CONDENSED CONSOLIDATED STATEMENTS OF EARNINGS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 31, 2016	Jul. 31, 2015	Jul. 31, 2016	Jul. 31, 2015
REVENUES
Revenues	$ 162,495	$ 97,434	$ 292,843	$ 182,921
COST OF REVENUES
Cost of revenues	118,483	68,941	220,529	133,261
GROSS PROFIT	44,012	28,493	72,314	49,660
Impairment loss	1,979		1,979
Selling, general and administrative expenses	7,534	4,848	14,581	10,387
INCOME FROM OPERATIONS	34,499	23,645	55,754	39,273
Other income, net	556	128	593	212
INCOME BEFORE INCOME TAXES	35,055	23,773	56,347	39,485
Income tax expense	11,756	7,939	18,928	12,800
NET INCOME	23,299	15,834	37,419	26,685
Net income attributable to noncontrolling interests	3,625	4,527	5,515	7,875
NET INCOME ATTRIBUTABLE TO THE STOCKHOLDERS OF ARGAN, INC.	19,674	11,307	31,904	18,810
OTHER COMPREHENSIVE (LOSS) INCOME, NET OF TAX
Foreign currency translation adjustments, net of income tax	(511)	(6)	134	(6)
COMPREHENSIVE INCOME ATTRIBUTABLE TO THE STOCKHOLDERS OF ARGAN, INC.	$ 19,163	$ 11,301	$ 32,038	$ 18,804
EARNINGS PER SHARE ATTRIBUTABLE TO THE STOCKHOLDERS OF ARGAN, INC.
Basic (in Dollars per share)	$ 1.32	$ 0.77	$ 2.14	$ 1.28
Diluted (in Dollars per share)	$ 1.29	$ 0.75	$ 2.09	$ 1.26
WEIGHTED AVERAGE NUMBER OF SHARES OUTSTANDING
Basic (in shares)	14,939	14,747	14,899	14,693
Diluted (in shares)	15,278	15,003	15,231	14,952
Power Industry Services
REVENUES
Revenues	$ 143,422	$ 93,471	$ 251,521	$ 176,355
COST OF REVENUES
Cost of revenues	100,035	66,136	183,733	128,515
GROSS PROFIT	43,387	27,335	67,788	47,840
Impairment loss	1,979		1,979
Selling, general and administrative expenses	4,065	2,849	7,298	6,432
INCOME FROM OPERATIONS	37,343	24,486	58,511	41,408
Other income, net	525	301	538	379
INCOME BEFORE INCOME TAXES	37,868	24,787	59,049	41,787
Industrial Fabrication And Field Services
REVENUES
Revenues	17,327		37,737
COST OF REVENUES
Cost of revenues	17,117		34,105
GROSS PROFIT	210		3,632
Selling, general and administrative expenses	1,487		3,121
INCOME FROM OPERATIONS	(1,277)		511
INCOME BEFORE INCOME TAXES	(1,277)		511
Telecommunications Infrastructure Services
REVENUES
Revenues	1,746	3,963	3,585	6,566
COST OF REVENUES
Cost of revenues	1,331	2,805	2,691	4,746
GROSS PROFIT	415	1,158	894	1,820
Selling, general and administrative expenses	301	415	628	718
INCOME FROM OPERATIONS	114	743	266	1,102
INCOME BEFORE INCOME TAXES	$ 114	$ 743	$ 266	$ 1,102