Condensed Consolidated Statements of Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Statement Of Income And Comprehensive Income [Abstract]
NET LOSS	$ (26,801)	$ (81,468)	$ (140,499)	$ (157,541)
Other comprehensive income (loss):
Pension obligation adjustment, net of tax		427		409
TOTAL COMPREHENSIVE LOSS	$ (26,801)	$ (81,041)	$ (140,499)	$ (157,132)