Document and Entity Information - shares	6 Months Ended
	Mar. 31, 2016	Apr. 27, 2016
Document and Entity Information [Abstract]
Entity Registrant Name	DIGI INTERNATIONAL INC.
Entity Central Index Key	0000854775
Current Fiscal Year End Date	--09-30
Entity Filer Category	Accelerated Filer
Document Type	10-Q
Document Period End Date	Mar. 31, 2016
Document Fiscal Year Focus	2016
Document Fiscal Period Focus	Q2
Amendment Flag	false
Entity Common Stock, Shares Outstanding		25,872,329