Segment Information - Underwriting income and reconciliations to Earnings before income taxes (Details) - USD ($)
$ in Thousands |
3 Months Ended |
Mar. 31, 2018 |
Mar. 31, 2017 |
| Segment Reporting Information [Line Items] |
|
|
| Statutory accident year underwriting income |
$ 7,737
|
$ 2,558
|
| Statutory accident year underwriting income, Combined Ratio |
94.70%
|
98.00%
|
| Bad debt charge-offs |
$ 3,711
|
$ 2,552
|
| Favorable (unfavorable) development on prior accident years |
8,856
|
6,368
|
| Statutory calendar year underwriting income |
$ 20,304
|
$ 11,478
|
| Statutory calendar year underwriting income, Combined Ratio |
91.30%
|
95.40%
|
| Statutory-to-GAAP underwriting income differences |
$ 6,005
|
$ 14
|
| GAAP calendar year underwriting income |
$ 26,309
|
$ 11,492
|
| GAAP calendar year underwriting income, Combined Ratio |
92.60%
|
96.60%
|
| Net investment income |
$ 9,786
|
$ 8,695
|
| Net realized gains on investments |
(2,832)
|
509
|
| Other income |
430
|
275
|
| Interest expense |
(3,509)
|
(3,512)
|
| Corporate general and administrative expenses |
(4,743)
|
(2,271)
|
| Other expenses |
(505)
|
(322)
|
| Earnings before income taxes |
24,937
|
14,868
|
| Personal Auto |
|
|
| Segment Reporting Information [Line Items] |
|
|
| Statutory accident year underwriting income |
$ 6,311
|
$ 1,594
|
| Statutory accident year underwriting income, Combined Ratio |
94.80%
|
98.30%
|
| Bad debt charge-offs |
$ 3,363
|
$ 2,251
|
| Favorable (unfavorable) development on prior accident years |
10,555
|
6,986
|
| Statutory calendar year underwriting income |
$ 20,229
|
$ 10,831
|
| Statutory calendar year underwriting income, Combined Ratio |
90.50%
|
95.20%
|
| Commercial Vehicle |
|
|
| Segment Reporting Information [Line Items] |
|
|
| Statutory accident year underwriting income |
$ 812
|
$ 629
|
| Statutory accident year underwriting income, Combined Ratio |
95.20%
|
95.30%
|
| Bad debt charge-offs |
$ 392
|
$ 291
|
| Favorable (unfavorable) development on prior accident years |
(1,362)
|
(874)
|
| Statutory calendar year underwriting income |
$ (158)
|
$ 45
|
| Statutory calendar year underwriting income, Combined Ratio |
97.80%
|
97.10%
|
| Classic Collector |
|
|
| Segment Reporting Information [Line Items] |
|
|
| Statutory accident year underwriting income |
$ 613
|
$ 335
|
| Statutory accident year underwriting income, Combined Ratio |
88.10%
|
95.30%
|
| Bad debt charge-offs |
$ (44)
|
$ 10
|
| Favorable (unfavorable) development on prior accident years |
(337)
|
256
|
| Statutory calendar year underwriting income |
$ 233
|
$ 602
|
| Statutory calendar year underwriting income, Combined Ratio |
98.20%
|
88.30%
|