Subsequent events (Details)
1 Months Ended
Jan. 31, 2020
USD ($)
employee
Dec. 31, 2019
USD ($)
Jun. 30, 2019
USD ($)
Subsequent Event [Line Items]      
Non-marketable equity interest   $ 458,000 $ 458,000
Equity method investment   $ 16,397,000 $ 0
Synq3 LLC | Subsequent Event      
Subsequent Event [Line Items]      
Equity method investment $ 4,000,000.0    
Equity interest percent 11.00%    
Intellectual Property and Workforce in Exchange for Equity Interest | Subsequent Event      
Subsequent Event [Line Items]      
Employees exchanged for non-marketable equity interest | employee 59