Comprehensive Earnings (Accumulated Other Comprehensive Earnings) (Details) (USD $) In Thousands	Sep. 30, 2011	Dec. 31, 2010
Comprehensive Earnings
Net unrealized gain on available-for-sale securities, net of tax	$ 1,019	$ 1,047
Net unrecognized losses and prior service costs related to post-retirement plans, net of tax	(4,167)	(4,650)
Net unrecognized losses on derivatives, net of tax	(34,867)	(9,594)
Foreign currency translation adjustment	81,886	185,064
Accumulated other comprehensive earnings	$ 43,871	$ 171,867