Inventories - Schedule of Finished Goods Inventories (Details) - USD ($) $ in Thousands	Jan. 02, 2021	Dec. 28, 2019
Inventory Disclosure [Abstract]
Finished beds, including retail display beds and deliveries in-transit to those customers who have utilized home delivery services	$ 21,442	$ 24,509
Finished components that were ready for assembly for the completion of beds	28,108	40,139
Retail accessories	19,110	16,155
Finished goods inventory	$ 68,660	$ 80,803

Carrying amount as of the balance sheet date of merchandise ready for assembly that are included in the finished goods inventory as finished components.

No definition available.

Name:	snbr_FinishedComponentsIncludedInFinishedGoodsInventoryNet
Namespace Prefix:	snbr_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant