Fair Value Of Financial Instruments (Amortized Cost And Estimated Fair Value Of Marketable Securities) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Fair Value Of Financial Instruments [Abstract]
Equity securities, Amortized Cost	$ 169,565	$ 103,189
Debt securities, Amortized Cost	276,053	271,260
Total, Amortized Cost	445,618	374,449
Equity securities, Estimated Fair Value	160,021	105,304
Debt securities, Estimated Fair Value	278,544	274,029
Total, Estimated Fair Value	$ 438,565	$ 379,333

For an unclassified balance sheet, this item represents investments in debt and equity securities which are categorized neither as held-to-maturity nor trading.

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+ Details

- Definition

This item represents the cost of debt and equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any.

+ References+ Details

- Definition

For an unclassified balance sheet, total of debt securities categorized neither as held-to-maturity nor trading.

+ References

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+ Details

- Definition

For an unclassified balance sheet, this item represents equity securities categorized neither as held-to-maturity nor trading.

+ References

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+ Details