Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Statement [Abstract]
Net revenues	$ 695,802	$ 1,107,156	$ 876,561
Cost of sales:
Cost of sales	584,566	763,120	615,876
Asset impairments	345,010	0	0
Total cost of sales	929,576	763,120	615,876
Gross profit (loss)	(233,774)	344,036	260,685
Goodwill impairment	(16,399)	0	0
Loss on commodity derivative contracts	0	0	(14,113)
Gain on disposition of assets, net	92	10,240	14,727
Selling, general and administrative expenses	(57,279)	(92,520)	(82,265)
Income (loss) from operations	(307,360)	261,756	179,034
Equity in earnings (losses) of investments	(124,345)	879	2,965
Net interest expense	(26,914)	(17,859)	(32,898)
Loss on early extinguishment of long-term debt	0	0	(12,100)
Other income (expense), net	(24,310)	814	6
Other income – oil and gas	4,759	16,931	6,581
Income (loss) before income taxes	(478,170)	262,521	143,588
Income tax provision (benefit)	(101,190)	66,971	31,612
Net income (loss) from continuing operations	(376,980)	195,550	111,976
Income from discontinued operations, net of tax	0	0	1,073
Net income (loss), including noncontrolling interests	(376,980)	195,550	113,049
Less net income applicable to noncontrolling interests	0	(503)	(3,127)
Net income (loss) applicable to common shareholders	$ (376,980)	$ 195,047	$ 109,922
Basic earnings (loss) per share of common stock:
Continuing operations (in dollars per share)	$ (3.58)	$ 1.85	$ 1.03
Discontinued operations (in dollars per share)	0.00	0.00	0.01
Net income (loss) per common share (in dollars per share)	(3.58)	1.85	1.04
Diluted earnings (loss) per share of common stock:
Continuing operations (in dollars per share)	(3.58)	1.85	1.03
Discontinued operations (in dollars per share)	0.00	0.00	0.01
Net income (loss) per common share (in dollars per share)	$ (3.58)	$ 1.85	$ 1.04
Weighted average common shares outstanding:
Basic (in shares)	105,416	105,029	105,032
Diluted (in shares)	105,416	105,045	105,184