Name:	iii_ShareBasedCompensationArrangementByShareBasedPaymentAwardEligibleServicePeriodOfEmployeesInCalendarYear
Namespace Prefix:	iii_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Represents the eligible service period of employees per week required for participating in the equity-based compensation plan.

No definition available.

Name:	iii_ShareBasedCompensationArrangementByShareBasedPaymentAwardEligibleServicePeriodOfEmployeesPerWeek
Namespace Prefix:	iii_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- References

No definition available.

Name:	iii_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsAdditionalDisclosuresAbstract
Namespace Prefix:	iii_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- References

No definition available.

Name:	iii_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsAggregateIntrinsicValueAbstract
Namespace Prefix:	iii_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

The number of shares into which fully or partially vested non-option equity instrument outstanding as of the balance sheet date can be currently converted.

No definition available.

Name:	iii_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsExercisableNumber
Namespace Prefix:	iii_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of non-option equity instruments outstanding and currently exercisable.

No definition available.

Name:	iii_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsExercisableWeightedAverageExercisePrice
Namespace Prefix:	iii_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

Represents the intrinsic value of non-option equity instruments exercised during the period.

No definition available.

Name:	iii_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsExercisedIntrinsicValue
Namespace Prefix:	iii_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

The weighted average fair value at the grant date for non-option equity instruments, which were exercised during the period on other than stock (or unit) option plans.

No definition available.

Name:	iii_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsExercisesInPeriodWeightedAverageExercisePrice
Namespace Prefix:	iii_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

The weighted average fair value at the grant date for non-option equity instruments, which were forfeited during the period on other than stock (or unit) option plans.

No definition available.

Name:	iii_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsForfeituresInPeriodWeightedAverageExercisePrice
Namespace Prefix:	iii_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

Represents the intrinsic value of non-option equity instruments outstanding.

No definition available.

Name:	iii_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingIntrinsicValue
Namespace Prefix:	iii_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Represents the weighted-average grant date fair value of non-option equity instruments outstanding.

No definition available.

Name:	iii_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingWeightedAverageExercisePrice
Namespace Prefix:	iii_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

Amount of difference between the fair value of the underlying shares reserved for issuance and exercise prices of fully vested and expected to vest non-option equity instrument outstanding.

No definition available.

Name:	iii_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsVestedAndExpectedToVestOutstandingAggregateIntrinsicValue
Namespace Prefix:	iii_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

As of the balance sheet date, the number of shares into which fully vested and expected to vest non-option equity instrument can be converted.

No definition available.

Name:	iii_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsVestedAndExpectedToVestOutstandingNumber
Namespace Prefix:	iii_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

As of the balance sheet date, the weighted-average exercise price for outstanding non-option equity instruments that are fully vested or expected to vest.

No definition available.

Name:	iii_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsVestedAndExpectedToVestOutstandingWeightedAverageExercisePrice
Namespace Prefix:	iii_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

The total fair value of non-option equity instruments for which the grantee gained the right during the reporting period, by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash in accordance with the terms of the arrangement.

No definition available.

Name:	iii_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsVestedInPeriodTotalFairValue
Namespace Prefix:	iii_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- References

No definition available.

Name:	iii_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsWeightedAverageExercisePriceRollForward
Namespace Prefix:	iii_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Represents the number of anniversaries under the equity-based compensation plan.

No definition available.

Name:	iii_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAnniversaries
Namespace Prefix:	iii_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

Represents the number of shares available for purchase under the employee stock purchase plan.

No definition available.

Name:	iii_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForPurchase
Namespace Prefix:	iii_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

Represents the offering period under the equity-based compensation plan.

No definition available.

Name:	iii_ShareBasedCompensationArrangementByShareBasedPaymentAwardOfferingPeriod
Namespace Prefix:	iii_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Represents the percentage of employees' eligible earnings as payroll deduction to purchase common stock under the equity-based compensation plan.

No definition available.

Name:	iii_ShareBasedCompensationArrangementByShareBasedPaymentAwardPercentageOfEligibleEarningsAsPayrollDeductionToPurchaseCommonStock
Namespace Prefix:	iii_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Represents the percentage of relevant period which has elapsed for the awards that will vest on a pro rata basis.

No definition available.

Name:	iii_ShareBasedCompensationArrangementByShareBasedPaymentAwardPercentageOfRelevantPeriodElapsedForProrataVesting
Namespace Prefix:	iii_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Represents the period following the fourth anniversary of the grant date after which the award will expire under the equity-based compensation plan.

No definition available.

Name:	iii_ShareBasedCompensationArrangementByShareBasedPaymentAwardPeriodFollowingFourthAnniversaryFromGrantDateAfterWhichAwardWillExpire
Namespace Prefix:	iii_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Represents the period following the date of the participant's termination of employment due to reasons other than death, disability or retirement after which the award will expire under the equity-based compensation plan.

No definition available.

Name:	iii_ShareBasedCompensationArrangementByShareBasedPaymentAwardPeriodFollowingParticipantTerminationOfEmploymentDueToReasonsOtherThanDeathDisabilityOrRetirementAfterWhichAwardWillExpire
Namespace Prefix:	iii_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Represents the period following the date of the employee's termination of services as a result of death or permanent disability after which the award will expire under the equity-based compensation plan.

No definition available.

Name:	iii_ShareBasedCompensationArrangementByShareBasedPaymentAwardPeriodFollowingTerminationOfEmployeeServicesDueToDeathOrPermanentDisabilityAfterWhichAwardWillExpire
Namespace Prefix:	iii_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Represents the period of interval between the occurrence of purchases under the equity-based compensation plan.

No definition available.

Name:	iii_ShareBasedCompensationArrangementByShareBasedPaymentAwardPurchaseIntervalPeriod
Namespace Prefix:	iii_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Represents the regulated cap for payroll deduction of employees participating in the equity-based compensation plan.

No definition available.

Name:	iii_ShareBasedCompensationArrangementByShareBasedPaymentAwardRegulatedCapForPayrollDeductionToPurchaseCommonStock
Namespace Prefix:	iii_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Amount of difference between the fair value of the underlying shares reserved for issuance and exercise price of vested portions of non-option equity instruments outstanding and currently exercisable.

No definition available.

Name:	iii_SharebasedCompensationArrangementBySharebasedPaymentAwardNonOptionEquityInstrumentsExercisableIntrinsicValue
Namespace Prefix:	iii_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Weighted average remaining contractual term for vested portions of non-option equity instrument outstanding and currently exercisable or convertible, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

No definition available.

Name:	iii_SharebasedCompensationArrangementBySharebasedPaymentAwardNonOptionEquityInstrumentsExercisableWeightedAverageRemainingContractualTerm
Namespace Prefix:	iii_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Weighted average remaining contractual term for non-option equity instrument outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

No definition available.

Name:	iii_SharebasedCompensationArrangementBySharebasedPaymentAwardNonOptionEquityInstrumentsOutstandingWeightedAverageRemainingContractualTerm
Namespace Prefix:	iii_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Weighted average remaining contractual term for fully vested and expected to vest non-option equity instrument outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

No definition available.

Name:	iii_SharebasedCompensationArrangementBySharebasedPaymentAwardNonOptionEquityInstrumentsVestedAndExpectedToVestOutstandingWeightedAverageRemainingContractualTerm
Namespace Prefix:	iii_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 14.F)
-URI http://asc.fasb.org/extlink&oid=27013229&loc=d3e301413-122809

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5047-113901

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(1)(i)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

Name:	us-gaap_AllocatedShareBasedCompensationExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

Name:	us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Unrecognized cost of unvested share-based awards, other than options, awarded to employees as compensation.

Name:	us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

The number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period.

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

Weighted average fair value as of the grant date of equity-based award plans other than stock (unit) option plans that were not exercised or put into effect as a result of the occurrence of a terminating event.

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

No definition available.

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

The weighted average fair value of nonvested awards on equity-based plans excluding option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, revenue or profit achievement stock award plan) for which the employer is contingently obligated to issue equity instruments or transfer assets to an employee who has not yet satisfied service or performance criteria necessary to gain title to proceeds from the sale of the award or underlying shares or units.

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

No definition available.

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

The number of equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period.

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

Fair value of share-based awards for which the grantee gained the right by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash.

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

The weighted average fair value as of grant date pertaining to an equity-based award plan other than a stock (or unit) option plan for which the grantee gained the right during the reporting period, by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash in accordance with the terms of the arrangement.

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Number of non-option equity instruments exercised by participants.

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsExercised
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

Number of shares under non-option equity instrument agreements that were cancelled as a result of occurrence of a terminating event.

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsForfeitures
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

Number of equity instruments other than options outstanding, including both vested and non-vested instruments.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(i)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(ii)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingNumber
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

No definition available.

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingRollForward
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Number of additional shares authorized for issuance under an established share-based compensation plan.

No definition available.

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorized
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

The maximum number of shares (or other type of equity) originally approved (usually by shareholders and board of directors), net of any subsequent amendments and adjustments, for awards under the equity-based compensation plan. As stock or unit options and equity instruments other than options are awarded to participants, the shares or units remain authorized and become reserved for issuance under outstanding awards (not necessarily vested).

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

Percentage of vesting of share-based compensation awards.

Name:	us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Period from grant date that an equity-based award expires, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

Name:	us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Purchase price of common stock expressed as a percentage of its fair value.

No definition available.

Name:	us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardPurchasePriceOfCommonStockPercent
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Number of shares issued during the period as a result of an employee stock purchase plan.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=84159872&loc=d3e21463-112644

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(29))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(28))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

Name:	us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

Name:	us-gaap_EmployeeStockOwnershipPlanESOPDisclosuresByPlanAxis=iii_EmployeeStockPurchasePlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_PlanNameAxis=iii_EquityIncentivePlan2007Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_AwardTypeAxis=us-gaap_StockAppreciationRightsSARSMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_VestingAxis=iii_AwardsVestingOnFourAnniversariesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_AwardTypeAxis=us-gaap_RestrictedStockUnitsRSUMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_VestingAxis=iii_AwardsVestingOnEmploymentThroughTheFourthAnniversaryOfGrantMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_AwardTypeAxis=us-gaap_RestrictedStockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_VestingAxis=iii_AwardsVestingOnChangeInControlMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: