Consolidated Balance Sheets (Parenthetical) (USD $)	Dec. 27, 2011	Dec. 28, 2010
Panera Bread Company stockholders' equity:
Treasury stock, shares	2,048,338	1,119,092
Common Stock Class A [Member]
Panera Bread Company stockholders' equity:
Common stock, par value	0.0001	0.0001
Common stock, authorized	112,500,000	112,500,000
Common stock, issued	30,330,759	30,125,936
Common stock, outstanding	28,265,672	29,006,844
Common Stock Class B [Member]
Panera Bread Company stockholders' equity:
Common stock, par value	0.0001	0.0001
Common stock, authorized	10,000,000	10,000,000
Common stock, issued	1,383,687	1,391,607
Common stock, outstanding	1,383,687	1,391,607