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Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions | Dec. 31, 2020 | Dec. 31, 2019
--- | --- | ---
Preferred stock, par value | $ 1 | $ 1
Preferred stock, authorized shares | 10,000,000 | 10,000,000
Preferred stock, issued | 0 | 0
Preferred stock, outstanding | 0 | 0
Common stock, par value | $ 1 | $ 1
Common stock, authorized shares | 400,000,000 | 400,000,000
Common stock, issued shares | 283,186,115 | 283,433,401
Accumulated other comprehensive income (loss), taxes | $ 8 | $ 8
Treasury stock, shares | 229,508,967 | 204,000,108
Non Variable Interest Entity [Member] |  |
Fixed-maturity securities held as available-for-sale, amortized cost | $ 2,078 | $ 2,705
Investments pledged as collateral, amortized cost | 6 | 15
Short-term investments, amortized cost | 281 | 423
Premiums receivable (net of allowance for credit losses) | 5 | 0
Medium-term notes, financial instruments carried at fair value | 110 | 108
Variable Interest Entity Primary Beneficiary [Member] |  |
Investments held-to-maturity, fair value | 0 | 892
Variable interest entity notes, financial instruments carried at fair value | $ 350 | $ 403

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