Condensed Consolidated Statements of Operations (USD $)	3 Months Ended		9 Months Ended
	Oct. 31, 2014	Oct. 31, 2013	Oct. 31, 2014	Oct. 31, 2013
Revenues	$ 127,564,000	$ 63,452,000	$ 280,785,000	$ 167,964,000
COST OF REVENUES
Cost of revenues	97,251,000	39,576,000	218,858,000	109,803,000
GROSS PROFIT	30,313,000	23,876,000	61,927,000	58,161,000
Selling, general and administrative expenses	5,473,000	3,545,000	13,332,000	8,589,000
INCOME FROM OPERATIONS	24,840,000	20,331,000	48,595,000	49,572,000
Gains on the deconsolidation of variable interest entities				2,444,000
Other income, net	99,000	261,000	162,000	827,000
INCOME BEFORE INCOME TAXES	24,939,000	20,592,000	48,757,000	52,843,000
Income tax expense	8,180,000	8,143,000	15,177,000	19,531,000
NET INCOME	16,759,000	12,449,000	33,580,000	33,312,000
NET INCOME ATTRIBUTABLE TO NONCONTROLLING INTERESTS	4,337,000	521,000	9,133,000	2,351,000
NET INCOME ATTRIBUTABLE TO THE STOCKHOLDERS OF ARGAN, INC.	12,422,000	11,928,000	24,447,000	30,961,000
EARNINGS PER SHARE ATTRIBUTABLE TO THE STOCKHOLDERS OF ARGAN, INC.
Basic	$ 0.86	$ 0.85	$ 1.70	$ 2.21
Diluted	$ 0.84	$ 0.83	$ 1.66	$ 2.16
WEIGHTED AVERAGE NUMBER OF SHARES OUTSTANDING
Basic	14,470,000	14,093,000	14,390,000	14,022,000
Diluted	14,795,000	14,365,000	14,761,000	14,302,000
CASH DIVIDEND DECLARED, PER COMMON SHARE (Note 3)	$ 0.70	$ 0.75	$ 0.70	$ 0.75
Power Industry Services [Member]
Revenues	125,660,000	61,103,000	275,902,000	160,392,000
COST OF REVENUES
Cost of revenues	95,863,000	38,012,000	215,174,000	104,062,000
Telecommunications Infrastructure Services [Member]
Revenues	1,904,000	2,349,000	4,883,000	7,572,000
COST OF REVENUES
Cost of revenues	$ 1,388,000	$ 1,564,000	$ 3,684,000	$ 5,741,000