Consolidated Statements of Financial Position (Parenthetical) - $ / shares	Dec. 31, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Ordinary shares, nominal or par value (in dollars per share)	$ 0.01	$ 0.01
Ordinary shares, Authorized shares	750,000,000	750,000,000
Ordinary shares, issued shares	247,600,000	262,000,000

Face amount or stated value per share of common stock.

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(29))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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- Definition

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

+ References

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- Definition

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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- References

No definition available.

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