| Document And Entity Information - shares | 9 Months Ended | |
| Sep. 30, 2017 | Oct. 31, 2017 | |
| Document Information [Line Items] | ||
| Document Type | 10-Q | |
| Amendment Flag | false | |
| Document Period End Date | Sep. 30, 2017 | |
| Document Fiscal Year Focus | 2,017 | |
| Document Fiscal Period Focus | Q3 | |
| Entity Registrant Name | CADUS CORP | |
| Entity Central Index Key | 911,148 | |
| Current Fiscal Year End Date | --12-31 | |
| Entity Filer Category | Smaller Reporting Company | |
| Trading Symbol | KDUS | |
| Entity Common Stock, Shares Outstanding | 26,288,080 |
| Condensed Consolidated Balance Sheets - USD ($) | Sep. 30, 2017 | Dec. 31, 2016 |
| Assets: | ||
| Real estate inventory | $ 36,050,111 | $ 35,121,788 |
| Cash and cash equivalents | 3,832,853 | 5,675,047 |
| Interest receivable | 2,709 | 1,835 |
| Prepaid and other assets | 193,469 | 61,109 |
| Investment in other venture | 194,143 | 193,086 |
| Website, net | 8,333 | 13,333 |
| Total assets | 40,281,618 | 41,066,198 |
| Liabilities: | ||
| Accrued expenses and other liabilities | 651,098 | 152,882 |
| Total liabilities | 651,098 | 152,882 |
| Commitments | ||
| Stockholders’ equity: | ||
| Common stock | 264,297 | 264,297 |
| Additional paid-in capital | 80,291,992 | 80,291,992 |
| Accumulated deficit | (40,625,694) | (39,342,898) |
| Treasury stock - at cost | (300,075) | (300,075) |
| Total stockholders’ equity | 39,630,520 | 40,913,316 |
| Total liabilities and stockholders’ equity | $ 40,281,618 | $ 41,066,198 |
| Condensed Consolidated Statements of Operations - USD ($) | 3 Months Ended | 9 Months Ended | ||
| Sep. 30, 2017 | Sep. 30, 2016 | Sep. 30, 2017 | Sep. 30, 2016 | |
| Total revenues | $ 0 | $ 0 | $ 0 | $ 0 |
| Costs and expenses: | ||||
| General and administrative expenses | 103,927 | 101,396 | 374,670 | 385,266 |
| Real estate expenses | 79,553 | 45,912 | 226,886 | 103,699 |
| Impairment to real estate inventory | 700,000 | 0 | 700,000 | 0 |
| Amortization of website | 1,667 | 1,667 | 5,000 | 5,000 |
| Equity in earnings in other venture | (629) | 81 | (1,057) | (152) |
| Total costs and expenses | 884,518 | 149,056 | 1,305,499 | 493,813 |
| Operating loss | (884,518) | (149,056) | (1,305,499) | (493,813) |
| Other income: | ||||
| Interest income | 8,591 | 5,727 | 22,703 | 14,227 |
| Loss before provision for income taxes | (875,927) | (143,329) | (1,282,796) | (479,586) |
| Provision for income taxes | 0 | 0 | 0 | 0 |
| Net loss | $ (875,927) | $ (143,329) | $ (1,282,796) | $ (479,586) |
| Basic and diluted net (loss) per weighted average share of common stock outstanding (in dollars per share) | $ (0.03) | $ (0.01) | $ (0.05) | $ (0.02) |
| Weighted average shares of common stock outstanding - basic and diluted (in shares) | 26,288,080 | 26,288,080 | 26,288,080 | 26,288,080 |
| Condensed Consolidated Statements of Cash Flows - USD ($) | 9 Months Ended | |
| Sep. 30, 2017 | Sep. 30, 2016 | |
| Cash flows from operating activities: | ||
| Net loss | $ (1,282,796) | $ (479,586) |
| Adjustments to reconcile net (loss) to net cash used in operating activities: | ||
| Impairment of real estate inventory | 700,000 | 0 |
| Amortization of website | 5,000 | 5,000 |
| Equity in earnings in other venture | (1,057) | (152) |
| Changes in assets and liabilities: | ||
| Increase in prepaid and other assets | (133,234) | (14,183) |
| Increase in real estate inventory | (1,314,961) | (1,838,078) |
| Increase in accrued expenses and other liabilities | 184,854 | 73,860 |
| Net cash used in operating activities | (1,842,194) | (2,253,139) |
| Financing activities | ||
| Net decrease in cash and cash equivalents | (1,842,194) | (2,253,139) |
| Cash and cash equivalents - beginning of period | 5,675,047 | 8,936,147 |
| Cash and cash equivalents - end of period | $ 3,832,853 | $ 6,683,008 |
| Organization and Basis of Preparation | 9 Months Ended |
| Sep. 30, 2017 | |
| Accounting Policies [Abstract] | |
| Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block] | Note - 1 Organization and Basis of Preparation The information presented as of September 30, 2017 and for the three and nine month periods then ended is unaudited, but includes all adjustments (consisting only of normal recurring accruals) that the Company's management believes to be necessary for the fair presentation of results for the periods presented. Certain information and footnote disclosures normally included in financial statements prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) have been omitted pursuant to the requirements of the Securities and Exchange Commission, although the Company believes that the disclosures included in these financial statements are adequate to make the information not misleading. The December 31, 2016 condensed consolidated balance sheet was derived from audited consolidated financial statements. These financial statements should be read in conjunction with the Company's annual report on Form 10-K for the year ended December 31, 2016. The consolidated condensed financial statements include the accounts of Cadus and its wholly owned subsidiaries, Cadus Technologies, Inc., Blivet LLC, MB 2013 LLC and Happy Dragon LLC. All intercompany balances and transactions have been eliminated in consolidation. The Company operates in one segment: the purchase of homes and land for purposes of renovation or construction and resale. The Company has decided not to maintain its drug discovery technologies. The results of operations for the three and nine month periods ended September 30, 2017 are not necessarily indicative of the results to be expected for the year ending December 31, 2017. |
| Cash Equivalents | 9 Months Ended |
| Sep. 30, 2017 | |
| Cash and Cash Equivalents [Abstract] | |
| Cash and Cash Equivalents Disclosure [Text Block] | Note - 2 Cash Equivalents The Company includes as cash equivalents all highly liquid investments with original maturities of three months or less when purchased. There were cash equivalents of $ 3,541,541 5,319,730 |
| Net (Loss) Per Share | 9 Months Ended |
| Sep. 30, 2017 | |
| Earnings Per Share [Abstract] | |
| Earnings Per Share [Text Block] | Note - 3 Net (Loss) Per Share Basic net (loss) per share is computed by dividing the net (loss) by the weighted average of common shares outstanding. Diluted earnings per share is calculated based on the weighted average of common shares outstanding plus the effect of common stock equivalents (stock options). There were no outstanding stock options for the three and nine month periods ended September 30, 2017 and 2016. |
| Fair Value of Financial Instruments | 9 Months Ended |
| Sep. 30, 2017 | |
| Fair Value Disclosures [Abstract] | |
| Fair Value Disclosures [Text Block] | Note - 4 Fair Value of Financial Instruments The Company uses financial instruments in the normal course of its business. The carrying values of cash and cash equivalents, prepaid expenses and other assets, and accrued expenses and other liabilities approximate fair value. The fair value of the Company’s investment in a privately held company is not readily available. The Company believes the fair value of this investment in a privately held company approximated its carrying value at September 30, 2017 and December 31, 2016. The Company evaluated whether the Company’s investment is a variable interest and concluded that it is a variable interest. The Company then evaluated whether Laurel Partners Limited Partnership (“Laurel”) is a variable interest entity. The Company, as the limited partner, has no substantive kick out rights, nor any substantive participating rights, therefore, Laurel Partners Limited Partnership is a variable interest entity. In order to determine whether the Company is the primary beneficiary of Laurel, the Company evaluated the extent of its power over the activities that most significantly impact Laurel’s economic performance. Based on this evaluation, the Company concluded that it was not the primary beneficiary and, therefore, would not consolidate Laurel. |
| Real Estate Operations | 9 Months Ended |
| Sep. 30, 2017 | |
| Real Estate [Abstract] | |
| Real Estate Disclosure [Text Block] | Note - 5 Real Estate Operations As of September 30, 2017, the Company had purchased for an aggregate original price of approximately $ 29.9 The Company incurred $ 226,886 103,699 Real estate inventory is recorded at cost upon acquisition. The cost of residential property includes the purchase price of the property, legal fees and other acquisition costs (e.g. recording, title search, survey, lien and permit searches, and inspection costs). Costs directly related to planning, developing and constructing a property are capitalized and classified as real estate inventory in the consolidated balance sheets. Capitalized development costs include interest, property taxes, insurance, and other direct project costs incurred during the period of development. After acquisition, real estate inventory is analyzed quarterly for changes in net realizable value and any subsequent write down is charged to operating expenses. For the three months ended September 30, 2017, the Company wrote down the value of two houses in Coconut Grove, Florida, one at 3506 Main Lodge Drive and the other at 3437 N. Moorings Way, by a total of $ 700,000 |
| Accrued Expenses | 9 Months Ended |
| Sep. 30, 2017 | |
| Payables and Accruals [Abstract] | |
| Accounts Payable, Accrued Liabilities, and Other Liabilities Disclosure, Current [Text Block] | Note - 6 Accrued Expenses September 30, 2017 December 31, 2016 Real estate taxes $ 320,332 $ Real estate inventory 313,362 150,554 Legal 8,271 1,373 Property expenses 9,133 Sundry 955 $ 651,098 $ 152,882 |
| Recently Issued Accounting Standards | 9 Months Ended |
| Sep. 30, 2017 | |
| Accounting Changes and Error Corrections [Abstract] | |
| Accounting Changes and Error Corrections [Text Block] | Note - 7 Recently Issued Accounting Standards Recent accounting pronouncements issued by the Financial Accounting Standards Board did not or are not believed by management to have a material impact on the Company’s present or future consolidated financial statements. |
| Accrued Expenses (Tables) | 9 Months Ended |
| Sep. 30, 2017 | |
| Payables and Accruals [Abstract] | |
| Schedule of Accrued Liabilities [Table Text Block] | Accrued expenses consist of the following: September 30, 2017 December 31, 2016 Real estate taxes $ 320,332 $ Real estate inventory 313,362 150,554 Legal 8,271 1,373 Property expenses 9,133 Sundry 955 $ 651,098 $ 152,882 |
| Cash Equivalents (Details Textual) - USD ($) | Sep. 30, 2017 | Dec. 31, 2016 |
| Cash and Cash Equivalents [Line Items] | ||
| Cash Equivalents, at Carrying Value | $ 3,541,541 | $ 5,319,730 |
| Real Estate Operations (Details Textual) - USD ($) | 3 Months Ended | 9 Months Ended | ||
| Sep. 30, 2017 | Sep. 30, 2016 | Sep. 30, 2017 | Sep. 30, 2016 | |
| Real Estate Properties [Line Items] | ||||
| Real Estate Expense | $ 79,553 | $ 45,912 | $ 226,886 | $ 103,699 |
| Impairment of Real Estate | 700,000 | $ 0 | 700,000 | $ 0 |
| Property In Miami-Dade Country [Member] | ||||
| Real Estate Properties [Line Items] | ||||
| Real Estate Investment Property, at Cost, Total | $ 29,900,000 | $ 29,900,000 | ||
| Accrued Expenses (Details) - USD ($) | Sep. 30, 2017 | Dec. 31, 2016 |
| Accrued Expenses and Other Current Liabilities [Line Items] | ||
| Real estate taxes | $ 320,332 | $ 0 |
| Real estate inventory | 313,362 | 150,554 |
| Legal | 8,271 | 1,373 |
| Property expenses | 9,133 | 0 |
| Sundry | 0 | 955 |
| Accrued Expenses | $ 651,098 | $ 152,882 |
