Shareholders Equity and Dividend Restrictions (Details) - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Statutory Accounting Practices [Line Items]
Statutory net income	$ 2.1	$ 2.0	$ 1.6
Statutory surplus	8.0	$ 7.5	$ 6.3
Minimum statutory surplus required by regulators	2.6
Investments on deposit with regulatory bodies	0.4
Maximum dividend distribution permitted in 2016 without state approval	1.5
Maximum loans to parent company without state approval	1.3
Restricted net assets of Cigna Corporation	8.6
Increase to statutory surplus resulting from deferral of certain policy acquisition costs permitted by foreign regulatory authority	$ 0.2