Fair Values of Financial Instruments (Quantitative Information) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	$ 2,950,677	$ 2,842,967
Financial and Nonfinancial Liabilities, Fair Value Disclosure	119,987	142,492
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	95,987	114,287
Financial and Nonfinancial Liabilities, Fair Value Disclosure	119,987	142,492
Derivatives, Index Options [Member] | Broker Prices [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	95,987	114,287
Other Liabilities [Member] | Black Scholes [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial and Nonfinancial Liabilities, Fair Value Disclosure	8,360	9,256
Policyholders Account Balance [Member] | Deterministic Cash Flow [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial and Nonfinancial Liabilities, Fair Value Disclosure	$ 111,627	$ 133,236