Accumulated Other Comprehensive Income (Loss) (Schedule of Amounts Reclassified from AOCI) (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2016	Mar. 31, 2015
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Gains on securities transactions, net		$ 728	$ 561
Provision for federal income taxes		(382)	(243)
Reclassifications for the period		1,912	1,466
Unrealized Gain (Losses) on Securities AFS [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Gains on securities transactions, net	[1]	728	561
Provision for federal income taxes	[1]	(248)	(191)
Reclassifications for the period	[1]	$ 480	$ 370

[1] Amounts in parentheses indicate debits.