Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 29, 2016	Mar. 31, 2015
Amounts used for basic and diluted per share calculations
Net income attributable to Panera Bread Company	$ 35,088	$ 31,860
Weighted average number of shares outstanding - basic (in shares)	24,105	26,478
Effect of dilutive stock-based employee compensation awards (in shares)	109	91
Weighted average number of shares outstanding - diluted (in shares)	24,214	26,569
Earnings per common share:
Basic (in dollars per share)	$ 1.46	$ 1.20
Diluted (in dollars per share)	$ 1.45	$ 1.20