Recent Accounting Pronouncements (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended
Jun. 30, 2014
New Accounting Pronouncements And Changes In Accounting Principles [Abstract]
Health Care Reform Industry Assessment Fee Liability	$ 245
Health Care Reform Industry Assessment Fee Expense	$ 122

Expense recognized for health insurance industry assessment fee mandated by the Patient Protection and Affordable Care Act of 2010.

No definition available.

Name:	ci_HealthCareReformIndustryAssessmentFeeExpense
Namespace Prefix:	ci_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration