Shareholders' Equity - Preferred stock authorized for issuance (Details)	Dec. 31, 2017 $ / shares shares
Voting Preferred Stock
Class of Stock [Line Items]
Preferred Stock, par value \| $ / shares	$ 0
Preferred Stock, shares authorized \| shares	12,500,000.0
Nonvoting Preferred Stock
Class of Stock [Line Items]
Preferred Stock, par value \| $ / shares	$ 0
Preferred Stock, shares authorized \| shares	12,500,000.0

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No definition available.

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- Definition

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

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(28))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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- Definition

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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