Basis Of Presentation (Details)	3 Months Ended
Mar. 31, 2015
Basis Of Presentation [Abstract]
Minimum percentage of ownership considered for consolidation (in hundredths)	50.00%
Minimum percentage of ownership considered for equity method of accounting for investments (in hundredths)	20.00%
Maximum percentage of ownership considered for equity method of accounting for investments (in hundredths)	50.00%

Maximum percentage of ownership considered for equity method of accounting for investments.

No definition available.

Name:	ish_PercentageOfOwnershipConsideredForEquityMethodOfAccountingForInvestmentsMaximum
Namespace Prefix:	ish_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration