Segment Information (Details) - USD ($)
$ in Thousands
 3 Months Ended 12 Months Ended
Dec. 31, 2015
Sep. 30, 2015
Jun. 30, 2015
Mar. 31, 2015
Dec. 31, 2014
Sep. 30, 2014
Jun. 30, 2014
Mar. 31, 2014
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Segment Reporting Information [Line Items]                      
Goodwill and other intangibles $ 42,911       $ 8,813       $ 42,911 $ 8,813  
Total assets 1,869,902       1,136,967       1,869,902 1,136,967  
Net interest income 16,458 $ 14,538 $ 9,749 $ 8,992 9,243 $ 9,285 $ 8,952 $ 8,856 49,737 36,336 $ 35,896
Provision for loan losses                 3,510 1,880 1,290
Service fees, security gains and other noninterest income 5,175 4,685 4,409 4,037 4,193 3,880 3,797 3,433 18,306 15,303 13,914
Noninterest expense                 51,521 36,280 37,212
Amortization and depreciation expense                 2,458 1,882 1,845
INCOME BEFORE INCOME TAXES 4,023 2,482 1,221 2,828 2,744 2,964 3,071 2,818 10,554 11,597 9,463
Income tax 848 625 409 617 597 688 720 627 2,499 2,632 1,683
NET INCOME 3,175 $ 1,857 $ 812 $ 2,211 2,147 $ 2,276 $ 2,351 $ 2,191 8,055 8,965 7,780
Eliminations And Others                      
Segment Reporting Information [Line Items]                      
Goodwill and other intangibles (646)       0       (646) 0  
Total assets 391       463       391 463  
Net interest income                 (33) (14) (14)
Provision for loan losses                 0 0 0
Service fees, security gains and other noninterest income                 (255) (254) (218)
Noninterest expense                 4,562 474 1,420
Amortization and depreciation expense                 0 0 0
INCOME BEFORE INCOME TAXES                 (4,850) (742) (1,652)
Income tax                 (991) (512) (562)
NET INCOME                 (3,859) (230) (1,090)
Trust Segment | Operating Segments                      
Segment Reporting Information [Line Items]                      
Goodwill and other intangibles 4,967       5,285       4,967 5,285  
Total assets 11,078       10,643       11,078 10,643  
Net interest income                 65 53 45
Provision for loan losses                 0 0 0
Service fees, security gains and other noninterest income                 6,239 6,170 5,667
Noninterest expense                 4,719 4,528 4,483
Amortization and depreciation expense                 339 378 416
INCOME BEFORE INCOME TAXES                 1,246 1,317 813
Income tax                 425 451 282
NET INCOME                 821 866 531
Bank Segment | Operating Segments                      
Segment Reporting Information [Line Items]                      
Goodwill and other intangibles 35,412       0       35,412 0  
Total assets 1,854,306       1,121,505       1,854,306 1,121,505  
Net interest income                 49,705 36,297 35,865
Provision for loan losses                 3,510 1,880 1,290
Service fees, security gains and other noninterest income                 10,192 7,577 7,838
Noninterest expense                 40,753 29,268 30,682
Amortization and depreciation expense                 1,759 1,081 1,193
INCOME BEFORE INCOME TAXES                 13,875 11,645 10,538
Income tax                 2,968 2,645 2,043
NET INCOME                 10,907 9,000 8,495
Retirement Consulting Segment | Operating Segments                      
Segment Reporting Information [Line Items]                      
Goodwill and other intangibles 3,178       3,528       3,178 3,528  
Total assets $ 4,127       $ 4,356       4,127 4,356  
Net interest income                 0 0 0
Provision for loan losses                 0 0 0
Service fees, security gains and other noninterest income                 2,130 1,810 627
Noninterest expense                 1,487 2,010 627
Amortization and depreciation expense                 360 423 236
INCOME BEFORE INCOME TAXES                 283 (623) (236)
Income tax                 97 48 (80)
NET INCOME                 $ 186 $ (671) $ (156)