Condensed Consolidating Financial Information (Details 3) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014	Mar. 31, 2013
Revenue:
Light building products	$ 94,139	$ 84,778	$ 187,151	$ 161,466
Heavy construction materials	59,093	54,014	130,614	122,172
Energy technology	3,280	2,196	4,362	6,923
Total revenue	156,512	140,988	322,127	290,561
Cost of revenue:
Light building products	70,828	64,126	140,166	120,627
Heavy construction materials	45,669	43,396	100,434	96,980
Energy technology	1,464	1,055	2,083	3,298
Total cost of revenue	117,961	108,577	242,683	220,905
Gross profit	38,551	32,411	79,444	69,656
Operating expenses:
Amortization	5,485	5,288	10,591	10,224
Selling, general and administrative	32,517	28,239	60,744	54,516
Total operating expenses	38,002	33,527	71,335	64,740
Operating income (loss)	549	(1,116)	8,109	4,916
Other income (expense):
Net interest expense	(12,234)	(11,139)	(22,290)	(21,611)
Other, net	(32)	202	(20)	238
Total other income (expense), net	(12,266)	(10,937)	(22,310)	(21,373)
Loss from continuing operations before income taxes	(11,717)	(12,053)	(14,201)	(16,457)
Income tax benefit (provision)	2,210	1,770	2,560	2,300
Loss from continuing operations	(9,507)	(10,283)	(11,641)	(14,157)
Income (loss) from discontinued operations, net of income taxes	(575)	2,023	125	25
Net loss	(10,082)	(8,260)	(11,516)	(14,132)
Net income attributable to non-controlling interest	(236)	0	(230)	0
Net loss attributable to Headwaters Incorporated	(10,318)	(8,260)	(11,746)	(14,132)
Eliminations
Other income (expense):
Equity in earnings of subsidiaries	(3,574)	(5,172)	(15,225)	(12,712)
Total other income (expense), net	(3,574)	(5,172)	(15,225)	(12,712)
Loss from continuing operations before income taxes	(3,574)	(5,172)	(15,225)	(12,712)
Loss from continuing operations	(3,574)	(5,172)	(15,225)	(12,712)
Net loss	(3,574)	(5,172)	(15,225)	(12,712)
Net loss attributable to Headwaters Incorporated	(3,574)		(15,225)
Guarantor Subsidiaries
Revenue:
Light building products	85,108	84,778	176,445	161,466
Heavy construction materials	59,093	54,014	130,614	122,172
Energy technology	3,280	2,196	4,362	6,923
Total revenue	147,481	140,988	311,421	290,561
Cost of revenue:
Light building products	64,458	64,126	132,327	120,627
Heavy construction materials	45,669	43,396	100,434	96,980
Energy technology	1,464	1,055	2,083	3,298
Total cost of revenue	111,591	108,577	234,844	220,905
Gross profit	35,890	32,411	76,577	69,656
Operating expenses:
Amortization	5,123	5,288	10,229	10,224
Selling, general and administrative	25,610	23,327	48,411	44,820
Total operating expenses	30,733	28,615	58,640	55,044
Operating income (loss)	5,157	3,796	17,937	14,612
Other income (expense):
Net interest expense	(146)	(44)	(167)	(58)
Other, net	29	167	74	203
Total other income (expense), net	(117)	123	(93)	145
Loss from continuing operations before income taxes	5,040	3,919	17,844	14,757
Income tax benefit (provision)	(1,571)	(770)	(3,350)	(2,070)
Loss from continuing operations	3,469	3,149	14,494	12,687
Income (loss) from discontinued operations, net of income taxes	(575)	2,023	125	25
Net loss	2,894	5,172	14,619	12,712
Net loss attributable to Headwaters Incorporated	2,894		14,619
Non-Guarantor Subsidiaries
Revenue:
Light building products	9,031		10,706
Total revenue	9,031		10,706
Cost of revenue:
Light building products	6,370		7,839
Total cost of revenue	6,370		7,839
Gross profit	2,661		2,867
Operating expenses:
Amortization	362		362
Selling, general and administrative	1,142		1,395
Total operating expenses	1,504		1,757
Operating income (loss)	1,157		1,110
Other income (expense):
Other, net	(61)		(94)
Total other income (expense), net	(61)		(94)
Loss from continuing operations before income taxes	1,096		1,016
Income tax benefit (provision)	(180)		(180)
Loss from continuing operations	916		836
Net loss	916		836
Net income attributable to non-controlling interest	(236)		(230)
Net loss attributable to Headwaters Incorporated	680		606
Parent Company
Operating expenses:
Selling, general and administrative	5,765	4,912	10,938	9,696
Total operating expenses	5,765	4,912	10,938	9,696
Operating income (loss)	(5,765)	(4,912)	(10,938)	(9,696)
Other income (expense):
Net interest expense	(12,088)	(11,095)	(22,123)	(21,553)
Equity in earnings of subsidiaries	3,574	5,172	15,225	12,712
Other, net		35		35
Total other income (expense), net	(8,514)	(5,888)	(6,898)	(8,806)
Loss from continuing operations before income taxes	(14,279)	(10,800)	(17,836)	(18,502)
Income tax benefit (provision)	3,961	2,540	6,090	4,370
Loss from continuing operations	(10,318)	(8,260)	(11,746)	(14,132)
Net loss	(10,318)	(8,260)	(11,746)	(14,132)
Net loss attributable to Headwaters Incorporated	$ (10,318)		$ (11,746)