Condensed Consolidated Statements of Operations (Unaudited) (USD $)	3 Months Ended		9 Months Ended
	Oct. 31, 2012	Oct. 31, 2011	Oct. 31, 2012	Oct. 31, 2011
Net revenues
Net revenues	$ 74,486,000	$ 43,597,000	$ 220,794,000	$ 85,932,000
Cost of revenues
Cost of revenues	61,350,000	37,130,000	184,678,000	70,920,000
Gross profit	13,136,000	6,467,000	36,116,000	15,012,000
Selling, general and administrative expenses	3,780,000	2,735,000	10,105,000	7,868,000
Income from operations	9,356,000	3,732,000	26,011,000	7,144,000
Other (expense) income, net	(11,000)	33,000	(29,000)	84,000
Income from continuing operations before income taxes	9,345,000	3,765,000	25,982,000	7,228,000
Income tax expense	3,632,000	1,460,000	9,741,000	2,658,000
Income from continuing operations	5,713,000	2,305,000	16,241,000	4,570,000
Discontinued operations
Income (loss) on discontinued operations (including gains on disposal of $58,000 and $1,286,000 for the three and nine months ended October 31, 2011, respectively)		(365,000)	(405,000)	444,000
Income tax benefit (expense)		72,000	120,000	(326,000)
Income (loss) on discontinued operations		(293,000)	(285,000)	118,000
Net income	5,713,000	2,012,000	15,956,000	4,688,000
Add - Loss attributable to noncontrolling interest	352,000		748,000
Net income attributable to the stockholders of Argan	6,065,000	2,012,000	16,704,000	4,688,000
Continuing operations (Note 13)
Basic	$ 0.44	$ 0.17	$ 1.24	$ 0.34
Diluted	$ 0.43	$ 0.17	$ 1.21	$ 0.33
Discontinued operations
Basic		$ (0.02)	$ (0.02)	$ 0.01
Diluted		$ (0.02)	$ (0.02)	$ 0.01
Net income
Basic	$ 0.44	$ 0.15	$ 1.22	$ 0.34
Diluted	$ 0.43	$ 0.15	$ 1.19	$ 0.34
Weighted average number of shares outstanding:
Basic	13,822,000	13,609,000	13,728,000	13,605,000
Diluted	14,106,000	13,744,000	14,075,000	13,715,000
Cash dividend declared per common share	$ 0.60	$ 0.50	$ 0.60	$ 0.50
Telecommunications Infrastructure Services [Member]
Net revenues
Net revenues	3,959,000	2,328,000	14,430,000	6,254,000
Cost of revenues
Cost of revenues	3,177,000	1,882,000	11,339,000	5,113,000
Power Industry Services [Member]
Net revenues
Net revenues	70,527,000	41,269,000	206,364,000	79,678,000
Cost of revenues
Cost of revenues	$ 58,173,000	$ 35,248,000	$ 173,339,000	$ 65,807,000