Supplemental Condensed Consolidating Financial Information (Schedule Of Condensed Consolidating Statements Of Cash Flows) (Details) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011
Cash provided by (used in) operating activities	$ 95,308	$ 314,200
Investing Activities
Acquisition of ICG, net of cash acquired		(2,910,380)
Change in restricted cash	4,582	(74,814)
Capital expenditures	(202,073)	(107,725)
Proceeds from dispositions of property, plant and equipment	22,551	1,411
Purchases of investments and advances to affiliates	(9,292)	(38,059)
Additions to prepaid royalties	(8,634)	(25,212)
Cash used in investing activities	(192,866)	(3,154,779)
Financing Activities
Proceeds from the issuance of senior notes		2,000,000
Proceeds from the sale of common stock, net		1,249,407
Proceeds from term note	1,386,000
Payments to retire debt	(452,654)	(307,984)
Change in restricted cash		(260,663)
Net increase (decrease) in borrowings under lines of credit and commercial paper program	(391,300)	303,096
Net payments on other debt	(11,164)	(8,845)
Debt financing costs	(34,381)	(112,334)
Dividends paid	(29,696)	(34,192)
Issuance of common stock under incentive plans	5,131	846
Cash provided by (used in) financing activities	471,936	2,829,331
Increase (decrease) in cash and cash equivalents	374,378	(11,248)
Cash and cash equivalents, beginning of period	138,149	93,593
Cash and cash equivalents, end of period	512,527	82,345
Parent/Issuer [Member]
Cash provided by (used in) operating activities	(139,288)	(109,358)
Investing Activities
Acquisition of ICG, net of cash acquired		(2,910,380)
Change in restricted cash	4,582	(74,814)
Capital expenditures	(3,973)	(2,459)
Purchases of investments and advances to affiliates	(3,683)	(725,938)
Cash used in investing activities	(3,074)	(3,713,591)
Financing Activities
Proceeds from the issuance of senior notes		2,000,000
Proceeds from the sale of common stock, net		1,249,407
Proceeds from term note	1,386,000
Net increase (decrease) in borrowings under lines of credit and commercial paper program	(391,300)	360,000
Net payments on other debt	(11,164)	(8,845)
Debt financing costs	(34,335)	(112,326)
Dividends paid	(29,696)	(34,192)
Issuance of common stock under incentive plans	5,131	846
Transactions with affiliates, net	(442,951)	363,696
Cash provided by (used in) financing activities	481,685	3,818,586
Increase (decrease) in cash and cash equivalents	339,323	(4,363)
Cash and cash equivalents, beginning of period	61,375	13,713
Cash and cash equivalents, end of period	400,698	9,350
Guarantor Subsidiaries [Member]
Cash provided by (used in) operating activities	221,019	278,596
Investing Activities
Capital expenditures	(160,423)	(65,927)
Proceeds from dispositions of property, plant and equipment	985	1,315
Purchases of investments and advances to affiliates	(6,992)	(27,058)
Additions to prepaid royalties	(5,187)	(21,440)
Cash used in investing activities	(171,617)	(113,110)
Financing Activities
Contributions from parent	1,383	714,937
Payments to retire debt	(1,383)	(307,984)
Change in restricted cash		(260,663)
Transactions with affiliates, net	(49,374)	(309,706)
Cash provided by (used in) financing activities	(49,374)	(163,416)
Increase (decrease) in cash and cash equivalents	28	2,070
Cash and cash equivalents, beginning of period	332	64
Cash and cash equivalents, end of period	360	2,134
Non-Guarantor Subsidiaries [Member]
Cash provided by (used in) operating activities	13,577	144,962
Investing Activities
Capital expenditures	(37,677)	(39,339)
Proceeds from dispositions of property, plant and equipment	21,566	96
Additions to prepaid royalties	(3,447)	(3,772)
Cash used in investing activities	(19,558)	(43,015)
Financing Activities
Payments to retire debt	(451,271)
Net increase (decrease) in borrowings under lines of credit and commercial paper program		(56,904)
Debt financing costs	(46)	(8)
Transactions with affiliates, net	492,325	(53,990)
Cash provided by (used in) financing activities	41,008	(110,902)
Increase (decrease) in cash and cash equivalents	35,027	(8,955)
Cash and cash equivalents, beginning of period	76,442	79,816
Cash and cash equivalents, end of period	111,469	70,861
Eliminations [Member]
Investing Activities
Purchases of investments and advances to affiliates	1,383	714,937
Cash used in investing activities	1,383	714,937
Financing Activities
Contributions from parent	(1,383)	(714,937)
Cash provided by (used in) financing activities	$ (1,383)	$ (714,937)