Quarterly report pursuant to Section 13 or 15(d)

Securities - Available for Sale Securities, Continuous Unrealized Loss Position, Fair value (Detail)

v3.5.0.2
Securities - Available for Sale Securities, Continuous Unrealized Loss Position, Fair value (Detail)
$ in Thousands
 9 Months Ended 12 Months Ended
Sep. 30, 2016
USD ($)
Security
Dec. 31, 2015
USD ($)
Security
Summary of Investment Holdings [Line Items]    
Available-for-Sale Within One Year, Gross Unrealized Loss $ 129 $ 2,628
Available-for-Sale Within One Year, Estimated Fair Value $ 52,707 $ 359,531
Available-for-Sale Within One Year, Number of Securities | Security 20 104
Available-for-Sale More than One Year, Gross Unrealized Loss $ 339 $ 2,191
Available-for-Sale More than One Year, Estimated Fair Value $ 29,843 $ 87,120
Available-for-Sale More than One Year, Number of Securities | Security 15 36
Available-for-Sale, Gross Unrealized Loss $ 468 $ 4,819
Available-for-Sale, Estimated Fair Value $ 82,550 $ 446,651
Available-for-Sale, Number of Securities | Security 35 140
Municipal bonds-tax exempt [Member]    
Summary of Investment Holdings [Line Items]    
Available-for-Sale Within One Year, Gross Unrealized Loss   $ 19
Available-for-Sale Within One Year, Estimated Fair Value   $ 8,922
Available-for-Sale Within One Year, Number of Securities | Security   6
Available-for-Sale More than One Year, Gross Unrealized Loss   $ 0
Available-for-Sale More than One Year, Estimated Fair Value   $ 0
Available-for-Sale More than One Year, Number of Securities | Security   0
Available-for-Sale, Gross Unrealized Loss   $ 19
Available-for-Sale, Estimated Fair Value   $ 8,922
Available-for-Sale, Number of Securities | Security   6
Municipal bonds-taxable [Member]    
Summary of Investment Holdings [Line Items]    
Available-for-Sale Within One Year, Gross Unrealized Loss   $ 88
Available-for-Sale Within One Year, Estimated Fair Value   $ 7,106
Available-for-Sale Within One Year, Number of Securities | Security   4
Available-for-Sale More than One Year, Gross Unrealized Loss   $ 0
Available-for-Sale More than One Year, Estimated Fair Value   $ 0
Available-for-Sale More than One Year, Number of Securities | Security   0
Available-for-Sale, Gross Unrealized Loss   $ 88
Available-for-Sale, Estimated Fair Value   $ 7,106
Available-for-Sale, Number of Securities | Security   4
Mutual funds [Member]    
Summary of Investment Holdings [Line Items]    
Available-for-Sale Within One Year, Gross Unrealized Loss $ 0 $ 66
Available-for-Sale Within One Year, Estimated Fair Value $ 0 $ 21,820
Available-for-Sale Within One Year, Number of Securities | Security 0 3
Available-for-Sale More than One Year, Gross Unrealized Loss $ 87 $ 97
Available-for-Sale More than One Year, Estimated Fair Value $ 938 $ 928
Available-for-Sale More than One Year, Number of Securities | Security 3 3
Available-for-Sale, Gross Unrealized Loss $ 87 $ 163
Available-for-Sale, Estimated Fair Value $ 938 $ 22,748
Available-for-Sale, Number of Securities | Security 3 6
Mortgage-backed securities [Member]    
Summary of Investment Holdings [Line Items]    
Available-for-Sale Within One Year, Gross Unrealized Loss $ 17 $ 1,734
Available-for-Sale Within One Year, Estimated Fair Value $ 9,799 $ 193,931
Available-for-Sale Within One Year, Number of Securities | Security 5 52
Available-for-Sale More than One Year, Gross Unrealized Loss $ 85 $ 727
Available-for-Sale More than One Year, Estimated Fair Value $ 11,639 $ 21,659
Available-for-Sale More than One Year, Number of Securities | Security 3 9
Available-for-Sale, Gross Unrealized Loss $ 102 $ 2,461
Available-for-Sale, Estimated Fair Value $ 21,438 $ 215,590
Available-for-Sale, Number of Securities | Security 8 61
Collateralized mortgage obligations [Member]    
Summary of Investment Holdings [Line Items]    
Available-for-Sale Within One Year, Gross Unrealized Loss $ 110 $ 335
Available-for-Sale Within One Year, Estimated Fair Value $ 34,898 $ 48,970
Available-for-Sale Within One Year, Number of Securities | Security 13 18
Available-for-Sale More than One Year, Gross Unrealized Loss $ 127 $ 662
Available-for-Sale More than One Year, Estimated Fair Value $ 12,721 $ 32,964
Available-for-Sale More than One Year, Number of Securities | Security 7 13
Available-for-Sale, Gross Unrealized Loss $ 237 $ 997
Available-for-Sale, Estimated Fair Value $ 47,619 $ 81,934
Available-for-Sale, Number of Securities | Security 20 31
U.S. government agency securities [Member]    
Summary of Investment Holdings [Line Items]    
Available-for-Sale Within One Year, Gross Unrealized Loss $ 1 $ 201
Available-for-Sale Within One Year, Estimated Fair Value $ 3,000 $ 23,289
Available-for-Sale Within One Year, Number of Securities | Security 1 8
Available-for-Sale More than One Year, Gross Unrealized Loss $ 0 $ 455
Available-for-Sale More than One Year, Estimated Fair Value $ 0 $ 24,533
Available-for-Sale More than One Year, Number of Securities | Security 0 8
Available-for-Sale, Gross Unrealized Loss $ 1 $ 656
Available-for-Sale, Estimated Fair Value $ 3,000 $ 47,822
Available-for-Sale, Number of Securities | Security 1 16
SBA loan pool securities [Member]    
Summary of Investment Holdings [Line Items]    
Available-for-Sale Within One Year, Gross Unrealized Loss $ 0 $ 161
Available-for-Sale Within One Year, Estimated Fair Value $ 0 $ 50,499
Available-for-Sale Within One Year, Number of Securities | Security 0 12
Available-for-Sale More than One Year, Gross Unrealized Loss $ 40 $ 250
Available-for-Sale More than One Year, Estimated Fair Value $ 4,545 $ 7,036
Available-for-Sale More than One Year, Number of Securities | Security 2 3
Available-for-Sale, Gross Unrealized Loss $ 40 $ 411
Available-for-Sale, Estimated Fair Value $ 4,545 $ 57,535
Available-for-Sale, Number of Securities | Security 2 15
Corporate bonds [Member]    
Summary of Investment Holdings [Line Items]    
Available-for-Sale Within One Year, Gross Unrealized Loss $ 1 $ 24
Available-for-Sale Within One Year, Estimated Fair Value $ 5,010 $ 4,994
Available-for-Sale Within One Year, Number of Securities | Security 1 1
Available-for-Sale More than One Year, Gross Unrealized Loss $ 0 $ 0
Available-for-Sale More than One Year, Estimated Fair Value $ 0 $ 0
Available-for-Sale More than One Year, Number of Securities | Security 0 0
Available-for-Sale, Gross Unrealized Loss $ 1 $ 24
Available-for-Sale, Estimated Fair Value $ 5,010 $ 4,994
Available-for-Sale, Number of Securities | Security 1 1