Income Taxes (Deferred Tax Assets and Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Deferred tax assets:
Insurance reserves	$ 427,843	$ 245,488
Net unrealized loss on securities	0	8,283
Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits	7,141	0
Other	1,969	1,897
Deferred tax assets	436,953	255,668
Deferred tax liabilities:
Deferred policy acquisition cost	67,431	55,030
Net unrealized gain on securities	83,801	0
Investments	142,028	95,294
Deferred tax liabilities	293,260	150,324
Net deferred tax asset (liability)	$ 143,693	$ 105,344