Carrying Value of Ownership Interests in and Advances to Partner Companies and Private Equity Funds (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Investments In And Advances To Affiliates [Line Items]
Fair value	$ 14,560	$ 20,972
Equity method investments	111,855	106,741
Cost method investments	15,048	12,634
Advances to partner companies	1,585	8,292
Ownership interests in and advances to partner companies and funds ($19,363 and $20,972 at fair value at June 30,2013 and December 31,2012, respectively)	143,048	148,639
Loan participations receivable	8,279	7,085
Available-for-sale securities	32	58
Partner companies [Member]
Investments In And Advances To Affiliates [Line Items]
Equity method investments	108,249	102,931
Cost method investments	12,530	10,000
Private equity funds [Member]
Investments In And Advances To Affiliates [Line Items]
Equity method investments	3,606	3,810
Cost method investments	$ 2,518	$ 2,634

Investments in debt and equity securities which are categorized neither as held-to-maturity nor trading and which are intended to be sold or mature more than one year from the balance sheet date or operating cycle, if longer. Such securities are reported at fair value; unrealized gains (losses) related to Available-for-sale Securities are excluded from earnings and reported in a separate component of shareholders' equity (other comprehensive income), unless the Available-for-sale security is designated as a hedge or is determined to have had an other than temporary decline in fair value below its amortized cost basis. All or a portion of the unrealized holding gain (loss) of an Available-for-sale security that is designated as being hedged in a fair value hedge is recognized in earnings during the period of the hedge, as are other than temporary declines in fair value below the cost basis for investments in equity securities and debt securities that an entity intends to sell or it is more likely than not that it will be required to sell before the recovery of its amortized cost basis. Other than temporary declines in fair value below the cost basis for debt securities categorized as Available-for-sale that an entity does not intend to sell and for which it is not more likely than not that the entity will be required to sell before the recovery of its amortized cost basis are bifurcated into credit losses and losses related to all other factors. Other than temporary declines in fair value below cost basis related to credit losses are recognized in earnings, and losses related to all other factors are recognized in other comprehensive income.

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

-Publisher FASB

-Name Accounting Standards Codification

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-URI http://asc.fasb.org/extlink&oid=6505594

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+ Details

- Definition

This item represents the aggregate carrying amount of all cost-method investments as reported on or included in the balance sheet. The original cost of the investments may differ from the aggregate carrying amount disclosed due to various adjustments such as: (i) dividends received in excess of earnings after the date of investment that are considered a return of investment and therefore recorded as reductions to cost of the investment, or (ii) a series of operating losses of an investee or other factors which may indicate that a decrease in value of the investment has occurred which is other than temporary and accordingly such decrease in value has been recognized.

+ References

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-Name Accounting Principles Board Opinion (APB)

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+ Details