Consolidated Statements Of Income (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Revenues
Premiums	$ 16,435.6	$ 14,138.5
Administrative fees	990.1	995.8
Other revenue	120.6	15.9
Total operating revenue	17,546.3	15,150.2
Net investment income	162.0	169.0
Net realized gains on investments	16.8	106.9
Other-than-temporary impairment losses on investments:
Total other-than-temporary impairment losses on investments	(37.9)	(13.7)
Portion of other-than-temporary impairment losses recognized in other comprehensive income	0	2.8
Other-than-temporary impairment losses recognized in income	(37.9)	(10.9)
Total revenues	17,687.2	15,415.2
Expenses
Benefit expense	13,748.7	11,771.9
Selling, general and administrative expense:
Selling expense	385.9	393.3
General and administrative expense	1,979.1	1,772.4
Total selling, general and administrative expense	2,365.0	2,165.7
Cost of products	65.0	0
Interest expense	153.5	109.1
Amortization of other intangible assets	67.9	58.7
Total expenses	16,400.1	14,105.4
Income before income tax expense	1,287.1	1,309.8
Income tax expense	401.9	453.3
Net income	$ 885.2	$ 856.5
Net income per share
Basic	$ 2.92	$ 2.56
Diluted	$ 2.89	$ 2.53
Dividends per share	$ 0.3750	$ 0.2875