Earnings Per Share - Basic and Diluted EPS (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Numerator:
Income from continuing operations	$ 17,527	$ 23,118	$ 33,076	$ 5,281
Income from continuing operations attributable to non-controlling interest	(269)	(191)	(848)	(695)
Numerator for basic and diluted earnings per share from continuing operations — income from continuing operations attributable to Headwaters Incorporated	17,258	22,927	32,228	4,586
Numerator for basic and diluted earnings per share from discontinued operations - income (loss) from discontinued operations, net of income taxes	258	(110)	(186)	(387)
Numerator for basic and diluted earnings per share — net income attributable to Headwaters Incorporated	$ 17,516	$ 22,817	$ 32,042	$ 4,199
Denominator:
Denominator for basic earnings per share - weighted-average shares outstanding	73,848	73,658	73,819	73,553
Effect of dilutive securities - shares issuable upon exercise of options and SARs and vesting of restricted stock	1,609	2,386	1,569	2,146
Denominator for diluted earnings per share - weighted-average shares outstanding after assumed exercises and vesting	75,457	76,044	75,388	75,699
Basic income per share attributable to Headwaters Incorporated:
From continuing operations (in dollars per share)	$ 0.23	$ 0.31	$ 0.43	$ 0.06
From discontinued operations (in dollars per share)	0.00	0.00	0.00	0.00
Basic income per share (in dollars per share)	0.23	0.31	0.43	0.06
Diluted income per share attributable to Headwaters Incorporated:
From continuing operations (in dollars per share)	0.23	0.30	0.43	0.06
From discontinued operations (in dollars per share)	0.00	0.00	0.00	0.00
Diluted income per share (in dollars per share)	$ 0.23	$ 0.30	$ 0.43	$ 0.06