Business	9 Months Ended
Sep. 30, 2019
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Business	1. Business Cara Therapeutics, Inc., or the Company, is a clinical-stage biopharmaceutical corporation formed on July 2, 2004. The Company is focused on developing and commercializing new chemical entities designed to alleviate pruritus by selectively targeting peripheral kappa opioid receptors. The Company’s primary activities to date have been organizing and staffing the Company, developing its product candidates and raising capital. As of September 30, 2019, the Company had raised aggregate net proceeds of approximately $519,700 from several rounds of equity financing, including its initial public offering, or IPO, which closed in February 2014 and four follow-on public offerings of common stock, which closed in July 2019, July 2018, April 2017 and August 2015, and the issuance of convertible preferred stock and debt prior to the IPO. The Company had also received $88,900 under its license agreements for CR845/difelikefalin, primarily with Vifor Fresenius Medical Care Renal Pharma Ltd., or VFMCRP, Maruishi Pharmaceutical Co. Ltd., or Maruishi, and Chong Kun Dang Pharmaceutical Corp., or CKDP, and an earlier product candidate for which development efforts ceased in 2007. Additionally, in May 2018, the Company received net proceeds of $14,556 from the issuance and sale of 1,174,827 shares of the Company’s common stock to Vifor (International) Ltd., or Vifor, in connection with the Company’s license agreement with VFMCRP (see Note 10, Collaboration and Licensing Agreements). As of September 30, 2019, the Company had unrestricted cash and cash equivalents and marketable securities of $249,074 and an accumulated deficit of $372,116. The Company has incurred substantial net losses and negative cash flows from operating activities in nearly every fiscal period since inception and expects this trend to continue for the foreseeable future. The Company recognized net losses of $32,842 and $19,400 for the three months ended September 30, 2019 and 2018, respectively, and $77,762 and $53,361 for the nine months ended September 30, 2019 and 2018, respectively, and had net cash (used in) provided by operating activities of $(78,059) and $2,060 for the nine months ended September 30, 2019 and 2018, respectively. The Company is subject to risks common to other life science companies including, but not limited to, uncertainty of product development and commercialization, lack of marketing and sales history, development by its competitors of new technological innovations, dependence on key personnel, market acceptance of products, product liability, protection of proprietary technology, ability to raise additional financing, and compliance with Food and Drug Administration, or FDA, and other government regulations. If the Company does not successfully commercialize any of its product candidates, it will be unable to generate recurring product revenue or achieve profitability.

1. Business

Cara Therapeutics, Inc., or the Company, is a clinical-stage biopharmaceutical corporation formed on July 2, 2004. The Company is focused on developing and commercializing new chemical entities designed to alleviate pruritus by selectively targeting peripheral kappa opioid receptors. The Company’s primary activities to date have been organizing and staffing the Company, developing its product candidates and raising capital.

As of September 30, 2019, the Company had raised aggregate net proceeds of approximately $519,700 from several rounds of equity financing, including its initial public offering, or IPO, which closed in February 2014 and four follow-on public offerings of common stock, which closed in July 2019, July 2018, April 2017 and August 2015, and the issuance of convertible preferred stock and debt prior to the IPO. The Company had also received $88,900 under its license agreements for CR845/difelikefalin, primarily with Vifor Fresenius Medical Care Renal Pharma Ltd., or VFMCRP, Maruishi Pharmaceutical Co. Ltd., or Maruishi, and Chong Kun Dang Pharmaceutical Corp., or CKDP, and an earlier product candidate for which development efforts ceased in 2007. Additionally, in May 2018, the Company received net proceeds of $14,556 from the issuance and sale of 1,174,827 shares of the Company’s common stock to Vifor (International) Ltd., or Vifor, in connection with the Company’s license agreement with VFMCRP (see Note 10, Collaboration and Licensing Agreements).

As of September 30, 2019, the Company had unrestricted cash and cash equivalents and marketable securities of $249,074 and an accumulated deficit of $372,116. The Company has incurred substantial net losses and negative cash flows from operating activities in nearly every fiscal period since inception and expects this trend to continue for the foreseeable future. The Company recognized net losses of $32,842 and $19,400 for the three months ended September 30, 2019 and 2018, respectively, and $77,762 and $53,361 for the nine months ended September 30, 2019 and 2018, respectively, and had net cash (used in) provided by operating activities of $(78,059) and $2,060 for the nine months ended September 30, 2019 and 2018, respectively.

The Company is subject to risks common to other life science companies including, but not limited to, uncertainty of product development and commercialization, lack of marketing and sales history, development by its competitors of new technological innovations, dependence on key personnel, market acceptance of products, product liability, protection of proprietary technology, ability to raise additional financing, and compliance with Food and Drug Administration, or FDA, and other government regulations. If the Company does not successfully commercialize any of its product candidates, it will be unable to generate recurring product revenue or achieve profitability.