Financial Instruments And Investments (Unrecognized Gross Unrealized Gains And The Fair Value) (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Unrealized Gain Position, Fair Value	$ 156,955	$ 158,634
Unrealized Gains	38,709	29,039
Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Unrealized Gain Position, Fair Value	45,153	65,759
Unrealized Gains	2,011	4,379
Collateralized Mortgage Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Unrealized Gain Position, Fair Value	13,753	17,289
Unrealized Gains	531	1,036
U.S. Government Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Unrealized Gain Position, Fair Value	7,023	13,295
Unrealized Gains	251	678
Municipal Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Unrealized Gain Position, Fair Value	14,296	22,797
Unrealized Gains	728	1,531
Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Unrealized Gain Position, Fair Value	10,081	12,378
Unrealized Gains	501	1,134
Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Unrealized Gain Position, Fair Value	89,534	73,210
Unrealized Gains	34,116	22,839
Mutual Funds - Equity [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Unrealized Gain Position, Fair Value	16,207	15,194
Unrealized Gains	2,582	1,821
Cash and Cash Equivalents [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Unrealized Gain Position, Fair Value	6,061	4,471
Unrealized Gains	$ 0	$ 0