Restructuring Reserve Utilizations

No definition available.

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Namespace Prefix:	iclr_
Data Type:	xbrli:monetaryItemType
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- Definition

Amount of expenses associated with exit or disposal activities pursuant to an authorized plan. Excludes expenses related to a discontinued operation or an asset retirement obligation.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section 45
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=109237686&loc=d3e17752-110868

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 5.P.3)
-URI http://asc.fasb.org/extlink&oid=115931487&loc=d3e140864-122747

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3602-108585

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SAB Topic 5.P.4(b)(1))
-URI http://asc.fasb.org/extlink&oid=115931487&loc=d3e140904-122747

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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- Definition

Carrying amount (including both current and noncurrent portions of the accrual) as of the balance sheet date pertaining to a specified type of cost associated with exit from or disposal of business activities or restructuring pursuant to a duly authorized plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)(2)
-URI http://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SAB TOPIC 5.P.4(b)(2))
-URI http://asc.fasb.org/extlink&oid=115931487&loc=d3e140904-122747

+ Details

Name:	us-gaap_RestructuringReserve
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

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

+ References

No definition available.

+ Details

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

- Definition

Amount of foreign currency translation gain (loss) which decreases (increases) the restructuring reserve.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)(2)
-URI http://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SAB Topic 5.P.4(b)(2))
-URI http://asc.fasb.org/extlink&oid=115931487&loc=d3e140904-122747

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

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- Details

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- Details

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- Details

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Restructuring - Rollforward Activity (Details) - USD ($)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Restructuring Reserve [Roll Forward]
Restructuring Charges	$ 0	$ 18,089,000	$ 0	$ 18,089,000
Resource rationalization, 2020
Restructuring Reserve [Roll Forward]
Restructuring Charges	0		0		$ 18,089,000
Utilization			(3,644,000)		(8,296,000)
Foreign exchange movement			4,000		325,000
Provision balance	6,478,000		6,478,000		10,118,000
Resource rationalization, 2020 \| Workforce reductions
Restructuring Reserve [Roll Forward]
Restructuring Charges					11,391,000
Utilization			(2,299,000)		(6,987,000)
Foreign exchange movement			0		0
Provision balance	2,105,000		2,105,000		4,404,000
Resource rationalization, 2020 \| Onerous Lease
Restructuring Reserve [Roll Forward]
Restructuring Charges					6,698,000
Utilization			(1,345,000)		(1,309,000)
Foreign exchange movement			4,000		325,000
Provision balance	4,373,000		4,373,000		5,714,000
Resource rationalizations 2018
Restructuring Reserve [Roll Forward]
Restructuring Charges			0				$ 12,490,000
Utilization			(97,000)		(1,007,000)	$ (4,782,000)	(6,071,000)
Provision balance	533,000		533,000		630,000	1,637,000	6,419,000
Resource rationalizations 2018 \| Workforce reductions
Restructuring Reserve [Roll Forward]
Restructuring Charges							9,684,000
Utilization			0		(731,000)	(3,554,000)	(5,399,000)
Provision balance	0		0		0	731,000	4,285,000
Resource rationalizations 2018 \| Onerous Lease
Restructuring Reserve [Roll Forward]
Restructuring Charges							2,806,000
Utilization			(97,000)		(276,000)	(1,228,000)	(672,000)
Provision balance	$ 533,000		$ 533,000		$ 630,000	$ 906,000	$ 2,134,000