Condensed Consolidated Statements of Cash Flows (USD $)	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
Operating Activities
Net loss	$ (26,064,000)	$ (70,336,000)
Adjustments to reconcile net loss to net cash provided by operating activities
Depreciation, depletion, accretion and amortization	152,557,000	169,283,000
Net gain on sale of property, plant & equipment and businesses	(40,550,000)	(31,014,000)
Contributions to pension plans	(2,308,000)	(2,248,000)
Share-based compensation	11,102,000	3,601,000
Deferred tax provision	(31,581,000)	(51,613,000)
Changes in assets and liabilities before initial effects of business acquisitions and dispositions	(108,295,000)	(20,033,000)
Other, net	(206,000)	(701,000)
Net cash used for operating activities	(45,345,000)	(3,061,000)
Investing Activities
Purchases of property, plant & equipment	(60,041,000)	(33,584,000)
Proceeds from sale of property, plant & equipment	2,517,000	26,069,000
Proceeds from sale of businesses, net of transaction costs	52,908,000	11,827,000
Payment for businesses acquired, net of acquired cash	(89,951,000)	0
Other, net	2,000	49,000
Net cash provided by (used for) investing activities	(94,565,000)	4,361,000
Financing Activities
Proceeds from line of credit	111,000,000	0
Payment of current maturities and long-term debt	(161,477,000)	(105,000)
Dividends paid	(2,598,000)	(2,590,000)
Proceeds from exercise of stock options	3,598,000	3,524,000
Other, net	888,000	333,000
Net cash provided by (used for) financing activities	(48,589,000)	1,162,000
Net increase (decrease) in cash and cash equivalents	(188,499,000)	2,462,000
Cash and cash equivalents at beginning of year	275,478,000	155,839,000
Cash and cash equivalents at end of period	$ 86,979,000	$ 158,301,000