CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Investments
Amortized Cost of Fixed Maturity Securities	$ 39,658.7	$ 38,803.4
Stockholders' Equity
Common Stock, Par	$ 0.10	$ 0.10
Common Stock, Authorized	725,000,000	725,000,000
Common Stock, Issued	302,702,811	301,834,556
Treasury Stock, Shares	61,785,466	49,524,849

This item represents the cost of debt securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
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Reference 2: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
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Face amount or stated value per share of common stock.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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