Derivative Instruments And Hedging Strategies (Recognized Gains (Losses) On Derivative Instruments Not Designated As Hedging Instruments) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Derivative [Line Items]
Derivative gains (losses), net	$ (8,323)	$ (2,754)	$ (30,009)
Options On Equities And Equity Indices [Member]
Derivative [Line Items]
Derivative gains (losses), net	(5,270)	(680)	1,693
U.S. Treasury Notes, Rate Locks And Bond Future And Option Contracts [Member]
Derivative [Line Items]
Derivative gains (losses), net	0	0	(28,301)
Forward Currency Exchange, Option And Future Contracts [Member]
Derivative [Line Items]
Derivative gains (losses), net	(451)	837	(621)
Interest Rate Swap [Member]
Derivative [Line Items]
Derivative gains (losses), net	(37)	(3,778)	(1,103)
Commodity Swap, Option And Future Contracts, Exchange Traded [Member]
Derivative [Line Items]
Derivative gains (losses), net	(3,915)	(1,020)	(2,008)
Commodity Swap, Option And Future Contracts, Non-Exchange Traded [Member]
Derivative [Line Items]
Derivative gains (losses), net	$ 1,350	$ 1,887	$ 331