0000001 - Document - Cover link:presentationLink link:calculationLink link:definitionLink 9952151 - Statement - UNAUDITED CONDENSED CONSOLIDATED BALANCE SHEETS link:presentationLink link:calculationLink link:definitionLink 9952152 - Statement - UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS link:presentationLink link:calculationLink link:definitionLink 9952153 - Statement - UNAUDITED STATEMENTS OF CHANGES IN STOCKHOLDERS’ EQUITY link:presentationLink link:calculationLink link:definitionLink 9952154 - Statement - UNAUDITED STATEMENTS OF CHANGES IN STOCKHOLDERS’ EQUITY (Parenthetical) link:presentationLink link:calculationLink link:definitionLink 9952155 - Statement - UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS link:presentationLink link:calculationLink link:definitionLink 9952156 - Disclosure - Organization and nature of operations link:presentationLink link:calculationLink link:definitionLink 9952157 - Disclosure - Summary of significant accounting policies link:presentationLink link:calculationLink link:definitionLink 9952158 - Disclosure - Revenue recognition link:presentationLink link:calculationLink link:definitionLink 9952159 - Disclosure - Investments link:presentationLink link:calculationLink link:definitionLink 9952160 - Disclosure - Fair value measurements link:presentationLink link:calculationLink link:definitionLink 9952161 - Disclosure - Accounts payable and accrued expenses link:presentationLink link:calculationLink link:definitionLink 9952162 - Disclosure - Common stock link:presentationLink link:calculationLink link:definitionLink 9952163 - Disclosure - Stock-based compensation link:presentationLink link:calculationLink link:definitionLink 9952164 - Disclosure - Net loss per share link:presentationLink link:calculationLink link:definitionLink 9952165 - Disclosure - Segment reporting link:presentationLink link:calculationLink link:definitionLink 9955511 - Disclosure - Summary of significant accounting policies (Policies) link:presentationLink link:calculationLink link:definitionLink 9955512 - Disclosure - Investments (Tables) link:presentationLink link:calculationLink link:definitionLink 9955513 - Disclosure - Fair value measurements (Tables) link:presentationLink link:calculationLink link:definitionLink 9955514 - Disclosure - Accounts payable and accrued expenses (Tables) link:presentationLink link:calculationLink link:definitionLink 9955515 - Disclosure - Stock-based compensation (Tables) link:presentationLink link:calculationLink link:definitionLink 9955516 - Disclosure - Net loss per share (Tables) link:presentationLink link:calculationLink link:definitionLink 9955517 - Disclosure - Segment reporting (Tables) link:presentationLink link:calculationLink link:definitionLink 9955518 - Disclosure - Revenue recognition (Details) link:presentationLink link:calculationLink link:definitionLink 9955519 - Disclosure - Investments - Amortized and Fair Value of our Investments (Details) link:presentationLink link:calculationLink link:definitionLink 9955520 - Disclosure - Investments - Narratives (Details) link:presentationLink link:calculationLink link:definitionLink 9955521 - Disclosure - Fair value measurements - Assets and Liabilities Measured on Recurring Basis (Details) link:presentationLink link:calculationLink link:definitionLink 9955522 - Disclosure - Accounts payable and accrued expenses (Details) link:presentationLink link:calculationLink link:definitionLink 9955523 - Disclosure - Common stock (Details) link:presentationLink link:calculationLink link:definitionLink 9955524 - Disclosure - Stock-based compensation - Narratives (Details) link:presentationLink link:calculationLink link:definitionLink 9955525 - Disclosure - Stock-based compensation - Allocated Share-based Compensation Expense (Details) link:presentationLink link:calculationLink link:definitionLink 9955525 - Disclosure - Stock-based compensation - Allocated Share-based Compensation Expense (Details) link:presentationLink link:calculationLink link:definitionLink 9955526 - Disclosure - Stock-based compensation - Stock Option Rollforward (Details) link:presentationLink link:calculationLink link:definitionLink 9955527 - Disclosure - Stock-based compensation - Restricted Stock (Details) link:presentationLink link:calculationLink link:definitionLink 9955528 - Disclosure - Net loss per share - Anti-dilutive Securities (Details) link:presentationLink link:calculationLink link:definitionLink 9955529 - Disclosure - Segment reporting - Narrative (Details) link:presentationLink link:calculationLink link:definitionLink 9955530 - Disclosure - Segment reporting - Segment Expenses (Details) link:presentationLink link:calculationLink link:definitionLink