Significant Accounting Policies (Premiums and Annuity Deposits, By Product Type) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Product Information [Line Items]
Fixed index annuities	$ 6,491,981	$ 3,911,109	$ 3,864,990
Annual reset fixed rate annuities	44,715	56,647	71,162
Multi-year fixed rate annuities	42,709	21,125	41,578
Single premium immediate annuities (SPIA)	32,752	24,580	52,142
Life insurance	10,917	10,810	10,556
Premiums and annuity deposits, net of coinsurance	$ 6,623,074	$ 4,024,271	$ 4,040,428