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Share-Based Transactions - Narrative (Details) - $ / shares |  | 6 Months Ended
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Feb. 26, 2018 | Jun. 30, 2018
Equity award granted with sales restrictions [Member] |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |
Share-based compensation arrangement by share-based payment award, sale restrictions expiration period |  | 3 years
Restricted stock units (RSUs) [Member] |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |
Number of shares awarded | 94,758 |
Measurement date fair value | $ 100.55 |
Share-based compensation arrangement by share-based payment award, award vesting period | 3 years |
Performance share units (PSUs) [Member] |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |
Number of shares awarded | 30,579 |
Measurement date fair value | $ 100.55 |
Share-based compensation arrangement by share-based payment award, award vesting period | 3 years |
Performance share units (PSUs) [Member] | Maximum [Member] |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |
Number of PSUs vested during the period | 45,868 |
Performance share units (PSUs) [Member] | Minimum [Member] |  |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |  |
Number of PSUs vested during the period | 0 |

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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://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901 + Details
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- Definition The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(2)(iii)(1) -URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901 + Details
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- Definition The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(2)(iii)(1) -URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901 + Details
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- Definition The number of equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(2)(iii)(2) -URI http://asc.fasb.org/extlink&oid=109197908&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 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. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a)(2) -URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901 + Details
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