Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Investments, Owned, Federal Income Tax Note [Line Items]
Current	$ 32,483	$ 10,042	$ 43,124	$ 38,137
Deferred	7,227	(13,721)	20,624	10,081
Total income tax provision	39,710	(3,679)	$ 63,748	$ 48,218
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%)	(2.70%)
Tax credits			(8.80%)	(0.40%)
State income taxes, net of federal benefit			2.80%	1.90%
Other, net			0.70%	0.70%
Effective income tax rate			27.00%	34.50%
Reconciliation of unrecognized tax benefits
Amount of unrecognized tax benefits if recognized, would impact the annual effective tax rate	2,477	$ 4,927	$ 2,477	$ 4,927
Minimum
Reconciliation of unrecognized tax benefits
Additional decrease to unrecognized tax benefits	5,000		5,000
Maximum
Reconciliation of unrecognized tax benefits
Additional decrease to unrecognized tax benefits	$ 6,000		$ 6,000