Document and Entity Information - shares	3 Months Ended
	Apr. 03, 2016	May. 02, 2016
Document and Entity Information [Abstract]
Entity Registrant Name	FEI CO
Entity Central Index Key	0000914329
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	Apr. 03, 2016
Document Fiscal Year Focus	2016
Document Fiscal Period Focus	Q1
Amendment Flag	false
Entity Common Stock, Shares Outstanding		40,859,878