Fair Value - Fair Value by Hierarchy (Details) - USD ($)
$ in Thousands |
Sep. 30, 2016 |
Dec. 31, 2015 |
| Fair Value, Assets and Liabilities Measured on Recurring Basis |
|
|
| Available-for-sale securities: |
$ 1,499,710
|
$ 1,476,053
|
| Recurring basis | Level 2 |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring Basis |
|
|
| Long-term debt |
292,100
|
281,600
|
| Fair Value |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring Basis |
|
|
| Cash and cash equivalents |
73,616
|
62,483
|
| Long-term debt |
292,075
|
281,581
|
| Fair Value | Fixed Maturities |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring Basis |
|
|
| Available-for-sale securities: |
1,404,633
|
1,381,467
|
| Fair Value | Equity securities |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring Basis |
|
|
| Available-for-sale securities: |
92,822
|
89,935
|
| Fair Value | Short-term investments |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring Basis |
|
|
| Available-for-sale securities: |
2,255
|
4,651
|
| Fair Value | Recurring basis |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring Basis |
|
|
| Cash and cash equivalents |
73,616
|
62,483
|
| Total cash and investments |
$ 1,573,327
|
$ 1,538,536
|
| Percentage of total cash and investments (percent) |
100.00%
|
100.00%
|
| Fair Value | Recurring basis | Fixed Maturities |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring Basis |
|
|
| Available-for-sale securities: |
$ 1,404,633
|
$ 1,381,467
|
| Fair Value | Recurring basis | U.S. government |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring Basis |
|
|
| Available-for-sale securities: |
63,942
|
64,669
|
| Fair Value | Recurring basis | State and Municipal |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring Basis |
|
|
| Available-for-sale securities: |
478,199
|
479,666
|
| Fair Value | Recurring basis | Mortgage- Backed Securities |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring Basis |
|
|
| Available-for-sale securities: |
415,845
|
405,008
|
| Fair Value | Recurring basis | Residential |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring Basis |
|
|
| Available-for-sale securities: |
339,655
|
334,784
|
| Fair Value | Recurring basis | Commercial |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring Basis |
|
|
| Available-for-sale securities: |
76,190
|
70,224
|
| Fair Value | Recurring basis | Asset-backed securities |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring Basis |
|
|
| Available-for-sale securities: |
44,465
|
54,018
|
| Fair Value | Recurring basis | Corporates |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring Basis |
|
|
| Available-for-sale securities: |
402,182
|
378,105
|
| Fair Value | Recurring basis | Equity securities |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring Basis |
|
|
| Available-for-sale securities: |
92,822
|
89,935
|
| Fair Value | Recurring basis | Short-term investments |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring Basis |
|
|
| Available-for-sale securities: |
2,255
|
4,651
|
| Fair Value | Recurring basis | Level 1 |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring Basis |
|
|
| Cash and cash equivalents |
73,616
|
62,483
|
| Total cash and investments |
$ 231,144
|
$ 217,056
|
| Percentage of total cash and investments (percent) |
14.70%
|
14.10%
|
| Fair Value | Recurring basis | Level 1 | Fixed Maturities |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring Basis |
|
|
| Available-for-sale securities: |
$ 63,937
|
$ 64,638
|
| Fair Value | Recurring basis | Level 1 | U.S. government |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring Basis |
|
|
| Available-for-sale securities: |
63,937
|
64,638
|
| Fair Value | Recurring basis | Level 1 | State and Municipal |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring Basis |
|
|
| Available-for-sale securities: |
0
|
0
|
| Fair Value | Recurring basis | Level 1 | Mortgage- Backed Securities |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring Basis |
|
|
| Available-for-sale securities: |
0
|
0
|
| Fair Value | Recurring basis | Level 1 | Residential |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring Basis |
|
|
| Available-for-sale securities: |
0
|
0
|
| Fair Value | Recurring basis | Level 1 | Commercial |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring Basis |
|
|
| Available-for-sale securities: |
0
|
0
|
| Fair Value | Recurring basis | Level 1 | Asset-backed securities |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring Basis |
|
|
| Available-for-sale securities: |
0
|
0
|
| Fair Value | Recurring basis | Level 1 | Corporates |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring Basis |
|
|
| Available-for-sale securities: |
0
|
0
|
| Fair Value | Recurring basis | Level 1 | Equity securities |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring Basis |
|
|
| Available-for-sale securities: |
92,822
|
89,935
|
| Fair Value | Recurring basis | Level 1 | Short-term investments |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring Basis |
|
|
| Available-for-sale securities: |
768
|
0
|
| Fair Value | Recurring basis | Level 2 |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring Basis |
|
|
| Cash and cash equivalents |
0
|
0
|
| Total cash and investments |
$ 1,340,065
|
$ 1,319,946
|
| Percentage of total cash and investments (percent) |
85.20%
|
85.80%
|
| Fair Value | Recurring basis | Level 2 | Fixed Maturities |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring Basis |
|
|
| Available-for-sale securities: |
$ 1,338,577
|
$ 1,315,295
|
| Fair Value | Recurring basis | Level 2 | U.S. government |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring Basis |
|
|
| Available-for-sale securities: |
5
|
32
|
| Fair Value | Recurring basis | Level 2 | State and Municipal |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring Basis |
|
|
| Available-for-sale securities: |
477,581
|
479,656
|
| Fair Value | Recurring basis | Level 2 | Mortgage- Backed Securities |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring Basis |
|
|
| Available-for-sale securities: |
415,845
|
405,008
|
| Fair Value | Recurring basis | Level 2 | Residential |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring Basis |
|
|
| Available-for-sale securities: |
339,655
|
334,784
|
| Fair Value | Recurring basis | Level 2 | Commercial |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring Basis |
|
|
| Available-for-sale securities: |
76,190
|
70,224
|
| Fair Value | Recurring basis | Level 2 | Asset-backed securities |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring Basis |
|
|
| Available-for-sale securities: |
43,969
|
54,018
|
| Fair Value | Recurring basis | Level 2 | Corporates |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring Basis |
|
|
| Available-for-sale securities: |
401,177
|
376,582
|
| Fair Value | Recurring basis | Level 2 | Equity securities |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring Basis |
|
|
| Available-for-sale securities: |
0
|
0
|
| Fair Value | Recurring basis | Level 2 | Short-term investments |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring Basis |
|
|
| Available-for-sale securities: |
1,487
|
4,651
|
| Fair Value | Recurring basis | Level 3 |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring Basis |
|
|
| Cash and cash equivalents |
0
|
0
|
| Total cash and investments |
$ 2,118
|
$ 1,534
|
| Percentage of total cash and investments (percent) |
0.10%
|
0.10%
|
| Fair Value | Recurring basis | Level 3 | Fixed Maturities |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring Basis |
|
|
| Available-for-sale securities: |
$ 2,118
|
$ 1,534
|
| Fair Value | Recurring basis | Level 3 | U.S. government |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring Basis |
|
|
| Available-for-sale securities: |
0
|
0
|
| Fair Value | Recurring basis | Level 3 | State and Municipal |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring Basis |
|
|
| Available-for-sale securities: |
618
|
10
|
| Fair Value | Recurring basis | Level 3 | Mortgage- Backed Securities |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring Basis |
|
|
| Available-for-sale securities: |
0
|
0
|
| Fair Value | Recurring basis | Level 3 | Residential |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring Basis |
|
|
| Available-for-sale securities: |
0
|
0
|
| Fair Value | Recurring basis | Level 3 | Commercial |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring Basis |
|
|
| Available-for-sale securities: |
0
|
0
|
| Fair Value | Recurring basis | Level 3 | Asset-backed securities |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring Basis |
|
|
| Available-for-sale securities: |
495
|
0
|
| Fair Value | Recurring basis | Level 3 | Corporates |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring Basis |
|
|
| Available-for-sale securities: |
1,005
|
1,524
|
| Fair Value | Recurring basis | Level 3 | Equity securities |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring Basis |
|
|
| Available-for-sale securities: |
0
|
0
|
| Fair Value | Recurring basis | Level 3 | Short-term investments |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring Basis |
|
|
| Available-for-sale securities: |
$ 0
|
$ 0
|