Fair Value Measurements (Details 3) (Recurring basis, USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Fair Value Measurements
Carrying value of debt	$ 649,976	$ 554,568
Total
Fair Value Measurements
Fair value of debt	655,093	547,943
Level 2
Fair Value Measurements
Fair value of debt	88,517	81,091
Level 3
Fair Value Measurements
Fair value of debt	$ 566,576	$ 466,852

Fair value portion of debt instrument payable, including, but not limited to, notes payable and loans payable.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 825

-SubTopic 10

-Section 50

-Paragraph 10

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=28364263&loc=d3e13433-108611

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 825

-SubTopic 10

-Section 50

-Paragraph 12

-URI http://asc.fasb.org/extlink&oid=28364263&loc=d3e13476-108611

Name:	us-gaap_DebtInstrumentFairValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant