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	$ 853	$ 546	$ 750	$ 569
Included in earnings:
Realized investment gains (losses), net	337	0	337	0
Asset management fees and other income	0	0	0	0
Included in other comprehensive income (loss)	(339)	65	(236)	106
Net investment income	0	0	0	0
Purchases	0	0	0	0
Sales	0	(1)	0	(65)
Issuances	0		0
Settlements	(677)	0	(677)	0
Transfers into Level 3	0	0	0	0
Transfers out of Level 3	0	0	0	0
Other			0
Fair Value, end of period	174	610	174	610
Included in earnings:
Realized investment gains (losses), net	0	0	0	0
Asset management fees and other income	0	0	0	0
Short Term Investments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning of period				18
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
Settlements				0
Transfers into Level 3				0
Transfers out of Level 3				0
Fair Value, end of period		18		18
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	80,482	22,097	84,801	18,293
Included in earnings:
Realized investment gains (losses), net	(1,245)	531	(1,541)	787
Asset management fees and other income	0	0	0	0
Included in other comprehensive income (loss)	(1)	406	281	791
Net investment income	(13)	18	(7)	49
Purchases	72,343	12,840	186,352	25,426
Sales	(54,841)	(1,844)	(164,876)	(7,035)
Issuances	0		0
Settlements	(8,379)	(5,101)	(9,982)	(6,937)
Transfers into Level 3	0	538	1,530	2,769
Transfers out of Level 3	1	0	(8,211)	(4,658)
Other			0
Fair Value, end of period	88,347	29,485	88,347	29,485
Included in earnings:
Realized investment gains (losses), net	(1,035)	0	(1,392)	(101)
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	172,200	66,179	100,217	80,934
Included in earnings:
Realized investment gains (losses), net	24	0	23	113
Asset management fees and other income	0	0	0	0
Included in other comprehensive income (loss)	(529)	89	180	196
Net investment income	141	(34)	125	88
Purchases	1	83,866	111,760	83,866
Sales	(2,500)	0	(39,631)	0
Issuances	0		0
Settlements	(1,949)	(15,202)	(2,075)	(48,644)
Transfers into Level 3	11,502	709	59,010	31,862
Transfers out of Level 3	(23,609)	(3,319)	(74,328)	(16,127)
Other			0
Fair Value, end of period	155,281	132,288	155,281	132,288
Included in earnings:
Realized investment gains (losses), net	0	0	0	0
Asset management fees and other income	0	0	0	0
Commercial mortgage and other loans | Commercial Mortgage- Backed 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				0
Included in other comprehensive income (loss)				(2)
Net investment income				0
Purchases				28,077
Sales				0
Settlements				0
Transfers into Level 3				0
Transfers out of Level 3				(28,075)
Fair Value, end of period		0		0
Included in earnings:
Realized investment gains (losses), net				0
Asset management fees and other income				0
Trading Account Assets- Equity Securities | Equity securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning of period	18,369	1,463	5,540	2,731
Included in earnings:
Realized investment gains (losses), net	0	0	0	0
Asset management fees and other income	(121)	0	2,207	107
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	0		0
Settlements	0	0	(1,500)	(1,375)
Transfers into Level 3	0	0	0	0
Transfers out of Level 3	0	0	0	0
Other			12,001
Fair Value, end of period	18,248	1,463	18,248	1,463
Included in earnings:
Realized investment gains (losses), net	0	0	0	0
Asset management fees and other income	(122)	0	2,162	109
Other long-term investments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning of period	2,327	1,805	2,115	1,168
Included in earnings:
Realized investment gains (losses), net	(630)	100	(785)	191
Asset management fees and other income	(21)	(42)	(10)	(47)
Interest credited to policyholders’ account balances		0	0	0
Included in other comprehensive income (loss)	0	0	0	0
Net investment income	(16)	0	0	0
Purchases	611	262	997	398
Sales	0	0	0	0
Issuances	0	0	0
Issuances				0
Settlements	(102)	0	(118)	(12)
Transfers into Level 3	0	0	0	427
Transfers out of Level 3	0	0	(30)	0
Fair Value, end of period	2,169	2,125	2,169	2,125
Included in earnings:
Realized investment gains (losses), net	(631)	100	(785)	191
Asset management fees and other income	(2)	(42)	10	(47)
Interest credited to policyholders’ account balances		0	0	0
Reinsurance Recoverables
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning of period	3,023,119	1,713,132	4,897,545	(376,868)
Included in earnings:
Realized investment gains (losses), net	2,194,352	1,061,086	(12,541)	2,862,059
Asset management fees and other income	0	0	0	0
Interest credited to policyholders’ account balances	0	0	0	0
Included in other comprehensive income (loss)	0	0	0	0
Net investment income	0	0	0	0
Purchases	171,329	149,405	503,796	438,432
Sales	0	0	0	0
Issuances	0	0	0
Issuances				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	5,388,800	2,923,623	5,388,800	2,923,623
Included in earnings:
Realized investment gains (losses), net	2,215,567	1,071,165	105,211	2,858,981
Asset management fees and other income	0	0	0	0
Interest credited to policyholders’ account balances	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	2,550	23,817	19,203	4,121
Included in earnings:
Realized investment gains (losses), net	0	0	0	0
Asset management fees and other income	0	0	0	0
Interest credited to policyholders’ account balances	0	0	0	0
Included in other comprehensive income (loss)	4	(41)	6	(25)
Net investment income	0	(25)	0	0
Purchases	0	(1)	0	18,648
Sales	0	0	$ 0	0
Issuances	0	0
Issuances				0
Settlements	0	0		0
Transfers into Level 3	2,468	0	$ 4,454	1,985
Transfers out of Level 3	(1,992)	(4,451)	(20,633)	(5,430)
Fair Value, end of period	3,030	19,299	3,030	19,299
Included in earnings:
Realized investment gains (losses), net	0	0	0	0
Asset management fees and other income	0	0	0	0
Interest credited to policyholders’ account balances	0	0	0	0
Separate Accounts Assets
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning of period	337,406	285,811	302,924	279,842
Included in earnings:
Realized investment gains (losses), net	1,243	721	5,863	2,706
Asset management fees and other income	0	0	0	0
Interest credited to policyholders’ account balances	(6,285)	3,450	(2,990)	10,172
Included in other comprehensive income (loss)	0	0	0	0
Net investment income	0	0	0	0
Purchases	123,150	13,763	246,975	53,532
Sales	(93,925)	(17,316)	(191,183)	(59,823)
Issuances	0	0	0
Issuances				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	361,589	286,429	361,589	286,429
Included in earnings:
Realized investment gains (losses), net	0	0	0	0
Asset management fees and other income	0	0	0	0
Interest credited to policyholders’ account balances	(6,284)	3,449	(2,990)	10,172
Future Policy Benefits
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning of period	(3,117,171)	(1,700,747)	(4,993,611)	348,399
Included in earnings:
Realized investment gains (losses), net	(2,365,205)	(1,080,155)	(135,978)	(2,812,836)
Asset management fees and other income	0	0	0	0
Interest credited to policyholders’ account balances	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	0
Sales	0	0	0	0
Issuances	(178,889)	(165,606)	(531,676)	(482,071)
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	(5,661,265)	(2,946,508)	(5,661,265)	(2,946,508)
Included in earnings:
Realized investment gains (losses), net	(2,388,177)	(1,087,120)	(235,170)	(2,806,201)
Asset management fees and other income	0	0	0	0
Interest credited to policyholders’ account balances	$ 0	$ 0	$ 0	$ 0