Development Agreements	12 Months Ended
Dec. 31, 2011
Development Agreements [Abstract]
Development Agreements	5. Development Agreements Insulet Corporation On January 7, 2008, we entered into a development agreement with Insulet to integrate our continuous glucose monitoring technology into Insulet's wireless, handheld OmniPod System Personal Diabetes Manager. The agreement is non-exclusive and does not impact either party's existing third party development agreements. Animas Corporation On January 10, 2008, we entered into a joint development agreement with Animas, as amended on January 12, 2009, July 30, 2009 and June 7, 2011 ("the Animas Amendments"), to integrate our continuous glucose monitoring technology into Animas insulin pumps. Under the terms of the amended agreement, Animas was to contribute up to $1.1 million to DexCom to offset certain development, clinical and regulatory expenses. The agreement is non-exclusive in the United States, but exclusive outside the United States and does not impact either party's existing third party development agreements. In January 2008 we received $0.5 million from Animas to offset development and other expenses. In January 2009 we received $0.3 million. We recorded $0.1 million in development grant and other revenue for the twelve months ended December 31, 2011, compared to $0.2 million for the same period in 2010. Pursuant to the Animas Amendments, we were to collaborate with Animas to develop a modified version of our transmitter to support a single, global CGM-enabled insulin pump launch by Animas. We were entitled to receive a one-time $1.0 million milestone payment upon the achievement of performance qualification of a manufacturing line for the modified transmitter, which was earned in December 2010. We were also entitled to receive an additional one-time $4.0 million milestone payment and a $0.3 million development payment upon the first regulatory body approval outside the United States for the new system, which was earned in May 2011. Edwards Lifesciences LLC On November 10, 2008, and as amended on May 5, 2009, we entered into a Collaboration Agreement (the "Collaboration Agreement") with Edwards. Pursuant to the Collaboration Agreement, we and Edwards agreed to develop jointly and to market an in-hospital automatic blood glucose monitoring system. Under the terms of the Collaboration Agreement, as amended, Edwards was obligated to pay us an upfront fee of $13.0 million. In addition, we were entitled to receive up to $10.0 million for product development costs. We will also receive either a profit-sharing payment of up to 10% on the product's gross profits, or a royalty of up to 6% of commercial sales of the product. The Collaboration Agreement provides Edwards with an exclusive license under our intellectual property to the critical care sector in the hospital market. Edwards will be responsible for global sales and marketing, and we will initially be responsible for manufacturing. In November 2008 we received $13.0 million. We received an additional $10.0 million during 2009 and 2010. We recorded $2.1 million in development grant and other revenue for the twelve months ended December 31, 2011, compared to $6.9 million for the same period in 2010. Each of the milestones related to the Collaboration Agreement is considered to be substantive under the terms of the Collaboration Agreement and we are entitled to receive up to $12.0 million in milestones related to regulatory approvals and manufacturing readiness, subject to reductions based on the timing of the receipt of approvals. We did not recognize any consideration for milestones related to the Collaboration Agreement for the twelve months ended December 31, 2011. Roche Diagnostics Operations, Inc. On November 1, 2011, we entered into a non-exclusive Research and Development Agreement (the "Roche Agreement") with Roche to integrate a future generation of our continuous glucose monitoring technology with Roche's next generation Accu-Chek^® insulin delivery system in the United States. Under the terms of the Roche Agreement, we are entitled to receive up to $1.0 million to offset certain development, clinical and regulatory expenses. We received an initial payment of $0.5 million as a result of the execution of the Roche Agreement, and we are entitled to receive an additional $0.5 million upon agreement of a development and regulatory plan, which is not considered to be substantive. We are also entitled to receive up to an additional $2.0 million upon the achievement of certain milestones related to regulatory submissions and approvals as set forth in the Roche Agreement, which are considered to be substantive.

5. Development Agreements

Insulet Corporation

On January 7, 2008, we entered into a development agreement with Insulet to integrate our continuous glucose monitoring technology into Insulet's wireless, handheld OmniPod System Personal Diabetes Manager. The agreement is non-exclusive and does not impact either party's existing third party development agreements.

Animas Corporation

On January 10, 2008, we entered into a joint development agreement with Animas, as amended on January 12, 2009, July 30, 2009 and June 7, 2011 ("the Animas Amendments"), to integrate our continuous glucose monitoring technology into Animas insulin pumps. Under the terms of the amended agreement, Animas was to contribute up to $1.1 million to DexCom to offset certain development, clinical and regulatory expenses. The agreement is non-exclusive in the United States, but exclusive outside the United States and does not impact either party's existing third party development agreements. In January 2008 we received $0.5 million from Animas to offset development and other expenses. In January 2009 we received $0.3 million. We recorded $0.1 million in development grant and other revenue for the twelve months ended December 31, 2011, compared to $0.2 million for the same period in 2010. Pursuant to the Animas Amendments, we were to collaborate with Animas to develop a modified version of our transmitter to support a single, global CGM-enabled insulin pump launch by Animas. We were entitled to receive a one-time $1.0 million milestone payment upon the achievement of performance qualification of a manufacturing line for the modified transmitter, which was earned in December 2010. We were also entitled to receive an additional one-time $4.0 million milestone payment and a $0.3 million development payment upon the first regulatory body approval outside the United States for the new system, which was earned in May 2011.

Edwards Lifesciences LLC

On November 10, 2008, and as amended on May 5, 2009, we entered into a Collaboration Agreement (the "Collaboration Agreement") with Edwards. Pursuant to the Collaboration Agreement, we and Edwards agreed to develop jointly and to market an in-hospital automatic blood glucose monitoring system. Under the terms of the Collaboration Agreement, as amended, Edwards was obligated to pay us an upfront fee of $13.0 million. In addition, we were entitled to receive up to $10.0 million for product development costs. We will also receive either a profit-sharing payment of up to 10% on the product's gross profits, or a royalty of up to 6% of commercial sales of the product. The Collaboration Agreement provides Edwards with an exclusive license under our intellectual property to the critical care sector in the hospital market. Edwards will be responsible for global sales and marketing, and we will initially be responsible for manufacturing. In November 2008 we received $13.0 million. We received an additional $10.0 million during 2009 and 2010. We recorded $2.1 million in development grant and other revenue for the twelve months ended December 31, 2011, compared to $6.9 million for the same period in 2010.

Each of the milestones related to the Collaboration Agreement is considered to be substantive under the terms of the Collaboration Agreement and we are entitled to receive up to $12.0 million in milestones related to regulatory approvals and manufacturing readiness, subject to reductions based on the timing of the receipt of approvals. We did not recognize any consideration for milestones related to the Collaboration Agreement for the twelve months ended December 31, 2011.

Roche Diagnostics Operations, Inc.

On November 1, 2011, we entered into a non-exclusive Research and Development Agreement (the "Roche Agreement") with Roche to integrate a future generation of our continuous glucose monitoring technology with Roche's next generation Accu-Chek^® insulin delivery system in the United States. Under the terms of the Roche Agreement, we are entitled to receive up to $1.0 million to offset certain development, clinical and regulatory expenses. We received an initial payment of $0.5 million as a result of the execution of the Roche Agreement, and we are entitled to receive an additional $0.5 million upon agreement of a development and regulatory plan, which is not considered to be substantive. We are also entitled to receive up to an additional $2.0 million upon the achievement of certain milestones related to regulatory submissions and approvals as set forth in the Roche Agreement, which are considered to be substantive.