Note 11 Business Segment Information (Detail) (USD $)	3 Months Ended		9 Months Ended
	Sep. 28, 2014	Sep. 29, 2013	Sep. 28, 2014	Sep. 29, 2013	Dec. 31, 2013
Revenues	$ 16,062,000	$ 20,361,000	$ 46,546,000	$ 58,659,000
Segment contribution	(55,000)	652,000	(2,475,000)	(847,000)
Interest, financing and miscellaneous expense, net	(211,000)	(61,000)	(269,000)	(203,000)
Tax provision	(60,000)	16,000	(177,000)	(135,000)
Discontinued operations	0	15,000	(61,000)	159,000
Noncontrolling interest	3,000	22,000	13,000	31,000
Net (loss) income attributable to Ultralife	(323,000)	644,000	(2,969,000)	(995,000)
Total assets	87,540,000	88,675,000	87,540,000	88,675,000	90,194,000
Battery and Energy Products
Revenues	13,913,000	13,507,000	40,000,000	41,216,000
Segment contribution	3,812,000	3,601,000	10,489,000	10,191,000
Total assets	39,568,000	42,679,000	39,568,000	42,679,000
Communications Systems
Revenues	2,149,000	6,854,000	6,546,000	17,443,000
Segment contribution	674,000	2,526,000	2,544,000	6,837,000
Total assets	29,649,000	32,268,000	29,649,000	32,268,000
Discontinued Operations
Revenues	0	0
Segment contribution	0	0
Discontinued operations	0	15,000	(61,000)	159,000
Total assets	0	0	0	0
Corporate
Revenues	0	0	0	0
Segment contribution	(4,541,000)	(5,475,000)	(15,508,000)	(17,875,000)
Interest, financing and miscellaneous expense, net	(211,000)	(61,000)	(269,000)	(203,000)
Tax provision	(60,000)	16,000	(177,000)	(135,000)
Noncontrolling interest	3,000	22,000	13,000	31,000
Total assets	$ 18,323,000	$ 13,728,000	$ 18,323,000	$ 13,728,000