Investment in Affiliated Companies (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2012 investment	Mar. 31, 2011	Dec. 31, 2011
Investment in Affiliated Companies
Number of equity method investments	4
Number of investments in limited partnership investment funds	3
Additional equity method investments	$ 742	$ 1,310
Equity investment in affiliated companies
Investment in affiliated companies	27,559		25,587
Excess of investment over share of equity	967		1,010
Investment in affiliated companies	28,526		26,597
Equity in Gains (Losses) of Affiliated Companies
Affiliated companies gains (losses)	$ 1,187	$ (556)

Represents the number of equity method investments.

No definition available.

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- Definition

Represents the number of equity method investments that are limited partnership investment funds.

+ References

No definition available.

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- Definition

The item represents the difference, if any, between the amount at which an investment accounted for under the equity method of accounting is carried (reported) on the balance sheet and the amount of underlying equity in net assets the reporting Entity has in the investee. A difference can arise between the carrying value of the equity method investment and the value of the Entity's amount of underlying equity in net assets of the investee, for example, from appreciation of certain assets which is not recognized in earnings, but is recognized in other comprehensive income (a separate component of shareholders' equity) by the investee.

+ References

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

-Publisher AICPA

-Name Accounting Principles Board Opinion (APB)

-Number 18

-Paragraph 20

-Subparagraph a(3)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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.

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 323

-SubTopic 10

-Section 50

-Paragraph 3

-Subparagraph (a)(3)

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- Definition

This item represents the carrying amount on the entity's balance sheet of its investment in common stock of an equity method investee. This is not an indicator of the fair value of the investment, rather it is the initial cost adjusted for the entity's share of earnings and losses of the investee, adjusted for any distributions (dividends) and other than temporary impairment (OTTI) losses recognized.

+ References

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 210.5-02.12)

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- Definition

This item represents the entity's ownership percentage in the investee multiplied by the investee's total equity.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

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- Definition

This item represents the entity's proportionate share for the period of the net income (loss) of its investee (such as unconsolidated subsidiaries and joint ventures) to which the equity method of accounting is applied. This item includes income or expense related to stock-based compensation based on the investor's grant of stock to employees of an equity method investee.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

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-Subparagraph c

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-Publisher FASB

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-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.

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- Definition

The cash outflow associated with the purchase of or advances to an equity method investments, which are investments in joint ventures and entities in which the entity has an equity ownership interest normally of 20 to 50 percent and exercises significant influence.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 17

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-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.

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