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).

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=6415400&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.

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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=6415400&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=6415400&loc=d3e5070-113901

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Long-Term Stock Incentive Plan (Details) - Restricted Shares - Long-Term Stock Incentive Plan - $ / shares	1 Months Ended
	Jul. 31, 2016	May 31, 2016
Third Anniversary
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage of restricted shares (percent)		50.00%
Fifth Anniversary
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage of restricted shares (percent)		50.00%
Certain Officers and Managers
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average grant date fair value (in dollars per share)		$ 33.49
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 \| Class A Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted shares awarded and issued under LTIP (in shares)		92,583
Certain Non-employee Directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average grant date fair value (in dollars per share)	$ 33.45
Certain Non-employee Directors \| Class A Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted shares awarded and issued under LTIP (in shares)	8,073
Vesting percentage of restricted shares (percent)	100.00%