CONSOLIDATED INTERIM STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2016	Sep. 30, 2015	Dec. 31, 2015
Statement Of Income And Comprehensive Income [Abstract]
Net loss	$ (35,437)	$ (23,273)	$ (111,581)
Other comprehensive loss, net of tax :
Pension benefit plan	(470)		(1,505)
Total comprehensive loss	$ (35,907)	$ (23,273)	$ (113,086)