Quality of Non-Covered Loans (Excluding PCI Loans) (Parenthetical) (Detail) - Non-Covered Loans - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	$ 62,829	$ 83,142
Loans 90 Days Or More Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	$ 1,100