CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
OPERATING ACTIVITIES
Net loss	$ (81,197)	$ (26,507)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation, amortization and other non-cash charges	118,799	137,914
Stock-based compensation expense	5,362	5,109
Gain on disposition of assets, net	(2,771)	(2,676)
Deferred income tax benefit	(21,008)	(26,802)
Excess tax benefits for share-based payments	(285)	(1,410)
(Increase) decrease in assets:
Accounts receivable	103,085	334,886
Income taxes receivable	1,112	(1,767)
Inventories	12,827	8,076
Prepaid expenses	3,853	2,713
Other current assets	302	1,234
Other non-current assets	(205)	149
Increase (decrease) in liabilities:
Accounts payable	(35,559)	(66,262)
Income taxes payable	528	3,107
Accrued payroll and related expenses	(993)	(25,758)
Accrued insurance expenses	(4)	1,246
Accrued state, local and other taxes	3,948	(854)
Other accrued expenses	(44)	(244)
Pension liabilities	(89)	1,009
Long-term accrued insurance expenses	(1,263)	1,225
Other long-term liabilities	(14,137)	(171)
Net cash provided by operating activities	92,261	344,217
INVESTING ACTIVITIES
Capital expenditures	(18,289)	(139,347)
Proceeds from sale of assets	5,130	6,084
Net cash used for investing activities	(13,159)	(133,263)
FINANCING ACTIVITIES
Payment of dividends		(33,599)
Borrowings from notes payable to banks		464,900
Repayments of notes payable to banks		(634,500)
Debt issuance costs for notes payable to banks	(35)
Excess tax benefits for share-based payments	285	1,410
Cash paid for common stock purchased and retired	(3,194)	(4,093)
Net cash used for financing activities	(2,944)	(205,882)
Net increase in cash and cash equivalents	76,158	5,072
Cash and cash equivalents at beginning of period	65,196	9,772
Cash and cash equivalents at end of period	141,354	14,844
Supplemental cash flows disclosure:
Interest paid, net of amounts capitalized	373	967
Income taxes (received) paid, net	(36,689)	9,478
Supplemental disclosure of noncash investing activities:
Capital expenditures included in accounts payable	$ 1,648	$ 5,989