Investment Securities (Amortized Cost And Estimated Fair Value By Contractual Maturity Of Investment Securities Available For Sale) (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014
Schedule of Available-for-sale Securities [Line Items]
Within One year, Amortized Cost	$ 18,407
1 to 5 Years, Amortized Cost	122,537
5 to 10 Years, Amortized Cost	1,940,198
More Than 10 years, Amortized Cost	963,039
No Stated Maturity, Amortized Cost	5,338
Total, Amortized Cost	3,049,519
Within One Year, Fair Value	18,434
1 to 5 Years, Fair Value	123,933
5 to 10 Years, Fair Value	1,926,768
More Than 10 years, Fair Value	972,758
No Stated Maturity, Fair Value	8,364
Total, Fair Value	3,050,257
U.S. Treasury Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Within One year, Amortized Cost	17,793
1 to 5 Years, Amortized Cost	24,834
5 to 10 Years, Amortized Cost	0
More Than 10 years, Amortized Cost	0
No Stated Maturity, Amortized Cost	0
Total, Amortized Cost	42,627
Within One Year, Fair Value	17,793
1 to 5 Years, Fair Value	24,875
5 to 10 Years, Fair Value	0
More Than 10 years, Fair Value	0
No Stated Maturity, Fair Value	0
Total, Fair Value	42,668
U.S. Government Agency Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Within One year, Amortized Cost	78
1 to 5 Years, Amortized Cost	12,577
5 to 10 Years, Amortized Cost	13,780
More Than 10 years, Amortized Cost	0
No Stated Maturity, Amortized Cost	0
Total, Amortized Cost	26,435
Within One Year, Fair Value	80
1 to 5 Years, Fair Value	13,014
5 to 10 Years, Fair Value	14,375
More Than 10 years, Fair Value	0
No Stated Maturity, Fair Value	0
Total, Fair Value	27,469
Securities Issued By U.S. Government Sponsored Enterprises [Member]
Schedule of Available-for-sale Securities [Line Items]
Within One year, Amortized Cost	0
1 to 5 Years, Amortized Cost	81,549
5 to 10 Years, Amortized Cost	0
More Than 10 years, Amortized Cost	0
No Stated Maturity, Amortized Cost	0
Total, Amortized Cost	81,549
Within One Year, Fair Value	0
1 to 5 Years, Fair Value	82,327
5 to 10 Years, Fair Value	0
More Than 10 years, Fair Value	0
No Stated Maturity, Fair Value	0
Total, Fair Value	82,327
Mortgage-Backed Securities Issued By U.S. Government Agencies [Member]
Schedule of Available-for-sale Securities [Line Items]
Within One year, Amortized Cost	5
1 to 5 Years, Amortized Cost	1
5 to 10 Years, Amortized Cost	0
More Than 10 years, Amortized Cost	176,248
No Stated Maturity, Amortized Cost	0
Total, Amortized Cost	176,254
Within One Year, Fair Value	5
1 to 5 Years, Fair Value	1
5 to 10 Years, Fair Value	0
More Than 10 years, Fair Value	177,389
No Stated Maturity, Fair Value	0
Total, Fair Value	177,395
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Schedule of Available-for-sale Securities [Line Items]
Within One year, Amortized Cost	431
1 to 5 Years, Amortized Cost	1,605
5 to 10 Years, Amortized Cost	1,926,129
More Than 10 years, Amortized Cost	395,396
No Stated Maturity, Amortized Cost	0
Total, Amortized Cost	2,323,561
Within One Year, Fair Value	456
1 to 5 Years, Fair Value	1,707
5 to 10 Years, Fair Value	1,912,088
More Than 10 years, Fair Value	402,357
No Stated Maturity, Fair Value	0
Total, Fair Value	2,316,608
Collateralized Mortgage-Backed Securities Issued By U.S. Government Sponsored Enterprises [Member]
Schedule of Available-for-sale Securities [Line Items]
Within One year, Amortized Cost	0
1 to 5 Years, Amortized Cost	0
5 to 10 Years, Amortized Cost	0
More Than 10 years, Amortized Cost	371,656
No Stated Maturity, Amortized Cost	0
Total, Amortized Cost	371,656
Within One Year, Fair Value	0
1 to 5 Years, Fair Value	0
5 to 10 Years, Fair Value	0
More Than 10 years, Fair Value	373,459
No Stated Maturity, Fair Value	0
Total, Fair Value	373,459
State And Municipal Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Within One year, Amortized Cost	100
1 to 5 Years, Amortized Cost	1,971
5 to 10 Years, Amortized Cost	289
More Than 10 years, Amortized Cost	2,739
No Stated Maturity, Amortized Cost	0
Total, Amortized Cost	5,099
Within One Year, Fair Value	100
1 to 5 Years, Fair Value	2,009
5 to 10 Years, Fair Value	305
More Than 10 years, Fair Value	2,887
No Stated Maturity, Fair Value	0
Total, Fair Value	5,301
Securities With No Stated Maturity (Equity Securities) [Member]
Schedule of Available-for-sale Securities [Line Items]
Within One year, Amortized Cost	0
1 to 5 Years, Amortized Cost	0
5 to 10 Years, Amortized Cost	0
More Than 10 years, Amortized Cost	0
No Stated Maturity, Amortized Cost	3,228
Total, Amortized Cost	3,228
Within One Year, Fair Value	0
1 to 5 Years, Fair Value	0
5 to 10 Years, Fair Value	0
More Than 10 years, Fair Value	0
No Stated Maturity, Fair Value	6,357
Total, Fair Value	6,357
Other Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Within One year, Amortized Cost	0
1 to 5 Years, Amortized Cost	0
5 to 10 Years, Amortized Cost	0
More Than 10 years, Amortized Cost	17,000
No Stated Maturity, Amortized Cost	2,110
Total, Amortized Cost	19,110
Within One Year, Fair Value	0
1 to 5 Years, Fair Value	0
5 to 10 Years, Fair Value	0
More Than 10 years, Fair Value	16,666
No Stated Maturity, Fair Value	2,007
Total, Fair Value	$ 18,673