Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Operating activities:
Net income (loss)	$ (754)		$ 213,026		$ 240,659
Income (loss) from discontinued operations, net of tax	13,567	[1]	(12,926)	[1]	(3,361)	[1]
Income (loss) from continuing operations	(14,321)		225,952		244,020
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation, depletion and amortization	359,205		343,395		328,843
Earnings, net of distributions, from equity method investments	(618)		(2,111)		(26,158)
Deferred income taxes	(7,503)		118,925		66,585
Write-downs of oil and natural gas properties (Note 1)	391,800		0		0
Changes in current assets and liabilities, net of acquisitions:
Receivables	(13,416)		(30,452)		(59,037)
Inventories	(42,334)		(24,226)		(4,728)
Other current assets	297		7,729		(7,424)
Accounts payable	6,352		(12,263)		17,833
Other current liabilities	(59,001)		33,738		12,289
Other noncurrent changes	(33,041)		(33,365)		(20,271)
Net cash provided by continuing operations	587,420		627,322		551,952
Net cash used in discontinued operations	(2,680)		(674)		(319)
Net cash provided by operating activities	584,740		626,648		551,633
Investing activities:
Capital expenditures	(872,920)		(497,000)		(449,282)
Acquisitions, net of cash acquired	(67,261)		(157)		(104,812)
Net proceeds from sale or disposition of property and other	40,110		40,107		76,386
Investments	9,725		(10,302)		704
Proceeds from sale of equity method investments	2,394		2,807		69,060
Net cash used in continuing operations	(887,952)		(464,545)		(407,944)
Net cash provided by discontinued operations	0		0		0
Net cash used in investing activities	(887,952)		(464,545)		(407,944)
Financing activities:
Issuance of short-term borrowings	20,100		0		20,000
Repayment of short-term borrowings	0		(20,000)		(10,300)
Issuance of long-term debt	467,957		300		20,200
Repayment of long-term debt	(138,775)		(85,151)		(13,668)
Proceeds from issuance of common stock	88		5,744		4,972
Dividends paid	(159,768)		(123,323)		(119,157)
Excess tax benefit on stock-based compensation	26		1,239		1,186
Net cash provided by (used in) continuing operations	189,628		(221,191)		(96,767)
Net cash provided by discontinued operations	0		0		0
Net cash provided by (used in) financing activities	189,628		(221,191)		(96,767)
Effect of exchange rate changes on cash and cash equivalents	(146)		(214)		38
Increase (decrease) in cash and cash equivalents	(113,730)		(59,302)		46,960
Cash and cash equivalents - beginning of year	162,772		222,074		175,114
Cash and cash equivalents - end of year	$ 49,042		$ 162,772		$ 222,074

[1] Reflected in the Other category.