Condensed Consolidated Statements of Operations (Unaudited) (USD $)	3 Months Ended		9 Months Ended
	Oct. 31, 2013	Oct. 31, 2012	Oct. 31, 2013	Oct. 31, 2012
Net revenues
Net revenues	$ 63,452,000	$ 74,486,000	$ 167,964,000	$ 220,794,000
Cost of revenues
Cost of revenues	39,576,000	61,350,000	109,803,000	184,678,000
Gross profit	23,876,000	13,136,000	58,161,000	36,116,000
Selling, general and administrative expenses	3,545,000	3,780,000	8,589,000	10,105,000
Income from operations	20,331,000	9,356,000	49,572,000	26,011,000
Gains on the deconsolidation of variable interest entities			2,444,000
Other income (expense), net	261,000	(11,000)	827,000	(29,000)
Income from continuing operations before income taxes	20,592,000	9,345,000	52,843,000	25,982,000
Income tax expense	8,143,000	3,632,000	19,531,000	9,741,000
Income from continuing operations	12,449,000	5,713,000	33,312,000	16,241,000
Discontinued operations (Note 16)
Loss on discontinued operations before income taxes				(405,000)
Income tax benefit				120,000
Loss on discontinued operations				(285,000)
Net income	12,449,000	5,713,000	33,312,000	15,956,000
Income (loss) attributable to noncontrolling interests	521,000	(352,000)	2,351,000	(748,000)
Net income attributable to the stockholders of Argan	11,928,000	6,065,000	30,961,000	16,704,000
Continuing operations (Note 12)
Basic	$ 0.85	$ 0.44	$ 2.21	$ 1.24
Diluted	$ 0.83	$ 0.43	$ 2.16	$ 1.21
Discontinued operations
Basic				$ (0.02)
Diluted				$ (0.02)
Net income
Basic	$ 0.85	$ 0.44	$ 2.21	$ 1.22
Diluted	$ 0.83	$ 0.43	$ 2.16	$ 1.19
Weighted average number of shares outstanding:
Basic	14,093,000	13,822,000	14,022,000	13,728,000
Diluted	14,365,000	14,106,000	14,302,000	14,075,000
Cash dividend declared per common share (Note 3)	$ 0.75	$ 0.60	$ 0.75	$ 0.60
Power Industry Services [Member]
Net revenues
Net revenues	61,103,000	70,527,000	160,392,000	206,364,000
Cost of revenues
Cost of revenues	38,012,000	58,173,000	104,062,000	173,339,000
Telecommunications Infrastructure Services [Member]
Net revenues
Net revenues	2,349,000	3,959,000	7,572,000	14,430,000
Cost of revenues
Cost of revenues	$ 1,564,000	$ 3,177,000	$ 5,741,000	$ 11,339,000