Changes and Reclassifications Out of Other Comprehensive Income Comprehensive Income (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net of Tax	$ (37,579)
Accumulated other comprehensive loss	(66,876)	(16,205)
Changes in unrealized securities' holding gains and (losses), net of taxes of $46.6 million, $2.2 million, and $10.2 million, respectively	(86,537)	4,154	26,205
Other Comprehensive Income Net Gain (Loss) Arising During the Period	(55,376)
Accumulated Other Comprehensive Reclass Amounts During Period-Total	1,822
Other Comprehensive Income (Loss), Amortization Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, for Net Prior Service (Cost) Credit, Net of Tax	(1)	(52)	256
Other Comprehensive (Income) Loss, Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, for Net (Gain) Loss, Net of Tax	2,884	6,836	4,702
Accumulated Net Unrealized Investment Gain (Loss)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax	(29,297)	55,418
Changes in unrealized securities' holding gains and (losses), net of taxes of $46.6 million, $2.2 million, and $10.2 million, respectively	(86,537)
Accumulated Other Comprehensive Reclass Amounts During Period-Total	1,822
Pension Benefits
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net of Tax		(71,623)
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net Unamortized Gain (Loss) Arising During Period, Net of Tax	$ 31,161