Investments (Summary Of Gross Unrealized Gains And Losses And Fair Values) (Details) (USD $) In Thousands, unless otherwise specified	6 Months Ended	12 Months Ended
	Jun. 30, 2013	Dec. 31, 2012
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost Basis	$ 110,045	$ 87,151
Available-for-sale Securities, Gross Unrealized Gains	11,052	3,400
Available-for-sale Securities, Gross Unrealized Losses	(269)	(534)
Available-for-sale Securities	120,828	90,017
Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost Basis	20,610	20,610
Available-for-sale Securities, Gross Unrealized Gains	10,941	3,251
Available-for-sale Securities, Gross Unrealized Losses	(81)	(367)
Available-for-sale Securities	31,470	23,494
Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost Basis	89,435	66,541
Available-for-sale Securities, Gross Unrealized Gains	111	149
Available-for-sale Securities, Gross Unrealized Losses	(188)	(167)
Available-for-sale Securities	$ 89,358	$ 66,523