Consolidated Balance Sheets (USD $) In Millions, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Current assets:
Cash and cash equivalents	$ 2,279.1	$ 2,201.6
Investments available-for-sale, at fair value:
Fixed maturity securities (amortized cost of $15,449.1 and $15,233.6)	16,196.5	15,913.1
Equity securities (cost of $871.0 and $937.7)	1,224.4	1,188.1
Other invested assets, current	21.6	14.8
Accrued investment income	167.3	172.0
Premium and self-funded receivables	3,722.1	3,402.9
Other receivables	943.2	943.9
Income taxes receivable	0	105.8
Securities lending collateral	715.5	871.4
Deferred tax assets, net	353.3	424.8
Other current assets	1,920.6	1,859.0
Total current assets	27,543.6	27,097.4
Long-term investments available-for-sale, at fair value:
Fixed maturity securities (amortized cost of $240.2 and $240.8)	245.3	246.8
Equity securities (cost of $26.8 and $28.4)	29.3	28.8
Other invested assets, long-term	1,041.3	1,003.7
Property and equipment, net	1,454.6	1,418.1
Goodwill	13,858.6	13,858.7
Other intangible assets	7,878.1	7,931.7
Other noncurrent assets	445.7	433.6
Total assets	52,496.5	52,018.8
Liabilities and shareholders' equity
Medical claims payable	5,403.3	5,489.0
Reserves for future policy benefits	60.8	55.1
Other policyholder liabilities	2,257.6	2,278.2
Total policy liabilities	7,721.7	7,822.3
Unearned income	1,624.1	926.5
Accounts payable and accrued expenses	2,809.9	3,124.1
Income taxes payable	265.8	0
Security trades pending payable	146.8	51.7
Securities lending payable	715.9	872.5
Short-term borrowings	100.0	100.0
Current portion of long-term debt	910.8	1,274.5
Other current liabilities	1,660.1	1,654.1
Total current liabilities	15,955.1	15,825.7
Long-term debt, less current portion	8,462.5	8,420.9
Reserves for future policy benefits, noncurrent	752.3	730.7
Deferred tax liabilities, net	2,773.2	2,724.0
Other noncurrent liabilities	1,025.0	1,029.3
Total liabilities	28,968.1	28,730.6
Commitment and contingencies-Note 8	0	0
Shareholders' equity
Preferred stock, without par value, shares authorized - 100,000,000; shares issued and outstanding - none	0	0
Common stock, par value $0.01, shares authorized-900,000,000; shares issued and outstanding: 331,807,383 and 339,372,680	3.3	3.4
Additional paid-in capital	11,369.0	11,679.2
Retained earnings	11,921.1	11,490.7
Accumulated other comprehensive income	235.0	114.9
Total shareholders' equity	23,528.4	23,288.2
Total liabilities and shareholders' equity	$ 52,496.5	$ 52,018.8