Development and Other Agreements	3 Months Ended
Mar. 31, 2016
Disclosure Development Agreements Additional Information [Abstract]
Development and Other Agreements	Development and Other Agreements Collaboration with Verily Life Sciences On August 10, 2015, we entered into a Collaboration and License Agreement (the “Verily Collaboration Agreement”) with Google Life Sciences LLC, now renamed Verily Life Sciences (“Verily”). Pursuant to the Verily Collaboration Agreement, we and Verily have agreed to jointly develop a series of next-generation CGM products. The Verily Collaboration Agreement provides us with an exclusive license to use certain intellectual property of Verily related to the development, manufacture and commercialization of the products contemplated under the Verily Collaboration Agreement. The Verily Collaboration Agreement provides for the establishment of a joint steering committee, joint development committee and joint commercialization committee to oversee and coordinate the parties’ activities under the collaboration. We and Verily have agreed to make committee decisions by consensus. The terms of Verily Collaboration Agreement required that we pay an upfront fee of $35.0 million in either cash or shares of our common stock at our sole election, with the number of shares calculated based on the volume weighted average trading price during a period of twenty consecutive trading days ending prior to the date of the Verily Collaboration Agreement. In addition, we will pay Verily up to $65.0 million in additional milestones upon achievement of various development and regulatory objectives, which payments may be paid in cash or shares of our common stock at our sole election, calculated based on the volume weighted average trading price during a period of twenty consecutive trading days ending on the trading day prior to the date on which the applicable objective has been achieved. On August 27, 2015, we filed a Registration Statement on Form S-3 with the SEC and issued 404,591 shares of our common stock to Verily in connection with the $35.0 million upfront payment. We recorded $36.5 million in research and development expense in our consolidated statement of operations during 2015 related to the issuance of the 404,591 shares of our common stock, based on our stock price of $90.29 per share as of the date of Verily Collaboration Agreement. In addition, Verily is eligible to receive tiered royalty payments associated with the commercialization of the products contemplated under the Verily Collaboration Agreement, which are subject to regulatory approval. Unless we attain annual product sales subject to the Verily Collaboration Agreement in excess of $750.0 million, there will be no royalty paid by us to Verily. Above this range, and upon marketing approval of the initial product contemplated by the Verily Collaboration Agreement, or upon commercialization of any other DexCom product that incorporates Verily intellectual property, we will pay to Verily a royalty percentage starting in the high single digits and declining to the mid-single digits based on our annual aggregate product sales. The Verily Collaboration Agreement shall be terminable by either party (a) upon uncured material breach of the Verily Collaboration Agreement by the other party, (b) if the second product contemplated by the Verily Collaboration Agreement has not been submitted to the FDA for approval by a specified date and (c) if the annual net sales for the products developed with Verily under the Verily Collaboration Agreement are less than a specified aggregate dollar amount. Additionally, we have the right to terminate the Verily Collaboration Agreement upon the expiration of the last to expire patent that covers a product developed under the Verily Collaboration Agreement. Tandem Diabetes Care, Inc. On February 1, 2012, we entered into a non-exclusive Development and Commercialization Agreement (the “Tandem Agreement”) with Tandem Diabetes Care, Inc. (“Tandem”) to integrate a future generation of our continuous glucose monitoring technology with Tandem’s t:slim^™ insulin delivery system in the United States. On January 4, 2013, the Tandem Agreement was amended to allow for the integration of our G4 PLATINUM systems with Tandem's t:slim insulin delivery system in the United States. We received an initial payment of $1.0 million as a result of the execution of the Tandem Agreement. In July 2014 we received an additional $1.0 million milestone payment related to the regulatory submission by Tandem of their CGM enabled insulin pump. In September 2015, we received a final $1.0 million milestone payment related to the regulatory approval of Tandem 's CGM enabled insulin pump, which was recognized in development grant and other revenue for the twelve months ended December 31, 2015. Under the terms of the Tandem Agreement, we are entitled to receive up to $1.0 million to offset certain development, clinical and regulatory expenses. Each of the milestones related to the Tandem Agreement is considered to be substantive. In September 2015, the Tandem Agreement was amended to eliminate Tandem’s obligation to pay DexCom a royalty of $100 for each Tandem t:slim G4 integrated pump system sold and instead to reallocate $100 for each Tandem t:slim G4 integrated pump system to incremental marketing activities for such pump systems, or marketing activities to support other jointly funded development projects.

Development and Other Agreements

Collaboration with Verily Life Sciences

On August 10, 2015, we entered into a Collaboration and License Agreement (the “Verily Collaboration Agreement”) with Google Life Sciences LLC, now renamed Verily Life Sciences (“Verily”). Pursuant to the Verily Collaboration Agreement, we and Verily have agreed to jointly develop a series of next-generation CGM products. The Verily Collaboration Agreement provides us with an exclusive license to use certain intellectual property of Verily related to the development, manufacture and commercialization of the products contemplated under the Verily Collaboration Agreement. The Verily Collaboration Agreement provides for the establishment of a joint steering committee, joint development committee and joint commercialization committee to oversee and coordinate the parties’ activities under the collaboration. We and Verily have agreed to make committee decisions by consensus.

The terms of Verily Collaboration Agreement required that we pay an upfront fee of $35.0 million in either cash or shares of our common stock at our sole election, with the number of shares calculated based on the volume weighted average trading price during a period of twenty consecutive trading days ending prior to the date of the Verily Collaboration Agreement. In addition, we will pay Verily up to $65.0 million in additional milestones upon achievement of various development and regulatory objectives, which payments may be paid in cash or shares of our common stock at our sole election, calculated based on the volume weighted average trading price during a period of twenty consecutive trading days ending on the trading day prior to the date on which the applicable objective has been achieved.

On August 27, 2015, we filed a Registration Statement on Form S-3 with the SEC and issued 404,591 shares of our common stock to Verily in connection with the $35.0 million upfront payment. We recorded $36.5 million in research and development expense in our consolidated statement of operations during 2015 related to the issuance of the 404,591 shares of our common stock, based on our stock price of $90.29 per share as of the date of Verily Collaboration Agreement.

In addition, Verily is eligible to receive tiered royalty payments associated with the commercialization of the products contemplated under the Verily Collaboration Agreement, which are subject to regulatory approval. Unless we attain annual product sales subject to the Verily Collaboration Agreement in excess of $750.0 million, there will be no royalty paid by us to Verily. Above this range, and upon marketing approval of the initial product contemplated by the Verily Collaboration Agreement, or upon commercialization of any other DexCom product that incorporates Verily intellectual property, we will pay to Verily a royalty percentage starting in the high single digits and declining to the mid-single digits based on our annual aggregate product sales.

The Verily Collaboration Agreement shall be terminable by either party (a) upon uncured material breach of the Verily Collaboration Agreement by the other party, (b) if the second product contemplated by the Verily Collaboration Agreement has not been submitted to the FDA for approval by a specified date and (c) if the annual net sales for the products developed with Verily under the Verily Collaboration Agreement are less than a specified aggregate dollar amount. Additionally, we have the right to terminate the Verily Collaboration Agreement upon the expiration of the last to expire patent that covers a product developed under the Verily Collaboration Agreement.

Tandem Diabetes Care, Inc.

On February 1, 2012, we entered into a non-exclusive Development and Commercialization Agreement (the “Tandem Agreement”) with Tandem Diabetes Care, Inc. (“Tandem”) to integrate a future generation of our continuous glucose monitoring technology with Tandem’s t:slim^™ insulin delivery system in the United States. On January 4, 2013, the Tandem Agreement was amended to allow for the integration of our G4 PLATINUM systems with Tandem's t:slim insulin delivery system in the United States. We received an initial payment of $1.0 million as a result of the execution of the Tandem Agreement. In July 2014 we received an additional $1.0 million milestone payment related to the regulatory submission by Tandem of their CGM enabled insulin pump.

In September 2015, we received a final $1.0 million milestone payment related to the regulatory approval of Tandem 's CGM enabled insulin pump, which was recognized in development grant and other revenue for the twelve months ended December 31, 2015. Under the terms of the Tandem Agreement, we are entitled to receive up to $1.0 million to offset certain development, clinical and regulatory expenses. Each of the milestones related to the Tandem Agreement is considered to be substantive.

In September 2015, the Tandem Agreement was amended to eliminate Tandem’s obligation to pay DexCom a royalty of $100 for each Tandem t:slim G4 integrated pump system sold and instead to reallocate $100 for each Tandem t:slim G4 integrated pump system to incremental marketing activities for such pump systems, or marketing activities to support other jointly funded development projects.