Condensed Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
Cash flows from continuing operating activities
Net income	$ 17,619	$ 47,044
Adjustments to reconcile net income to net cash provided by continuing operating activities:
Net loss from discontinued operations	49	120
Deferred income taxes	6,170	1,793
Depreciation, depletion and amortization of property, plant and equipment	20,062	14,857
Other	5,008	2,910
Cash provided (used) by changes in assets and liabilities (net of effects of discontinued operations):
Accounts receivable	(317)	(7,501)
Inventories	5,446	(6,422)
Prepaid and accrued income taxes	(9,459)	5,309
Other supplies, prepaid items and other	2,839	4,638
Accounts payable	(7,141)	3,588
Customer deposits	(3,693)	7,735
Other current and noncurrent liabilities	6,695	(691)
Deferred gain on insurance recoveries	2,000
Net cash provided by continuing operating activities	45,278	73,380
Cash flows from continuing investing activities
Expenditures for property, plant and equipment	(113,727)	(61,613)
Acquisition of working interests in natural gas properties	(9,205)
Proceeds from property insurance recoveries associated with property, plant and equipment	23,671
Proceeds from sales of property and equipment	1,439	213
Proceeds from short-term investments		20,037
Purchase of short-term investments		(10,032)
Deposits of current and noncurrent restricted cash	(110,015)	(23)
Purchase of noncurrent restricted investments	(169,988)
Payments on contractual obligations-carbon credits		(180)
Other assets	(818)	(398)
Net cash used by continuing investing activities	(378,643)	(51,996)
Cash flows from continuing financing activities
Proceeds from senior secured notes, net of pay off of secured term loan and fees	350,957
Proceeds from other long-term debt, net of fees	39,825
Payments on other long-term debt	(6,657)	(5,830)
Payments of debt issuance costs	(1,607)	(88)
Payments on short-term financing	(8,351)	(5,077)
Proceeds from revolving debt facility		209,238
Payments on revolving debt facility		(209,238)
Payments on loans secured by cash value of life insurance policies		(1,918)
Proceeds from exercise of stock options	865	543
Excess income tax benefit associated with stock-based compensation	411	353
Acquisition of redeemable preferred stock		(39)
Dividends paid on preferred stocks	(300)	(300)
Net cash provided (used) by continuing financing activities	375,143	(12,356)
Cash flows of discontinued operations:
Operating cash flows	(145)	(184)
Net increase (decrease) in cash and cash equivalents	41,633	8,844
Cash and cash equivalents at beginning of period	98,020	124,929
Cash and cash equivalents at end of period	139,653	133,773
Supplemental cash flow information:
Cash payments for income taxes, net of refunds	12,865	19,596
Noncash investing and financing activities:
Insurance claims receivable associated with property, plant and equipment	250	11,415
Other assets, accounts payable and long-term debt associated with additions of property, plant and equipment	19,488	9,379
Long-term debt associated with additions of capitalized internal-use software and software development (included in other assets)	2,775
Secured term loan extinguished	66,563
Debt issuance costs incurred associated with senior secured notes	6,498
Debt issuance costs written off associated with secured term loan	630
Prepayment premium incurred associated with secured term loan	$ 666