Guarantor/Non Guarantor Condensed Consolidated Financial Statements (Cash Flows (Unaudited)) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Condensed Financial Statements, Captions [Line Items]
Net cash flows from operating activities	$ (11,262)	$ 7,644
Cash flows from investing activities:
Purchases of property and equipment	(52,806)	(25,584)
Proceeds from sale of property and equipment	10,407	2,743
Proceeds from insurance recoveries	3,119	0
Net cash provided by (used in) investing activities	(39,280)	(22,841)
Cash flows from financing activities:
Debt repayments	(13,267)	(500)
Proceeds from issuance of debt	65,000	12,000
Debt issuance costs	0	(819)
Proceeds from exercise of options	0	183
Purchase of treasury stock	(533)	(124)
Intercompany contributions / distributions	0	0
Net cash provided by (used in) financing activities	51,200	10,740
Net increase (decrease) in cash and cash equivalents	658	(4,457)
Beginning cash and cash equivalents	10,194	14,160
Ending cash and cash equivalents	10,852	9,703
Eliminations [Member]
Condensed Financial Statements, Captions [Line Items]
Net cash flows from operating activities	0	0
Cash flows from investing activities:
Purchases of property and equipment	270	0
Proceeds from sale of property and equipment	(270)	0
Proceeds from insurance recoveries	0
Net cash provided by (used in) investing activities	0	0
Cash flows from financing activities:
Debt repayments	0	0
Proceeds from issuance of debt	0	0
Debt issuance costs		0
Proceeds from exercise of options		0
Purchase of treasury stock	0	0
Intercompany contributions / distributions	0	0
Net cash provided by (used in) financing activities	0	0
Net increase (decrease) in cash and cash equivalents	0	0
Beginning cash and cash equivalents	0	0
Ending cash and cash equivalents	0	0
Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Net cash flows from operating activities	19,768	44,422
Cash flows from investing activities:
Purchases of property and equipment	(48,490)	(24,997)
Proceeds from sale of property and equipment	10,528	2,689
Proceeds from insurance recoveries	3,119
Net cash provided by (used in) investing activities	(34,843)	(22,308)
Cash flows from financing activities:
Debt repayments	0	0
Proceeds from issuance of debt	0	0
Debt issuance costs		0
Proceeds from exercise of options		0
Purchase of treasury stock	0	0
Intercompany contributions / distributions	14,614	(17,524)
Net cash provided by (used in) financing activities	14,614	(17,524)
Net increase (decrease) in cash and cash equivalents	(461)	4,590
Beginning cash and cash equivalents	(764)	(5,612)
Ending cash and cash equivalents	(1,225)	(1,022)
Non-Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Net cash flows from operating activities	4,346	326
Cash flows from investing activities:
Purchases of property and equipment	(4,023)	(235)
Proceeds from sale of property and equipment	149	54
Proceeds from insurance recoveries	0
Net cash provided by (used in) investing activities	(3,874)	(181)
Cash flows from financing activities:
Debt repayments	0	0
Proceeds from issuance of debt	0	0
Debt issuance costs		0
Proceeds from exercise of options		0
Purchase of treasury stock	0	0
Intercompany contributions / distributions	(235)	(70)
Net cash provided by (used in) financing activities	(235)	(70)
Net increase (decrease) in cash and cash equivalents	237	75
Beginning cash and cash equivalents	1,060	2,551
Ending cash and cash equivalents	1,297	2,626
Parent [Member]
Condensed Financial Statements, Captions [Line Items]
Net cash flows from operating activities	(35,376)	(37,104)
Cash flows from investing activities:
Purchases of property and equipment	(563)	(352)
Proceeds from sale of property and equipment	0	0
Proceeds from insurance recoveries	0
Net cash provided by (used in) investing activities	(563)	(352)
Cash flows from financing activities:
Debt repayments	(13,267)	(500)
Proceeds from issuance of debt	65,000	12,000
Debt issuance costs		(819)
Proceeds from exercise of options		183
Purchase of treasury stock	(533)	(124)
Intercompany contributions / distributions	(14,379)	17,594
Net cash provided by (used in) financing activities	36,821	28,334
Net increase (decrease) in cash and cash equivalents	882	(9,122)
Beginning cash and cash equivalents	9,898	17,221
Ending cash and cash equivalents	$ 10,780	$ 8,099