Consolidated Statements of Cash Flows (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Operating activities
Net income (loss)	$ 218.9	$ 208.8
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Amortization of deferred policy acquisition costs	(131.1)	37.8
Additions to deferred policy acquisition costs	(101.0)	(82.7)
Accrued investment income	(7.3)	(9.5)
Net cash flows for trading securities	7.0	65.3
Premiums due and other receivables	97.3	(42.2)
Contractholder and policyholder liabilities and dividends	521.9	309.1
Current and deferred income taxes (benefits)	(31.1)	41.0
Net realized capital (gains) losses	6.7	58.0
Depreciation and amortization expense	36.8	31.4
Mortgage loans held for sale, acquired or originated	(22.0)	(25.9)
Mortgage loans held for sale, sold or repaid, net of gain	24.0	15.9
Real estate acquired through operating activities	(2.9)
Real estate sold through operating activities	1.2	76.9
Stock-based compensation	25.1	9.2
Other	258.2	502.4
Net adjustments	682.8	986.7
Net cash provided by (used in) operating activities	901.7	1,195.5
Investing activities
Available-for-sale securities: Purchases	(2,060.5)	(1,666.4)
Available-for-sale securities: Sales	428.5	536.4
Available-for-sale securities: Maturities	1,612.1	1,725.6
Mortgage loans acquired or originated	(919.6)	(123.9)
Mortgage loans sold or repaid	361.4	323.7
Real estate acquired	(21.3)	(7.0)
Net (purchases) sales of property and equipment	(17.3)	(4.1)
Net change in other investments	(73.8)	(68.4)
Net cash provided by (used in) investing activities	(690.5)	715.9
Financing activities
Issuance of common stock	9.1	9.1
Acquisition of treasury stock	(64.2)	(5.9)
Proceeds from financing element derivatives	20.4	19.4
Payments for financing element derivatives	(16.2)	(12.1)
Excess tax benefits from share-based payment arrangements	9.9	1.6
Dividends to common stockholders	(54.3)
Dividends to preferred stockholders	(8.2)	(8.2)
Issuance of long-term debt	1.0	0.6
Principal repayments of long-term debt	(0.8)	(1.7)
Net proceeds from (repayments of) short-term borrowings	(7.5)	0.2
Investment contract deposits	1,618.6	893.3
Investment contract withdrawals	(2,885.9)	(2,674.2)
Net increase (decrease) in banking operation deposits	(13.4)	(25.8)
Other	(1.7)	(0.9)
Net cash provided by (used in) financing activities	(1,393.2)	(1,804.6)
Net increase (decrease) in cash and cash equivalents	(1,182.0)	106.8
Cash and cash equivalents at beginning of period	2,833.9	1,877.4
Cash and cash equivalents at end of period	$ 1,651.9	$ 1,984.2