Document And Entity Information (USD $)	12 Months Ended
	Sep. 30, 2012	Nov. 23, 2012	Mar. 31, 2012
Document and Entity Information [Abstract]
Entity Registrant Name	International Game Technology
Document Type	10-K
Current Fiscal Year End Date	--09-29
Entity Common Stock, Shares Outstanding		266,100,000
Entity Public Float			$ 5,000,000,000
Amendment Flag	false
Entity Central Index Key	0000353944
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Large Accelerated Filer
Entity Well-known Seasoned Issuer	Yes
Document Period End Date	Sep. 30, 2012
Document Fiscal Year Focus	2012
Document Fiscal Period Focus	FY