Fair Value Measurements (Summary Of Change In The Fair Values Of Financial Instruments Categorized As Level 3) (Details) (USD $)
In Thousands, unless otherwise specified
3 Months Ended
Mar. 31, 2015
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]  
Balance, beginning of period $ 3,040
Realized and unrealized losses recognized in earnings, net (1,347)
Realized and unrealized gains recognized in other comprehensive income, net 1,450
Purchases 7,783
Issuances (1,656)
Ending balance $ 9,270