Annual report pursuant to Section 13 and 15(d)

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

v3.6.0.2
Income Taxes - Reconciliation between Federal Statutory Income Tax Rate and Effective Tax Rate (Detail)
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Income Tax Disclosure [Abstract]      
Federal statutory income tax rate 35.00% 35.00% 35.00%
State taxes, net of federal tax benefits 7.04% 8.32% 5.86%
Tax-exempt municipal securities (0.26%) (0.26%) (0.07%)
Tax credit - federal (2.50%) (2.51%) (2.27%)
Bargain purchase gain 0.00% 0.00% (7.03%)
Other (2.48%) 0.95% (0.01%)
Effective tax rate 36.80% 41.50% 31.48%