Income Taxes (Deferred Tax Assets and Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Deferred tax assets:
Insurance reserves	$ 1,521,729	$ 2,064,659
Investments	276,880	404,703
Net unrealized loss on securities	86,742	7,048
Other	638	205
Deferred tax assets	1,885,989	2,476,615
Deferred tax liabilities:
DeferredTaxLiabilitiesVOBAandDAC	929,849	960,841
Deferred sales inducements	186,816	214,365
Deferred tax liabilities	1,116,665	1,175,206
Deferred Tax Assets, Net	$ 769,324	$ 1,301,409