Share Incentive and Other Compensation - Schedule of Unvested Shares and LTIP Units (Details) - $ / shares	9 Months Ended	12 Months Ended
Sep. 30, 2019	Dec. 31, 2018
Restricted shares
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Shares unvested, Beginning of period (in shares)	38,455	41,327
Shares granted (in shares)	25,359	22,817
Shares vested (in shares)	(21,424)	(25,261)
Shares forfeited (in shares)		(428)
Shares unvested, End of period (in shares)	42,390	38,455
Weighted Grant-Date Fair Value
Shares unvested, Weighted average grant date fair value, Beginning of period (in dollars per share)	$ 22.44	$ 26.92
Shares granted, Weighted average grant date fair value (in dollars per share)	28.56	23.65
Shares vested, Weighted average grant date fair value (in dollars per share)	27.12	30.79
Shares forfeited, Weighted average grant date fair value (in dollars per share)		27.25
Shares unvested, Weighted average grant date fair value, End of period (in dollars per share)	$ 23.73	$ 22.44
LTIP Units
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Shares unvested, Beginning of period (in shares)	891,886	910,099
Shares granted (in shares)	348,726	425,880
Shares vested (in shares)	(290,753)	(431,827)
Shares forfeited (in shares)	(15,679)	(12,266)
Shares unvested, End of period (in shares)	934,180	891,886
Weighted Grant-Date Fair Value
Shares unvested, Weighted average grant date fair value, Beginning of period (in dollars per share)	$ 26.87	$ 28.28
Shares granted, Weighted average grant date fair value (in dollars per share)	32.78	26.80
Shares vested, Weighted average grant date fair value (in dollars per share)	29.30	29.72
Shares forfeited, Weighted average grant date fair value (in dollars per share)	31.49	28.57
Shares unvested, Weighted average grant date fair value, End of period (in dollars per share)	$ 28.24	$ 26.87

The number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period.

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)(1)(iv)(3)
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Weighted average fair value as of the grant date of equity-based award plans other than stock (unit) option plans that were not exercised or put into effect as a result of the occurrence of a terminating event.

+ References

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-Publisher FASB
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-Topic 718
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-Section 50
-Paragraph 2
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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

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-Publisher FASB
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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

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The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Per share or unit weighted-average fair value of nonvested award under share-based payment arrangement. Excludes share and unit options.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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The number of equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period.

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-Publisher FASB
-Name Accounting Standards Codification
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- Definition

The weighted average fair value as of grant date pertaining to an equity-based award plan other than a stock (or unit) option plan for which the grantee gained the right during the reporting period, by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash in accordance with the terms of the arrangement.

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