Annual report pursuant to Section 13 and 15(d)

Fair Value Measurement - Assets and Liabilities Measured on a Recurring Basis (Details)

v3.20.4
Fair Value Measurement - Assets and Liabilities Measured on a Recurring Basis (Details) - USD ($)
$ in Thousands
Dec. 31, 2020
Dec. 31, 2019
Assets:    
Investments $ 150,359 $ 0
Total 422,709 306,019
Deposits held with banks    
Assets:    
Cash and cash equivalents: 130,807 286,019
Short-term highly liquid investments    
Assets:    
Cash and cash equivalents: 141,543 20,000
Level 1    
Assets:    
Investments 69,746 0
Total 342,096 306,019
Level 1 | Deposits held with banks    
Assets:    
Cash and cash equivalents: 130,807 286,019
Level 1 | Short-term highly liquid investments    
Assets:    
Cash and cash equivalents: 141,543 20,000
Level 2    
Assets:    
Investments 80,613
Total 80,613 0
Level 2 | Deposits held with banks    
Assets:    
Cash and cash equivalents: 0 0
Level 2 | Short-term highly liquid investments    
Assets:    
Cash and cash equivalents: 0 0
Level 3    
Assets:    
Investments
Total 0 0
Level 3 | Deposits held with banks    
Assets:    
Cash and cash equivalents: 0 0
Level 3 | Short-term highly liquid investments    
Assets:    
Cash and cash equivalents: $ 0 $ 0