Stockholders' Equity (Details 3) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Reclassifications included in net income:
Net of tax	$ 1,115	$ 2,653	$ 1,948	$ 4,242
Reclassifications from accumulated other comprehensive income
Reclassifications included in net income:
Pre-tax	952	2,049	1,582	3,071
Tax (expense) benefit	163	604	366	1,171
Net of tax	1,115	2,653	1,948	4,242
Realized gain on sale of available for sale investment securities
Reclassifications included in net income:
Net of tax	884	2,047	1,629	3,582
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	1,404	3,236	2,586	5,662
Tax (expense) benefit	(520)	(1,189)	(957)	(2,080)
Net of tax	884	2,047	1,629	3,582
Valuation allowance
Reclassifications included in net income:
Net of tax	516	1,198	951	2,098
Valuation allowance | Provision for income taxes | Reclassifications from accumulated other comprehensive income
Reclassifications included in net income:
Tax (expense) benefit	516	1,198	951	2,098
Net of tax	516	1,198	951	2,098
Amortization of pension and postretirement benefits
Reclassifications included in net income:
Net of tax	(285)	(592)	(632)	(1,438)
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	(452)	(1,187)	(1,004)	(2,591)
Tax (expense) benefit	167	595	372	1,153
Net of tax	$ (285)	$ (592)	$ (632)	$ (1,438)