Document and Entity Information - USD ($)	3 Months Ended
	Jun. 30, 2018	Jul. 13, 2018	Sep. 30, 2017
Document and Entity Information [Abstract]
Entity Registrant Name	BLACK BOX CORP
Entity Central Index Key	0000849547
Document Type	10-Q
Document Period End Date	Jun. 30, 2018
Amendment Flag	false
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q1
Current Fiscal Year End Date	--03-31
Entity Current Reporting Status	Yes
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding		15,234,162
Entity Public Float			$ 0