Consolidated Statements of Cash Flows (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Operating activities
Net income	$ 2,489.7	$ 2,655.5	$ 2,646.7
Adjustments to reconcile net income to net cash provided by operating activities:
Net realized gains on investments	(271.9)	(334.9)	(235.1)
Other-than-temporary impairment losses recognized in income	98.9	37.8	93.3
Loss on extinguishment of debt	145.3	0	0
Loss on disposal from discontinued operations	221.8	0	0
Loss on disposal of assets	3.9	4.7	3.3
Deferred income taxes	59.1	127.5	74.3
Amortization, net of accretion	800.9	633.6	541.5
Depreciation expense	107.9	107.1	95.7
Impairment of property and equipment	47.7	66.8	0
Share-based compensation	146.0	146.5	134.8
Excess tax benefits from share-based compensation	(30.1)	(28.8)	(42.2)
Changes in operating assets and liabilities, net of effect of business combinations:
Receivables, net	(418.3)	189.9	(401.8)
Other invested assets	(15.1)	(38.9)	(8.9)
Other assets	(33.6)	79.2	(259.2)
Policy liabilities	(345.8)	(53.7)	978.0
Unearned income	(73.8)	(193.7)	35.1
Accounts payable and accrued expenses	303.6	(406.5)	(208.7)
Other liabilities	(154.6)	(132.8)	(13.6)
Income taxes	9.3	(73.9)	(44.6)
Other, net	(38.6)	(40.8)	(14.2)
Net cash provided by operating activities	3,052.3	2,744.6	3,374.4
Investing activities
Purchases of fixed maturity securities	(13,704.5)	(15,040.4)	(11,914.8)
Proceeds from fixed maturity securities:
Sales	10,977.9	13,675.9	10,446.2
Maturities, calls and redemptions	1,836.8	1,781.5	1,891.3
Purchases of equity securities	(820.3)	(232.8)	(259.0)
Proceeds from sales of equity securities	721.0	422.7	287.4
Purchases of other invested assets	(251.5)	(303.7)	(207.9)
Proceeds from sales of other invested assets	127.1	35.5	29.4
Settlement of non-hedging derivatives	(109.8)	(59.8)	(96.6)
Changes in securities lending collateral	(405.1)	307.9	28.9
Purchases of subsidiaries, net of cash acquired	0	(4,597.0)	(600.0)
Purchases of property and equipment	(646.5)	(544.9)	(519.5)
Proceeds from sales of property and equipment	39.2	0.4	3.7
Other, net	1.3	3.1	(31.1)
Net cash used in investing activities	(2,234.4)	(4,551.6)	(942.0)
Financing activities
Net proceeds from (repayments of) commercial paper borrowings	(191.7)	(229.0)	463.6
Proceeds from long-term borrowings	1,250.0	6,468.9	1,097.4
Repayments of long-term borrowings	(1,801.9)	(1,251.3)	(705.1)
Proceeds from short-term borrowings	1,100.0	642.0	100.0
Repayments of short-term borrowings	(950.0)	(492.0)	(100.0)
Changes in securities lending payable	405.0	(307.8)	(29.0)
Changes in bank overdrafts	9.9	(17.6)	264.3
Premiums paid on equity options	(25.8)	0	0
Repurchase and retirement of common stock	(1,620.1)	(2,496.8)	(3,039.8)
Cash dividends	(448.0)	(367.1)	(357.8)
Proceeds from issuance of common stock under employee stock plans	524.7	110.8	245.0
Excess tax benefits from share-based compensation	30.1	28.8	42.2
Net cash (used in) provided by financing activities	(1,717.8)	2,088.9	(2,019.2)
Effect of foreign exchange rates on cash and cash equivalents	2.2	1.1	(0.4)
Change in cash and cash equivalents	(897.7)	283.0	412.8
Cash and cash equivalents at beginning of year	2,484.6	2,201.6	1,788.8
Cash and cash equivalents at end of year	1,586.9	2,484.6	2,201.6
Less cash and cash equivalents of discontinued operations at end of year	(4.8)	(9.3)	0
Cash and cash equivalents of continuing operations at end of year	$ 1,582.1	$ 2,475.3	$ 2,201.6