The calculated weighted-average amortization period of customer relations intangible assets acquired during the current period either individually or as part of a group of assets (in either an asset acquisition or business combination). A major class is composed of intangible assets that can be grouped together because they are similar, either by their nature or by their use in the operations of a company.

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- Details

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Acquisition (Details) (USD $)	1 Months Ended		1 Months Ended	0 Months Ended
Acquisition (Details) (USD $)	Aug. 31, 2010 Vanbreda [Member]	Aug. 31, 2010 Vanbreda [Member] Customer Relationships [Member]	Sep. 30, 2011 FirstAssist [Member]	Oct. 24, 2011 HealthSpring [Member]
Vanbreda Condensed Balance Sheet Acquisition Date [Abstract]
Investments	$ 39,000,000
Cash and cash equivalents	73,000,000
Premiums, accounts and notes receivable	22,000,000
Property and equipment	1,000,000
Deferred income taxes	(71,000,000)
Goodwill	229,000,000
Other assets, including other intangibles	220,000,000
Total assets acquired	513,000,000
Accounts payable, accrued expenses and other liabilities	101,000,000
Total liabilities acquired	101,000,000
Net assets acquired	412,000,000
Acquisition Text Details [Abstract]
Business Acquisition Effective Date Of Acquisition [Text Block]	August 31, 2010
Business Acquisition Percentage Of Voting Interests Acquired	100.00%
Business Acquisition Name Of Acquired Entity [Text Block]	Vanbreda International NV		FirstAssist Group Holdings Limited	HealthSpring, Inc.
Business Acquisition Cost Of Acquired Entity Cash Paid	412,000,000		110,000,000
Business Acquisition Description Of Acquired Entity [Text Block]	Vanbreda International specializes in providing worldwide medical insurance and employee benefits to intergovernmental and non-governmental organizations, including international humanitarian operations, as well as corporate clients.		. FirstAssist is based in the United Kingdom and provides travel and protection insurance services
Business Combination Reason For Business Combination [Text Block]	Vanbreda International’s strong presence in Europe complements the Company’s position in providing expatriate benefits primarily to corporate clients in North America, as well as in Europe and Asia.		the Company expects will enhance its individual business in the U.K. and around the world.
Business Acquisition Purchase Price Allocation Methodology [Text Block]	In accordance with GAAP, the total purchase price has been allocated to the tangible and intangible net assets acquired based on management’s estimates of their fair values.
Business Combination Goodwill Recognized Segment Allocation [Text Block]	Goodwill is allocated to the International segment.
Business Acquisition Period Results Included In Combined Entity [Text Block]	from the date of acquisition
Average amortization period for customer relationships	15 years
Business Acquisition, Date of Acquisition Agreement			September 2011	October 24, 2011
Acquired Finite Lived Intangible Asset Amount		210,000,000
Price per share				55
Estimated Acquisition Cost				$ 3,900,000,000