Derivatives And Fair Value Measurements (Related Tax Effects Of Designated Hedging Activities Allocated To Each Component Of Other Comprehensive Income) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended				6 Months Ended				12 Months Ended
	Jun. 30, 2011		Jun. 30, 2010		Jun. 30, 2011		Jun. 30, 2010		Jun. 30, 2011		Jun. 30, 2010
Derivatives And Fair Value Measurements
Realized/unrealized gain (loss), Before Tax	$ (3,816)		$ (20,272)		$ (3,145)		$ (21,259)		$ (332)		$ (21,259)
Amounts reclassified into net income, Before Tax	293				585				682
Other comprehensive (income) loss, Before Tax	(3,523)		(20,272)		(2,560)		(21,259)		350		(21,259)
Realized/unrealized gain (loss), Tax	1,450	[1]	7,703	[1]	1,195	[1]	8,078	[1]	127	[1]	8,078	[1]
Amounts reclassified into net income, Tax	(111)	[1]			(222)	[1]			(259)	[1]
Other comprehensive (income) loss, Tax	1,339	[1]	7,703	[1]	973	[1]	8,078	[1]	(132)	[1]	8,078	[1]
Realized/unrealized gain (loss), Net of Tax	(2,366)		(12,569)		(1,950)		(13,181)		(205)		(13,181)
Amounts reclassified to net income, net of tax (Note 4)	182				363				423
Other Comprehensive Income (Loss), Net of Tax	$ (2,184)		$ (12,569)		$ (1,587)	[2]	$ (13,181)		$ 218		$ (13,181)
Calculated Tax Rate	38.00%		38.00%		38.00%		38.00%		38.00%		38.00%

[1] (1) Tax amounts are calculated using a 38% rate.

[2] FSIRS unrealized loss of $1,950,000 recognized in other comprehensive income less the portion of the previous FSIRS realized loss that was reclassified to net income in the current period ($363,000).