Document And Entity Information	6 Months Ended
Jul. 01, 2011	Jul. 29, 2011
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	true
Amendment Description	Tellabs, Inc. originally filed its Quarterly Report on Form 10-Q for the quarter ended July 1, 2011 on August 10, 2011. We are filing this amendment on Form 10-Q/A to restate our consolidated financial statements and other financial information for the three and six month periods ended July 1, 2011. The impact of the restatement is more fully described in Note 1a to the Consolidated Financial Statements contained in this Amendment No. 1. This Form 10-Q/A amends and restates in their entireties Items 1, 2 and 4 of Part 1 and supplements Item 1A of Part II of our original Quarterly Report on Form 10-Q, filed with the Securities and Exchange Commission (SEC) on August 10, 2011, and no other information included in that report is amended hereby. In addition to the filing of this Form 10-Q/A, we are also filing an amendment to our Quarterly Report on Form 10-Q for the quarter ended September 30, 2011, to restate our consolidated financial statements and other financial information for the three and nine month periods then ended. The previously issued unaudited consolidated financial statements and other financial information for the fiscal quarters ending July 1, 2011 and September 30, 2011 filed on Forms 10-Q should no longer be relied upon. This Amendment No. 1 continues to speak as of the date of the filing of that original Quarterly Report on Form 10-Q, and we have not updated the disclosures contained herein to reflect any events that occurred at a later date. Accordingly, this Amendment No. 1 should be read in conjunction with other subsequent filings we have made with the SEC, including the Form 10-Q/A for the quarter ended September 30, 2011.
Document Period End Date	Jul. 01, 2011
Document Fiscal Year Focus	2011
Document Fiscal Period Focus	Q2
Trading Symbol	tlab
Entity Registrant Name	TELLABS INC
Entity Central Index Key	0000317771
Current Fiscal Year End Date	--12-30
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		364,884,602

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