Segment Information - Revenue by Product Type (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Revenue from External Customer [Line Items]
Premiums and fees, mail order pharmacy revenues and other revenues	$ 9,118ci_NonInvestmentRevenue	$ 8,177ci_NonInvestmentRevenue

Revenue excluding net investment income and realized investment results.

No definition available.