Loans - Total Loans on Nonaccrual (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans on nonaccrual	$ 49,668	$ 53,891
Gaming [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans on nonaccrual	12,172	16,249
Residential and land development [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans on nonaccrual	20,971	21,083
Real estate, construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans on nonaccrual	4,954	5,171
Real estate, mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans on nonaccrual	11,571	11,174
Commercial and Industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans on nonaccrual		$ 214