Significant Accounting Policies - Property and Equipment and Long Lived Assets (Details)	12 Months Ended
	Dec. 29, 2018
Low end of range
Property and Equipment
Useful life	3 years
Long-Lived Assets
Useful life of purchased intangible assets	3 years
High end of range
Property and Equipment
Useful life	10 years
Long-Lived Assets
Useful life of purchased intangible assets	12 years
Buildings
Property and Equipment
Useful life	40 years
Leasehold interest in ground leases
Property and Equipment
Useful life	86 years