Investments - Available-for-sale Securities in Unrealized Loss Positions (Details) $ in Thousands | Jun. 30, 2018USD ($)security | Dec. 31, 2017USD ($)security |
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract] | | |
Less than 12 months, number of issues | security | | 110 |
Greater than 12 months, number of issues | security | | 59 |
Total Number of Issues | security | | 169 |
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract] | | |
Less than 12 months, fair value | | $ 53,517 |
Greater than 12 months, fair value | | 37,028 |
Total Fair Value | | 90,545 |
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract] | | |
Less than 12 months, unrealized losses | | (301) |
Greater than 12 months, unrealized losses | | (880) |
Total Unrealized losses | | $ (1,181) |
Asset-backed securities | | |
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract] | | |
Less than 12 months, number of issues | security | 32 | 20 |
Greater than 12 months, number of issues | security | 3 | 3 |
Total Number of Issues | security | 35 | 23 |
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract] | | |
Less than 12 months, fair value | $ 17,619 | $ 13,948 |
Greater than 12 months, fair value | 558 | 915 |
Total Fair Value | 18,177 | 14,863 |
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract] | | |
Less than 12 months, unrealized losses | (145) | (29) |
Greater than 12 months, unrealized losses | (8) | (6) |
Total Unrealized losses | $ (153) | $ (35) |
Corporate debt | | |
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract] | | |
Less than 12 months, number of issues | security | 55 | 38 |
Greater than 12 months, number of issues | security | 8 | 10 |
Total Number of Issues | security | 63 | 48 |
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract] | | |
Less than 12 months, fair value | $ 17,978 | $ 15,236 |
Greater than 12 months, fair value | 5,481 | 6,555 |
Total Fair Value | 23,459 | 21,791 |
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract] | | |
Less than 12 months, unrealized losses | (327) | (46) |
Greater than 12 months, unrealized losses | (412) | (163) |
Total Unrealized losses | $ (739) | $ (209) |
State and local government | | |
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract] | | |
Less than 12 months, number of issues | security | 36 | 10 |
Greater than 12 months, number of issues | security | 7 | 7 |
Total Number of Issues | security | 43 | 17 |
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract] | | |
Less than 12 months, fair value | $ 9,190 | $ 3,511 |
Greater than 12 months, fair value | 1,371 | 1,424 |
Total Fair Value | 10,561 | 4,935 |
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract] | | |
Less than 12 months, unrealized losses | (163) | (20) |
Greater than 12 months, unrealized losses | (58) | (34) |
Total Unrealized losses | $ (221) | $ (54) |
U.S. Government | | |
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract] | | |
Less than 12 months, number of issues | security | 13 | 12 |
Greater than 12 months, number of issues | security | 6 | 7 |
Total Number of Issues | security | 19 | 19 |
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract] | | |
Less than 12 months, fair value | $ 13,457 | $ 11,555 |
Greater than 12 months, fair value | 1,958 | 2,207 |
Total Fair Value | 15,415 | 13,762 |
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract] | | |
Less than 12 months, unrealized losses | (218) | (64) |
Greater than 12 months, unrealized losses | (48) | (35) |
Total Unrealized losses | $ (266) | $ (99) |
Mortgage-backed securities | | |
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract] | | |
Less than 12 months, number of issues | security | 19 | 6 |
Greater than 12 months, number of issues | security | 27 | 26 |
Total Number of Issues | security | 46 | 32 |
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract] | | |
Less than 12 months, fair value | $ 8,208 | $ 4,935 |
Greater than 12 months, fair value | 22,162 | 24,939 |
Total Fair Value | 30,370 | 29,874 |
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract] | | |
Less than 12 months, unrealized losses | (223) | (19) |
Greater than 12 months, unrealized losses | (1,108) | (503) |
Total Unrealized losses | $ (1,331) | $ (522) |
Commercial mortgage-backed securities | | |
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract] | | |
Less than 12 months, number of issues | security | 4 | 3 |
Greater than 12 months, number of issues | security | 2 | 2 |
Total Number of Issues | security | 6 | 5 |
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract] | | |
Less than 12 months, fair value | $ 2,718 | $ 2,026 |
Greater than 12 months, fair value | 659 | 722 |
Total Fair Value | 3,377 | 2,748 |
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract] | | |
Less than 12 months, unrealized losses | (37) | (12) |
Greater than 12 months, unrealized losses | (59) | (32) |
Total Unrealized losses | $ (96) | $ (44) |
Collateralized mortgage obligations | | |
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract] | | |
Less than 12 months, number of issues | security | 10 | 8 |
Greater than 12 months, number of issues | security | 0 | 0 |
Total Number of Issues | security | 10 | 8 |
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract] | | |
Less than 12 months, fair value | $ 1,881 | $ 1,870 |
Greater than 12 months, fair value | 0 | 0 |
Total Fair Value | 1,881 | 1,870 |
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract] | | |
Less than 12 months, unrealized losses | (63) | (36) |
Greater than 12 months, unrealized losses | 0 | 0 |
Total Unrealized losses | $ (63) | $ (36) |
Equity securities | | |
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract] | | |
Less than 12 months, number of issues | security | | 13 |
Greater than 12 months, number of issues | security | | 4 |
Total Number of Issues | security | | 17 |
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract] | | |
Less than 12 months, fair value | | $ 436 |
Greater than 12 months, fair value | | 266 |
Total Fair Value | | 702 |
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract] | | |
Less than 12 months, unrealized losses | | (75) |
Greater than 12 months, unrealized losses | | (107) |
Total Unrealized losses | | $ (182) |
Total debt securities available for sale | | |
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract] | | |
Less than 12 months, number of issues | security | 169 | 97 |
Greater than 12 months, number of issues | security | 53 | 55 |
Total Number of Issues | security | 222 | 152 |
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract] | | |
Less than 12 months, fair value | $ 71,051 | $ 53,081 |
Greater than 12 months, fair value | 32,189 | 36,762 |
Total Fair Value | 103,240 | 89,843 |
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract] | | |
Less than 12 months, unrealized losses | (1,176) | (226) |
Greater than 12 months, unrealized losses | (1,693) | (773) |
Total Unrealized losses | $ (2,869) | $ (999) |