Consolidated Statements of Cash Flows (USD $)	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Operating Activities
Net loss	$ (52,593,000)		$ (70,778,000)		$ (96,490,000)
Adjustments to reconcile net earnings to net cash provided by operating activities
Depreciation, depletion, accretion and amortization	331,959,000	[1]	361,719,000	[1]	382,093,000	[1]
Net gain on sale of property, plant & equipment and businesses	(78,654,000)		(58,808,000)		(68,095,000)
Contributions to pension plans	(4,509,000)		(4,892,000)		(24,496,000)
Share-based compensation	17,474,000		18,454,000		20,637,000
Excess tax benefits from share-based compensation	(267,000)		(121,000)		(808,000)
Deferred tax provision	(69,830,000)		(93,739,000)		(51,684,000)
Cost of debt purchase	0		19,153,000		0
(Increase) decrease in assets before initial effects of business acquisitions and dispositions
Accounts and notes receivable	17,412,000		5,035,000		(49,656,000)
Inventories	(9,028,000)		(6,927,000)		6,708,000
Prepaid expenses	(117,000)		(1,354,000)		22,945,000
Other assets	(29,043,000)		7,673,000		(58,243,000)
Increase (decrease) in liabilities before initial effects of business acquisitions and dispositions
Accrued interest and income taxes	(15,709,000)		5,831,000		12,661,000
Trade payables and other accruals	27,091,000		(27,871,000)		44,573,000
Proceeds from sale of future production, net of transaction costs (Note 19)	73,583,000		0		0
Other noncurrent liabilities	29,772,000		5,707,000		40,950,000
Other, net	934,000		9,961,000		21,611,000
Net cash provided by operating activities	238,475,000		169,043,000		202,706,000
Investing Activities
Purchases of property, plant & equipment	(93,357,000)		(98,912,000)		(86,324,000)
Proceeds from sale of property, plant & equipment	80,829,000		13,675,000		13,602,000
Proceeds from sale of businesses, net of transaction costs	21,166,000		74,739,000		50,954,000
Payment for businesses acquired, net of acquired cash	0		(10,531,000)		(70,534,000)
Other, net	1,761,000		1,550,000		3,926,000
Net cash provided by (used for) investing activities	10,399,000		(19,479,000)		(88,376,000)
Financing Activities
Net short-term borrowings (payments)	0		(285,500,000)		48,988,000
Payment of current maturities and long-term debt	(134,780,000)		(743,075,000)		(519,204,000)
Cost of debt purchase	0		(19,153,000)		0
Proceeds from issuance of long-term debt, net of discounts	0		1,100,000,000		450,000,000
Debt issuance costs	0		(27,426,000)		(3,058,000)
Proceeds from settlement of interest rate swap agreements	0		23,387,000		0
Proceeds from issuance of common stock	0		4,936,000		41,734,000
Dividends paid	(5,183,000)		(98,172,000)		(127,792,000)
Proceeds from exercise of stock options	10,462,000		3,615,000		20,502,000
Excess tax benefits from share-based compensation	267,000		121,000		808,000
Other, net	(1,000)		1,000		(1,032,000)
Net cash used for financing activities	(129,235,000)		(41,266,000)		(89,054,000)
Net increase in cash and cash equivalents	119,639,000		108,298,000		25,276,000
Cash and cash equivalents at beginning of year	155,839,000		47,541,000		22,265,000
Cash and cash equivalents at end of year	$ 275,478,000		$ 155,839,000		$ 47,541,000

[1] The allocation of indirect depreciation to our operating segments was changed in 2012 to better align the presentation with how management views information internally. The 2011 and 2010 DDA&A amounts presented above have been revised to conform to the 2012 presentation.