Annual report pursuant to Section 13 and 15(d)

Income Taxes - Reconciliation between Federal Statutory Income Tax Rate and Effective Tax Rate (Detail)

v3.10.0.1
Income Taxes - Reconciliation between Federal Statutory Income Tax Rate and Effective Tax Rate (Detail)
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Income Tax Disclosure [Abstract]      
Federal statutory income tax rate 21.00% 35.00% 35.00%
State taxes, net of federal tax benefits 9.50% 6.64% 7.04%
Tax-exempt municipal securities (0.16%) (0.24%) (0.26%)
Tax credit - federal (2.37%) (2.37%) (2.50%)
Federal rate adjustment, net of federal benefit of state 1.32% 4.18% 0.00%
Other 1.80% (0.58%) (2.48%)
Effective tax rate 31.09% 42.63% 36.80%