Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Investments, Owned, Federal Income Tax Note [Line Items]
Current	$ 29,568	$ 18,062	$ 67,705	$ 71,658
Deferred	1,140	11,728	11,221	48,666
Total income tax provision	30,708	29,790	$ 78,926	$ 120,324
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			(2.80%)	(2.00%)
Tax credits			(0.30%)	(0.30%)
State income taxes, net of federal benefit			1.90%	1.50%
Other, net			(0.70%)	0.10%
Effective income tax rate			33.10%	34.30%
Reconciliation of unrecognized tax benefits
Amount of unrecognized tax benefits if recognized, would impact the annual effective tax rate	1,008	$ 1,401	$ 1,008	$ 1,401
Minimum
Reconciliation of unrecognized tax benefits
Additional increase to unrecognized tax benefits	6,000		6,000
Maximum
Reconciliation of unrecognized tax benefits
Additional increase to unrecognized tax benefits	$ 7,000		$ 7,000