Condensed Consolidated Statement of Changes in Stockholder's Equity (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2015	Dec. 31, 2014
Series D-1 Preferred Stock for Cash [Member]
Stock Transactions, Parenthetical Disclosures [Abstract]
Offering expenses	$ 85	$ 37
Series D-2 Preferred Stock for Cash [Member]
Stock Transactions, Parenthetical Disclosures [Abstract]
Offering expenses	$ 16

Direct Professional Expenses Associated With Preferred Stock Offering.

No definition available.

Name:	isgn_DirectProfessionalExpensesAssociatedWithPreferredStockOffering
Namespace Prefix:	isgn_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration