Selected Quarterly Financial Data Selected Quartely Financial Data (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 27, 2016	Sep. 27, 2016	Jun. 28, 2016	Mar. 29, 2016	Dec. 29, 2015	Sep. 29, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 27, 2016	Dec. 29, 2015	Dec. 30, 2014
Selected Quarterly Financial Information [Abstract]
Total revenue	$ 727,106	$ 684,206	$ 698,900	$ 685,153	$ 691,765	$ 664,654	$ 676,657	$ 648,504	$ 2,795,365	$ 2,681,580	$ 2,529,195
Operating profit	70,680	52,221	60,231	56,631	69,883	52,102	68,412	51,197	239,763	241,594	275,943
Net income attributable to Panera Bread Company	$ 44,010	$ 31,975	$ 34,501	$ 35,088	$ 43,160	$ 32,393	$ 41,929	$ 31,860	$ 145,574	$ 149,342	$ 179,293
Earnings Per Share, Basic (in dollars per share)	$ 1.93	$ 1.37	$ 1.46	$ 1.46	$ 1.75	$ 1.28	$ 1.60	$ 1.20	$ 6.21	$ 5.81	$ 6.67
Earnings Per Share, Diluted (in dollars per share)	$ 1.92	$ 1.37	$ 1.46	$ 1.45	$ 1.74	$ 1.27	$ 1.60	$ 1.20	$ 6.18	$ 5.79	$ 6.64