Fair Value of Financial Instruments (Quantitative Information) (Details) - USD ($) $ in Thousands |
Dec. 31, 2016 |
Dec. 31, 2015 |
|---|---|---|
| Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items] | ||
| Assets | $ 3,181,007 | $ 2,917,992 |
| Liabilities | 134,693 | 66,028 |
| Level 3 | ||
| Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items] | ||
| Assets | 120,644 | 38,409 |
| Liabilities | 134,693 | 66,028 |
| Level 3 | Derivatives, index options | Broker prices | ||
| Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items] | ||
| Assets | 120,644 | 38,409 |
| Policyholder account balances | Level 3 | Deterministic cash flow model | ||
| Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items] | ||
| Liabilities | 122,666 | 58,359 |
| Other liabilities | Level 3 | Black Scholes | ||
| Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items] | ||
| Liabilities | $ 12,027 | $ 7,669 |