Accumulated Other Comprehensive Income (Schedule Of Accumulated Other Comprehensive Income) (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015	Dec. 31, 2014
Accumulated other comprehensive income		$ 134,424	$ 48,789	$ 134,424	$ 48,789	$ 32,470	$ 62,093
Other Comprehensive Income Before Reclassifications				163,014	(20,437)
Reclassified from Accumulated Oher Comprehensive Income				1,428	(1,021)
Other Comprehensive Income (Loss), before Tax				164,442	(21,458)
Other Comprehensive Income (Loss), Tax				(62,488)	8,154
Other comprehensive income (loss), net of tax		31,495	(42,928)	101,954	(13,304)
Reclassification Where Impairment Was Not Previously Recognized				0	0
Unrealized Gain Loss on Securities OTTI [Member]
Accumulated other comprehensive income	[1]	2,918	3,855	2,918	3,855	3,316	3,791
Other Comprehensive Income Before Reclassifications	[1]			(911)	(449)
Reclassified from Accumulated Oher Comprehensive Income	[1]			270	483
Other Comprehensive Income (Loss), before Tax	[1]			(641)	34
Other Comprehensive Income (Loss), Tax	[1]			243	(13)
Other comprehensive income (loss), net of tax	[1]			(398)	21
Reclassification Where Impairment Was Not Previously Recognized	[1]			0	43
Unrealized Gain Loss on Securities Other [Member]
Accumulated other comprehensive income	[1]	151,384	67,130	151,384	67,130	49,750	81,310
Other Comprehensive Income Before Reclassifications	[1]			163,925	(19,988)
Reclassified from Accumulated Oher Comprehensive Income	[1]			0	(2,813)
Other Comprehensive Income (Loss), before Tax	[1]			163,925	(22,801)
Other Comprehensive Income (Loss), Tax	[1]			(62,291)	8,664
Other comprehensive income (loss), net of tax	[1]			101,634	(14,137)
Reclassification Where Impairment Was Not Previously Recognized	[1]			0	(43)
Pension Loss [Member]
Accumulated other comprehensive income	[2]	$ (19,878)	$ (22,196)	(19,878)	(22,196)	$ (20,596)	$ (23,008)
Other Comprehensive Income Before Reclassifications	[2]			0	0
Reclassified from Accumulated Oher Comprehensive Income	[2]			1,158	1,309
Other Comprehensive Income (Loss), before Tax	[2]			1,158	1,309
Other Comprehensive Income (Loss), Tax	[2]			(440)	(497)
Other comprehensive income (loss), net of tax	[2]			718	812
Reclassification Where Impairment Was Not Previously Recognized	[2]			$ 0	$ 0

[1] The pre-tax amounts reclassified from accumulated other comprehensive income are included in "investment securities gains (losses), net" in the consolidated statements of income.

[2] The pre-tax amounts reclassified from accumulated other comprehensive income are included in the computation of net periodic pension cost as "amortization of prior service cost" and "amortization of unrecognized net loss" (see Note 6), for inclusion in the consolidated statements of income.