Accumulated Other Comprehensive Loss (Schedule Of Amounts Reclassified Out of Accumulated Other Comprehensive Income) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 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	$ (5,606)	$ (7,003)	(15,369)	(21,463)
Net income	20,692	13,932	59,283	44,646
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	0	0	(4,276)
Related income tax expense	0	0	0	(1,578)
Net income	$ 0	$ 0	$ 0	$ 2,698