Income Taxes - Effective Tax Rate (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Reconciliation of the Federal statutory income tax rate to the effective income tax rate, Amount
Federal statutory income tax expense	$ 51,182	$ 80,157	$ 75,217
State and local taxes, net of federal income tax benefit	10,327	21,179	20,817
Tax credits	(3,914)	(400)	(61)
Nontaxable income	(3,678)	(3,269)	(2,037)
Other	4,053	(361)	(152)
Total provision for income taxes	$ 57,970	$ 97,306	$ 93,784
Reconciliation of the Federal statutory income tax rate to the effective income tax rate, Percent
Federal statutory income tax rate, Percent	21.00%	21.00%	21.00%
State and local taxes, net of federal income tax benefit (as a percent)	4.24%	5.55%	5.81%
Tax credits (as a percent)	(1.60%)	(0.10%)	(0.02%)
Nontaxable income (as a percent)	(1.51%)	(0.86%)	(0.57%)
Other (as a percent)	1.66%	(0.10%)	(0.04%)
Effective Income Tax Rate Reconciliation, Percent, Total	23.79%	25.49%	26.18%