Income Taxes (Details) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Investments, Owned, Federal Income Tax Note [Line Items]
Current	$ 28,094,000	$ 31,044,000
Deferred	23,802,000	19,310,000
Total income tax provision	51,896,000	50,354,000
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	(2.00%)	(2.10%)
Tax credits	(0.20%)	(0.20%)
State income taxes, net of federal benefit	1.30%	1.50%
Other, net	0.40%	0.50%
Effective income tax rate	34.50%	34.70%
Reconciliation of unrecognized tax benefits
Amount of unrecognized tax benefits if recognized, would impact the annual effective tax rate	2,695,000	1,992,000
Minimum
Reconciliation of unrecognized tax benefits
Additional increase to unrecognized tax benefits	4,000,000
Maximum
Reconciliation of unrecognized tax benefits
Additional increase to unrecognized tax benefits	$ 5,000,000