SHARE INCENTIVE PLAN Schedule of Unvested Shares and LTIP Units (Details) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Total unrecognized compensation cost related to nonvested awards	$ 16.1
Weighted-average period over which cost is expected to be recognized	2 years 4 months 24 days
Restricted Stock [Member]
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)	63,737	60,916
Shares granted (in shares)	28,563	31,830
Shares vested (in shares)	(34,598)	(28,179)
Shares forfeited (in shares)	(2,684)	(830)
Shares unvested, End of period (in shares)	55,018	63,737	60,916
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Shares unvested, Weighted average grant date fair value, Beginning of period (in dollars per share)	$ 23.34	$ 19.36
Shares granted, Weighted average grant date fair value (in dollars per share)	$ 27.18	$ 23.75
Shares vested, Weighted average grant date fair value (in dollars per share)	$ 23.40	$ 18.77
Shares forfeited, Weighted average grant date fair value (in dollars per share)	$ 23.54	$ 23.00
Shares unvested, Weighted average grant date fair value, End of period(in dollars per share)	$ 25.90	$ 23.34	$ 19.36
Total fair value of shares that vested	0.8	0.5	0.8
LTIP Units [Member]
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)	884,334	943,686
Shares granted (in shares)	441,946	290,912
Shares vested (in shares)	(263,556)	(350,264)
Shares forfeited (in shares)	(800)	0
Shares unvested, End of period (in shares)	1,061,924	884,334	943,686
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Shares unvested, Weighted average grant date fair value, Beginning of period (in dollars per share)	$ 21.62	$ 19.27
Shares granted, Weighted average grant date fair value (in dollars per share)	$ 26.24	$ 26.69
Shares vested, Weighted average grant date fair value (in dollars per share)	$ 20.23	$ 19.51
Shares forfeited, Weighted average grant date fair value (in dollars per share)	$ 24.66	$ 0.00
Shares unvested, Weighted average grant date fair value, End of period(in dollars per share)	$ 23.92	$ 21.62	$ 19.27
Total fair value of shares that vested	$ 5.3	$ 6.8	$ 3.0

Unrecognized cost of unvested share-based compensation awards.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (i)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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

+ 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)(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

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)(3)

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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

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

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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

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)

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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

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)(i)-(ii)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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The weighted average fair value of nonvested awards on equity-based plans excluding option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, revenue or profit achievement stock award plan) for which the employer is contingently obligated to issue equity instruments or transfer assets to an employee who has not yet satisfied service or performance criteria necessary to gain title to proceeds from the sale of the award or underlying shares or units.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

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

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

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-SubTopic 10

-Section 50

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Fair value of share-based awards for which the grantee gained the right by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash.

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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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-SubTopic 10

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-Subparagraph (c)(2)(iii)(2)

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