Subsequent Events (Details) (Subsequent Events, USD $)	1 Months Ended
Apr. 30, 2013 Archstone	Apr. 30, 2013 Repayment of notes 4.81% secured mortgage note	May 31, 2013 Repayment of notes 5.55% secured notes
Subsequent Events
Stated interest rate, percentage		4.81%	5.55%
Principal amount of debt repaid		$ 170,125,000	$ 5,465,000
Preferred redemption obligations proportionate share paid	$ 30,000,000

Interest rate stated in the contractual debt agreement.

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.22(a)(1))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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