Accumulated Other Comprehensive Loss (Schedule Of Amounts Reclassified Out of Accumulated Other Comprehensive Income) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Reclassifications Out Of Accumulated Other Comprehensive Income [Line Items]
Net securities gains reclassified into earnings	$ 4,276	$ 0
Related income tax expense	(7,647)	(5,866)
Other comprehensive income (loss), net of tax	873	2,743
Accumulated Net Unrealized Investment Gain (Loss) [Member] | Reclassification Out Of Accumulated Other Comprehensive Income [Member]
Reclassifications Out Of Accumulated Other Comprehensive Income [Line Items]
Net securities gains reclassified into earnings	(4,276)	0
Related income tax expense	1,578	0
Other comprehensive income (loss), net of tax	$ (2,698)	$ 0