Consolidated Statements of Cash Flows (USD $) In Millions, unless otherwise specified	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
Operating activities
Net income (loss)	$ 685.7	$ 598.7
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Amortization of deferred acquisition costs	136.0	27.6
Additions to deferred acquisition costs	(338.5)	(298.9)
Accrued investment income	13.2	0.8
Net cash flows for trading securities	(40.5)	135.3
Premiums due and other receivables	(43.8)	65.7
Contractholder and policyholder liabilities and dividends	993.0	1,578.8
Current and deferred income taxes (benefits)	175.6	(29.6)
Net realized capital (gains) losses	181.9	(81.2)
Depreciation and amortization expense	114.5	99.1
Mortgage loans held for sale, acquired or originated		(48.2)
Mortgage loans held for sale, sold or repaid, net of gain	0.2	90.1
Real estate acquired through operating activities	(81.5)	(25.5)
Real estate sold through operating activities	12.2	4.1
Stock-based compensation	51.7	50.2
Other	(461.8)	206.7
Net adjustments	712.2	1,775.0
Net cash provided by (used in) operating activities	1,397.9	2,373.7
Investing activities
Available-for-sale securities: Purchases	(7,012.3)	(6,467.5)
Available-for-sale securities: Sales	1,626.7	946.5
Available-for-sale securities: Maturities	5,783.2	4,702.7
Mortgage loans acquired or originated	(2,020.0)	(1,811.8)
Mortgage loans sold or repaid	1,570.8	1,166.7
Real estate acquired	(59.0)	(114.8)
Net (purchases) sales of property and equipment	(22.7)	(35.6)
Purchases of interest in subsidiaries, net of cash acquired	(1,268.3)	(62.5)
Net change in other investments	(31.2)	(42.9)
Net cash provided by (used in) investing activities	(1,432.8)	(1,719.2)
Financing activities
Issuance of common stock	80.2	24.7
Acquisition of treasury stock	(153.4)	(272.7)
Proceeds from financing element derivatives	46.7	51.6
Payments for financing element derivatives	(36.9)	(38.3)
Excess tax benefits from share-based payment arrangements	8.6	9.8
Purchase of subsidiary shares from noncontrolling interest	(51.7)
Sale of subsidiary shares to noncontrolling interest	32.1
Dividends to common stockholders	(211.7)	(169.6)
Dividends to preferred stockholders	(24.7)	(16.5)
Issuance of long-term debt	24.1	602.9
Principal repayments of long-term debt	(212.2)	(2.1)
Net proceeds from (repayments of) short-term borrowings	131.6	(81.0)
Investment contract deposits	5,270.2	4,798.7
Investment contract withdrawals	(7,055.6)	(6,126.0)
Net increase (decrease) in banking operation deposits	(276.2)	14.9
Other	(6.3)	(5.8)
Net cash provided by (used in) financing activities	(2,435.2)	(1,209.4)
Net increase (decrease) in cash and cash equivalents	(2,470.1)	(554.9)
Cash and cash equivalents at beginning of period	4,177.2	2,833.9
Cash and cash equivalents at end of period	$ 1,707.1	$ 2,279.0