Income Taxes (Deferred Tax Assets and Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Deferred tax assets
Insurance reserves	$ 148,115	$ 1,668,038
Other	1,966	1,442
Deferred tax assets	150,081	1,669,480
Deferred tax liabilities
Deferred policy acquisition costs	45,405	1,398,775
Deferred sales inducements	0	239,695
Net unrealized gains on securities	24,949	23,991
Investments	171,303	69,163
Deferred tax liabilities	241,657	1,731,624
Deferred tax liabilities	$ (91,576)	$ (62,144)