Segment Information (Schedule Of Revenues By Geographic Segment) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Segment Reporting Information [Line Items]
Revenues	$ 545,150	$ 601,396	$ 710,784	$ 917,235	$ 1,178,626	$ 1,209,026	$ 1,107,552	$ 1,061,418	$ 2,774,565	$ 4,556,622	$ 4,350,057
Total, Revenues	545,150	$ 601,396	$ 710,784	$ 917,235	1,178,626	$ 1,209,026	$ 1,107,552	$ 1,061,418	2,774,565	4,556,622	4,350,057
Property, plant and equipment, net	2,123,291				2,733,839				2,123,291	2,733,839
UNITED STATES
Segment Reporting Information [Line Items]
Revenues									2,185,071	3,848,929	3,674,825
Total, Revenues									2,185,071	3,848,929	3,674,825
Long-lived assets	1,799,418				2,416,306				1,799,418	2,416,306
Other Countries Member
Segment Reporting Information [Line Items]
Revenues									589,494	707,693	675,232
Total, Revenues									589,494	707,693	$ 675,232
Long-lived assets	$ 323,873				$ 317,533				$ 323,873	$ 317,533