Investment Securities (Securities With Unrealized Losses And Length Of Impairment Period) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Investment [Line Items]
Less than 12 months, Fair Value	$ 730,059	$ 1,398,179
Less than 12 months, Unrealized Losses	5,474	6,971
12 months or longer, Fair Value	171,823	317,003
12 months or longer, Unrealized Losses	14,697	18,929
Total, Fair Value	901,882	1,715,182
Total, Unrealized Losses	20,171	25,900
U.S. government and federal agency obligations [Member]
Investment [Line Items]
Less than 12 months, Fair Value	71,464
Less than 12 months, Unrealized Losses	1,607
12 months or longer, Fair Value	0
12 months or longer, Unrealized Losses	0
Total, Fair Value	71,464
Total, Unrealized Losses	1,607
Government-sponsored enterprise obligations [Member]
Investment [Line Items]
Less than 12 months, Fair Value	102,082
Less than 12 months, Unrealized Losses	677
12 months or longer, Fair Value	0
12 months or longer, Unrealized Losses	0
Total, Fair Value	102,082
Total, Unrealized Losses	677
State and municipal obligations [Member]
Investment [Line Items]
Less than 12 months, Fair Value	173,600	65,962
Less than 12 months, Unrealized Losses	2,107	712
12 months or longer, Fair Value	80,530	110,807
12 months or longer, Unrealized Losses	14,188	10,507
Total, Fair Value	254,130	176,769
Total, Unrealized Losses	16,295	11,219
Agency mortgage-backed securities [Member]
Investment [Line Items]
Less than 12 months, Fair Value	5,874	72,019
Less than 12 months, Unrealized Losses	5	493
12 months or longer, Fair Value	0	0
12 months or longer, Unrealized Losses	0	0
Total, Fair Value	5,874	72,019
Total, Unrealized Losses	5	493
Non-agency mortgage-backed securities [Member]
Investment [Line Items]
Less than 12 months, Fair Value	0	23,672
Less than 12 months, Unrealized Losses	0	784
12 months or longer, Fair Value	12,609	118,972
12 months or longer, Unrealized Losses	118	7,028
Total, Fair Value	12,609	142,644
Total, Unrealized Losses	118	7,812
Other asset-backed securities [Member]
Investment [Line Items]
Less than 12 months, Fair Value	338,007	1,236,526
Less than 12 months, Unrealized Losses	976	4,982
12 months or longer, Fair Value	78,684	87,224
12 months or longer, Unrealized Losses	391	1,394
Total, Fair Value	416,691	1,323,750
Total, Unrealized Losses	1,367	6,376
Total mortgage and asset-backed securities [Member]
Investment [Line Items]
Less than 12 months, Fair Value	343,881	1,332,217
Less than 12 months, Unrealized Losses	981	6,259
12 months or longer, Fair Value	91,293	206,196
12 months or longer, Unrealized Losses	509	8,422
Total, Fair Value	435,174	1,538,413
Total, Unrealized Losses	1,490	14,681
Other debt securities [Member]
Investment [Line Items]
Less than 12 months, Fair Value	39,032
Less than 12 months, Unrealized Losses	102
12 months or longer, Fair Value	0
12 months or longer, Unrealized Losses	0
Total, Fair Value	39,032
Total, Unrealized Losses	$ 102