Consolidated Statements of Comprehensive (Loss) Income - USD ($) $ in Thousands	12 Months Ended
	Aug. 31, 2016	Aug. 31, 2015	Aug. 31, 2014
Statement of Comprehensive Income [Abstract]
Net (loss) income	$ (6,362)	$ 82,051	$ 71,113
Other comprehensive loss, net of taxes:
Unrecognized post-retirement loss, net of taxes of $(12,150), $(4,787) and $(1,384) for the years ended August 31, 2016, 2015 and 2014, respectively	(19,679)	(7,488)	(2,106)
Other comprehensive loss	(19,679)	(7,488)	(2,106)
Total comprehensive (loss) income	$ (26,041)	$ 74,563	$ 69,007