Income Taxes - Effective Tax Rate (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Reconciliation of the Federal statutory income tax rate to the effective income tax rate, Amount
Federal statutory income tax expense	$ 80,157	$ 75,217	$ 128,924
State and local taxes, net of federal income tax benefit	21,179	20,817	16,106
Impact of Tax Reform			47,598
Nontaxable income	(3,269)	(2,037)	(4,974)
Other	(761)	(213)	(2,981)
Total provision for income taxes	$ 97,306	$ 93,784	$ 184,673
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%	35.00%
State and local taxes, net of federal income tax benefit (as a percent)	5.55%	5.81%	4.37%
Impact of Tax Reform (as a percent)			12.92%
Nontaxable income (as a percent)	(0.86%)	(0.57%)	(1.35%)
Other (as a percent)	(0.20%)	(0.06%)	(0.81%)
Effective Income Tax Rate Reconciliation, Percent, Total	25.49%	26.18%	50.13%