Accumulated Other Comprehensive Income (Changes in AOCI by Component) (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	[1]	$ 12,343	$ 14,286	$ (6,295)	$ 5,621
Other comprehensive income before reclassifications	[1]	8,508	(11,341)	27,278	(2,245)
Amounts reclassified from accumulated other comprehensive income (loss)	[1]	(40)	(156)	(172)	(587)
Net current-period other comprehensive income	[1]	8,468	(11,497)	27,106	(2,832)
Ending balance	[1]	20,811	2,789	20,811	2,789
Unrealized Gains and Losses on Available-for-Sale Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	[1]	18,918	16,379	386	7,462
Other comprehensive income before reclassifications	[1]	8,508	(11,341)	27,278	(1,965)
Amounts reclassified from accumulated other comprehensive income (loss)	[1]	(146)	(219)	(384)	(678)
Net current-period other comprehensive income	[1]	8,362	(11,560)	26,894	(2,643)
Ending balance	[1]	27,280	4,819	27,280	4,819
Unrealized Gains and Losses on Pension Plan Liability [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	[1]	(6,575)	(2,093)	(6,681)	(1,841)
Other comprehensive income before reclassifications	[1]	0	0	0	(280)
Amounts reclassified from accumulated other comprehensive income (loss)	[1]	106	63	212	91
Net current-period other comprehensive income	[1]	106	63	212	(189)
Ending balance	[1]	$ (6,469)	$ (2,030)	$ (6,469)	$ (2,030)

[1] All amounts are net of tax. Amounts in parenthesis indicate debits.