Earnings Per Share Earnings Per Share (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 24, 2013	Jun. 25, 2013	Mar. 26, 2013	Dec. 25, 2012	Sep. 25, 2012	Jun. 26, 2012	Mar. 27, 2012	Dec. 31, 2013	Dec. 25, 2012	Dec. 27, 2011
Earnings Per Share [Abstract]
Net income attributable to Panera Bread Company	$ 54,248	$ 42,762	$ 51,042	$ 48,117	$ 51,612	$ 36,515	$ 44,137	$ 41,184	$ 196,169	$ 173,448	$ 135,952
Weighted Average Number of Shares Outstanding, Basic (in shares)									28,629	29,217	29,601
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements									165	238	302
Weighted Average Number of Shares Outstanding, Diluted (in shares)									28,794	29,455	29,903
Earnings Per Share, Basic (in dollars per share)	$ 1.97	$ 1.49	$ 1.75	$ 1.65	$ 1.77	$ 1.25	$ 1.51	$ 1.41	$ 6.85	$ 5.94	$ 4.59
Earnings Per Share, Diluted (in dollars per share)	$ 1.96	$ 1.48	$ 1.74	$ 1.64	$ 1.75	$ 1.24	$ 1.50	$ 1.40	$ 6.81	$ 5.89	$ 4.55