Note 11 Business Segment Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 29, 2014	Jun. 30, 2013	Jun. 29, 2014	Jun. 30, 2013	Dec. 31, 2013
Revenues	$ 15,199	$ 17,279	$ 30,484	$ 38,298
Segment contribution	(1,324)	(1,874)	(2,420)	(1,499)
Interest, financing and miscellaneous expense, net	5	(29)	(58)	(142)
Tax provision	(57)	(53)	(117)	(151)
Discontinued operations	0	(120)	(61)	144
Noncontrolling interest	16	3	10	9
Net (loss) income attributable to Ultralife	(1,360)	(2,073)	(2,646)	(1,639)
Total assets	86,931	91,135	86,931	91,135	90,194
Battery and Energy Products
Revenues	12,165	14,656	26,087	27,709
Segment contribution	2,876	3,490	6,677	6,590
Total assets	37,586	44,357	37,586	44,357
Communications Systems
Revenues	3,034	2,623	4,397	10,589
Segment contribution	1,336	1,032	1,870	4,311
Total assets	29,866	31,711	29,866	31,711
Discontinued Operations
Revenues	0	0	0	0
Segment contribution	0	0	0	0
Discontinued operations		(120)	(61)	144
Total assets	0	0	0	0
Corporate
Revenues	0	0	0	0
Segment contribution	(5,536)	(6,396)	(10,967)	(12,400)
Interest, financing and miscellaneous expense, net	5	(29)	(58)	(142)
Tax provision	(57)	(53)	(117)	(151)
Noncontrolling interest	16	3	10	9
Total assets	$ 19,479	$ 15,067	$ 19,479	$ 15,067