Quarterly report pursuant to Section 13 or 15(d)

Fair Value Measurements (Recurring) (Details)

v3.21.1
Fair Value Measurements (Recurring) (Details) - Fair Value, Recurring [Member] - USD ($)
$ in Thousands
Mar. 31, 2021
Dec. 31, 2020
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Total assets $ 195,051 $ 87,081
Total liabilities 1,893 3,358
Fair Value, Inputs, Level 1 [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Total assets 194,518 87,081
Total liabilities 0 0
Fair Value, Inputs, Level 2 [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Total assets 533 0
Total liabilities 1,893 3,358
Fair Value, Inputs, Level 3 [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Total assets 0 0
Total liabilities 0 0
Short-term government securities [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Short-term government securities (cash and cash equivalents) 194,518 87,081
Short-term government securities [Member] | Fair Value, Inputs, Level 1 [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Short-term government securities (cash and cash equivalents) 194,518 87,081
Short-term government securities [Member] | Fair Value, Inputs, Level 2 [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Short-term government securities (cash and cash equivalents) 0 0
Short-term government securities [Member] | Fair Value, Inputs, Level 3 [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Short-term government securities (cash and cash equivalents) 0 0
Interest Rate Swap [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Interest rate swaps (prepaids and other assets) 533  
Interest rate swaps (other liabilities) 1,893 3,358
Interest Rate Swap [Member] | Fair Value, Inputs, Level 1 [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Interest rate swaps (prepaids and other assets) 0  
Interest rate swaps (other liabilities) 0 0
Interest Rate Swap [Member] | Fair Value, Inputs, Level 2 [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Interest rate swaps (prepaids and other assets) 533  
Interest rate swaps (other liabilities) 1,893 3,358
Interest Rate Swap [Member] | Fair Value, Inputs, Level 3 [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Interest rate swaps (prepaids and other assets) 0  
Interest rate swaps (other liabilities) $ 0 $ 0