Number of common shares reserved for future issuance related to deferred compensation arrangements with individuals.

No definition available.

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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://www.xbrl.org/2003/role/presentationRef
-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=96867065&loc=d3e5070-113901

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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

Number of share instruments newly issued under a share-based compensation plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

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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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Long-Term Stock Incentive Plan (Details) - Class A Common Stock - Restricted Shares - Long-Term Stock Incentive Plan - $ / shares	1 Months Ended
	Jul. 31, 2017	May 31, 2017	Apr. 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate shares reserved for grants under the 2017 Plan (shares)			1,500,000
Certain Officers and Managers
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted shares awarded and issued under LTIP (in shares)		97,486
Weighted average grant date fair value (in dollars per share)		$ 37.10
Certain Officers and Managers \| Third Anniversary
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage of restricted shares (percent)		50.00%
Certain Officers and Managers \| Fifth Anniversary
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage of restricted shares (percent)		50.00%
Non-employee Directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted shares awarded and issued under LTIP (in shares)	7,281
Weighted average grant date fair value (in dollars per share)	$ 37.10
Non-employee Directors \| Third Anniversary
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage of restricted shares (percent)	100.00%