Income Taxes - Effective Income Tax Rate Reconciliation (Details)
12 Months Ended
Dec. 31, 2017
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Effective Income Tax Rate Reconciliation, Percent        
U.S. federal statutory income tax rate   21.00% 21.00% 35.00%
State taxes, net of federal benefit   2.30% 2.50% 1.80%
Foreign tax rate differential   0.00% 0.10% (2.20%)
Tax Cuts and Jobs Act adjustment 0.072 0 (0.005) 0.072
Other   (0.20%) 0.50% 0.00%
Effective income tax rate   23.10% 23.60% 41.80%