Accumulated Other Comprehensive Loss (Schedule Of Amounts Reclassified Out of Accumulated Other Comprehensive Income) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net unrealized securities gains (losses) reclassified into earnings	$ 0	$ 4,276
Related income tax expense	(4,405)	(7,647)
Net income	17,616	16,026
Unrealized Gain (Losses) on Securities Available-for-Sale | Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net unrealized securities gains (losses) reclassified into earnings	0	(4,276)
Related income tax expense	0	(1,578)
Net income	$ 0	$ 2,698