CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $)	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013
Operating Activities
Net earnings	$ 166,902,000	$ 15,300,000
Adjustments to reconcile net earnings to net cash provided by operating activities
Depreciation, depletion, accretion and amortization	208,858,000	230,877,000
Net gain on sale of property, plant & equipment and businesses	(238,527,000)	(48,597,000)
Proceeds from sale of future production, net of transactions costs (Note 16)	0	153,095,000
Contributions to pension plans	(4,115,000)	(3,535,000)
Share-based compensation	18,425,000	16,789,000
Excess tax benefits from share-based compensation	(3,375,000)	(896,000)
Deferred tax provision (benefit)	13,158,000	(25,862,000)
Cost of debt purchase	72,949,000	0
Changes in assets and liabilities before initial effects of business acquisitions and dispositions	(89,888,000)	(78,947,000)
Other, net	5,339,000	1,788,000
Net cash provided by operating activities	149,726,000	260,012,000
Investing Activities
Purchases of property, plant & equipment	(169,220,000)	(117,310,000)
Proceeds from sale of property, plant & equipment	21,320,000	14,974,000
Proceeds from sale of businesses, net of transaction costs	719,089,000	51,604,000
Payment for businesses acquired, net of acquired cash	(268,604,000)	(89,951,000)
Other, net	0	2,000
Net cash provided by (used for) investing activities	302,585,000	(140,681,000)
Financing Activities
Proceeds from line of credit	70,000,000	156,000,000
Payment of current maturities, long-term debt and line of credit	(649,711,000)	(306,493,000)
Proceeds from issuance of common stock	30,620,000	0
Dividends paid	(20,973,000)	(3,890,000)
Proceeds from exercise of stock options	12,513,000	4,491,000
Excess tax benefits from share-based compensation	3,375,000	896,000
Other, net	(5,000)	0
Net cash used for financing activities	(554,181,000)	(148,996,000)
Net decrease in cash and cash equivalents	(101,870,000)	(29,665,000)
Cash and cash equivalents at beginning of year	193,738,000	275,478,000
Cash and cash equivalents at end of period	$ 91,868,000	$ 245,813,000