CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Cash flows from continuing operating activities
Net income (loss)	$ (14,941)	$ 6,649
Adjustments to reconcile net income (loss) to net cash provided by continuing operating activities:
Deferred income taxes	(1,329)	3,176
Depreciation, depletion and amortization of property, plant and equipment	11,679	9,001
Other	2,271	(795)
Cash provided (used) by changes in assets and liabilities (net of effects of discontinued operations):
Accounts receivable	(1,910)	(2,348)
Inventories	7,051	(1,477)
Prepaid insurance	2,604	3,744
Prepaid and accrued income taxes	858	4,640
Other supplies, prepaid items and other	342	932
Accounts payable	10,843	1,629
Accrued interest	(8,078)	(8,086)
Customer deposits	1,022	(3,003)
Other current and noncurrent liabilities	3,681	(1,459)
Net cash provided by continuing operating activities	14,093	12,603
Cash flows from continuing investing activities
Expenditures for property, plant and equipment	(104,290)	(66,837)
Purchases of short-term investments		(10,000)
Proceeds from noncurrent restricted cash and cash equivalents		45,969
Other investing activities	(514)	(1,080)
Net cash used by continuing investing activities	(104,804)	(31,948)
Cash flows from continuing financing activities
Proceeds from revolving debt facility	25,000
Payments on revolving debt facility	(25,000)
Proceeds from other long-term debt, net of fees	9,951
Payments on other long-term debt	(3,014)	(2,881)
Payments of debt issuance costs	(476)
Payments of issuance costs relating to preferred stocks and warrants	(785)
Payments on short-term financing	(2,720)	(3,566)
Proceeds from exercises of stock options	49	742
Excess income tax benefit associated with stock-based compensation		129
Dividends paid on convertible preferred stocks		(300)
Net cash provided (used) by continuing financing activities	3,005	(5,876)
Cash flows of discontinued operations:
Operating cash flows	(79)	(32)
Net decrease in cash and cash equivalents	(87,785)	(25,253)
Cash and cash equivalents at beginning of period	127,314	186,811
Cash and cash equivalents at end of period	$ 39,529	$ 161,558