Note 6 - Investments in Joint Ventures (Tables)

9 Months Ended

May 31, 2013

Equity Method Investments and Joint Ventures Disclosure [Text Block]

Condensed Balance Sheet [Table Text Block]

	At May 31, 2013
	Total		EXCOR		China		All Other
Current assets	$	63,547,204	$	23,056,084	$	13,964,465	$	26,526,655
Total assets		69,688,319		25,425,172		13,993,902		30,269,245
Current liabilities		19,288,471		3,056,560		6,212,433		10,019,478
Noncurrent liabilities		3,358,593		—		869,532		2,489,061
Joint ventures’ equity		47,041,255		22,368,612		6,911,937		17,760,706
Northern Technologies International Corporation’s share of joint ventures’ equity		23,320,080		11,184,308		3,455,969		8,679,803
Northern Technologies International Corporation’s share of joint ventures’ undistributed earnings	$	20,877,265	$	11,153,403	$	3,405,969	$	6,327,893

	At August 31, 2012
	Total		EXCOR		NTI ASEAN		All Other
Current assets	$	61,973,725	$	24,357,139	$	15,358,967	$	22,257,619
Total assets		68,585,974		26,620,589		15,522,456		26,442,929
Current liabilities		18,686,181		4,749,574		5,763,857		8,172,750
Noncurrent liabilities		4,700,458		—		1,055,965		3,644,493
Joint ventures’ equity		45,199,335		21,871,015		8,702,634		14,625,686
Northern Technologies International Corporation’s share of joint ventures’ equity		21,461,492		10,935,509	$	3,685,404		6,840,579
Northern Technologies International Corporation’s share of joint ventures’ undistributed earnings	$	19,403,150	$	10,904,604	$	3,314,445	$	5,184,101

Condensed Income Statement [Table Text Block]

	Nine Months Ended May 31, 2013
	Total		EXCOR		China		All Other
Net sales	$	82,788,711	$	26,043,775	$	10,802,206	$	45,942,730
Gross profit		39,447,084		13,624,792		5,134,820		20,687,472
Net income		7,626,711		4,954,595		815,664		1,856,452
Northern Technologies International Corporation’s share of equity in income of joint ventures	$	3,733,069	$	2,478,109	$	407,809	$	847,151

	Nine Months Ended May 31, 2012
	Total		EXCOR		NTI ASEAN		All Other
Net sales	$	83,746,872	$	25,785,840	$	16,366,258	$	41,594,775
Gross profit		40,201,265		13,423,067		7,183,786		19,594,413
Net income		8,165,791		4,830,477		1,941,417		1,393,897
Northern Technologies International Corporation’s share of equity in income of joint ventures	$	4,405,327	$	2,396,596	$	1,076,230	$	932,501