Fair Value of Financial Instruments (Details 2) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Investments
Other investments, Carrying Amount	$ 6,801,280	$ 6,539,473
Financial Liabilities
Fixed annuity contract liabilities, Carrying Amount	3,564,453	3,515,865
Fixed annuity contract liabilities, Fair value	3,347,970	3,302,333
Policyholder account balances on interest-sensitive life contracts, Carrying Amount	78,187	78,598
Policyholder account balances on interest-sensitive life contracts, Fair value	79,262	79,678
Other policyholder funds, Carrying Amount	344,838	346,292
Other policyholder funds, Fair Value	344,838	346,292
Short-term debt, Carrying Amount	38,000	38,000
Short-term debt, Fair Value	38,000	38,000
Long-term debt, Carrying Amount	199,890	199,874
Long-term debt, Fair Value	216,773	218,565
Other liabilities, repurchase agreement obligations, Carrying Amount	49,232	25,864
Other liabilities, repurchase agreement obligations, Fair Value	49,232	25,864
Other investments [Member]
Investments
Other investments, Carrying Amount	140,651	140,685
Other investments, Fair Value	144,894	144,921
Level 1 [Member]
Financial Liabilities
Fixed annuity contract liabilities, Fair value	0	0
Policyholder account balances on interest-sensitive life contracts, Fair value	0	0
Other policyholder funds, Fair Value	0	0
Short-term debt, Fair Value	0	0
Long-term debt, Fair Value	216,773	218,565
Other liabilities, repurchase agreement obligations, Fair Value	0	0
Level 1 [Member] | Other investments [Member]
Investments
Other investments, Fair Value	0	0
Level 2 [Member]
Financial Liabilities
Fixed annuity contract liabilities, Fair value	0	0
Policyholder account balances on interest-sensitive life contracts, Fair value	0	0
Other policyholder funds, Fair Value	250,051	250,000
Short-term debt, Fair Value	38,000	38,000
Long-term debt, Fair Value	0	0
Other liabilities, repurchase agreement obligations, Fair Value	49,232	25,864
Level 2 [Member] | Other investments [Member]
Investments
Other investments, Fair Value	0	0
Level 3 [Member]
Financial Liabilities
Fixed annuity contract liabilities, Fair value	3,347,970	3,302,333
Policyholder account balances on interest-sensitive life contracts, Fair value	79,262	79,678
Other policyholder funds, Fair Value	94,787	96,292
Short-term debt, Fair Value	0	0
Long-term debt, Fair Value	0	0
Other liabilities, repurchase agreement obligations, Fair Value	0	0
Level 3 [Member] | Other investments [Member]
Investments
Other investments, Fair Value	$ 144,894	$ 144,921