Summary of Significant Accounting Policies - Additional Information (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($) channel facility	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Jan. 01, 2019 USD ($)	Jul. 11, 2018	Jan. 01, 2018 USD ($)
Business Acquisition [Line Items]
Number of products sales channels | channel	2
Operating lease right-of-use assets	$ 245.4	$ 0.0
Operating lease, liability	256.2
Depreciation expense	73.8	71.8	$ 64.8
Sales returns accrual	39.3	34.3	30.0			$ 31.7
Allowance for doubtful accounts included in accounts receivable, net	71.9	47.6
Shipping and handling included in cost of sales	192.5	169.1	155.9
Advertising costs charged to expense	280.5	259.3	283.5
Advertising costs deferred and included in prepaid expenses and other current assets	3.6	8.5
Research and development costs charged to expense	$ 23.0	21.9	$ 21.7
Number of active plants | facility	2
Number of previously closed US facilities | facility	10
Bedding | Non-prorated | International
Business Acquisition [Line Items]
Warranty term (in years)	5 years
Bedding | Prorated | International
Business Acquisition [Line Items]
Warranty term (in years)	10 years
Pillows Two | Non-prorated
Business Acquisition [Line Items]
Warranty term (in years)	3 years
Accrued liabilities and other current liabilities
Business Acquisition [Line Items]
Sales returns accrual	$ 26.2	22.0
Other non-current liabilities
Business Acquisition [Line Items]
Sales returns accrual	13.1	12.3
Standard product warranty accrual	22.2	21.5
Accounts payable and accrued liabilities
Business Acquisition [Line Items]
Standard product warranty accrual	$ 19.4	$ 14.9
Maximum | Bedding | North America
Business Acquisition [Line Items]
Warranty term (in years)	25 years
Maximum | Bedding | International
Business Acquisition [Line Items]
Warranty term (in years)	15 years
Maximum | Bedding | Non-prorated | North America
Business Acquisition [Line Items]
Warranty term (in years)	15 years
Minimum | Bedding | North America
Business Acquisition [Line Items]
Warranty term (in years)	10 years
Minimum | Bedding | International
Business Acquisition [Line Items]
Warranty term (in years)	5 years
Minimum | Bedding | Non-prorated | North America
Business Acquisition [Line Items]
Warranty term (in years)	10 years
Leasehold improvements | Maximum
Business Acquisition [Line Items]
Property, plant and equipment, useful life	7 years
Leasehold improvements | Minimum
Business Acquisition [Line Items]
Property, plant and equipment, useful life	4 years
Variable Interest Entity, Primary Beneficiary
Business Acquisition [Line Items]
Equity method investment, acquired remaining interest, percentage					55.00%
Sealy Canada
Business Acquisition [Line Items]
Ownership percentage by parent	100.00%
Accounting Standards Update 2016-02
Business Acquisition [Line Items]
Operating lease right-of-use assets				$ 197.2
Operating lease, liability				$ 203.3