Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Statement Of Income And Comprehensive Income [Abstract]
Net loss	$ (111,581)	$ (80,682)	$ (77,370)
Other comprehensive loss, net of tax :
Pension benefit plan, net of tax	(1,505)
Total comprehensive loss	$ (113,086)	$ (80,682)	$ (77,370)