Share and Unit-Based Plans - LTIP units granted (Details)	9 Months Ended
Sep. 30, 2019 $ / shares shares
Service-based
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	343,431
1/1/2019 \| Service-based \| First vesting period
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	81,732
Fair value per LTIP unit (in dollars per share) \| $ / shares	$ 43.28
1/1/2019 \| Market-indexed \| First vesting period
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	250,852
Fair value per LTIP unit (in dollars per share) \| $ / shares	$ 29.25
9/1/2019 \| Service-based \| First vesting period
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	4,393
Fair value per LTIP unit (in dollars per share) \| $ / shares	$ 28.53
9/1/2019 \| Market-indexed \| First vesting period
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	6,454
Fair value per LTIP unit (in dollars per share) \| $ / shares	$ 19.42

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).

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=116856206&loc=d3e5070-113901

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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).

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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.

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