Investment Securities (Proceeds From Sales Of Securities And Components Of Investment Securities Gains And Losses) (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015		Jun. 30, 2014
Investment [Line Items]
Proceeds from sales of available for sale securities				$ 675,870		$ 30,998
Proceeds from sales of non-marketable securities				7,332		32,901
Total proceeds	[1]			683,202		63,899
Investment securities gains (losses), net		$ 2,143	$ (2,558)	8,178	[1]	7,479	[1]
Available-for-sale Securities [Member]
Investment [Line Items]
Available-for-sale Securities, gross realized gains on sales				2,813		0
Available-for-sale Securities, gross realized loss on sales				0		(5,197)
Gain realized on donation				0		1,570
Other-than-temporary impairment recognized on debt securities				(483)		(977)
Non-Marketable [Member]
Investment [Line Items]
Gains realized on sales				1,673		1,472
Losses realized on sales				0		(134)
Fair value adjustments, net				$ 4,175		$ 10,745

[1] Available for sale and non-marketable securities