GUARANTOR - Condensed Balance Sheets (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Assets Abstract
Current Assets	$ 146,685	$ 106,065
Property And Equipment - Net	63,375	57,993
Deferred Charges And Other Assets - Net	10,260	5,471
Investments In Affiliates Subsidiaries Associates And Joint Ventures	0	0
Assets	1,076,233	1,015,645
LIABILITIES AND SHAREHOLDERS' EQUITY
Liabilities Current	67,717	68,601
Liabilities Noncurrent	587,410	557,975
Liabilities, Total	655,127	626,576
Perpetual Convertible Preferred Stock, Value, Issued	27,732	27,619
Stockholders Equity Abstract
Common Stock Value	407	397
Additional Paid In Capital Common Stock	605,603	611,754
Retained Earnings Accumulated Deficit	(212,636)	(250,701)
Accumulated Other Comprehensive Income Loss Net Of Tax	0	0
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	393,374	361,450	$ 329,021	$ 298,393
Liabilities And Stockholders Equity	1,076,233	1,015,645
Parent Company [Member]
Assets Abstract
Current Assets	7,228	7,289
Property And Equipment - Net	2,866	472
Deferred Charges And Other Assets - Net	1,813	3,807
Investments In Affiliates Subsidiaries Associates And Joint Ventures	456,161	424,493
Assets	468,068	436,061
LIABILITIES AND SHAREHOLDERS' EQUITY
Liabilities Current	20,042	19,631
Liabilities Noncurrent	26,920	27,361
Liabilities, Total	46,962	46,992
Perpetual Convertible Preferred Stock, Value, Issued	27,732	27,619
Stockholders Equity Abstract
Common Stock Value	407	397
Additional Paid In Capital Common Stock	605,603	611,754
Retained Earnings Accumulated Deficit	(212,636)	(250,701)
Accumulated Other Comprehensive Income Loss Net Of Tax	0	0
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	393,374	361,450	$ 329,021	$ 298,393
Liabilities And Stockholders Equity	$ 468,068	$ 436,061