Financial Instruments And Investments (Marketable Securities Fair Value And Unrealized Losses) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012 securities		Dec. 31, 2011 securities
Financial Instruments and Investments [Line Items]
Contractual Maturity Due For, Mortgaged Backed Securities	10 years
Fair Value, Less than 12 Months	$ 17,786	[1]	$ 17,103	[2]
Fair Value, 12 Months or Longer	10,633	[1]	11,351	[2]
Fair Value, Total	28,419	[1]	28,454	[2]
Unrealized Losses, Less than 12 Months	(543)	[1]	(2,223)	[2]
Unrealized Losses, 12 Months or Longer	(364)	[1]	(737)	[2]
Unrealized Losses, Total	(907)	[1]	(2,960)	[2]
Number of securities	65		96
Collateralized Mortgage Backed Securities
Financial Instruments and Investments [Line Items]
Fair Value, Less than 12 Months	1,792	[1]	515	[2]
Fair Value, 12 Months or Longer	416	[1]	1,233	[2]
Fair Value, Total	2,208	[1]	1,748	[2]
Unrealized Losses, Less than 12 Months	(5)	[1]	(8)	[2]
Unrealized Losses, 12 Months or Longer	(9)	[1]	(23)	[2]
Unrealized Losses, Total	(14)	[1]	(31)	[2]
U.S. Government Bonds
Financial Instruments and Investments [Line Items]
Fair Value, Less than 12 Months	6,633	[1]	100	[2]
Fair Value, 12 Months or Longer	4,457	[1]	2,413	[2]
Fair Value, Total	11,090	[1]	2,513	[2]
Unrealized Losses, Less than 12 Months	(79)	[1]	(1)	[2]
Unrealized Losses, 12 Months or Longer	(114)	[1]	(38)	[2]
Unrealized Losses, Total	(193)	[1]	(39)	[2]
Municipal Bonds
Financial Instruments and Investments [Line Items]
Fair Value, Less than 12 Months	5,306	[1]	2,275	[2]
Fair Value, 12 Months or Longer	5,760	[1]	4,731	[2]
Fair Value, Total	11,066	[1]	7,006	[2]
Unrealized Losses, Less than 12 Months	(39)	[1]	(31)	[2]
Unrealized Losses, 12 Months or Longer	(241)	[1]	(144)	[2]
Unrealized Losses, Total	(280)	[1]	(175)	[2]
Corporate Debt Securities
Financial Instruments and Investments [Line Items]
Fair Value, Less than 12 Months	452	[1]	3,525	[2]
Fair Value, 12 Months or Longer	0	[1]	1,234	[2]
Fair Value, Total	452	[1]	4,759	[2]
Unrealized Losses, Less than 12 Months	(11)	[1]	(118)	[2]
Unrealized Losses, 12 Months or Longer	0	[1]	(43)	[2]
Unrealized Losses, Total	(11)	[1]	(161)	[2]
Debt Securities
Financial Instruments and Investments [Line Items]
Fair Value, Less than 12 Months	14,183	[1]	6,415	[2]
Fair Value, 12 Months or Longer	10,633	[1]	9,611	[2]
Fair Value, Total	24,816	[1]	16,026	[2]
Unrealized Losses, Less than 12 Months	(134)	[1]	(158)	[2]
Unrealized Losses, 12 Months or Longer	(364)	[1]	(248)	[2]
Unrealized Losses, Total	(498)	[1]	(406)	[2]
Equity Securities
Financial Instruments and Investments [Line Items]
Fair Value, Less than 12 Months	3,603	[1]	10,688	[2]
Fair Value, 12 Months or Longer	0	[1]	1,740	[2]
Fair Value, Total	3,603	[1]	12,428	[2]
Unrealized Losses, Less than 12 Months	(409)	[1]	(2,065)	[2]
Unrealized Losses, 12 Months or Longer	0	[1]	(489)	[2]
Unrealized Losses, Total	$ (409)	[1]	$ (2,554)	[2]
Maximum
Financial Instruments and Investments [Line Items]
Debt Instrument, Expected Weighted Average Maturity Year	7 years
Minimum
Financial Instruments and Investments [Line Items]
Debt Instrument, Expected Weighted Average Maturity Year	3 years

[1] Includes approximately 65 securities.

[2] Includes approximately 96 securities.