Document and Entity Information (USD $)	12 Months Ended
	Mar. 31, 2013	May 06, 2013	Sep. 30, 2012
Document Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Mar. 31, 2013
Document Fiscal Year Focus	2013
Document Fiscal Period Focus	FY
Trading Symbol	BMC
Entity Registrant Name	BMC SOFTWARE INC
Entity Central Index Key	0000835729
Current Fiscal Year End Date	--03-31
Entity Well-known Seasoned Issuer	Yes
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		143,973,000
Entity Public Float			$ 6,429,383,000