XML 30 R39.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2

Business and Summary of Significant Accounting Policies - Dividends - Additional Information (Details)	12 Months Ended
	Dec. 28, 2019
Accounting Policies [Abstract]
Leverage Ratio	375.00%

X

- Definition

Leverage ratio.

+ References

No definition available.

+ Details

Name:	snbr_LeverageRatio
Namespace Prefix:	snbr_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

X

- References

No definition available.

+ Details

Name:	us-gaap_AccountingPoliciesAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration