Fair Value of Assets and Liabilities (Changes in Level 3 Assets and Liabilities) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Fixed Maturities Available-For-Sale | U.S. Corporate Public Securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning of period	$ 15,000	$ 16,860
Included in earnings:
Realized investment gains (losses), net	0	0
Asset management fees and other income	0	0
Included in other comprehensive income (loss)	0	(23)
Net investment income	0	9
Purchases	0	15,000
Sales	0	(15,000)
Issuances	0	0
Settlements	0	(119)
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Other	0
Fair Value, end of period	15,000	16,727
Included in earnings:
Realized investment gains (losses), net	0	0
Asset management fees and other income	0	0
Fixed Maturities Available-For-Sale | U.S. Corporate Private Securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning of period	107,777	98,544
Included in earnings:
Realized investment gains (losses), net	(962)	0
Asset management fees and other income	0	0
Included in other comprehensive income (loss)	(1,437)	(145)
Net investment income	1,381	1,267
Purchases	119	2,270
Sales	0	(212)
Issuances	0	0
Settlements	(210)	(129)
Transfers into Level 3	10,176	0
Transfers out of Level 3	0	0
Other	0
Fair Value, end of period	116,844	101,595
Included in earnings:
Realized investment gains (losses), net	(962)	0
Asset management fees and other income	0	0
Fixed Maturities Available-For-Sale | Foreign Corporate Private Securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning of period	4,531	666
Included in earnings:
Realized investment gains (losses), net	0	62
Asset management fees and other income	0	0
Included in other comprehensive income (loss)	(2,538)	(51)
Net investment income	50	1
Purchases	0	0
Sales	0	0
Issuances	0	0
Settlements	(1,740)	(678)
Transfers into Level 3	8,686	0
Transfers out of Level 3	0	0
Other	0
Fair Value, end of period	8,989	0
Included in earnings:
Realized investment gains (losses), net	0	0
Asset management fees and other income	0	0
Fixed Maturities Available-For-Sale | Asset-Backed Securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning of period	46,493	40,524
Included in earnings:
Realized investment gains (losses), net	0	0
Asset management fees and other income	0	0
Included in other comprehensive income (loss)	(225)	81
Net investment income	54	12
Purchases	0	0
Sales	0	0
Issuances	0	0
Settlements	(440)	(579)
Transfers into Level 3	17,824	9,783
Transfers out of Level 3	(987)	(983)
Other	0
Fair Value, end of period	62,719	48,838
Included in earnings:
Realized investment gains (losses), net	0	0
Asset management fees and other income	0	0
Trading Account Assets | Equity Securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning of period	0
Included in earnings:
Realized investment gains (losses), net	0
Asset management fees and other income	471
Included in other comprehensive income (loss)	0
Net investment income	0
Purchases	0
Sales	0
Issuances	0
Settlements	0
Transfers into Level 3	0
Transfers out of Level 3	0
Other	1,565
Fair Value, end of period	2,036
Included in earnings:
Realized investment gains (losses), net	470
Short-term investments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning of period	450
Included in earnings:
Realized investment gains (losses), net	0
Asset management fees and other income	0
Included in other comprehensive income (loss)	0
Net investment income	0
Purchases	0
Sales	0
Issuances	0
Settlements	0
Transfers into Level 3	0
Transfers out of Level 3	0
Other	0
Fair Value, end of period	450
Included in earnings:
Realized investment gains (losses), net	0
Asset management fees and other income	0
Cash Equivalents
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning of period	225	225
Included in earnings:
Realized investment gains (losses), net	0	0
Asset management fees and other income	0	0
Included in other comprehensive income (loss)	0	0
Net investment income	0	0
Purchases	150	0
Sales	0	0
Issuances	0	0
Settlements	0	0
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Other	0	0
Fair Value, end of period	375	225
Included in earnings:
Realized investment gains (losses), net	0	0
Asset management fees and other income	0	0
Other Long- term Investments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning of period	1,565	0
Included in earnings:
Realized investment gains (losses), net	0	0
Asset management fees and other income	0	0
Included in other comprehensive income (loss)	0	0
Net investment income	0	0
Purchases	0	0
Sales	0	0
Issuances	0	0
Settlements	0	0
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Other	(1,565)	0
Fair Value, end of period	0	0
Included in earnings:
Realized investment gains (losses), net	0	0
Asset management fees and other income	0	0
Reinsurance Recoverables
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning of period	3,012,653	2,996,154
Included in earnings:
Realized investment gains (losses), net	624,974	246,814
Asset management fees and other income	0	0
Included in other comprehensive income (loss)	0	0
Net investment income	0	0
Purchases	55,635	57,644
Sales	0	0
Issuances	0	0
Settlements	0	0
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Other	0	0
Fair Value, end of period	3,693,262	3,300,612
Included in earnings:
Realized investment gains (losses), net	643,330	272,379
Asset management fees and other income	0	0
Receivables from Parent and Affiliates
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning of period	7,664	22,320
Included in earnings:
Realized investment gains (losses), net	(13)	1
Asset management fees and other income	0	0
Included in other comprehensive income (loss)	141	(292)
Net investment income	0	0
Purchases	0	0
Sales	(1,988)	0
Issuances	0	0
Settlements	0	0
Transfers into Level 3	0	1,986
Transfers out of Level 3	(2,957)	0
Other	0	0
Fair Value, end of period	2,847	24,015
Included in earnings:
Realized investment gains (losses), net	0	0
Asset management fees and other income	0	0
Future Policy Benefits
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning of period	(3,134,077)	(3,112,411)
Included in earnings:
Realized investment gains (losses), net	(650,030)	(257,315)
Asset management fees and other income	0	0
Included in other comprehensive income (loss)	0	0
Net investment income	0	0
Purchases	0	0
Sales	0	0
Issuances	(58,500)	(60,523)
Settlements	0	0
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Other	0	0
Fair Value, end of period	(3,842,607)	(3,430,249)
Included in earnings:
Realized investment gains (losses), net	(669,159)	(283,739)
Asset management fees and other income	$ 0	$ 0