Summary of Significant Accounting Policies - Additional Information (Details) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2017 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2017 USD ($) channel facility shares	Dec. 31, 2016 USD ($) shares	Dec. 31, 2015 USD ($)	Oct. 03, 2016
Business Acquisition [Line Items]
Number of products sales channels | channel			2
Depreciation expense		$ 53.5	$ 65.3	$ 56.1
Allowance for doubtful accounts included in accounts receivable, net			27.4	22.4
Shipping and handling included in net sales		11.1	11.3	11.7
Shipping and handling included in cost of sales		161.6	159.3	155.1
Advertising costs charged to expense		360.5	284.1	352.7
Advertising costs deferred and included in prepaid expenses and other current assets			3.8	7.4
Research and development costs charged to expense		$ 28.7	21.7	26.7
Royalty revenue, net of royalty expense			20.8	19.5	$ 18.3
Treasury stock repurchased			40.1	533.0	1.3
Self insurance reserve, excess loss coverage per claim per year			0.8
Self insurance reserve, current			4.8	8.6
Self insurance reserve, noncurrent			15.9	12.3
Estimated insurance recoveries, current			2.4	0.0
Estimated insurance recoveries, noncurrent			$ 7.6	14.2
Number of active plants | facility			2
Number of previously closed US facilities | facility			10
Restructuring expenses				8.3
Customer termination charges, net			$ 14.4	0.0	$ 0.0
Mattress Firm
Business Acquisition [Line Items]
Restructuring charges	$ 25.9
Customer termination charges, net	14.4
Accelerated compensation cost	0.9
Mattress Firm | Write Off Incentives, Marketing Assets and Other
Business Acquisition [Line Items]
Customer termination charges, net	22.8
Mattress Firm | Cost of Sales
Business Acquisition [Line Items]
Restructuring charges	11.5
Mattress Firm | Cost of Sales | Write Off Inventory
Business Acquisition [Line Items]
Restructuring charges	5.4
Mattress Firm | Cost of Sales | Warranty Costs
Business Acquisition [Line Items]
Restructuring charges	6.1
Mattress Firm | Other Income
Business Acquisition [Line Items]
Payments for restructuring	9.3
February 2016 Program
Business Acquisition [Line Items]
Treasury stock repurchased (in shares) | shares			600,000
Treasury stock repurchased			$ 4.8	$ 2.0
Stock repurchase program, amount remaining under share repurchase authorization (in shares) | shares			226,900,000
Performance-based Restricted Stock Units
Business Acquisition [Line Items]
Shares paid for tax withholding for share based compensation(in shares) | shares			100,000.0	0
Performance-based Restricted Stock Units | Mattress Firm
Business Acquisition [Line Items]
Stock compensation, forfeited benefit	$ 9.3
North America
Business Acquisition [Line Items]
Ownership percentage by parent				51.00%		51.00%
Mattresses | Non-prorated | International
Business Acquisition [Line Items]
Warranty term (in years)			5 years
Mattresses | 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
Accounts Payable and Accrued Liabilities
Business Acquisition [Line Items]
Standard product warranty accrual			$ 16.7	$ 14.3
Other Noncurrent Liabilities
Business Acquisition [Line Items]
Standard product warranty accrual			$ 20.0	$ 15.6
Maximum | Mattresses | North America
Business Acquisition [Line Items]
Warranty term (in years)			25 years
Maximum | Mattresses | International
Business Acquisition [Line Items]
Warranty term (in years)			15 years
Maximum | Mattresses | Non-prorated | North America
Business Acquisition [Line Items]
Warranty term (in years)			15 years
Minimum | Mattresses | North America
Business Acquisition [Line Items]
Warranty term (in years)			10 years
Minimum | Mattresses | International
Business Acquisition [Line Items]
Warranty term (in years)			5 years
Minimum | Mattresses | 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
Comfort Revolution
Business Acquisition [Line Items]
Percentage of noncontrolling interest from the acquisition			55.00%
Comfort Revolution | Variable Interest Entity, Primary Beneficiary
Business Acquisition [Line Items]
Equity method investment, ownership percentage			45.00%
Sealy Canada
Business Acquisition [Line Items]
Ownership percentage by parent			100.00%