Consolidated Statements of Cash Flows (Unaudited) (USD $) In Thousands	6 Months Ended
Jun. 30, 2011	Jun. 30, 2010
Cash Flows from Operating Activities:
Net cash used in operating activities	$ (10,392)	$ (9,011)
Cash Flows from Investing Activities:
Investment in restricted cash equivalents for interest on convertible senior debentures		(19,009)
Proceeds from sales of and distributions from companies and funds	137,991	2,755
Advances to partner companies	(750)	(5,986)
Repayment of advances to partner companies		1,300
Acquisitions of ownership interests in partner companies and funds	(59,108)	(7,546)
Increase in marketable securities	(70,389)	(20,791)
Decrease in marketable securities	53,067	18,676
Capital expenditures	(7)
Proceeds from sale of discontinued operations, net	1	477
Other, net	107
Net cash provided by (used in) investing activities	60,912	(30,124)
Cash Flows from Financing Activities:
Costs on exchange of convertible senior debentures		(750)
Repurchase of convertible senior debentures	(30,848)
Issuance of Company common stock, net	346	717
Net cash used in financing activities	(30,502)	(33)
Net Increase (Decrease) in Cash and Cash Equivalents	20,018	(39,168)
Cash and Cash Equivalents at beginning of period	183,419	67,347
Cash and Cash Equivalents at end of period	$ 203,437	$ 28,179

Includes currency on hand as well as demand deposits with banks or financial institutions. It also includes other kinds of accounts that have the general characteristics of demand deposits in that the Entity may deposit additional funds at any time and also effectively may withdraw funds at any time without prior notice or penalty. Cash equivalents, excluding items classified as marketable securities, include short-term, highly liquid investments that are both readily convertible to known amounts of cash, and so near their maturity that they present minimal risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three years ago does not become a cash equivalent when its remaining maturity is three months. Compensating balance arrangements that do not legally restrict the withdrawal or usage of cash amounts may be reported as Cash and Cash Equivalents, while legally restricted deposits held as compensating balances against borrowing arrangements, contracts entered into with others, or company statements of intention with regard to particular deposits are not generally reported as cash and cash equivalents. Includes cash and cash equivalents associated with the entity's continuing operations. Excludes cash and cash equivalents associated with the disposal group (and discontinued operation).

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.1)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 1
-Article 5

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 95
-Paragraph 7
-Footnote 1
-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 230
-SubTopic 10
-Section 45
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3044-108585

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 95
-Paragraph 8, 9
-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 Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section 45
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6361293&loc=d3e6676-107765

Reference 7: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Cash
-URI http://asc.fasb.org/extlink&oid=6506951

Reference 8: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 95
-Paragraph 7, 26
-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 9: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Cash Equivalents
-URI http://asc.fasb.org/extlink&oid=6507016