Document and Entity Information - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2015	Dec. 01, 2015	Mar. 31, 2015
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Sep. 30, 2015
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	FY
Trading Symbol	SRDX
Entity Registrant Name	SURMODICS INC
Entity Central Index Key	0000924717
Current Fiscal Year End Date	--09-30
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		12,944,326
Entity Public Float			$ 245