Comprehensive Income (Loss) (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Comprehensive Income (Loss)
Net income (loss)	$ (1,061,956,000)	$ 87,080,000	$ (989,404,000)	$ 283,346,000
Change in pension and other postretirement benefit plans, net of deferred taxes	3,898,000	3,086,000	11,693,000	9,320,000
Change in pension and other postretirement benefit plans, deferred taxes	2,400,000	1,900,000	7,300,000	5,600,000
Change in foreign currency translation adjustment	3,132,000	835,000	2,342,000	(266,000)
Change in unrealized loss on hedges, net of deferred taxes	(545,000)	(1,434,000)	(3,815,000)	(2,147,000)
Change in unrealized loss on hedges, deferred taxes	300,000	900,000	2,400,000	1,300,000
Change in unrealized loss on investments, net of deferred taxes	1,135,000	3,302,000	766,000	(1,192,000)
Change in unrealized loss on investments, deferred taxes		1,700,000
Comprehensive income (loss)	$ (1,054,336,000)	$ 92,869,000	$ (978,418,000)	$ 289,061,000