Other Comprehensive Income (Loss) (Classifications out 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
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income Tax Expense	$ (4,106)	$ (2,429)	$ (10,120)	$ (8,668)
Amount Reclassified From Accumulated Other Comprehensive Income (Loss)
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amount Reclassified From Accumulated Other Comprehensive Income (Loss)	298	0	927	471
Unrealized Gains and Losses on Available-for-Sale Securities | Amount Reclassified From Accumulated Other Comprehensive Income (Loss)
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net Gains on Securities	458	0	1,426	725
Income Tax Expense	(160)	0	(499)	(254)
Amount Reclassified From Accumulated Other Comprehensive Income (Loss)	$ 298	$ 0	$ 927	$ 471