Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Preferred stock, no par value (in USD per share)
Preferred stock, shares authorized (in shares)	1,164,000	1,164,000,000
Preferred stock, shares issued (in shares)	1,164,000	500,000,000
Preferred stock, shares outstanding (in shares)	1,164,000	500,000,000
Common shares, no par value (in USD per share)
Common shares, shares issued (in shares)	55,518,800	55,060,650
Common shares, shares outstanding (in shares)	55,518,800	55,060,650

Face amount per share of no-par value common stock.

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Total number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury). These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized. Shares issued include shares outstanding and shares held in the treasury.

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Number of shares of common stock outstanding. Common stock represent the ownership interest in a corporation.

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Face amount per share of no-par value preferred stock nonredeemable or redeemable solely at the option of the issuer.

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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.

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Total number of nonredeemable preferred shares (or preferred stock redeemable solely at the option of the issuer) issued to shareholders (includes related preferred shares that were issued, repurchased, and remain in the treasury). May be all or portion of the number of preferred shares authorized. Excludes preferred shares that are classified as debt.

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Aggregate share number for all nonredeemable preferred stock (or preferred stock redeemable solely at the option of the issuer) held by stockholders. Does not include preferred shares that have been repurchased.

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