Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Cash flows from operating activities:
Net income (loss)	$ (155,140)	$ (38,018)	$ (35,932)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	150,939	183,376	187,918
Allowance for doubtful accounts	248	1,445	801
Write-off of obsolete inventory	0	331	152
Gain on dispositions of property and equipment, net	(4,344)	(1,859)	(1,421)
Stock-based compensation expense	3,629	7,617	6,371
Amortization of debt issuance costs, discount and premium	1,691	2,669	3,095
Gain on sale of fishing and rental services operations	0	(10,702)	0
Loss on extinguishment of debt	2,186	31,221	0
Impairment charges	129,152	73,025	54,292
Deferred income taxes	(39,286)	(14,761)	(22,125)
Change in other long-term assets	420	2,958	(5,741)
Change in other long-term liabilities	(132)	(1,352)	(1,928)
Changes in current assets and liabilities:
Receivables	114,644	(11,993)	(16,168)
Inventory	1,267	(1,068)	(1,273)
Prepaid expenses and other current assets	1,769	(55)	3,729
Accounts payable	(30,514)	7,167	(166)
Deferred revenues	1,922	2,616	(3,181)
Accrued expenses	(35,732)	424	6,157
Net cash provided by operating activities	142,719	233,041	174,580
Cash flows from investing activities:
Purchases of property and equipment	(159,615)	(175,378)	(165,356)
Proceeds from sale of fishing and rental services operations	0	15,090	0
Proceeds from sale of property and equipment	57,674	8,370	13,836
Proceeds from insurance recoveries	285	0	844
Net cash used in investing activities	(101,656)	(151,918)	(150,676)
Cash flows from financing activities:
Debt repayments	(60,002)	(490,025)	(60,874)
Proceeds from issuance of debt	0	440,000	40,000
Debt issuance costs	(1,877)	(9,239)	(13)
Tender premium costs	0	(21,553)	0
Proceeds from exercise of options	781	8,368	1,266
Purchase of treasury stock	(729)	(1,135)	(631)
Net cash used in financing activities	(61,827)	(73,584)	(20,252)
Net increase (decrease) in cash and cash equivalents	(20,764)	7,539	3,652
Beginning cash and cash equivalents	34,924	27,385	23,733
Ending cash and cash equivalents	14,160	34,924	27,385
Supplementary disclosure:
Interest paid	22,506	43,690	46,274
Income tax paid	2,691	5,012	3,154
Noncash investing and financing activity:
Change in capital expenditure accruals	$ (16,708)	$ 12,743	$ (39,936)