STATEMENTS OF OPERATIONS - USD ($)	3 Months Ended	12 Months Ended
Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019
Total net sales	$ 5,054,000	$ 4,435,000	$ 3,347,000	$ 4,646,000	$ 6,175,000	$ 4,549,000	$ 5,727,000	$ 5,077,000	$ 17,482,000	$ 21,528,000
Cost of goods sold	41,000	112,000	208,000	172,000	498,000	214,000	333,000	392,000	14,467,000	17,193,000
Impairment loss									159,000	0
Total cost of sales	4,022,000	3,876,000	3,015,000	3,713,000	4,722,000	3,728,000	4,377,000	4,366,000	14,626,000	17,193,000
Gross profit	1,032,000	559,000	332,000	933,000	1,453,000	821,000	1,350,000	711,000	2,856,000	4,335,000
Operating Expenses:
Selling	645,000	585,000	927,000	720,000	654,000	573,000	693,000	738,000	2,877,000	2,658,000
Marketing	215,000	192,000	243,000	365,000	585,000	559,000	585,000	665,000	1,015,000	2,394,000
General and administrative	1,162,000	840,000	992,000	1,004,000	897,000	878,000	884,000	716,000	3,998,000	3,375,000
Gain on sale of custom print business	0	(195,000)	0	0	0	0	0	0	(195,000)	0
Impairment loss									0	2,014,000
Total operating expenses	2,022,000	1,422,000	2,162,000	2,089,000	4,150,000	2,010,000	2,162,000	2,119,000	7,695,000	10,441,000
Operating loss	(990,000)	(863,000)	(1,830,000)	(1,156,000)	(2,697,000)	(1,189,000)	(812,000)	(1,408,000)	(4,839,000)	(6,106,000)
Other income	41,000	(15,000)	(2,000)	9,000	15,000	36,000	22,000	32,000	33,000	105,000
Loss before taxes	(949,000)	(878,000)	(1,832,000)	(1,147,000)	(2,682,000)	(1,153,000)	(790,000)	(1,376,000)	(4,806,000)	(6,001,000)
Income tax benefit	12,000	8,000	11,000	(222,000)	(77,000)	(56,000)	(131,000)	(160,000)	(191,000)	(424,000)
Net loss	$ (961,000)	$ (886,000)	$ (1,843,000)	$ (925,000)	$ (2,605,000)	$ (1,097,000)	$ (659,000)	$ (1,216,000)	$ (4,615,000)	$ (5,577,000)
Net loss per share:
Basic	$ (.55)	$ (.51)	$ (1.07)	$ (.53)	$ (1.52)	$ (.64)	$ (.39)	$ (.72)	$ (2.66)	$ (3.27)
Diluted	$ (0.55)	$ (.51)	$ (1.07)	$ (.53)	$ (1.52)	$ (.64)	$ (.39)	$ (.72)	$ (2.66)	$ (3.27)
Shares used in calculation of net loss per share:
Basic	1,745,000	1,740,000	1,725,000	1,724,000	1,720,000	1,712,000	1,698,000	1,694,000	1,734,000	1,706,000
Diluted	1,745,000	1,740,000	1,725,000	1,724,000	1,720,000	1,712,000	1,698,000	1,694,000	1,734,000	1,706,000
Services
Total net sales	$ 5,054,000	$ 4,317,000	$ 3,133,000	$ 4,400,000	$ 5,612,000	$ 4,295,000	$ 5,320,000	$ 4,576,000	$ 16,904,000	$ 19,803,000
Cost of goods sold									13,934,000	15,756,000
Impairment loss									159,000	0
Products
Total net sales	$ 0	$ 118,000	$ 214,000	$ 246,000	$ 563,000	$ 254,000	$ 407,000	$ 501,000	578,000	1,725,000
Cost of goods sold									$ 533,000	$ 1,437,000

No definition available.

Name:	isig_AssetImpairmentChargesOther
Namespace Prefix:	isig_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The aggregate costs related to goods produced and sold and services rendered by an entity during the reporting period. This excludes costs incurred during the reporting period related to financial services rendered and other revenue generating activities.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 924
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 11.L)
-URI http://asc.fasb.org/extlink&oid=6472922&loc=d3e499488-122856

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.2(a),(d))
-URI http://asc.fasb.org/extlink&oid=120395209&loc=SL114868664-224227