New Accounting Standards (Details) - USD ($)
$ in Thousands |
|
3 Months Ended |
12 Months Ended |
Jan. 01, 2018 |
Mar. 31, 2018 |
Mar. 31, 2017 |
Dec. 31, 2017 |
| New Accounting Pronouncements or Change in Accounting Principle [Line Items] |
|
|
|
|
| Retained earnings |
|
$ 279,830
|
|
$ 265,007
|
| Noninterest Income |
|
$ 17,830
|
$ 17,240
|
|
| Accounting Standards Update 2014-09 |
|
|
|
|
| New Accounting Pronouncements or Change in Accounting Principle [Line Items] |
|
|
|
|
| Cumulative effect of new accounting principle |
|
|
|
1,780
|
| Accounting Standards Update 2016-01 |
|
|
|
|
| New Accounting Pronouncements or Change in Accounting Principle [Line Items] |
|
|
|
|
| Cumulative effect of new accounting principle |
$ 65
|
|
|
0
|
| Accounting Standards Update 2018-02 |
|
|
|
|
| New Accounting Pronouncements or Change in Accounting Principle [Line Items] |
|
|
|
|
| Reclassified from AOCI to retained earnings due to Tax Cuts and Jobs Act |
|
|
|
$ 10,000
|
| Difference between Revenue Guidance in Effect before and after Topic 606 | Contingent commissions | Insurance Business Segment |
|
|
|
|
| New Accounting Pronouncements or Change in Accounting Principle [Line Items] |
|
|
|
|
| Noninterest Income |
1,800
|
|
|
|
| Difference between Revenue Guidance in Effect before and after Topic 606 | Accounting Standards Update 2014-09 |
|
|
|
|
| New Accounting Pronouncements or Change in Accounting Principle [Line Items] |
|
|
|
|
| Retained earnings |
$ 1,800
|
|
|
|