Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Expense (Benefit), Continuing Operations [Abstract]
Current Federal Tax Expense (Benefit)	$ 36,461	$ 40,578	$ 39,562
Deferred Federal Income Tax Expense (Benefit)	9,549	6,840	7,773
Income Tax Expense (Benefit)	46,010	47,418	47,335
Tax impact of Income from Equity Method Investments	(15,498)	(15,706)	(13,372)
Income Tax Effects Allocated Directly to Equity [Abstract]
Change in net unrealized investment gains/losses - deferred, Tax	18,882	(77,473)	75,032
Issuance of shares under stock option plan, current	(846)	(1,363)	(1,148)
Income Tax Effects Allocated Directly to Equity	18,036	(78,836)	73,884
Total tax from all sources provided in our financial statements	$ 48,548	$ (47,124)	$ 107,847