Schedule II - Condensed Financial Information, Notes (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Maturities Of Debt Excluding Capital Leases [Abstract]
Maturities of Debt in 2016	$ 0
Maturities of Debt in 2017	250
Maturities of Debt in 2018	131
Maturities of Debt in 2019	0
Maturities of Debt in 2020	550
Maturities of Debt in years after 2020	4,078
Interest expense on long-term and short-term debt	252	$ 265	$ 270
Interest paid on long-term and short-term debt	245	259	265
Parent Company [Member]
Maturities Of Debt Excluding Capital Leases [Abstract]
Maturities of Debt in 2016	0
Maturities of Debt in 2017	250
Maturities of Debt in 2018	131
Maturities of Debt in 2019	0
Maturities of Debt in 2020	550
Maturities of Debt in years after 2020	3,997
Interest expense on long-term and short-term debt	246	252	$ 259
Intercompany liabilities consisting primarily of loans payable	$ 1,086	$ 1,138
Average Interest Rate On Intercompany Loan	0.60%	0.52%
Parent Company [Member] | Cigna Holdings, Inc. [Member]
Maturities Of Debt Excluding Capital Leases [Abstract]
Intercompany liabilities consisting primarily of loans payable	$ 875	$ 877