Consolidated Statements of Income (USD $) In Millions, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Revenues
Premiums	$ 66,119.1	$ 56,496.7	$ 55,969.6
Administrative fees	4,031.9	3,934.1	3,854.6
Other revenue	40.4	83.2	41.0
Total operating revenue	70,191.4	60,514.0	59,865.2
Net investment income	659.1	686.1	703.7
Net realized gains on investments	271.9	334.9	235.1
Other than temporary impairment losses on investments:
Total other-than-temporary impairment losses on investments	(100.6)	(41.2)	(114.7)
Portion of other-than-temporary impairment losses recognized in other comprehensive income	1.7	3.4	21.4
Other-than-temporary impairment losses recognized in income	(98.9)	(37.8)	(93.3)
Total revenues	71,023.5	61,497.2	60,710.7
Expenses
Benefit expense	56,237.1	48,213.6	47,647.5
Selling, general and administrative expense:
Selling expense	1,526.9	1,586.9	1,616.8
General and administrative expense	8,426.0	7,093.6	6,818.8
Total selling, general and administrative expense	9,952.9	8,680.5	8,435.6
Interest expense	602.7	511.8	430.3
Amortization of other intangible assets	245.3	233.0	239.4
Loss on extinguishment of debt	145.3	0	0
Total expenses	67,183.3	57,638.9	56,752.8
Income from continuing operations before income tax expense	3,840.2	3,858.3	3,957.9
Income tax expense	1,205.9	1,207.3	1,311.2
Income from continuing operations	2,634.3	2,651.0	2,646.7
(Loss) income from discontinued operations, net of tax	(144.6)	4.5	0
Net income	$ 2,489.7	$ 2,655.5	$ 2,646.7
Basic net income (loss) per share:
Basic - continuing operations (in dollars per share)	$ 8.83	$ 8.25	$ 7.35
Basic - discontinued operations (in dollars per share)	$ (0.49)	$ 0.01	$ 0.00
Basic net income per share	$ 8.34	$ 8.26	$ 7.35
Diluted net income (loss) per share:
Diluted - continuing operations (in dollars per share)	$ 8.67	$ 8.17	$ 7.25
Diluted - discontinued operations (in dollars per share)	$ (0.47)	$ 0.01	$ 0.00
Diluted net income per share	$ 8.20	$ 8.18	$ 7.25
Dividends per share	$ 1.50	$ 1.15	$ 1.00