XML 91 R72.htm IDEA: XBRL DOCUMENT v3.20.4
Income Taxes (Schedule of Effective Income Tax Rate Reconciliation) (Details)
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Income Tax Disclosure [Abstract]      
Federal tax expense at statutory rate 21.00% 21.00% 21.00%
State income tax expense (net of federal income tax benefit) 4.00% 4.00% 4.00%
Permanent differences associated with general business credits 6.00% 7.00% 1.00%
Change in valuation allowance (23.00%) (31.00%) (25.00%)
Other permanent differences (7.00%) 1.00% (1.00%)
Other (3.00%) 0.00% 0.00%
Net income tax expense (2.00%) 2.00% 0.00%