CONDENSED CONSOLIDATED STATEMENTS OF EARNINGS - USD ($)	3 Months Ended		9 Months Ended
	Oct. 31, 2015	Oct. 31, 2014	Oct. 31, 2015	Oct. 31, 2014
Revenues	$ 113,967,000	$ 127,564,000	$ 296,888,000	$ 280,785,000
COST OF REVENUES
Cost of revenues	87,705,000	97,251,000	220,966,000	218,858,000
GROSS PROFIT	26,262,000	30,313,000	75,922,000	61,927,000
Selling, general and administrative expenses	5,590,000	5,473,000	15,977,000	13,332,000
INCOME FROM OPERATIONS	20,672,000	24,840,000	59,945,000	48,595,000
Other income, net	732,000	99,000	944,000	162,000
INCOME BEFORE INCOME TAXES	21,404,000	24,939,000	60,889,000	48,757,000
Income tax expense	7,045,000	8,180,000	19,845,000	15,177,000
NET INCOME	14,359,000	16,759,000	41,044,000	33,580,000
Net income attributable to noncontrolling interests (Note 3)	3,552,000	4,337,000	11,427,000	9,133,000
NET INCOME ATTRIBUTABLE TO THE STOCKHOLDERS OF ARGAN, INC.	$ 10,807,000	$ 12,422,000	$ 29,617,000	$ 24,447,000
EARNINGS PER SHARE ATTRIBUTABLE TO THE STOCKHOLDERS OF ARGAN, INC.
Basic (in Dollars per share)	$ 0.73	$ 0.86	$ 2.01	$ 1.70
Diluted (in Dollars per share)	$ 0.72	$ 0.84	$ 1.97	$ 1.66
WEIGHTED AVERAGE NUMBER OF SHARES OUTSTANDING
Basic (in shares)	14,810,000	14,470,000	14,732,000	14,390,000
Diluted (in shares)	15,066,000	14,795,000	15,004,000	14,761,000
CASH DIVIDENDS DECLARED (Note 12)	$ 0.70	$ 0.70	$ 0.70	$ 0.70
Power Industry Services [Member]
Revenues	$ 111,592,000	$ 125,660,000	$ 287,947,000	$ 275,902,000
COST OF REVENUES
Cost of revenues	86,103,000	95,863,000	214,618,000	215,174,000
GROSS PROFIT	25,489,000	29,797,000	73,329,000	60,728,000
Selling, general and administrative expenses	3,240,000	3,486,000	9,671,000	8,042,000
INCOME FROM OPERATIONS	22,249,000	26,311,000	63,658,000	52,686,000
Other income, net	304,000	98,000	683,000	160,000
INCOME BEFORE INCOME TAXES	22,553,000	26,409,000	64,341,000	52,846,000
Telecommunications Infrastructure Services [Member]
Revenues	2,375,000	1,904,000	8,941,000	4,883,000
COST OF REVENUES
Cost of revenues	1,602,000	1,388,000	6,348,000	3,684,000
GROSS PROFIT	773,000	516,000	2,593,000	1,199,000
Selling, general and administrative expenses	303,000	311,000	1,022,000	971,000
INCOME FROM OPERATIONS	470,000	205,000	1,571,000	228,000
INCOME BEFORE INCOME TAXES	$ 470,000	$ 205,000	$ 1,571,000	$ 228,000