Document and Entity Information	9 Months Ended
	Sep. 25, 2012	Oct. 23, 2012 Common Stock Class A [Member]	Oct. 23, 2012 Common Stock Class B [Member]
Entity Registrant Name	Panera Bread Company
Entity Central Index Key	0000724606
Current Fiscal Year End Date	--12-25
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	Sep. 25, 2012
Document Fiscal Year Focus	2012
Document Fiscal Period Focus	Q3
Amendment Flag	false
Entity Common Stock, Shares Outstanding		28,360,474	1,383,687