Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Income Tax Disclosure [Abstract]
Current (benefit) expense	$ (1,399)	$ 29,568	$ 41,725	$ 67,705
Deferred expense	16,694	1,140	37,318	11,221
Total income tax provision	15,295	30,708	$ 79,043	$ 78,926
Reconciliation between the statutory federal income tax rate and the effective income tax rate from continuing operations
Statutory federal income tax rate			35.00%	35.00%
Investment income not subject to federal tax			(2.70%)	(2.80%)
Tax credits			(7.30%)	(0.30%)
State income taxes, net of federal benefit			2.50%	1.90%
Other, net			(0.40%)	(0.70%)
Effective income tax rate			27.10%	33.10%
Reconciliation of unrecognized tax benefits
Additional decrease to unrecognized tax benefits	$ 5,824	$ (1,008)	$ 5,824	$ (1,008)