Financial Instruments (Details) (USD $)	3 Months Ended	12 Months Ended
Mar. 31, 2014	Dec. 31, 2013
Disclosure About Significant Unobservable Inputs
Investments	$ 19,476,000	$ 18,889,000
Level 1
Disclosure About Significant Unobservable Inputs
Cash equivalents	3,500,000	3,800,000
Financial instruments owned related to legacy deferred compensation plans	700,000	700,000
Investments \| Level 3
Disclosure About Significant Unobservable Inputs
Investments	19,500,000	18,900,000
Investments \| Level 3 \| Market comparable companies \| Minimum
Disclosure About Significant Unobservable Inputs
Enterprise value/Revenue multiple	2.4	2.7
Discount rate (as a percent)	26.00%	30.00%
Investments \| Level 3 \| Market comparable companies \| Maximum
Disclosure About Significant Unobservable Inputs
Enterprise value/Revenue multiple	6.6	7.0
Discount rate (as a percent)	35.00%	35.00%
Investments \| Level 3 \| Market comparable companies \| Weighted average
Disclosure About Significant Unobservable Inputs
Enterprise value/Revenue multiple	4.9	5.5
Discount rate (as a percent)	27.00%	30.00%
Investments \| Level 3 \| Venture capital method \| Weighted average
Disclosure About Significant Unobservable Inputs
Enterprise value/EBITDA multiple	5.0	5.0
Discount rate (as a percent)	55.00%	55.00%
Investment in FATV
Disclosure About Significant Unobservable Inputs
Investments	18,226,000	17,624,000
Investment in FATV \| Level 3
Disclosure About Significant Unobservable Inputs
Investments	$ 18,200,000	$ 17,600,000
Number of privately held companies	6	6

Represents the number of privately held companies held as investment.

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Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Cash

-URI http://asc.fasb.org/extlink&oid=6506951

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Cash Equivalents

-URI http://asc.fasb.org/extlink&oid=6507016

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- Definition

Carrying amount as of the balance sheet date of assets held under deferred compensation agreements.

+ 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 210.5-02.17)

-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 17

-Article 5

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- Definition

Interest rate used to find the present value of an amount to be paid or received in the future as an input to measure fair value. For example, but not limited to, weighted average cost of capital (WACC), cost of capital, cost of equity and cost of debt.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (bbb)

-URI http://asc.fasb.org/extlink&oid=25499696&loc=d3e19207-110258

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- Definition

Market valuation of entity divided by earnings before interest, taxes, depreciation, and amortization (EBITDA), used as an input to measure fair value.

+ References

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- Definition

Market valuation of entity divided by revenue, used as an input to measure fair value.

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- Definition

The fair value as of the balance sheet date of firm holdings in private equity, mezzanine, venture capital, merchant banking, real estate and special situations investments. Includes both pledged (to counterparties as collateral for financing transactions) and unpledged holdings.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 940

-SubTopic 320

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=29643736&loc=d3e42546-110969

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