Loans and leases and the allowance for credit losses (Details 3) (USD $) In Thousands	Jun. 30, 2011	Dec. 31, 2010
Impaired loans and leases
Recorded Investment, with an allowance recorded	$ 819,808	$ 904,504
Unpaid Principal Balance, with an allowance recorded	984,605	1,043,304
Related Allowance, with an allowance recorded	206,016	213,933
Recorded investment, with no related allowance recorded	463,114	349,223
Unpaid Principal Balance, with no related allowance recorded	589,462	433,129
Recorded Investment, Total	1,282,922	1,253,727
Unpaid Principal Balance, Total	1,574,067	1,476,433
Related Allowance, Total	206,016	213,933
Commercial, financial, leasing [Member]
Impaired loans and leases
Recorded Investment, with an allowance recorded	94,843	121,744
Unpaid Principal Balance, with an allowance recorded	137,532	170,888
Related Allowance, with an allowance recorded	32,827	40,909
Recorded investment, with no related allowance recorded	75,477	65,827
Unpaid Principal Balance, with no related allowance recorded	100,760	86,332
Recorded Investment, Total	170,320	187,571
Unpaid Principal Balance, Total	238,292	257,220
Related Allowance, Total	32,827	40,909
Commercial Real Estate Excluding Residential Builder and Developer and Other Construction [Member]
Impaired loans and leases
Recorded Investment, with an allowance recorded	132,723	110,975
Unpaid Principal Balance, with an allowance recorded	169,915	140,015
Related Allowance, with an allowance recorded	29,670	17,393
Recorded investment, with no related allowance recorded	105,755	101,939
Unpaid Principal Balance, with no related allowance recorded	122,637	116,316
Recorded Investment, Total	238,478	212,914
Unpaid Principal Balance, Total	292,552	256,331
Related Allowance, Total	29,670	17,393
Residential builder and developer [Member]
Impaired loans and leases
Recorded Investment, with an allowance recorded	178,636	263,545
Unpaid Principal Balance, with an allowance recorded	224,646	295,031
Related Allowance, with an allowance recorded	79,506	78,597
Recorded investment, with no related allowance recorded	207,803	100,799
Unpaid Principal Balance, with no related allowance recorded	259,984	124,383
Recorded Investment, Total	386,439	364,344
Unpaid Principal Balance, Total	484,630	419,414
Related Allowance, Total	79,506	78,597
Other commercial construction [Member]
Impaired loans and leases
Recorded Investment, with an allowance recorded	87,407	80,934
Unpaid Principal Balance, with an allowance recorded	94,610	85,432
Related Allowance, with an allowance recorded	13,073	22,067
Recorded investment, with no related allowance recorded	27,989	46,656
Unpaid Principal Balance, with no related allowance recorded	31,712	50,496
Recorded Investment, Total	115,396	127,590
Unpaid Principal Balance, Total	126,322	135,928
Related Allowance, Total	13,073	22,067
Residential real estate excluding Alt-A [Member]
Impaired loans and leases
Recorded Investment, with an allowance recorded	86,574	73,006
Unpaid Principal Balance, with an allowance recorded	105,454	85,279
Related Allowance, with an allowance recorded	3,044	3,375
Recorded investment, with no related allowance recorded	15,483	5,035
Unpaid Principal Balance, with no related allowance recorded	21,383	7,723
Recorded Investment, Total	102,057	78,041
Unpaid Principal Balance, Total	126,837	93,002
Related Allowance, Total	3,044	3,375
Residential Alt-A [Member]
Impaired loans and leases
Recorded Investment, with an allowance recorded	165,539	180,665
Unpaid Principal Balance, with an allowance recorded	176,915	191,445
Related Allowance, with an allowance recorded	32,000	36,000
Recorded investment, with no related allowance recorded	30,607	28,967
Unpaid Principal Balance, with no related allowance recorded	52,986	47,879
Recorded Investment, Total	196,146	209,632
Unpaid Principal Balance, Total	229,901	239,324
Related Allowance, Total	32,000	36,000
Home equity lines and loans [Member]
Impaired loans and leases
Recorded Investment, with an allowance recorded	12,050	11,799
Unpaid Principal Balance, with an allowance recorded	13,497	13,378
Related Allowance, with an allowance recorded	2,547	2,227
Recorded Investment, Total	12,050	11,799
Unpaid Principal Balance, Total	13,497	13,378
Related Allowance, Total	2,547	2,227
Automobile [Member]
Impaired loans and leases
Recorded Investment, with an allowance recorded	57,827	58,858
Unpaid Principal Balance, with an allowance recorded	57,827	58,858
Related Allowance, with an allowance recorded	12,351	12,597
Recorded Investment, Total	57,827	58,858
Unpaid Principal Balance, Total	57,827	58,858
Related Allowance, Total	12,351	12,597
Other [Member]
Impaired loans and leases
Recorded Investment, with an allowance recorded	4,209	2,978
Unpaid Principal Balance, with an allowance recorded	4,209	2,978
Related Allowance, with an allowance recorded	998	768
Recorded Investment, Total	4,209	2,978
Unpaid Principal Balance, Total	4,209	2,978
Related Allowance, Total	$ 998	$ 768