Stockholders' Equity (Details 3) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Reclassifications included in net income:
Net of tax	$ 973	$ 1,411	$ 2,921	$ 5,653
Reclassifications from accumulated other comprehensive income
Reclassifications included in net income:
Pre-tax	789	929	2,370	4,000
Tax (expense) benefit	184	482	551	1,653
Net of tax	973	1,411	2,921	5,653
Realized gain on sale of available for sale investment securities
Reclassifications included in net income:
Net of tax	813	1,408	2,441	4,989
Realized gain on sale of available for sale investment securities | Investment and other income | Reclassifications from accumulated other comprehensive income
Reclassifications included in net income:
Pre-tax	1,290	2,225	3,875	7,887
Tax (expense) benefit	(477)	(817)	(1,434)	(2,898)
Net of tax	813	1,408	2,441	4,989
Valuation allowance
Reclassifications included in net income:
Net of tax	475	819	1,427	2,918
Valuation allowance | Provision for income taxes | Reclassifications from accumulated other comprehensive income
Reclassifications included in net income:
Tax (expense) benefit	475	819	1,427	2,918
Net of tax	475	819	1,427	2,918
Amortization of pension and postretirement benefits
Reclassifications included in net income:
Net of tax	(315)	(816)	(947)	(2,254)
Amortization of pension and postretirement benefits | Underwriting and distribution expense and Compensation and related costs | Reclassifications from accumulated other comprehensive income
Reclassifications included in net income:
Pre-tax	(501)	(1,296)	(1,505)	(3,887)
Tax (expense) benefit	186	480	558	1,633
Net of tax	$ (315)	$ (816)	$ (947)	$ (2,254)