Annual report pursuant to Section 13 and 15(d)

Fair Value Measures (Narrative) (Details)

v3.20.4
Fair Value Measures (Narrative) (Details) - USD ($)
$ in Thousands
Dec. 31, 2020
Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets, Fair Value Disclosure $ 378,023 $ 391,233
Fair Value, Inputs, Level 3 [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets, Fair Value Disclosure 0 0
Fair Value, Inputs, Level 1 [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets, Fair Value Disclosure 139,318 304,558
Fair Value, Inputs, Level 2 [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets, Fair Value Disclosure $ 238,705 $ 86,675