Fair Value of Assets and Liabilities (Changes in Level 3 Assets and Liabilities) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 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	$ 16,727	$ 15,000	$ 16,860
Included in earnings:
Realized investment gains (losses), net	0	0	0	0
Asset management fees and other income	0	0	0	0
Included in other comprehensive income (loss)	0	0	0	(23)
Net investment income	0	0	0	9
Purchases	0	15,000	0	30,000
Sales	0	(15,000)	0	(30,000)
Issuances	0	0	0	0
Settlements	0	0	0	(119)
Transfers into Level 3	0	0	0	0
Transfers out of Level 3	0	(1,727)	0	(1,727)
Other	0		0
Fair Value, end of period	15,000	15,000	15,000	15,000
Included in earnings:
Realized investment gains (losses), net	0	0	0	0
Asset management fees and other income	0	0	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	116,844	101,595	107,777	98,544
Included in earnings:
Realized investment gains (losses), net	0	0	(962)	0
Asset management fees and other income	0	0	0	0
Included in other comprehensive income (loss)	(1,450)	(344)	(2,887)	(490)
Net investment income	1,400	1,309	2,781	2,576
Purchases	11,108	337	11,227	2,608
Sales	0	(217)	0	(429)
Issuances	0	0	0	0
Settlements	(214)	(197)	(424)	(326)
Transfers into Level 3	0	0	10,176	0
Transfers out of Level 3	(1,015)	0	(1,015)	0
Other	0		0
Fair Value, end of period	126,673	102,483	126,673	102,483
Included in earnings:
Realized investment gains (losses), net	0	0	(962)	0
Asset management fees and other income	0	0	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	8,989	0	4,531	666
Included in earnings:
Realized investment gains (losses), net	0	0	0	62
Asset management fees and other income	0	0	0	0
Included in other comprehensive income (loss)	3,525	0	987	(51)
Net investment income	77	0	127	1
Purchases	1,991	0	1,990	0
Sales	0	0	0	0
Issuances	0	0	0	0
Settlements	0	0	(1,739)	(678)
Transfers into Level 3	0	0	8,686	0
Transfers out of Level 3	0	0	0	0
Other	0		0
Fair Value, end of period	14,582	0	14,582	0
Included in earnings:
Realized investment gains (losses), net	0	0	0	0
Asset management fees and other income	0	0	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	62,719	48,838	46,493	40,524
Included in earnings:
Realized investment gains (losses), net	2	(1)	2	(1)
Asset management fees and other income	0	0	0
Included in other comprehensive income (loss)	263	130	38	211
Net investment income	34	(1)	88	11
Purchases	54,119	7,871	54,119	7,871
Sales	(250)	(7,884)	(250)	(7,884)
Issuances	0	0	0
Settlements	(48)	(559)	(488)	(1,138)
Transfers into Level 3	0	985	17,824	10,768
Transfers out of Level 3	(29,468)	(5,938)	(30,455)	(6,921)
Other	0		0
Fair Value, end of period	87,371	43,441	87,371	43,441
Included in earnings:
Realized investment gains (losses), net	0	0	0
Asset management fees and other income	0	0	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	2,036		0
Included in earnings:
Realized investment gains (losses), net	0		0
Asset management fees and other income	(383)		88
Included in other comprehensive income (loss)	0		0
Net investment income	0		0
Purchases	3,423		3,423
Sales	0		0
Issuances	0		0
Settlements	0		0
Transfers into Level 3	0		0
Transfers out of Level 3	0		0
Other	0		1,565
Fair Value, end of period	5,076		5,076
Included in earnings:
Realized investment gains (losses), net	0		0
Asset management fees and other income	(383)		88
Short-term investments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning of period	450	0	450	0
Included in earnings:
Realized investment gains (losses), net	0	0	0	0
Asset management fees and other income	0	0	0	0
Included in other comprehensive income (loss)	0	0	0	0
Net investment income	0	0	0	0
Purchases	0	300	0	300
Sales	0	0	0	0
Issuances	0	0	0	0
Settlements	0	0	0	0
Transfers into Level 3	0	0	0	0
Transfers out of Level 3	0	0	0	0
Other	0		0
Fair Value, end of period	450	300	450	300
Included in earnings:
Realized investment gains (losses), net	0	0	0	0
Asset management fees and other income	0	0	0	0
Cash Equivalents
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning of period	375	225	225	225
Included in earnings:
Realized investment gains (losses), net	0	0	0	0
Asset management fees and other income		0	0	0
Included in other comprehensive income (loss)	0	0	0	0
Net investment income	0	0	0	0
Purchases	0	0	150	0
Sales	0	0	0	0
Issuances	0	0	0	0
Settlements	0	0	0	0
Transfers into Level 3	0	0	0	0
Transfers out of Level 3	0	0	0	0
Other	0		0
Fair Value, end of period	375	225	375	225
Included in earnings:
Realized investment gains (losses), net	0	0	0	0
Asset management fees and other income	0	0	0	0
Other Long- term Investments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning of period	0	635	1,565	633
Included in earnings:
Realized investment gains (losses), net	0	0	0	0
Asset management fees and other income		3	0	5
Included in other comprehensive income (loss)	0	0	0	0
Net investment income	0	0	0	7
Purchases	0	0	0	0
Sales	0	0	0	0
Issuances	0	0	0	0
Settlements	0	0	0	(7)
Transfers into Level 3	0	0	0	0
Transfers out of Level 3	0	0	0	0
Other	0		(1,565)
Fair Value, end of period	0	638	0	638
Included in earnings:
Realized investment gains (losses), net	0	0	0	0
Asset management fees and other income	0	3	0	5
Reinsurance Recoverables
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning of period	3,693,262	3,300,612	3,012,653	2,996,154
Included in earnings:
Realized investment gains (losses), net	(3,352,275)	(1,144,189)	(2,727,301)	(897,375)
Asset management fees and other income		0	0	0
Included in other comprehensive income (loss)	0	0	0	0
Net investment income	0	0	0	0
Purchases	4,931	57,543	60,566	115,187
Sales	0	0	0	0
Issuances	0	0	0	0
Settlements	0	0	0	0
Transfers into Level 3	0	0	0	0
Transfers out of Level 3	0	0	0	0
Other	0		0
Fair Value, end of period	345,918	2,213,966	345,918	2,213,966
Included in earnings:
Realized investment gains (losses), net	35,619	(846,449)	90,507	(846,449)
Asset management fees and other income	0	0	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	2,847	24,015	7,664	22,320
Included in earnings:
Realized investment gains (losses), net	0	(1)	0	0
Asset management fees and other income		0	0	0
Included in other comprehensive income (loss)	(71)	104	69	(188)
Net investment income	0	0	0	0
Purchases	0	0	0	0
Sales	0	0	(2,000)	0
Issuances	0	0	0	0
Settlements	0	0	0	0
Transfers into Level 3	0	0	0	1,986
Transfers out of Level 3	0	(19,341)	(2,957)	(19,341)
Other	0		0
Fair Value, end of period	2,776	4,777	2,776	4,777
Included in earnings:
Realized investment gains (losses), net	0	(296,305)	0	0
Asset management fees and other income	0	0	0	0
Future Policy Benefits
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning of period	(3,842,607)	(3,430,249)	(3,134,077)	(3,112,411)
Included in earnings:
Realized investment gains (losses), net	(8,248,454)	1,190,254	(8,898,484)	932,939
Asset management fees and other income		0	0	0
Included in other comprehensive income (loss)	0	0	0	0
Net investment income	0	0	0	0
Purchases	0	0	0	0
Sales	0	0	0	0
Issuances	(235,472)	(60,424)	(293,972)	(120,947)
Settlements	0	0	0	0
Transfers into Level 3	0	0	0	0
Transfers out of Level 3	0	0	0	0
Other	0		0
Fair Value, end of period	(12,326,533)	(2,300,419)	(12,326,533)	(2,300,419)
Included in earnings:
Realized investment gains (losses), net	(8,060,058)	1,160,988	(8,526,179)	880,403
Asset management fees and other income	$ 0	$ 0	$ 0	$ 0