Investments Available-For-Sale Securities (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2013	Dec. 31, 2012
Schedule of Available-for-sale Securities [Line Items]
Cost	$ 126,809	$ 129,799
Gross Unrealized Gain	3,209	6,250
Gross Unrealized Loss	(605)	(26)
Available-for-sale equity securities	129,413	136,023
Equity Funds [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost	24,737	44,944
Gross Unrealized Gain	2,423	4,814
Gross Unrealized Loss	0	(5)
Available-for-sale equity securities	27,160	49,753
Fixed Income Funds [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost	102,072	84,855
Gross Unrealized Gain	786	1,436
Gross Unrealized Loss	(605)	(21)
Available-for-sale equity securities	$ 102,253	$ 86,270

Amount of unrealized gain before deducting unrealized loss on investments in equity securities classified as available-for-sale securities.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27161-111563

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Amount of unrealized loss before deducting unrealized gain on investments in available-for-sale equity securities.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27161-111563

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- Definition

Amount of investment in debt and equity securities categorized neither as trading securities nor held-to-maturity securities and intended be sold or mature one year or operating cycle, if longer.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 25

-Paragraph 1

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=28360136&loc=d3e22054-111558

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6871852&loc=d3e26626-111562

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Amount of investments in equity securities and other forms of securities that provide ownership interests classified as available-for-sale, expected to be converted to cash, sold or exchanged within one year or the normal operating cycle, if longer.

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