Supplemental Comprehensive Income Disclosures Supplemental Comprehensive Income Disclosures (Details 2) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Accumulated Other Comprehensive Income [Line Items]
Accumulated other comprehensive (loss) income, net	$ (4,499)	$ (20,588)	$ 1,259	$ 2,001
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	16,657	(22,742)	(423)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	(364)	753	(125)
Other Comprehensive Income (Loss), Reclassification, Pension and Other Postretirement Benefit Plans, Net Transition Asset (Obligation), Recognized in Net Periodic Benefit Cost, Net of Tax	0	0	1
Net (loss) gain, Net of Tax Amount	(204)	142	(195)
Total other comprehensive (loss) income, Net of Tax Amount	16,089	(21,847)	(742)
Accumulated Net Unrealized Investment Gain (Loss) [Member]
Accumulated Other Comprehensive Income [Line Items]
Accumulated other comprehensive (loss) income, net	(4,875)	(20,868)	1,121	1,669
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	16,350	(22,742)	(423)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	(357)	753	(125)
Total other comprehensive (loss) income, Net of Tax Amount	15,993	(21,989)	(548)
Other Postretirement Benefit Plans, Defined Benefit [Member]
Accumulated Other Comprehensive Income [Line Items]
Accumulated other comprehensive (loss) income, net	300	280	138	332
Other Comprehensive Income (Loss), Reclassification, Pension and Other Postretirement Benefit Plans, Net Transition Asset (Obligation), Recognized in Net Periodic Benefit Cost, Net of Tax	0	0	1
Net (loss) gain, Net of Tax Amount	(204)	142	(195)
Total other comprehensive (loss) income, Net of Tax Amount	$ (204)	$ 142	$ (194)