Income Taxes - Effective Income Tax Rate Reconciliation (Details)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Effective Income Tax Rate Reconciliation, Percent
U.S. federal statutory income tax rate	21.00%	21.00%	21.00%
State taxes, net of federal benefit	1.90%	2.30%	2.50%
Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Percent	(2.60%)	0.70%	0.00%
Other	0.20%	(0.90%)	0.10%
Effective income tax rate	20.50%	23.10%	23.60%