XML 61 R42.htm IDEA: XBRL DOCUMENT v3.8.0.1

Summary of Significant Accounting Policies - Goodwill and Intangible Assets (Details)		6 Months Ended	12 Months Ended
	Apr. 13, 2016 segment	Jul. 02, 2016 segment	Dec. 30, 2017 segment item
Goodwill
Number of reporting units | segment	2	2	1
Number of trailing quarters used to determine the control premium | item			4
Minimum
Intangible Assets
Estimated useful life (in years)			5 years
Maximum
Intangible Assets
Estimated useful life (in years)			10 years

X

- References

No definition available.

+ Details

Name:	crai_GoodwillAbstract
Namespace Prefix:	crai_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Number of trailing quarters used to determine the control premium utilizing data from publicly available premium studies.

+ References

No definition available.

+ Details

Name:	crai_NumberOfTrailingQuartersToDetermineControlPremium
Namespace Prefix:	crai_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Useful life of finite-lived intangible assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

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

X

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

X

- Definition

Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements.

+ References

No definition available.

+ Details

Name:	us-gaap_NumberOfReportableSegments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

X

- Details

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

X

- Details

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