DERIVATIVE INSTRUMENTS - Schedule of Derivatives (Details) - Cash Flow Hedges - Designated as Hedging Instrument - USD ($)	Sep. 30, 2021	Dec. 31, 2020
Derivative [Line Items]
Estimated Fair Value, Asset (Liability)	$ (54,814,000)	$ (93,769,000)
1-Month USD LIBOR
Derivative [Line Items]
Notional amount	1,775,000,000	1,875,000,000
1-Month USD LIBOR \| Interest Rate Swap Designated March 27, 2017
Derivative [Line Items]
Notional amount	$ 0	100,000,000
Fixed Interest Rate	1.971%
Estimated Fair Value, Asset (Liability)	$ 0	(929,000)
1-Month USD LIBOR \| Interest Rate Swap Designated December 13, 2017 Tranche 1
Derivative [Line Items]
Notional amount	$ 300,000,000	300,000,000
Fixed Interest Rate	2.201%
Estimated Fair Value, Asset (Liability)	$ (7,693,000)	(12,557,000)
1-Month USD LIBOR \| Interest Rate Swap Designated December 13, 2017 Tranche 3
Derivative [Line Items]
Notional amount	$ 150,000,000	150,000,000
Fixed Interest Rate	2.423%
Estimated Fair Value, Asset (Liability)	$ (7,859,000)	(11,502,000)
1-Month USD LIBOR \| Interest Rate Swap Designated December 13, 2017 Tranche 5
Derivative [Line Items]
Notional amount	$ 200,000,000	200,000,000
Fixed Interest Rate	2.313%
Estimated Fair Value, Asset (Liability)	$ (10,795,000)	(16,243,000)
1-Month USD LIBOR \| Interest Rate Swap Designated October 10, 2018 Tranche 1
Derivative [Line Items]
Notional amount	$ 75,000,000	75,000,000
Fixed Interest Rate	3.22%
Estimated Fair Value, Asset (Liability)	$ (6,964,000)	(9,836,000)
1-Month USD LIBOR \| Interest Rate Swap Designated October 10, 2018 Tranche 2
Derivative [Line Items]
Notional amount	$ 75,000,000	75,000,000
Fixed Interest Rate	3.199%
Estimated Fair Value, Asset (Liability)	$ (6,931,000)	(9,826,000)
1-Month USD LIBOR \| Interest Rate Swap Designated October 10, 2018 Tranche 3
Derivative [Line Items]
Notional amount	$ 75,000,000	75,000,000
Fixed Interest Rate	3.209%
Estimated Fair Value, Asset (Liability)	$ (6,906,000)	(9,783,000)
1-Month USD LIBOR \| Interest Rate Swap Designated December 18, 2018 Tranche 1
Derivative [Line Items]
Notional amount	$ 100,000,000	100,000,000
Fixed Interest Rate	2.885%
Estimated Fair Value, Asset (Liability)	$ (7,253,000)	(10,407,000)
1-Month USD LIBOR \| Interest Rate Swap Designated December 18, 2018 Tranche 2
Derivative [Line Items]
Notional amount	$ 100,000,000	100,000,000
Fixed Interest Rate	2.867%
Estimated Fair Value, Asset (Liability)	$ (7,211,000)	(10,431,000)
1-Month USD LIBOR \| Interest Rate Swap Designated December 15, 2020 Tranche 1
Derivative [Line Items]
Notional amount	$ 575,000,000	575,000,000
Fixed Interest Rate	1.415%
Estimated Fair Value, Asset (Liability)	$ 5,483,000	(1,907,000)
1-Month USD LIBOR \| Interest Rate Swap Designated December 15, 2020 Tranche 2
Derivative [Line Items]
Notional amount	$ 125,000,000	125,000,000
Fixed Interest Rate	1.404%
Estimated Fair Value, Asset (Liability)	$ 1,315,000	$ (348,000)

Fair value of the assets less the liabilities of a derivative or group of derivatives.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 10
-URI http://asc.fasb.org/extlink&oid=123594938&loc=d3e13433-108611

+ Details

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

- Definition

Fixed interest rate related to the interest rate derivative.

+ References

No definition available.

+ Details

Name:	us-gaap_DerivativeFixedInterestRate
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

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.

+ References

No definition available.

+ Details

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

- Definition

Nominal or face amount used to calculate payment on derivative.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1B
-URI http://asc.fasb.org/extlink&oid=125515794&loc=SL5580258-113959

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1A
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=125515794&loc=SL5579245-113959

+ Details

Name:	us-gaap_DerivativeNotionalAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis=us-gaap_CashFlowHedgingMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_HedgingDesignationAxis=us-gaap_DesignatedAsHedgingInstrumentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableRateAxis=iart_OneMonthUSDLIBORMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=iart_InterestRateSwapDesignatedMarch272017Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=iart_InterestRateSwapDesignatedDecember132017Tranche1Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=iart_InterestRateSwapDesignatedDecember132017Tranche3Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=iart_InterestRateSwapDesignatedDecember132017Tranche5Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=iart_InterestRateSwapDesignatedOctober102018Tranche1Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=iart_InterestRateSwapDesignatedOctober102018Tranche2Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=iart_InterestRateSwapDesignatedOctober102018Tranche3Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=iart_InterestRateSwapDesignatedDecember182018Tranche1Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=iart_InterestRateSwapDesignatedDecember182018Tranche2Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=iart_InterestRateSwapDesignatedDecember152020Tranche1Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=iart_InterestRateSwapDesignatedDecember152020Tranche2Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: