Document and Entity Information Document (USD $)	12 Months Ended
	Dec. 31, 2013	Jun. 25, 2013	Feb. 18, 2014 Common Class A [Member]	Feb. 18, 2014 Common Class B [Member]
Document Information [Line Items]
Entity Registrant Name	Panera Bread Company
Entity Central Index Key	0000724606
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-K
Document Period End Date	Dec. 31, 2013
Document Fiscal Year Focus	2013
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity Common Stock, Shares Outstanding			26,344,580	1,381,865
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float		$ 3,716,017,782