Document and Entity Information (USD $) In Millions, except Share data, unless otherwise specified	9 Months Ended
	Sep. 30, 2012	Oct. 15, 2012
Document and Entity Information [Abstract]
Document Type	10-Q
Document Period End Date	Sep. 30, 2012
Entity Registrant Name	CIGNA Corporation
Entity Central Index Key	0000701221
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Trading Symbol	CI
Entity Common Stock Shares Outstanding		285,890,413
Amendment Flag	false
Entity Current Reporting Status	Yes
Entity Well Known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Public Float	$ 13,524
Document Fiscal Year Focus	2012
Document Fiscal Period Focus	Q3