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Comprehensive Income (Components of Accumulated Other Comprehensive Income) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance, December 31, 2015	$ (9,425)
Amounts reclassified into net income: Non-credit OTTI	0	$ 232
OCI before reclassifications, Defined Benefit Pension and Post Retirement Plans	0
Amount reclassified into net income: Net actuarial loss	986	1,111
Amounts reclassified from AOCI, HTM related	(47)	(170)
Amounts reclassified from AOCI, All Other	1,754	(12,932)
Other comprehensive income	45,422	3,827
Other Comprehensive Income, Defined Benefit Pension and Post Retirement Plans, Adjustment, Net of Tax	986	1,111
Ending Balance, March 31, 2016	35,997
Available-for-sale Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance, December 31, 2015	45,083
OCI before reclassifications	42,729
Other comprehensive income	44,483
Ending Balance, March 31, 2016	89,566
Investments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance, December 31, 2015	44,995
OCI before reclassifications	42,729
Amounts reclassified from AOCI	1,707
Other comprehensive income	44,436
Ending Balance, March 31, 2016	89,431
Accumulated Other-than-Temporary Impairment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance, December 31, 2015	(282)
OCI before reclassifications	0
Other comprehensive income	0
Ending Balance, March 31, 2016	(282)
Accumulated Net Unrealized Investment Gain (Loss) [Member] | Held-to-maturity Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance, December 31, 2015	194
OCI before reclassifications	0
Other comprehensive income	(47)
Ending Balance, March 31, 2016	147
Accumulated Defined Benefit Plans Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance, December 31, 2015	(54,420)
Amount reclassified into net income: Net actuarial loss	986
Ending Balance, March 31, 2016	(53,434)
Accumulated other comprehensive income (loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance, December 31, 2015	(9,425)
OCI before reclassifications	42,729
Amounts reclassified from AOCI	2,693
Other comprehensive income	45,422	$ 3,827
Ending Balance, March 31, 2016	$ 35,997

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Net of tax amount of the reclassification adjustment related to held-to-maturity securities transferred from the available-for-sale category. This amount includes amortization and amounts realized from the disposal of these securities.

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