Fair Value Of Financial Instruments (Estimated Fair Values Of Financial Instruments) (Details) (USD $) In Thousands	Sep. 30, 2011	Dec. 31, 2010
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity contracts	$ 625	$ 2,776
Investments [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, fair value	3,037,561	3,155,257
Interest Rate Swap Agreements [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financial instruments at fair value, assets	0	4,240
Interest rate swap agreements	1,348	3,042
Secured Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes	138,000	138,332
Unsecured Note [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes	$ 0	$ 128,280

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- Definition

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+ Details

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- Definition

Fair values as of the balance sheet date of all assets resulting from contracts that meet the criteria of being accounted for as derivative instruments, net of the effects of master netting arrangements.

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- Definition

Derivative instrument obligations meeting the definition of a liability which the Company is a party to as of the balance sheet date.

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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- Definition

This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents investment securities as of the balance sheet date which may include marketable securities, derivative financial instruments, and investments accounted for under the equity method.

+ References

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

-Publisher FASB

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-Glossary Available-for-Sale Securities

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-Number 210

-Article 7

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