Document and Entity Information (USD $)	6 Months Ended
	Mar. 31, 2012	Apr. 30, 2012	Mar. 31, 2011
Document and Entity Information [Abstract]
Entity Registrant Name	DIGI INTERNATIONAL INC.
Entity Central Index Key	0000854775
Document Type	10-Q
Document Period End Date	Mar. 31, 2012
Amendment Flag	false
Document Fiscal Year Focus	2012
Document Fiscal Period Focus	Q2
Current Fiscal Year End Date	--09-30
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		25,756,337
Document Information [Line Items]
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$ 264,853,102