Comprehensive Income Other Comprehensive Income (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Schedule of Comprehensive Income [Line Items]
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	$ (2,961)	$ 3,500	$ (2,246)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	168	589	479
Other Comprehensive Income (Loss), before Tax	(4,547)	6,772	(2,925)
Other Comprehensive Income (Loss), Tax	1,754	(2,683)	1,158
Other Comprehensive (Loss) Income	(2,793)	4,089	(1,767)
Accumulated Net Unrealized Investment Gain (Loss) [Member]
Schedule of Comprehensive Income [Line Items]
Other Comprehensive Income (Loss), before Reclassifications, before Tax	356	(4,843)	(1,094)
Other Comprehensive Income Loss Before Reclassifications Tax (Expense) Benefit	(124)	1,918	433
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	232	(2,925)	(661)
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	(110)	(540)	(865)
Reclassification From Accumulated Other Comprehensive Income Current Period Tax (Expense) Benefit	43	214	343
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	(67)	(326)	(522)
Other Comprehensive (Loss) Income	165	(3,251)	(1,183)
Accumulated Defined Benefit Plans Adjustment, Net Unamortized Gain (Loss) [Member]
Schedule of Comprehensive Income [Line Items]
Other Comprehensive Income (Loss), before Reclassifications, before Tax	(4,610)	10,640	(2,218)
Other Comprehensive Income Loss Before Reclassifications Tax (Expense) Benefit	1,764	(4,215)	878
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	(2,846)	6,425	(1,340)
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	474	1,513	1,677
Reclassification From Accumulated Other Comprehensive Income Current Period Tax (Expense) Benefit	(186)	(599)	(664)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	288	914	1,013
Other Comprehensive (Loss) Income	(2,558)	7,339	(327)
Accumulated Defined Benefit Plans Adjustment, Net Prior Service Cost (Credit) [Member]
Schedule of Comprehensive Income [Line Items]
Other Comprehensive Income (Loss), before Reclassifications, before Tax	(570)		(405)
Other Comprehensive Income Loss Before Reclassifications Tax (Expense) Benefit	223		160
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	(347)	0	(245)
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	(87)	2	(20)
Reclassification From Accumulated Other Comprehensive Income Current Period Tax (Expense) Benefit	34	(1)	8
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	(53)	1	(12)
Other Comprehensive (Loss) Income	$ (400)	$ 1	$ (257)