Investment Securities (Summary Of Available For Sale Investment Securities) (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014		Dec. 31, 2013
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 3,061,268	[1]	$ 3,224,749	[1]
Gross Unrealized Gains	33,125		19,170
Gross Unrealized Losses	(14,208)		(44,561)
Fair Value	3,080,185		3,199,358
U.S. Treasury Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	17,793	[1]	17,791	[1]
Gross Unrealized Gains	0		0
Gross Unrealized Losses	0		0
Fair Value	17,793		17,791
U.S. Government Agency Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	33,264	[1]	33,480	[1]
Gross Unrealized Gains	1,028		1,161
Gross Unrealized Losses	0		0
Fair Value	34,292		34,641
Securities Issued By U.S. Government Sponsored Enterprises [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	111,795	[1]	112,305	[1]
Gross Unrealized Gains	1,014		1,440
Gross Unrealized Losses	0		0
Fair Value	112,809		113,745
Mortgage-Backed Securities Issued By U.S. Government Agencies [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	173,296	[1]	196,521	[1]
Gross Unrealized Gains	1,848		2,257
Gross Unrealized Losses	(766)		(3,661)
Fair Value	174,378		195,117
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	2,327,735	[1]	2,443,282	[1]
Gross Unrealized Gains	21,176		9,718
Gross Unrealized Losses	(10,616)		(31,640)
Fair Value	2,338,295		2,421,360
Collateralized Mortgage Obligations Issued By U.S. Government Sponsored Enterprises [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	384,836	[1]	406,717	[1]
Gross Unrealized Gains	4,125		698
Gross Unrealized Losses	(2,488)		(8,875)
Fair Value	386,473		398,540
State And Municipal Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	5,222	[1]	6,723	[1]
Gross Unrealized Gains	209		168
Gross Unrealized Losses	(2)		(2)
Fair Value	5,429		6,889
Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	3,228	[1]	3,856	[1]
Gross Unrealized Gains	3,725		3,728
Gross Unrealized Losses	0		0
Fair Value	6,953		7,584
Other Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	4,099	[1]	4,074	[1]
Gross Unrealized Gains	0		0
Gross Unrealized Losses	(336)		(383)
Fair Value	$ 3,763		$ 3,691

[1] Amortized cost is adjusted for other-than-temporary impairment charges in 2014 and 2013, which have been recognized in the consolidated statements of income in the applicable year, and were considered inconsequential.