Unaudited Quarterly Financial Data (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended												12 Months Ended
	Sep. 28, 2013	Jun. 29, 2013	Mar. 30, 2013	Dec. 29, 2012	Sep. 29, 2012	Jun. 23, 2012	Mar. 24, 2012	Dec. 24, 2011	Sep. 24, 2011	Jun. 25, 2011	Mar. 26, 2011	Dec. 25, 2010	Sep. 28, 2013	Sep. 29, 2012	Sep. 24, 2011
Unaudited Quarterly Financial Data
Net sales	$ 1,047,177	$ 967,072	$ 1,004,792	$ 1,339,059	$ 946,736	$ 869,194	$ 885,052	$ 1,158,216	$ 711,883	$ 717,210	$ 647,658	$ 574,148	$ 4,358,100	$ 3,859,198	$ 2,650,899
Gross profit	377,459	407,618	415,146	419,163	316,446	303,311	313,038	336,604	254,090	264,080	242,855	143,600	1,619,386	1,269,399	904,625
Net income attributable to GMCR	$ 126,956	$ 116,272	$ 132,421	$ 107,583	$ 91,887	$ 73,296	$ 93,031	$ 104,414	$ 75,369	$ 56,348	$ 65,372	$ 2,412
Earnings per share basic (in dollars per share)	$ 0.84	$ 0.78	$ 0.89	$ 0.72	$ 0.59	$ 0.47	$ 0.60	$ 0.67	$ 0.49	$ 0.38	$ 0.46	$ 0.02	$ 3.23	$ 2.34	$ 1.36
Earnings per share diluted (in dollars per share)	$ 0.83	$ 0.76	$ 0.87	$ 0.70	$ 0.58	$ 0.46	$ 0.58	$ 0.66	$ 0.47	$ 0.37	$ 0.44	$ 0.02	$ 3.16	$ 2.28	$ 1.31