Fair Value Measurements (Assets Measured At Fair Value On Recurring Basis Using Significant Unobservable Inputs (Level 3), Reconciliation) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Fair Value Measurements [Abstract]
Balance at beginning of period	$ (18,924)	$ (115)
Total gains or losses: Included in earnings	(51,367)	(59,025)
Total gains or losses: Included in other comprehensive income
Purchases, issuances, and settlements:
Purchases
Issuances
Settlements	14,270	(1,007)
Transfers into/out of Level 3
Balance at end of period	(56,021)	(60,147)
Change in losses included in earnings relating to derivatives still held as of March 31	$ (37,097)	$ (60,032)