Statements of Operations (Unaudited) (USD $)	3 Months Ended		9 Months Ended
	Sep. 28, 2014	Sep. 29, 2013	Sep. 28, 2014	Sep. 29, 2013
Income Statement [Abstract]
Revenues	$ 16,062,000	$ 20,361,000	$ 46,546,000	$ 58,659,000
Cost of products sold	11,576,000	14,234,000	33,513,000	41,631,000
Gross profit	4,486,000	6,127,000	13,033,000	17,028,000
Operating expenses:
Research and development	1,014,000	1,418,000	4,010,000	4,456,000
Selling, general and administrative	3,527,000	4,057,000	11,498,000	13,419,000
Total operating expenses	4,541,000	5,475,000	15,508,000	17,875,000
Operating (loss) income	(55,000)	652,000	(2,475,000)	(847,000)
Other (expense) income:
Interest income	3,000	13,000	12,000	27,000
Interest and financing expense	(56,000)	(66,000)	(153,000)	(199,000)
Miscellaneous	(158,000)	(8,000)	(128,000)	(31,000)
(Loss) income from continuing operations before income taxes	(266,000)	591,000	(2,744,000)	(1,050,000)
Income tax provision (benefit)	60,000	(16,000)	177,000	135,000
Net (loss) income from continuing operations	(326,000)	607,000	(2,921,000)	(1,185,000)
Income (loss) from discontinued operations, net of tax	0	15,000	(61,000)	159,000
Net (loss) income	(326,000)	622,000	(2,982,000)	(1,026,000)
Net loss attributable to 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)
Other comprehensive income:
Foreign currency translation adjustments	29,000	32,000	164,000	53,000
Comprehensive loss attributable to Ultralife	$ (294,000)	$ 676,000	$ (2,805,000)	$ (942,000)
Net (loss) income per share attributable to Ultralife common shareholders - Basic:
Continuing operations (in dollars per share)	$ (0.02)		$ (0.17)	$ (0.07)
Discontinued operations (in dollars per share)	$ 0		$ 0	$ 0.01
Total (in dollars per share)	$ (0.02)		$ (0.17)	$ 0.06
Weighted average shares outstanding - basic	17,490	17,467	17,510	17,461
Net income per share attributable to Ultralife common shareholders - Diluted
Continuing operations (in dollars per share)		$ 0.04
Discontinued operations (in dollars per share)		$ 0
Total (in dollars per share)		$ 0.04