Annual report pursuant to Section 13 and 15(d)

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

v3.10.0.1
Securities - Available for Sale Securities, Continuous Unrealized Loss Position, Fair value (Detail)
$ in Thousands
Dec. 31, 2018
USD ($)
Security
Dec. 31, 2017
USD ($)
Security
Summary of Investment Holdings [Line Items]    
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Gross Unrealized Loss $ 321 $ 2,691
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Estimated Fair Value $ 78,252 $ 276,372
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Number of Positions | Security 20 93
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Gross Unrealized Loss $ 8,616 $ 2,593
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Estimated Fair Value $ 410,128 $ 138,033
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Number of Positions | Security 188 67
Debt Securities, Available-for-sale, Unrealized Loss Position, Gross Unrealized Loss $ 8,937 $ 5,284
Debt Securities, Available-for-sale, Unrealized Loss Position, Estimated Fair Value $ 488,380 $ 414,405
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions | Security 208 160
Mortgage-backed securities    
Summary of Investment Holdings [Line Items]    
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Gross Unrealized Loss $ 226 $ 1,855
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Estimated Fair Value $ 41,527 $ 197,621
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Number of Positions | Security 10 66
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Gross Unrealized Loss $ 5,758 $ 847
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Estimated Fair Value $ 244,550 $ 56,998
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Number of Positions | Security 106 25
Debt Securities, Available-for-sale, Unrealized Loss Position, Gross Unrealized Loss $ 5,984 $ 2,702
Debt Securities, Available-for-sale, Unrealized Loss Position, Estimated Fair Value $ 286,077 $ 254,619
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions | Security 116 91
Collateralized mortgage obligations    
Summary of Investment Holdings [Line Items]    
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Gross Unrealized Loss $ 59 $ 773
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Estimated Fair Value $ 13,732 $ 65,726
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Number of Positions | Security 3 20
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Gross Unrealized Loss $ 2,273 $ 1,125
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Estimated Fair Value $ 92,532 $ 49,986
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Number of Positions | Security 49 32
Debt Securities, Available-for-sale, Unrealized Loss Position, Gross Unrealized Loss $ 2,332 $ 1,898
Debt Securities, Available-for-sale, Unrealized Loss Position, Estimated Fair Value $ 106,264 $ 115,712
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions | Security 52 52
U.S. government agency securities    
Summary of Investment Holdings [Line Items]    
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Gross Unrealized Loss $ 0 $ 15
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Estimated Fair Value $ 0 $ 1,484
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Number of Positions | Security 0 1
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Gross Unrealized Loss $ 97 $ 70
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Estimated Fair Value $ 7,402 $ 5,930
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Number of Positions | Security 3 2
Debt Securities, Available-for-sale, Unrealized Loss Position, Gross Unrealized Loss $ 97 $ 85
Debt Securities, Available-for-sale, Unrealized Loss Position, Estimated Fair Value $ 7,402 $ 7,414
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions | Security 3 3
Municipal bonds-tax exempt    
Summary of Investment Holdings [Line Items]    
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Gross Unrealized Loss $ 29 $ 48
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Estimated Fair Value $ 8,196 $ 11,541
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Number of Positions | Security 5 6
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Gross Unrealized Loss $ 488 $ 21
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Estimated Fair Value $ 65,644 $ 2,737
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Number of Positions | Security 30 2
Debt Securities, Available-for-sale, Unrealized Loss Position, Gross Unrealized Loss $ 517 $ 69
Debt Securities, Available-for-sale, Unrealized Loss Position, Estimated Fair Value $ 73,840 $ 14,278
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions | Security 35 8
U.S. treasury securities    
Summary of Investment Holdings [Line Items]    
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Gross Unrealized Loss $ 7  
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Estimated Fair Value $ 14,797  
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Number of Positions | Security 2  
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Gross Unrealized Loss $ 0  
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Estimated Fair Value $ 0  
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Number of Positions | Security 0  
Debt Securities, Available-for-sale, Unrealized Loss Position, Gross Unrealized Loss $ 7  
Debt Securities, Available-for-sale, Unrealized Loss Position, Estimated Fair Value $ 14,797  
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions | Security 2  
Mutual funds    
Summary of Investment Holdings [Line Items]    
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Gross Unrealized Loss   $ 0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Estimated Fair Value   $ 0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Number of Positions | Security   0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Gross Unrealized Loss   $ 530
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Estimated Fair Value   $ 22,382
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Number of Positions | Security   6
Debt Securities, Available-for-sale, Unrealized Loss Position, Gross Unrealized Loss   $ 530
Debt Securities, Available-for-sale, Unrealized Loss Position, Estimated Fair Value   $ 22,382
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions | Security   6