Investment Securities Available for Sale (Amortized Cost And Estimated Fair Value By Contractual Maturity Of Investment Securities Available For Sale) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost, Within One year	$ 49,890
Amortized Cost, 1 to 5 Years	97,632
Amortized Cost, 5 to 10 Years	2,049,302
Amortized Cost, More Than 10 years	1,021,995
Amortized Cost, Amortized Cost, No Stated Maturity	5,930
Total Amortized Cost	3,224,749
Fair Value, Within One year	50,483
Fair Value, 1 to 5 Years	99,175
Fair Value, 5 to 10 Years	2,026,160
Fair Value, More Than 10 years	1,013,987
Fair Value, No Stated Maturity	9,553
Total Fair Value	3,199,358
U.S. Treasury Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost, Within One year	17,791
Amortized Cost, 1 to 5 Years	0
Amortized Cost, 5 to 10 Years	0
Amortized Cost, More Than 10 years	0
Amortized Cost, Amortized Cost, No Stated Maturity	0
Total Amortized Cost	17,791
Fair Value, Within One year	17,791
Fair Value, 1 to 5 Years	0
Fair Value, 5 to 10 Years	0
Fair Value, More Than 10 years	0
Fair Value, No Stated Maturity	0
Total Fair Value	17,791
U.S. Government Agency Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost, Within One year	114
Amortized Cost, 1 to 5 Years	9,157
Amortized Cost, 5 to 10 Years	24,209
Amortized Cost, More Than 10 years	0
Amortized Cost, Amortized Cost, No Stated Maturity	0
Total Amortized Cost	33,480
Fair Value, Within One year	114
Fair Value, 1 to 5 Years	9,501
Fair Value, 5 to 10 Years	25,026
Fair Value, More Than 10 years	0
Fair Value, No Stated Maturity	0
Total Fair Value	34,641
Securities Issued By U.S. Government Sponsored Enterprises [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost, Within One year	30,109
Amortized Cost, 1 to 5 Years	82,196
Amortized Cost, 5 to 10 Years	0
Amortized Cost, More Than 10 years	0
Amortized Cost, Amortized Cost, No Stated Maturity	0
Total Amortized Cost	112,305
Fair Value, Within One year	30,642
Fair Value, 1 to 5 Years	83,103
Fair Value, 5 to 10 Years	0
Fair Value, More Than 10 years	0
Fair Value, No Stated Maturity	0
Total Fair Value	113,745
Mortgage-Backed Securities Issued By U.S. Government Agencies [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost, Within One year	40
Amortized Cost, 1 to 5 Years	1
Amortized Cost, 5 to 10 Years	729
Amortized Cost, More Than 10 years	195,751
Amortized Cost, Amortized Cost, No Stated Maturity	0
Total Amortized Cost	196,521
Fair Value, Within One year	41
Fair Value, 1 to 5 Years	1
Fair Value, 5 to 10 Years	753
Fair Value, More Than 10 years	194,322
Fair Value, No Stated Maturity	0
Total Fair Value	195,117
Mortgage-Backed Securities Issued By U.S. Government Sponsored Enterprises [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost, Within One year	782
Amortized Cost, 1 to 5 Years	3,450
Amortized Cost, 5 to 10 Years	2,024,280
Amortized Cost, More Than 10 years	414,770
Amortized Cost, Amortized Cost, No Stated Maturity	0
Total Amortized Cost	2,443,282
Fair Value, Within One year	829
Fair Value, 1 to 5 Years	3,684
Fair Value, 5 to 10 Years	2,000,297
Fair Value, More Than 10 years	416,550
Fair Value, No Stated Maturity	0
Total Fair Value	2,421,360
Collateralized Mortgage-Backed Securities Issued By U.S. Government Sponsored Enterprises [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost, Within One year	0
Amortized Cost, 1 to 5 Years	0
Amortized Cost, 5 to 10 Years	84
Amortized Cost, More Than 10 years	406,633
Amortized Cost, Amortized Cost, No Stated Maturity	0
Total Amortized Cost	406,717
Fair Value, Within One year	0
Fair Value, 1 to 5 Years	0
Fair Value, 5 to 10 Years	84
Fair Value, More Than 10 years	398,456
Fair Value, No Stated Maturity	0
Total Fair Value	398,540
State And Municipal Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost, Within One year	1,054
Amortized Cost, 1 to 5 Years	2,828
Amortized Cost, 5 to 10 Years	0
Amortized Cost, More Than 10 years	2,841
Amortized Cost, Amortized Cost, No Stated Maturity	0
Total Amortized Cost	6,723
Fair Value, Within One year	1,066
Fair Value, 1 to 5 Years	2,886
Fair Value, 5 to 10 Years	0
Fair Value, More Than 10 years	2,937
Fair Value, No Stated Maturity	0
Total Fair Value	6,889
Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost, Within One year	0
Amortized Cost, 1 to 5 Years	0
Amortized Cost, 5 to 10 Years	0
Amortized Cost, More Than 10 years	0
Amortized Cost, Amortized Cost, No Stated Maturity	3,856
Total Amortized Cost	3,856
Fair Value, Within One year	0
Fair Value, 1 to 5 Years	0
Fair Value, 5 to 10 Years	0
Fair Value, More Than 10 years	0
Fair Value, No Stated Maturity	7,584
Total Fair Value	7,584
Other Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost, Within One year	0
Amortized Cost, 1 to 5 Years	0
Amortized Cost, 5 to 10 Years	0
Amortized Cost, More Than 10 years	2,000
Amortized Cost, Amortized Cost, No Stated Maturity	2,074
Total Amortized Cost	4,074
Fair Value, Within One year	0
Fair Value, 1 to 5 Years	0
Fair Value, 5 to 10 Years	0
Fair Value, More Than 10 years	1,722
Fair Value, No Stated Maturity	1,969
Total Fair Value	$ 3,691