Derivative Instruments and Hedging Activities (Details Textual)	9 Months Ended
Sep. 30, 2012	Apr. 01, 2010 Interest rate swap [Member] Contract	Sep. 30, 2012 First half of mortgage [Member] Interest rate swap [Member]	Sep. 30, 2012 Second half of mortgage [Member] Interest rate swap [Member]
Derivative Instruments and Hedging Activities (Textual) [Abstract]
Strike rate			5.91%	6.07%
Number of Interest rate swap agreements		2
Mortgage loan expiry date	Apr. 16, 2019

Stated maturity date of the mortgage loan receivable on real estate, in CCYY-MM-DD format.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 948

-SubTopic 310

-Section S99

-Paragraph 1

-Subparagraph (SX 210.12-29)

-URI http://asc.fasb.org/extlink&oid=6589523&loc=d3e617274-123014

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 205

-SubTopic 10

-Section S99

-Paragraph 6

-Subparagraph (SX 210.5-04.(c) Schedule IV)

-URI http://asc.fasb.org/extlink&oid=6882300&loc=d3e5864-122674

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 29

-Article 12

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Paragraph c

-Subparagraph Schedule IV

-Article 5

Name:	us-gaap_MortgageLoanOnRealEstateFinalMaturityDate
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration