CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($)	3 Months Ended		6 Months Ended
	Jul. 31, 2015	Jul. 31, 2014	Jul. 31, 2015	Jul. 31, 2014
Revenues	$ 97,434,000	$ 102,030,000	$ 182,921,000	$ 153,221,000
COST OF REVENUES
Cost of revenues	68,941,000	80,466,000	133,261,000	121,607,000
GROSS PROFIT	28,493,000	21,564,000	49,660,000	31,614,000
Selling, general and administrative expenses	4,848,000	4,481,000	10,387,000	7,859,000
INCOME FROM OPERATIONS	23,645,000	17,083,000	39,273,000	23,755,000
Other income, net	128,000	41,000	212,000	63,000
INCOME BEFORE INCOME TAXES	23,773,000	17,124,000	39,485,000	23,818,000
Income tax expense	7,939,000	5,104,000	12,800,000	6,997,000
NET INCOME	15,834,000	12,020,000	26,685,000	16,821,000
Net income attributable to noncontrolling interests	4,527,000	3,470,000	7,875,000	4,796,000
NET INCOME ATTRIBUTABLE TO THE STOCKHOLDERS OF ARGAN, INC.	$ 11,307,000	$ 8,550,000	$ 18,810,000	$ 12,025,000
EARNINGS PER SHARE ATTRIBUTABLE TO THE STOCKHOLDERS OF ARGAN, INC.
Basic	$ 0.77	$ 0.59	$ 1.28	$ 0.84
Diluted	$ 0.75	$ 0.58	$ 1.26	$ 0.82
WEIGHTED AVERAGE NUMBER OF SHARES OUTSTANDING
Basic	14,747,000	14,399,000	14,693,000	14,350,000
Diluted	15,003,000	14,655,000	14,952,000	14,641,000
Power Industry Services [Member]
Revenues	$ 93,471,000	$ 100,418,000	$ 176,355,000	$ 150,242,000
COST OF REVENUES
Cost of revenues	66,136,000	79,261,000	128,515,000	119,311,000
GROSS PROFIT	27,335,000	21,157,000	47,840,000	30,931,000
Selling, general and administrative expenses	2,849,000	2,769,000	6,432,000	4,556,000
INCOME FROM OPERATIONS	24,486,000	18,388,000	41,408,000	26,375,000
Other income, net	301,000	40,000	379,000	62,000
INCOME BEFORE INCOME TAXES	24,787,000	18,428,000	41,787,000	26,437,000
Telecommunications Infrastructure Services [Member]
Revenues	3,963,000	1,612,000	6,566,000	2,979,000
COST OF REVENUES
Cost of revenues	2,805,000	1,205,000	4,746,000	2,296,000
GROSS PROFIT	1,158,000	407,000	1,820,000	683,000
Selling, general and administrative expenses	415,000	309,000	718,000	660,000
INCOME FROM OPERATIONS	743,000	98,000	1,102,000	23,000
INCOME BEFORE INCOME TAXES	$ 743,000	$ 98,000	$ 1,102,000	$ 23,000