Significant Accounting Policies (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 29, 2012	Dec. 31, 2011	Jan. 01, 2011
Basis of Presentation and Principles of Consolidation
Length of fiscal year	364 days	364 days	364 days
Advertising
Advertising expenses	$ 1.7	$ 1.6	$ 1.4
Buildings
Property and Equipment
Useful life	40 years
Leasehold interest in ground leases
Property and Equipment
Useful life	86 years
Minimum
Basis of Presentation and Principles of Consolidation
Length of fiscal year	364 days	364 days	364 days
Long-Lived Assets
Useful live of purchased intangible assets	2 years
Property and Equipment
Useful life	3 years
Maximum
Basis of Presentation and Principles of Consolidation
Length of fiscal year	371 days	371 days	371 days
Long-Lived Assets
Useful live of purchased intangible assets	12 years
Property and Equipment
Useful life	5 years