Consolidated Statements of Shareholders' Equity (USD $)	Common Stock [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Loss [Member]	Total NTS Shareholders' Equity [Member]	Noncontrolling Interests [Member]	Total
Balances at Jan. 31, 2011	$ 20,754,000	$ 34,361,000	$ (147,000)	$ 54,968,000	$ 715,000	$ 55,683,000
Balances (in shares) at Jan. 31, 2011	10,243,000
Net income	0	491,000	0	491,000	866,000	1,357,000
Foreign currency translation	0	0	(41,000)	(41,000)	0	(41,000)
Stock retired for option exercise	(26,000)	0	0	(26,000)	0	(26,000)
Stock retired for option exercise (in shares)	(4,000)					4,000
Stock options exercised	222,000	0	0	222,000	0	222,000
Stock options exercised (in shares)	86,000					(86,000)
Stock issued to Mill Road	5,503,000	0	0	5,503,000	0	5,503,000
Stock issued to Mill Road (in shares)	933,000					933,000
Vesting of restricted stock	0	0	0	0	0	0
Vesting of restricted stock (in shares)	48,000
Issuance of restricted stock	269,000	0	0	269,000	0	269,000
Tax benefit from stock options exercise	77,000	0	0	77,000	0	77,000
Dividends paid to noncontrolling interests	0	0	0	0	(200,000)	(200,000)
Warrants issued to Mill Road	1,855,000	0	0	1,855,000	0	1,855,000
Balances at Jan. 31, 2012	28,654,000	34,852,000	(188,000)	63,318,000	1,381,000	64,699,000
Balances (in shares) at Jan. 31, 2012	11,306,000					11,306,000
Net income	0	4,444,000	0	4,444,000	976,000	5,420,000
Foreign currency translation	0	0	46,000	46,000	0	46,000
Stock options exercised	418,000	0	0	418,000	0	418,000
Stock options exercised (in shares)	118,000					(118,000)
Vesting of restricted stock	0	0	0	0	0	0
Vesting of restricted stock (in shares)	51,000
Issuance of restricted stock	237,000	0	0	237,000	0	237,000
Tax benefit from stock options exercise	76,000	0	0	76,000	0	76,000
Dividends paid to noncontrolling interests	0	0	0	0	(2,444,000)	(2,444,000)
Allocation of gain on Unitek sale	(332,000)	0	0	(332,000)	332,000	0
Balances at Jan. 31, 2013	$ 29,053,000	$ 39,296,000	$ (142,000)	$ 68,207,000	$ 245,000	$ 68,452,000
Balances (in shares) at Jan. 31, 2013	11,475,000					11,475,000