Allowance for Loan and Lease Losses (Allocation of Allowance for Loan and Lease Losses) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Dec. 31, 2011
Total impaired noncovered loans and leases	$ 112,030	$ 123,728	$ 122,135
Average balance	116,623	115,362
Unpaid principal balance	126,877	124,802
Interest Income Recognized	787	1,065
Troubled debt restructurings	318,323
Construction and Land Development - Commercial [Member]
Total impaired noncovered loans and leases	19,768	30,369	24,994
Average balance	23,129	29,181
Unpaid principal balance	33,430	29,018
Interest Income Recognized	58	72
Commercial Mortgage [Member]
Total impaired noncovered loans and leases	63,366	69,017	65,527
Average balance	64,206	65,364
Unpaid principal balance	64,551	71,442
Interest Income Recognized	530	738
Other Commercial Real Estate [Member]
Total impaired noncovered loans and leases	1,521	946	2,580
Average balance	2,050	955
Unpaid principal balance	1,521	946
Interest Income Recognized	15	10
Commercial And Industrial [Member]
Total impaired noncovered loans and leases	12,598	14,631	14,268
Average balance	12,466	11,706
Unpaid principal balance	12,598	14,631
Interest Income Recognized	66	165
Lease Financing [Member]
Total impaired noncovered loans and leases	79	963	322
Average balance	201	828
Unpaid principal balance	79	963
Interest Income Recognized	1	12
Other Loans [Member]
Total impaired noncovered loans and leases	0	0	0
Average balance	0	38
Unpaid principal balance	0	0
Interest Income Recognized	0	0
Residential Mortgage [Member]
Total impaired noncovered loans and leases	10,438	7,186	9,776
Average balance	10,107	6,674
Unpaid principal balance	10,438	7,186
Interest Income Recognized	90	60
Construction And Land Development - Non - Commercial [Member]
Total impaired noncovered loans and leases	3,345	514	3,676
Average balance	3,510	514
Unpaid principal balance	3,345	514
Interest Income Recognized	23	6
Consumer [Member]
Total impaired noncovered loans and leases	915	102	992
Average balance	954	102
Unpaid principal balance	915	102
Interest Income Recognized	4	2
With No Recorded Allowance [Member]
Total impaired noncovered loans and leases	14,574	10,368	19,973
With No Recorded Allowance [Member] | Construction and Land Development - Commercial [Member]
Total impaired noncovered loans and leases	0	0	0
With No Recorded Allowance [Member] | Commercial Mortgage [Member]
Total impaired noncovered loans and leases	8,773	3,210	11,840
With No Recorded Allowance [Member] | Other Commercial Real Estate [Member]
Total impaired noncovered loans and leases	0	0	1,022
With No Recorded Allowance [Member] | Commercial And Industrial [Member]
Total impaired noncovered loans and leases	5,801	7,158	7,111
With No Recorded Allowance [Member] | Lease Financing [Member]
Total impaired noncovered loans and leases	0	0	0
With No Recorded Allowance [Member] | Other Loans [Member]
Total impaired noncovered loans and leases	0	0	0
With No Recorded Allowance [Member] | Residential Mortgage [Member]
Total impaired noncovered loans and leases	0	0	0
With No Recorded Allowance [Member] | Construction And Land Development - Non - Commercial [Member]
Total impaired noncovered loans and leases	0	0	0
With No Recorded Allowance [Member] | Consumer [Member]
Total impaired noncovered loans and leases	0	0	0
With A Recorded Allowance [Member]
Impaired noncovered loans and leases	9,037	12,115	6,122
Total impaired noncovered loans and leases	97,456	113,360	102,162
With A Recorded Allowance [Member] | Construction and Land Development - Commercial [Member]
Impaired noncovered loans and leases	2,487	6,170	1,027
Total impaired noncovered loans and leases	19,768	30,369	24,994
With A Recorded Allowance [Member] | Commercial Mortgage [Member]
Impaired noncovered loans and leases	4,915	4,716	3,813
Total impaired noncovered loans and leases	54,593	65,807	53,687
With A Recorded Allowance [Member] | Other Commercial Real Estate [Member]
Impaired noncovered loans and leases	196	62	114
Total impaired noncovered loans and leases	1,521	946	1,558
With A Recorded Allowance [Member] | Commercial And Industrial [Member]
Impaired noncovered loans and leases	574	727	549
Total impaired noncovered loans and leases	6,797	7,473	7,157
With A Recorded Allowance [Member] | Lease Financing [Member]
Impaired noncovered loans and leases	4	73	16
Total impaired noncovered loans and leases	79	963	322
With A Recorded Allowance [Member] | Other Loans [Member]
Impaired noncovered loans and leases	0	0	0
Total impaired noncovered loans and leases	0	0	0
With A Recorded Allowance [Member] | Residential Mortgage [Member]
Impaired noncovered loans and leases	674	354	411
Total impaired noncovered loans and leases	10,438	7,186	9,776
With A Recorded Allowance [Member] | Construction And Land Development - Non - Commercial [Member]
Impaired noncovered loans and leases	145	5	145
Total impaired noncovered loans and leases	3,345	514	3,676
With A Recorded Allowance [Member] | Consumer [Member]
Impaired noncovered loans and leases	42	8	47
Total impaired noncovered loans and leases	915	102	992
Noncovered Loans [Member]
Troubled debt restructurings	42,246
Covered Loans [Member] | With No Recorded Allowance [Member]
Loans with an adverse change in expected cash flows	$ 291,148