Document And Entity Information	6 Months Ended
	Dec. 31, 2011	Jan. 31, 2012 Class A Common Stock [Member]	Jan. 31, 2012 Class B Common Stock [Member]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Dec. 31, 2011
Document Fiscal Period Focus	Q2
Document Fiscal Year Focus	2012
Entity Registrant Name	Madison Square Garden Co
Entity Central Index Key	0001469372
Current Fiscal Year End Date	--06-30
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		62,213,924	13,588,555