Legal Matters	12 Months Ended
Jan. 03, 2015
Commitments and Contingencies Disclosure [Abstract]
Legal Matters	Legal Matters In November 2014, a patent infringement lawsuit was filed by Papst Licensing GmbH & Co., KG ("Papst") against us in the U.S. District Court for the District of Delaware. In the complaint, Papst alleges that certain of the simulator or simulation products sold by the Company may infringe one or more of the patents held by Papst. No discovery has been conducted with respect to these allegations. At this stage of the proceedings, Lattice does not have an estimate of the likelihood or the amount of any potential exposure to the Company. The Company believes that it possesses defenses to these claims and intends to vigorously defend this litigation. It is reasonably possible that the actual losses may exceed our accrued liabilities, however, and we cannot currently estimate such amount. On or about January 29, 2015, Silicon Image, Inc., members of its Board, the Company and the Company’s wholly-owned merger acquisition subsidiary, were named as defendants in two complaints filed in Santa Clara Superior Court by alleged stockholders in connection with the proposed merger of Silicon Image and the Company. Both complaints were dated January 29, 2015 and were captioned respectively Molland v. George, et al. and Stein v. Silicon Image, Inc. et. al. Five additional complaints were subsequently filed on January 30, 2015, February 4, 2015 and February 9, 2015 in Delaware Chancery Court by alleged stockholders of Silicon Image, Inc. in connection with the Merger, captioned respectively Pfeiffer v. Martino et. al.; Lipinski v. Silicon Image, Inc. et. al.; Feldbaum et. al. v. Silicon Image, Inc. et. al; Nelson v. Silicon Image, Inc. et. al. and Partansky v. Silicon Image, Inc. et. al. The five Delaware matters were subsequently consolidated into an action captioned In re Silicon Image Stockholders Litigation by order of the Delaware Chancery Court on February 11, 2015, and a consolidated amended complaint was filed in the matter on February 13, 2015. Two complaints captioned Tapia v. Silicon Image, Inc. et. al. and Caldwel v. Silicon Image, Inc. were also filed on February 4, 2015 and February 9, 2015 in Santa Clara Superior Court by alleged stockholders in connection with the Merger. Amended complaints were filed in the Molland and Stein actions on February 11, 2015. Each of these lawsuits are purported class actions brought on behalf of Silicon Image stockholders, asserting claims against each member of the Board for breach of fiduciary duty, and against various of the Silicon Image, Silicon Image’s Board, the Company, and the Company’s wholly-owned merger subsidiary for aiding and abetting breach of fiduciary duty. The lawsuits allege that the Merger does not appropriately value Silicon Image, was the result of an inadequate process, and includes preclusive deal devices. The amended complaints also assert that the Silicon Image’s disclosures regarding the Merger in its Schedule 14D-9 omitted material information regarding the Merger. Each of these complaints purport to seek unspecified damages and may seek injunctive relief preventing consummation of the transactions. The Company believes that the claims in these complaints are without merit and intends to vigorously defend this litigation. An adverse judgment for monetary damages could have an adverse effect on the operations of the Company. A preliminary injunction could delay or jeopardize the completion of the Merger, and an adverse judgment granting permanent injunctive relief could indefinitely enjoin completion of the Merger. We are also exposed to certain other asserted and unasserted potential claims. There can be no assurance that, with respect to potential claims made against us, we could resolve such claims under terms and conditions that would not have a material adverse effect on our business, our liquidity or our financial results. Periodically, we review the status of each significant matter and assess its potential financial exposure. If the potential loss from any claim or legal proceeding is considered probable and a range of possible losses can be estimated, we then accrue a liability for the estimated loss based on the provisions of FASB ASC 450, “Contingencies" (“ASC 450”). Legal proceedings are subject to uncertainties, and the outcomes are difficult to predict. Because of such uncertainties, accruals are based only on the best information available at the time. As additional information becomes available, we reassess the potential liability related to pending claims and litigation and may revise estimates. Presently, no accrual has been estimated under ASC 450 for potential losses that may or may not arise from the current lawsuits in which we are involved.

Legal Matters

In November 2014, a patent infringement lawsuit was filed by Papst Licensing GmbH & Co., KG ("Papst") against us in the U.S. District Court for the District of Delaware. In the complaint, Papst alleges that certain of the simulator or simulation products sold by the Company may infringe one or more of the patents held by Papst. No discovery has been conducted with respect to these allegations. At this stage of the proceedings, Lattice does not have an estimate of the likelihood or the amount of any potential exposure to the Company. The Company believes that it possesses defenses to these claims and intends to vigorously defend this litigation. It is reasonably possible that the actual losses may exceed our accrued liabilities, however, and we cannot currently estimate such amount.

On or about January 29, 2015, Silicon Image, Inc., members of its Board, the Company and the Company’s wholly-owned merger acquisition subsidiary, were named as defendants in two complaints filed in Santa Clara Superior Court by alleged stockholders in connection with the proposed merger of Silicon Image and the Company. Both complaints were dated January 29, 2015 and were captioned respectively Molland v. George, et al. and Stein v. Silicon Image, Inc. et. al. Five additional complaints were subsequently filed on January 30, 2015, February 4, 2015 and February 9, 2015 in Delaware Chancery Court by alleged stockholders of Silicon Image, Inc. in connection with the Merger, captioned respectively Pfeiffer v. Martino et. al.; Lipinski v. Silicon Image, Inc. et. al.; Feldbaum et. al. v. Silicon Image, Inc. et. al; Nelson v. Silicon Image, Inc. et. al. and Partansky v. Silicon Image, Inc. et. al. The five Delaware matters were subsequently consolidated into an action captioned In re Silicon Image Stockholders Litigation by order of the Delaware Chancery Court on February 11, 2015, and a consolidated amended complaint was filed in the matter on February 13, 2015. Two complaints captioned Tapia v. Silicon Image, Inc. et. al. and Caldwel v. Silicon Image, Inc. were also filed on February 4, 2015 and February 9, 2015 in Santa Clara Superior Court by alleged stockholders in connection with the Merger. Amended complaints were filed in the Molland and Stein actions on February 11, 2015.

Each of these lawsuits are purported class actions brought on behalf of Silicon Image stockholders, asserting claims against each member of the Board for breach of fiduciary duty, and against various of the Silicon Image, Silicon Image’s Board, the Company, and the Company’s wholly-owned merger subsidiary for aiding and abetting breach of fiduciary duty. The lawsuits allege that the Merger does not appropriately value Silicon Image, was the result of an inadequate process, and includes preclusive deal devices. The amended complaints also assert that the Silicon Image’s disclosures regarding the Merger in its Schedule 14D-9 omitted material information regarding the Merger. Each of these complaints purport to seek unspecified damages and may seek injunctive relief preventing consummation of the transactions.

The Company believes that the claims in these complaints are without merit and intends to vigorously defend this litigation.

An adverse judgment for monetary damages could have an adverse effect on the operations of the Company. A preliminary injunction could delay or jeopardize the completion of the Merger, and an adverse judgment granting permanent injunctive relief could indefinitely enjoin completion of the Merger.

We are also exposed to certain other asserted and unasserted potential claims. There can be no assurance that, with respect to potential claims made against us, we could resolve such claims under terms and conditions that would not have a material adverse effect on our business, our liquidity or our financial results. Periodically, we review the status of each significant matter and assess its potential financial exposure. If the potential loss from any claim or legal proceeding is considered probable and a range of possible losses can be estimated, we then accrue a liability for the estimated loss based on the provisions of FASB ASC 450, “Contingencies" (“ASC 450”). Legal proceedings are subject to uncertainties, and the outcomes are difficult to predict. Because of such uncertainties, accruals are based only on the best information available at the time. As additional information becomes available, we reassess the potential liability related to pending claims and litigation and may revise estimates. Presently, no accrual has been estimated under ASC 450 for potential losses that may or may not arise from the current lawsuits in which we are involved.