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Comprehensive Income (Components of Accumulated Other Comprehensive Income) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance, December 31, 2015			$ (9,425)
Amounts reclassified into net income: Non-credit OTTI	$ 0	$ 0	0	$ 232
OCI before reclassifications, Defined Benefit Pension and Post Retirement Plans			0
Amount reclassified into net income: Net actuarial loss	1,050	1,110	3,021	3,332
Amounts reclassified from AOCI, HTM related	(9)	(63)	(68)	(353)
Amounts reclassified from AOCI, All Other	(2,395)	(199)	(1,786)	(10,906)
Other comprehensive income	(9,798)	6,290	71,634	(25,827)
Other Comprehensive Income, Defined Benefit Pension and Post Retirement Plans, Adjustment, Net of Tax	1,050	$ 1,110	3,021	3,332
Ending Balance, September 30, 2016	62,209		62,209
Available-for-sale Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance, December 31, 2015			45,083
OCI before reclassifications			70,473
Other comprehensive income			68,687
Ending Balance, September 30, 2016	113,770		113,770
Investments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance, December 31, 2015			44,995
OCI before reclassifications			70,467
Amounts reclassified from AOCI			(1,854)
Other comprehensive income			68,613
Ending Balance, September 30, 2016	113,608		113,608
Accumulated Other-than-Temporary Impairment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance, December 31, 2015			(282)
OCI before reclassifications			(6)
Other comprehensive income			(6)
Ending Balance, September 30, 2016	(288)		(288)
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			(68)
Ending Balance, September 30, 2016	126		126
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			3,021
Ending Balance, September 30, 2016	(51,399)		(51,399)
Accumulated other comprehensive income (loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance, December 31, 2015			(9,425)
OCI before reclassifications			70,467
Amounts reclassified from AOCI			1,167
Other comprehensive income			71,634	$ (25,827)
Ending Balance, September 30, 2016	$ 62,209		$ 62,209

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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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