Reinsurance (Income Statement Reinsurance Results) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Premiums:
Direct	$ 11,909	$ 7,887	$ 28,958	$ 25,189
Assumed	(10,248)	0	821,089	0
Ceded	(2,256)	0	(2,554)	0
Net premiums	(595)	7,887	847,493	25,189
Policy charges and fee income:
Direct	163,547	184,134	487,837	568,677
Assumed	392,156	0	766,451	0
Ceded	(11,522)	(208)	(34,582)	(1,959)
Net policy charges and fee income	544,181	183,926	1,219,706	566,718
Asset administration fees and other income:
Direct	29,814	38,192	97,246	146,951
Assumed	69,493	0	135,902	0
Ceded	(2,502)	0	(7,316)	0
Net asset administration fees and other income	96,805	38,192	225,832	146,951
Interest credited to policyholders’ account balances:
Direct	(64,111)	110,894	87,752	218,792
Assumed	(27,278)	0	18,816	0
Ceded	5,774	0	(5,384)	0
Net interest credited to policyholders’ account balances	(85,615)	110,894	101,184	218,792
Policyholders' benefits (including change in reserves):
Direct	10,835	37,711	49,471	61,357
Assumed	(8,895)	0	526,292	0
Ceded	(10,873)	242	(21,417)	242
Net policyholders' benefits (including change in reserves)	(8,933)	37,953	554,346	61,599
Realized investment gains (losses), net:
Direct	(409,674)	(985,269)	507,527	(61,179)
Assumed	394,419	0	(3,366,784)	0
Ceded	(20,470)	990,956	361,596	71,185
Total realized investment gains (losses), net	(35,725)	5,687	(2,497,661)	10,006
Net reinsurance expense allowances, net of capitalization and amortization	(14,625)	(928)	504,820	(2,858)
Unaffiliated activity
Policy charges and fee income:
Ceded	(300)	(200)	(1,000)	(2,000)
Policyholders' benefits (including change in reserves):
Ceded	$ 0	$ 200	$ (200)	$ 200