Earnings Per Share Earnings Per Share (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 30, 2014	Sep. 30, 2014	Jul. 01, 2014	Apr. 01, 2014	Dec. 31, 2013	Sep. 24, 2013	Jun. 25, 2013	Mar. 26, 2013	Dec. 30, 2014	Dec. 31, 2013	Dec. 25, 2012
Earnings Per Share [Abstract]
Net income attributable to Panera Bread Company	$ 48,492	$ 39,214	$ 49,192	$ 42,395	$ 54,248	$ 42,762	$ 51,042	$ 48,117	$ 179,293	$ 196,169	$ 173,448
Weighted Average Number of Shares Outstanding, Basic (in shares)									26,881	28,629	29,217
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements									118	165	238
Weighted Average Number of Shares Outstanding, Diluted (in shares)									26,999	28,794	29,455
Earnings Per Share, Basic (in dollars per share)	$ 1.82	$ 1.47	$ 1.83	$ 1.55	$ 1.97	$ 1.49	$ 1.75	$ 1.65	$ 6.67	$ 6.85	$ 5.94
Earnings Per Share, Diluted (in dollars per share)	$ 1.82	$ 1.46	$ 1.82	$ 1.55	$ 1.96	$ 1.48	$ 1.74	$ 1.64	$ 6.64	$ 6.81	$ 5.89