XML 99 R75.htm IDEA: XBRL DOCUMENT v3.8.0.1
Securities - Gross Unrealized Losses and Fair Value of Company's Investments (Detail) - USD ($)
$ in Thousands
Dec. 31, 2017
Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]    
Fair Value less than 12 months $ 229,768 $ 425,635
Fair value more than 12 months 193,869 10,199
Total fair value 423,637 435,834
Unrealized losses less than 12 months (4,554) (9,413)
Unrealized losses more than 12 months (4,974) (252)
Total unrealized losses (9,528) (9,665)
U.S. Treasury and Federal Agencies [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Fair Value less than 12 months 15,882 6,987
Fair value more than 12 months 2,870  
Total fair value 18,752 6,987
Unrealized losses less than 12 months (180) (64)
Unrealized losses more than 12 months (45)  
Total unrealized losses (225) (64)
State and Municipal [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Fair Value less than 12 months 54,312 142,466
Fair value more than 12 months 30,691  
Total fair value 85,003 142,466
Unrealized losses less than 12 months (2,758) (3,544)
Unrealized losses more than 12 months (844)  
Total unrealized losses (3,602) (3,544)
Federal Agency Collateralized Mortgage Obligations [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Fair Value less than 12 months 54,006 112,414
Fair value more than 12 months 73,462 10,199
Total fair value 127,468 122,613
Unrealized losses less than 12 months (589) (1,918)
Unrealized losses more than 12 months (2,031) (252)
Total unrealized losses (2,620) (2,170)
Federal Agency Mortgage-backed Pools [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Fair Value less than 12 months 103,926 163,768
Fair value more than 12 months 86,846  
Total fair value 190,772 163,768
Unrealized losses less than 12 months (1,019) (3,887)
Unrealized losses more than 12 months (2,054)  
Total unrealized losses (3,073) $ (3,887)
Private Labeled Mortgage-backed Pools [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Fair Value less than 12 months 1,642  
Total fair value 1,642  
Unrealized losses less than 12 months (8)  
Total unrealized losses $ (8)