Consolidated Statements of Operations (Parenthetical) (USD $) In Thousands, unless otherwise specified	3 Months Ended	6 Months Ended
Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Parent Company [Member]
Interest income	$ 377	$ 587	$ 913	$ 1,188
Trading Securities, Unrealized Holding Gain	(499)	88	725	731
Partnership Interest [Member]
Interest income	377	587	913	1,188
Trading Securities, Unrealized Holding Gain	$ (499)	$ 88	$ 725	$ 731

The increase (decrease) resulting in a gain from the difference between the fair value and the carrying value, or in the comparative fair values, of trading securities held at each balance sheet date, that was included in earnings for the period.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.7(c))

-URI http://asc.fasb.org/extlink&oid=6880815&loc=d3e20235-122688

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 9

-Subparagraph (e)

-URI http://asc.fasb.org/extlink&oid=6872113&loc=d3e27357-111563

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 115

-Paragraph 13

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 35

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-URI http://asc.fasb.org/extlink&oid=6956420&loc=d3e24584-111560

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 115

-Paragraph 12

-Subparagraph a

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 115

-Paragraph 21

-Subparagraph e

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details