Investments in Equity Securities Available for Sale (Investments in Equity Securities Available for Sale) (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Cost	$ 324,090	$ 342,393
Gross Unrealized, Gains	104,672	118,799
Gross Unrealized, Losses	(3,440)	(17,753)
Fair Value	425,322	443,439
Carrying Value	425,322	443,439
Common Stock [Member]
Cost	228,524	209,210
Gross Unrealized, Gains	96,648	113,660
Gross Unrealized, Losses	(291)	(2,888)
Fair Value	324,881	319,982
Carrying Value	324,881	319,982
Preferred Stock [Member]
Cost	95,566	133,183
Gross Unrealized, Gains	8,024	5,139
Gross Unrealized, Losses	(3,149)	(14,865)
Fair Value	100,441	123,457
Carrying Value	$ 100,441	$ 123,457

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

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Reference 10: http://www.xbrl.org/2003/role/presentationRef

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