Financial Instruments And Investments (Unrecognized Gross Unrealized Gains And The Fair Value) (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Financial Instruments and Investments [Line Items]
Available-for-sale Securities, Unrealized Gain Position, Fair Value	$ 143,853	$ 166,161
Available-for-sale Securities, Gross Unrealized Gain	36,923	50,930
Debt Securities
Financial Instruments and Investments [Line Items]
Available-for-sale Securities, Unrealized Gain Position, Fair Value	65,737	60,808
Available-for-sale Securities, Gross Unrealized Gain	1,891	2,677
Collateralized Mortgage Backed Securities
Financial Instruments and Investments [Line Items]
Available-for-sale Securities, Unrealized Gain Position, Fair Value	18,780	15,388
Available-for-sale Securities, Gross Unrealized Gain	562	665
U.S. Government Bonds
Financial Instruments and Investments [Line Items]
Available-for-sale Securities, Unrealized Gain Position, Fair Value	25,250	20,016
Available-for-sale Securities, Gross Unrealized Gain	468	567
Municipal Bonds
Financial Instruments and Investments [Line Items]
Available-for-sale Securities, Unrealized Gain Position, Fair Value	10,288	11,642
Available-for-sale Securities, Gross Unrealized Gain	371	595
Corporate Debt Securities
Financial Instruments and Investments [Line Items]
Available-for-sale Securities, Unrealized Gain Position, Fair Value	11,419	13,762
Available-for-sale Securities, Gross Unrealized Gain	490	850
Equity Securities
Financial Instruments and Investments [Line Items]
Available-for-sale Securities, Unrealized Gain Position, Fair Value	72,309	99,160
Available-for-sale Securities, Gross Unrealized Gain	35,032	48,253
Cash and Cash Equivalents
Financial Instruments and Investments [Line Items]
Available-for-sale Securities, Unrealized Gain Position, Fair Value	5,807	6,193
Available-for-sale Securities, Gross Unrealized Gain	$ 0	$ 0