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Investment Securities (Proceeds From Sales Of Securities And Components Of Investment Securities Gains And Losses) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Investment [Line Items]
Proceeds from Sale of Available-for-sale Securities		$ 602,475	$ 402,103	$ 667,227
Proceeds from sale of equity securities		2	3,856	41,637
Proceeds from sales of other securities		0	7,244	0
Total proceeds	[1]	602,477	413,203	708,864
Investment securities gains (losses), net	[1]	11,032	3,626	(488)
Available-for-sale Securities [Member]
Investment [Line Items]
Gains realized on sales		21,096	2,354	448
Loss realized on sales		0	(2,568)	(10,101)
Other-than-temporary impairment recognized on debt securities		0	(133)	(68)
Equity securities [Member]
Investment [Line Items]
Gains realized on sales		2	3,262	1,759
Loss realized on sales		0	0	(8,917)
Equity Securities, FV-NI, Unrealized Gain		37	344	2,542
Other Investments [Member]
Investment [Line Items]
Gains realized on sales		0	1,094	0
Fair value adjustments, net		$ (10,103)	$ (727)	$ 13,849
[1] Available for sale debt securities, equity securities, and other securities.

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