Loans (Detail) - 1-4 Family Mortgage Loans Sales - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Loan sales
Proceeds		$ 185,308	$ 148,680	$ 152,130
Book Value		180,017	144,909	147,413
Net Gains	[1]	5,291	3,771	4,717
Loans originated with intent to sell
Loan sales
Proceeds		157,499	95,422	37,788
Book Value		153,130	92,525	36,592
Net Gains	[1]	4,369	2,897	1,196
Loans held-for-investment
Loan sales
Proceeds		27,809	53,258	114,342
Book Value		26,887	52,384	110,821
Net Gains	[1]	$ 922	$ 874	$ 3,521

[1] Net gains on mortgage loan sales are included in mortgage banking income in the Consolidated Statements of Income.