Inventories (Details) - USD ($) $ in Thousands	Dec. 30, 2017	Dec. 31, 2016
Inventory Disclosure [Abstract]
Raw materials	$ 6,577	$ 7,973
Work in progress	170	72
Finished goods	77,551	66,981
Inventories	84,298	75,026
Components of finished goods inventory [Abstract]
Finished beds included in finished goods inventory	25,000	21,000
Finished components included in finished goods inventory	35,000	29,000
Retail accessories included in finished goods inventory	$ 18,000	$ 17,000