	589,000,000.0		29,000,000.0
Goodwill				654,635,000	$ 654,635,000	654,635,000		334,680,000		334,680,000
Impairment loss of goodwill				137,100,000		$ 137,100,000	[1]	0	[1]
Number of reporting units | Segment		1			2	2
Accrued liabilities				56,068,000	$ 56,068,000	$ 56,068,000		42,563,000
Media expense						128,700,000		1,000,000.0		0
Prepaid for future advertisements and promotions				5,000,000.0	5,000,000.0	5,000,000.0		0
Accounting Standards Update 2016-09 [Member]
Accounting Policies [Line Items]
Increase in retained earnings			$ 6,500,000							6,538,000
Network Locations Visits
Accounting Policies [Line Items]
Accrued liabilities				28,800,000	28,800,000	28,800,000		26,100,000
Accrued advertising expenses				11,300,000	11,300,000	11,300,000		0
Nutrisystem
Accounting Policies [Line Items]
Intangible assets not subject to amortization											$ 800,000,000.0
Goodwill												$ 457,100,000
Impairment loss of goodwill				137,100,000
Nutrisystem | Tradename
Accounting Policies [Line Items]
Impairment loss of intangibles				240,000,000.0
Healthcare
Accounting Policies [Line Items]
Intangible assets not subject to amortization				29,000,000.0	29,000,000.0	29,000,000.0		29,000,000.0
Goodwill				334,680,000	334,680,000	334,680,000		334,680,000		$ 334,680,000
Impairment loss of goodwill	[1]					$ 0		0
Number of reporting units | Segment						2
Nutrition
Accounting Policies [Line Items]
Goodwill				319,955,000	319,955,000	$ 319,955,000		$ 0
Impairment loss of goodwill				137,100,000		137,100,000	[1]
Reduced cost of revenue, rebate earned						800,000
Amount of rebate receivable recorded in balance sheet				$ 200,000	$ 200,000	$ 200,000
Minimum
Accounting Policies [Line Items]
Remaining lease terms						1 year
Estimated useful life						3 years		3 years
Maximum
Accounting Policies [Line Items]
Remaining lease terms						6 years
Estimated useful life						10 years		10 years
Computer Software and Hardware | Minimum
Accounting Policies [Line Items]
Useful life						3 years
Computer Software and Hardware | Maximum
Accounting Policies [Line Items]
Useful life						7 years
Furniture and Office Equipment | Minimum
Accounting Policies [Line Items]
Useful life						4 years
Furniture and Office Equipment | Maximum
Accounting Policies [Line Items]
Useful life						7 years
Equipment | Minimum
Accounting Policies [Line Items]
Useful life						3 years
Equipment | Maximum
Accounting Policies [Line Items]
Useful life						5 years
Leasehold Improvements | Minimum
Accounting Policies [Line Items]
Useful life						2 years
Leasehold Improvements | Maximum
Accounting Policies [Line Items]
Useful life						15 years

[1] See Note 13 for explanation.