Covered Loans Thirty to Eighty Nine Days, Ninety Days or More Past Due (Detail) - Covered Loans - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Loans 90 Days Or More Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	$ 133,077	$ 137,182
Loans 90 Days Or More Past Due | One-to-four family
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	126,612	130,626
Loans 90 Days Or More Past Due | Other loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	6,465	6,556
Financing Receivable, 30-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	26,431	32,824
Financing Receivable, 30-89 Days Past Due | One-to-four family
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	24,973	30,455
Financing Receivable, 30-89 Days Past Due | Other loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	$ 1,458	$ 2,369