BUSINESS, BASIS OF PRESENTATION, AND ACCOUNTING POLICIES (DETAILS) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jul. 04, 2014	Jun. 28, 2013	Jul. 04, 2014 segments	Jun. 28, 2013
Change in accounting estimate [Line Items]
Revenues	$ 2,555	$ 2,792	$ 5,092	$ 5,595
Organization, consolidation and presentation of financial statements, as shown (Textuals) [Abstract]
Number of operating segments			4
Merger agreement [Member]
Pending merger [Line Items]
Pending merger description			Pending Merger On July 11, 2014, we entered into an Agreement and Plan of Merger (the “Merger Agreement”) with AECOM Technology Corporation (“AECOM”), ACM Mountain I, LLC, a direct wholly-owned subsidiary of AECOM (“Merger Sub”), and ACM Mountain II, LLC, a direct wholly-owned subsidiary of AECOM (“Merger Sub I”). The Merger Agreement provides for the merger of Merger Sub with and into our company, with our company continuing as the surviving company and a direct wholly-owned subsidiary of AECOM (the “Merger”). Immediately thereafter, as part of a single integrated transaction with the Merger, pursuant to the Merger Agreement, we will merge with and into Merger Sub I, with Merger Sub I continuing as the surviving company and a direct wholly-owned subsidiary of AECOM. Subject to the terms and conditions of the Merger Agreement, holders of URS common stock will receive consideration to be determined at closing based on the average closing price of AECOM common stock during the five business days prior to the closing date. Each outstanding share of URS common stock will be exchanged for per share consideration consisting of 0.734 shares of AECOM common stock and $33.00 in cash. URS stockholders may elect to receive cash or stock consideration, subject to proration in the event of oversubscription or undersubscription for cash consideration. Completion of the Merger is subject to certain customary conditions, including approval by both the AECOM and URS stockholders, approval of the listing of the shares of AECOM common stock to be issued in the Merger on the New York Stock Exchange, receipt of required regulatory approvals and/or expiration or termination of applicable waiting periods, effectiveness of AECOM’s registration statement on Form S-4 and receipt of customary opinions related to certain tax matters from the parties’ respective counsels. On August 4, 2014, the Federal Trade Commission granted URS and AECOM early termination of the waiting period under the Hart-Scott-Rodino Antitrust Improvements Act of 1976, as amended. The financial statements included in this Quarterly Report on Form 10-Q do not reflect any adjustments or otherwise give effect to the proposed Merger.
Exchange ratio per share for acquiror stock			0.734
Business combination cash per share to shareholders			$ 33
Performance-based Incentive Fees [Member]
Change in accounting estimate [Line Items]
Revenues			26
Impact on operating income			26
Impact on net income			$ 16
Impact on EPS			$ 0.21