Investments: Gain/Loss on Investments (Details) - USD ($) $ in Thousands |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2015 |
Dec. 31, 2014 |
Dec. 31, 2013 |
|
| Investments [Abstract] | |||
| Proceeds | $ 27,327 | $ 4,980 | $ 45,137 |
| Gross gains | 449 | 0 | 11 |
| Gross losses | $ (357) | $ (20) | $ (49) |