Document and Entity Information	6 Months Ended
	Mar. 30, 2013	May 02, 2013
Document Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 30, 2013
Document Fiscal Year Focus	2013
Document Fiscal Period Focus	Q2
Trading Symbol	HOLX
Entity Registrant Name	Hologic Inc.
Entity Central Index Key	0000859737
Current Fiscal Year End Date	--09-28
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		269,305,920