Summary of Significant Accounting Policies (Policies)	3 Months Ended
Mar. 29, 2025
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The unaudited condensed consolidated financial statements include the accounts of CRA which require consolidation, after the elimination of intercompany accounts and transactions. These financial statements have been prepared in accordance with the rules and regulations of the U.S. Securities and Exchange Commission (“SEC”) for Quarterly Reports on Form 10-Q. Accordingly, these financial statements do not include all the information and note disclosures required by accounting principles generally accepted in the United States of America (“U.S. GAAP”) for annual financial statements. In the opinion of management, these financial statements reflect all adjustments of a normal, recurring nature necessary for the fair presentation of CRA’s results of operations, financial position, cash flows, and shareholders’ equity for the interim periods presented in conformity with U.S. GAAP. Results of operations for the interim periods presented herein are not necessarily indicative of results of operations for a full year. These financial statements should be read in conjunction with the consolidated financial statements and notes thereto for the fiscal year ended December 28, 2024 included in CRA’s Annual Report on Form 10-K filed with the SEC on February 20, 2025.
Recent Accounting Standards Not Yet Adopted	Recent Accounting Standards Not Yet Adopted Income Taxes (Topic 740): Improvements to Income Tax Disclosures In December 2023, the FASB issued ASU No. 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures ("ASU 2023-09"). The ASU expands annual disclosures in an entity’s income tax rate reconciliation table and requires annual disclosures regarding cash taxes paid both in the U.S. (federal, state and local) and foreign jurisdictions. ASU 2023-09 also requires income (or loss) from continuing operations before income tax expense (or benefit) disaggregated between domestic and foreign and income tax expense (or benefit) from continuing operations disaggregated by federal (national), state, and foreign. ASU 2023-09 is effective for CRA for annual periods beginning after December 15, 2024. CRA plans to adopt the amendment during the annual reporting for fiscal year 2025. CRA has begun to assess the impact of the amendment and has modeled out the changes to its income tax disclosures. As the amendment relates solely to disclosures, the adoption is not expected to have an effect on CRA's financial results. Income Statement—Reporting Comprehensive Income—Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses In November 2024, the FASB issued ASU No. 2024-03, Income Statement - Reporting Comprehensive Income - Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses ("ASU 2024-03"). The ASU requires disclosure, in the notes to the financial statements, specified information about certain costs and expenses including employee compensation, depreciation, and intangible asset amortization. ASU 2024-03, further clarified in ASU 2025-01, Income Statement—Reporting Comprehensive Income—Expense Disaggregation Disclosures (Subtopic 220-40): Clarifying the Effective Date is effective for CRA for annual reporting periods beginning after December 15, 2026, and interim reporting periods beginning after December 15, 2027. CRA is in the process of evaluating the impact of adopting ASU 2024-03.

Summary of Significant Accounting Policies (Policies)

3 Months Ended

Mar. 29, 2025

The unaudited condensed consolidated financial statements include the accounts of CRA which require consolidation, after the elimination of intercompany accounts and transactions. These financial statements have been prepared in accordance with the rules and regulations of the U.S. Securities and Exchange Commission (“SEC”) for Quarterly Reports on Form 10-Q. Accordingly, these financial statements do not include all the information and note disclosures required by accounting principles generally accepted in the United States of America (“U.S. GAAP”) for annual financial statements. In the opinion of management, these financial statements reflect all adjustments of a normal, recurring nature necessary for the fair presentation of CRA’s results of operations, financial position, cash flows, and shareholders’ equity for the interim periods presented in conformity with U.S. GAAP. Results of operations for the interim periods presented herein are not necessarily indicative of results of operations for a full year. These financial statements should be read in conjunction with the consolidated financial statements and notes thereto for the fiscal year ended December 28, 2024 included in CRA’s Annual Report on Form 10-K filed with the SEC on February 20, 2025.

Recent Accounting Standards Not Yet Adopted

Income Taxes (Topic 740): Improvements to Income Tax Disclosures

In December 2023, the FASB issued ASU No. 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures ("ASU 2023-09"). The ASU expands annual disclosures in an entity’s income tax rate reconciliation table and requires annual disclosures regarding cash taxes paid both in the U.S. (federal, state and local) and foreign jurisdictions. ASU 2023-09 also requires income (or loss) from continuing operations before income tax expense (or benefit) disaggregated between domestic and foreign and income tax expense (or benefit) from continuing operations disaggregated by federal (national), state, and foreign.

ASU 2023-09 is effective for CRA for annual periods beginning after December 15, 2024. CRA plans to adopt the amendment during the annual reporting for fiscal year 2025. CRA has begun to assess the impact of the amendment and has

modeled out the changes to its income tax disclosures. As the amendment relates solely to disclosures, the adoption is not expected to have an effect on CRA's financial results.

Income Statement—Reporting Comprehensive Income—Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses

In November 2024, the FASB issued ASU No. 2024-03, Income Statement - Reporting Comprehensive Income - Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses ("ASU 2024-03"). The ASU requires disclosure, in the notes to the financial statements, specified information about certain costs and expenses including employee compensation, depreciation, and intangible asset amortization.

ASU 2024-03, further clarified in ASU 2025-01, Income Statement—Reporting Comprehensive Income—Expense

Disaggregation Disclosures (Subtopic 220-40): Clarifying the Effective Date is effective for CRA for annual reporting periods beginning after December 15, 2026, and interim reporting periods beginning after December 15, 2027. CRA is in the process of evaluating the impact of adopting ASU 2024-03.