Deposits - Time Deposits by Remaining Maturity (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Time Deposits [Line Items]
Three months or less	$ 96,493
Three to six months	123,403
Six to twelve months	211,905
Over twelve months	429,241
Total, time deposits of $100,000 or more	861,042	$ 895,505
Certificates of Deposit [Member]
Time Deposits [Line Items]
Three months or less	88,520
Three to six months	113,475
Six to twelve months	187,347
Over twelve months	311,127
Total, time deposits of $100,000 or more	700,469
Other Time Deposits [Member]
Time Deposits [Line Items]
Three months or less	7,973
Three to six months	9,928
Six to twelve months	24,558
Over twelve months	118,114
Total, time deposits of $100,000 or more	$ 160,573