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Summary of Significant Accounting Policies (Stock-Based Compensation) (Details) | 12 Months Ended
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Dec. 31, 2017
Stock Options |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Vesting period | 4 years
Stock Options | Minimum |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Vesting period | 3 years
Stock Options | Maximum |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Vesting period | 4 years
RSAs | Ratably |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Vesting period | 3 years
RSAs | Cliff |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Vesting period | 3 years
RSAs | Fourth year of employment |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Vesting rights (as a percent) | 50.00%
RSAs | Fifth year of employment |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Vesting rights (as a percent) | 50.00%
RSAs | Fifth year of employment | Minimum |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Vesting rights (as a percent) | 50.00%
RSUs | Ratably |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Vesting period | 3 years
RSUs | Cliff | Minimum |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Vesting period | 3 years
RSUs | Cliff | Maximum |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Vesting period | 5 years

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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. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901 + Details
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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. + References No definition available. + Details
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- Definition Percentage of vesting of share-based compensation awards. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901 + Details
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