Financial Instruments And Investments (Unrecognized Gross Unrealized Gains And The Fair Value) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Financial Instruments and Investments [Line Items]
Available-for-sale Securities, Unrealized Gain Position, Fair Value	$ 140,096	$ 166,161
Available-for-sale Securities, Gross Unrealized Gain	38,366	50,930
Debt Securities
Financial Instruments and Investments [Line Items]
Available-for-sale Securities, Unrealized Gain Position, Fair Value	40,403	60,808
Available-for-sale Securities, Gross Unrealized Gain	1,274	2,677
Collateralized Mortgage Backed Securities
Financial Instruments and Investments [Line Items]
Available-for-sale Securities, Unrealized Gain Position, Fair Value	9,589	15,388
Available-for-sale Securities, Gross Unrealized Gain	438	665
U.S. Government Bonds
Financial Instruments and Investments [Line Items]
Available-for-sale Securities, Unrealized Gain Position, Fair Value	12,033	20,016
Available-for-sale Securities, Gross Unrealized Gain	136	567
Municipal Bonds
Financial Instruments and Investments [Line Items]
Available-for-sale Securities, Unrealized Gain Position, Fair Value	8,671	11,642
Available-for-sale Securities, Gross Unrealized Gain	332	595
Corporate Debt Securities
Financial Instruments and Investments [Line Items]
Available-for-sale Securities, Unrealized Gain Position, Fair Value	10,110	13,762
Available-for-sale Securities, Gross Unrealized Gain	368	850
Equity Securities
Financial Instruments and Investments [Line Items]
Available-for-sale Securities, Unrealized Gain Position, Fair Value	72,636	99,160
Available-for-sale Securities, Gross Unrealized Gain	37,001	48,253
Equity Mutual Funds
Financial Instruments and Investments [Line Items]
Available-for-sale Securities, Unrealized Gain Position, Fair Value	18,853	0
Available-for-sale Securities, Gross Unrealized Gain	91	0
Cash and Cash Equivalents
Financial Instruments and Investments [Line Items]
Available-for-sale Securities, Unrealized Gain Position, Fair Value	8,204	6,193
Available-for-sale Securities, Gross Unrealized Gain	$ 0	$ 0