Fair Value of Assets and Liabilities (Changes in Level 3 Assets and Liabilities) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Equity Securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning of period				$ 192
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				(192)
Issuances				0
Settlements				0
Transfers into Level 3				0
Transfers out of Level 3				0
Fair Value, end of period		$ 0		0
Included in earnings:
Realized investment gains (losses), net				0
Asset management fees and other income				0
Fixed Maturities Available-For-Sale | Corporate Securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning of period	$ 117,483	102,008	$ 116,070	96,796
Included in earnings:
Realized investment gains (losses), net	(17)	149	45	149
Asset management fees and other income	0	0	0	0
Included in other comprehensive income (loss)	(1,178)	(996)	(1,741)	(513)
Net investment income	1,325	1,265	3,911	3,738
Purchases	16,179	2,122	48,786	5,362
Sales	(14,935)	(202)	(45,364)	(202)
Issuances	0	0	0	0
Settlements	(1,336)	(400)	(2,459)	(1,384)
Transfers into Level 3	0	0	0	0
Transfers out of Level 3	0	0	(1,727)	0
Fair Value, end of period	117,521	103,946	117,521	103,946
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	43,441	74,301	40,524	63,789
Included in earnings:
Realized investment gains (losses), net	4	0	3	0
Asset management fees and other income	0	0	0	0
Included in other comprehensive income (loss)	(154)	94	57	394
Net investment income	16	28	27	110
Purchases	1,099	0	8,970	14,933
Sales	(1,750)	0	(9,634)	0
Issuances	0	0	0	0
Settlements	(2,074)	(10,260)	(3,212)	(39,600)
Transfers into Level 3	15,253	0	26,021	28,152
Transfers out of Level 3	(5,945)	(1,263)	(12,866)	(4,878)
Fair Value, end of period	49,890	62,900	49,890	62,900
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 | Commercial Mortgage- Backed Securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning of period	0	0	0	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	(83)
Net investment income	0	0	0	0
Purchases	1,565	7,070	1,565	52,518
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	(45,365)
Fair Value, end of period	1,565	7,070	1,565	7,070
Included in earnings:
Realized investment gains (losses), net	0	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				313
Included in earnings:
Realized investment gains (losses), net				0
Asset management fees and other income				15
Included in other comprehensive income (loss)				0
Net investment income				0
Purchases				0
Sales				0
Issuances				0
Settlements				(328)
Transfers into Level 3				0
Transfers out of Level 3				0
Fair Value, end of period		0		0
Included in earnings:
Realized investment gains (losses), net				0
Asset management fees and other income				15
Short-term investments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning of period	300		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	150		450
Sales	0		0
Issuances	0		0
Settlements	0		0
Transfers into Level 3	0		0
Transfers out of Level 3	0		0
Fair Value, end of period	450		450
Included in earnings:
Realized investment gains (losses), net	0		0
Asset management fees and other income	0		0
Cash Equivalents
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning of period	225	400	225	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	0	0	400
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
Fair Value, end of period	225	400	225	400
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	638	536	633	486
Included in earnings:
Realized investment gains (losses), net	0	0	0	0
Asset management fees and other income	(27)	(17)	(22)	(19)
Included in other comprehensive income (loss)	0	0	0	0
Net investment income	11	0	18	0
Purchases	19	109	19	166
Sales	0	0	0	0
Issuances	0	0	0	0
Settlements	(42)	0	(49)	(5)
Transfers into Level 3	0	0	0	0
Transfers out of Level 3	0	0	0	0
Fair Value, end of period	599	628	599	628
Included in earnings:
Realized investment gains (losses), net	0	0	0	0
Asset management fees and other income	(27)	(17)	(22)	(19)
Reinsurance Recoverables
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning of period	2,213,966	1,594,311	2,996,154	748,005
Included in earnings:
Realized investment gains (losses), net	1,000,406	578,588	103,031	1,307,462
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	56,855	58,581	172,042	176,013
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
Fair Value, end of period	3,271,227	2,231,480	3,271,227	2,231,480
Included in earnings:
Realized investment gains (losses), net	1,017,556	592,438	177,725	1,327,516
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	4,777	27,762	22,320	6,347
Included in earnings:
Realized investment gains (losses), net	0	(1)	0	0
Asset management fees and other income	0	0	0	0
Included in other comprehensive income (loss)	9	(292)	(179)	(213)
Net investment income	0	0	0	0
Purchases	0	0	0	19,350
Sales	0	0	0	0
Issuances	0	0	0	0
Settlements	0	0	0	0
Transfers into Level 3	2,962	0	4,948	1,985
Transfers out of Level 3	(1,993)	(4,943)	(21,334)	(4,943)
Fair Value, end of period	5,755	22,526	5,755	22,526
Included in earnings:
Realized investment gains (losses), net	0	0	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	(2,300,419)	(1,662,957)	(3,112,411)	(778,226)
Included in earnings:
Realized investment gains (losses), net	(1,041,737)	(592,334)	(108,798)	(1,353,916)
Asset management fees and other income	0	$ 0	0	0
Included in other comprehensive income (loss)	0		0	0
Net investment income	0	$ 0	0	0
Purchases	0	0	0	0
Sales	0	0	0	0
Issuances	(58,443)	(61,450)	(179,390)	(184,599)
Settlements	0	0	0	0
Transfers into Level 3	0	$ 0	0	0
Transfers out of Level 3	0		0	0
Fair Value, end of period	(3,400,599)	$ (2,316,741)	(3,400,599)	(2,316,741)
Included in earnings:
Realized investment gains (losses), net	(1,059,644)	(606,724)	(186,067)	(1,374,751)
Asset management fees and other income	$ 0	$ 0	$ 0	$ 0