Condensed Consolidated Statements of Cash Flows - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Operating activities
Net cash provided by (used in) operating activities	$ 2,046.1	$ 2,678.4
Investing activities
Fixed maturities available-for-sale and equity securities with intent to hold: Purchases	(7,717.3)	(5,771.8)
Fixed maturities available-for-sale and equity securities with intent to hold: Sales	1,855.0	1,477.2
Fixed maturities available-for-sale and equity securities with intent to hold: Maturities	4,059.2	3,025.9
Mortgage loans acquired or originated	(1,460.9)	(2,008.5)
Mortgage loans sold or repaid	1,198.6	1,243.9
Real estate acquired	(98.2)	(48.5)
Real estate sold		57.0
Net (purchases) sales of property and equipment	(46.4)	(65.4)
Net change in other investments	(11.1)	(253.8)
Net cash provided by (used in) investing activities	(2,221.1)	(2,344.0)
Financing activities
Issuance of common stock	23.1	22.1
Acquisition of treasury stock	(231.8)	(153.7)
Payments for financing element derivatives	(14.7)	(13.1)
Purchase of subsidiary shares from noncontrolling interest	(0.9)
Dividends to common stockholders	(307.1)	(300.6)
Issuance of long-term debt	493.1	502.7
Principal repayments of long-term debt	(64.9)	(0.7)
Net proceeds from (repayments of) short-term borrowings	(9.3)	33.1
Investment contract deposits	5,398.7	3,627.4
Investment contract withdrawals	(4,801.5)	(3,800.8)
Net increase (decrease) in banking operation deposits	324.7	82.0
Other	0.1	5.6
Net cash provided by (used in) financing activities	809.5	4.0
Net increase (decrease) in cash and cash equivalents	634.5	338.4
Cash and cash equivalents at beginning of period	2,515.9	2,977.5
Cash and cash equivalents at end of period	3,150.4	3,315.9
Supplemental disclosure of non-cash activities:
Lease assets established upon adoption of accounting guidance		168.8
Lease liabilities established upon adoption of accounting guidance		164.0
Assets received in kind from pension risk transfer transactions	$ 1,062.4	$ 139.0