Derivative Financial Instruments Activity of Hedging Instruments in Accumulated OCI (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Net unrealized loss on hedging instruments at beginning			$ (14,380)	$ (10,034)
Unrealized gain (loss) on derivative instruments	(828)	2,086	(1,677)	1,922
Net unrealized gain (loss) on nonderivative hedging instruments	0	408	0	(8,854)
Realized (gains) losses reclassified into net income (loss)	0	(176)	0	2,598
Net unrealized loss on hedging instruments at end	(16,057)	(14,368)	(16,057)	(14,368)
Net Investment Hedging [Member]
Net unrealized loss on hedging instruments at end	$ (14,400)		$ (14,400)