XML 92 R78.htm IDEA: XBRL DOCUMENT v3.20.4
Income Taxes - Changes in Valuation Allowance (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Changes In Valuation Allowance [Roll Forward]      
Valuation allowance, at beginning of year $ 0 $ 23,002 $ 23,827
Decrease in valuation allowance 0 (23,002) (825)
Valuation allowance, at end of year $ 0 $ 0 $ 23,002