Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Investments, Owned, Federal Income Tax Note [Line Items]
Current	$ 10,640	$ 28,094
Deferred	13,398	23,802
Total income tax provision	$ 24,038	$ 51,896
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	(2.30%)	(2.00%)
Tax credits	(16.30%)	(0.20%)
State income taxes, net of federal benefit	2.30%	1.30%
Other, net	0.90%	0.40%
Effective income tax rate	19.60%	34.50%
Reconciliation of unrecognized tax benefits
Amount of unrecognized tax benefits if recognized, would impact the annual effective tax rate	$ 1,843	$ 2,695
Minimum
Reconciliation of unrecognized tax benefits
Additional increase to unrecognized tax benefits	5,000
Maximum
Reconciliation of unrecognized tax benefits
Additional increase to unrecognized tax benefits	$ 7,000