Annual report pursuant to Section 13 and 15(d)

Defined Contribution Plan (Details)

v3.19.3.a.u2
Defined Contribution Plan (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Defined Contribution Plan Disclosure [Line Items]      
Contribution plan cost (less than) $ 1 $ 1 $ 1
First 4% of Employee's Contribution      
Defined Contribution Plan Disclosure [Line Items]      
Defined contribution plan, employer's matching contribution, percentage of match 100.00%    
Defined contribution plan, employer matching contribution, percent of employees' gross pay 4.00%    
Next 2% of Employee's Contribution      
Defined Contribution Plan Disclosure [Line Items]      
Defined contribution plan, employer's matching contribution, percentage of match 50.00%    
Defined contribution plan, employer matching contribution, percent of employees' gross pay 2.00%