Stock-Based Compensation (Details 4) (USD $)	3 Months Ended
Mar. 31, 2014
Stockholders' Equity
Awards exercised (in shares)	433,000
Weighted-average exercise price of awards exercised (in dollars per share)	$ 15.34
Total cash proceed	$ 6,636,000

Number of share options (or share units) exercised during the current period.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Article 3

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

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Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

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Reference 4: http://www.xbrl.org/2003/role/presentationRef

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-Name Accounting Standards Codification

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Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

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Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

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