Consolidated Balance Sheets (Parenthetical) - USD ($) shares in Thousands, $ in Millions	Dec. 31, 2019	Sep. 30, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Held-to-maturity, fair value	$ 597
Preferred stock, authorized shares	4,400		4,400
Common stock, authorized shares	350,000		350,000
Common stock, outstanding shares	165,057	187,554

The maximum number of common shares permitted to be issued by an entity's charter and bylaws.

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-Subparagraph (SX 210.5-02(29))
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Number of shares of common stock outstanding. Common stock represent the ownership interest in a corporation.

+ References

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-Topic 505
-SubTopic 10
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Fair value of investment in debt security measured at amortized cost (held-to-maturity).

+ References

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-Publisher FASB
-Name Accounting Standards Codification
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The maximum number of nonredeemable preferred shares (or preferred stock redeemable solely at the option of the issuer) permitted to be issued by an entity's charter and bylaws.

+ References

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-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(28))
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