Debt - Narrative (Details) (USD $) In Millions, unless otherwise specified	0 Months Ended
Mar. 31, 2015	Dec. 31, 2014
Mortgage Notes [Member]
Debt Instrument [Line Items]
Unamortized premium	$ 78.2	$ 83.8
Unsecured Debt [Member]
Debt Instrument [Line Items]
Unamortized premium	23.2	27.5
The Huxley And The Dylan [Member] \| Mortgage Notes [Member]
Debt Instrument [Line Items]
Principal balance of mortgage loans assumed	$ 114.4
Remaining contractual term	32 years
Municipal Market Data [Member] \| The Huxley And The Dylan [Member] \| Mortgage Notes [Member]
Debt Instrument [Line Items]
Variable interest rate	3.45%

Amount of long-term debt due after one year or the normal operating cycle, if longer, assumed at the acquisition date.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=39739317&loc=d3e4845-128472

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

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- Details

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- Definition

Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

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Period Type:	duration

- Definition

The amount of debt premium that was originally recognized at the issuance of the instrument that has yet to be amortized.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 45

-Paragraph 1A

-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28541-108399

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 55

-Paragraph 8

-URI http://asc.fasb.org/extlink&oid=34725769&loc=d3e28878-108400

+ Details

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- Details

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- Details

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- Details

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- Details

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