| Equity (Narrative) (Details) - USD ($) $ / shares in Units, $ in Millions | 6 Months Ended | |
|---|---|---|
| Jun. 30, 2017 | Jun. 30, 2016 | |
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||
| Weighted average fair value of options granted | $ 10.78 | |
| Number of options exercised | 140,476 | 93,591 | 
| Increase in equity | $ 2.2 | $ 0.7 | 
| Stock option term | 10 years | |
| Vesting period | 4 years | |
| Unrecognized compensation cost | $ 23.2 | |
| Weighted average period for recognition | 3 years 2 months 12 days | |
| Restricted Stock Units (RSUs) [Member] | ||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||
| Unrecognized compensation cost | $ 10.6 | |
| Weighted average period for recognition | 2 years 10 months 25 days | |
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- Definition Unrecognized cost of unvested share-based compensation awards. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Definition Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Definition Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available. 
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- Definition The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Definition Period from grant date that an equity-based award expires, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Definition Number of share options (or share units) exercised during the current period. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Definition The increase (decrease) in stockholders' equity during the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Details 
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