Allowance for Non-Covered Loan Loss and Credit Quality (Internal Risk Rating By Loan Class) (Details) (USD $)	Jun. 30, 2011	Dec. 31, 2010
Commercial real estate, Term & multifamily	$ 3,532,134,000	$ 3,483,475,000
Commercial real estate, Construction & development	184,707,000	247,814,000
Commercial real estate, Residential development	112,657,000	147,813,000
Commercial, Term	572,402,000	509,453,000
Commercial, LOC & other	788,268,000	747,419,000
Residential, Mortgage	245,034,000	222,416,000
Residential, Home equity loans & lines	277,453,000	278,585,000
Consumer & other	34,584,000	33,043,000
Total	5,747,239,000	5,670,018,000
Deferred loan fees, net	(11,686,000)	(11,031,000)
Total loans and leases	5,735,553,000	5,658,987,000
Pass/Watch [Member]
Commercial real estate, Term & multifamily	3,004,552,000	2,978,116,000
Commercial real estate, Construction & development	111,702,000	145,108,000
Commercial real estate, Residential development	24,704,000	27,428,000
Commercial, Term	509,666,000	472,512,000
Commercial, LOC & other	690,219,000	646,163,000
Residential, Mortgage	238,198,000	216,899,000
Residential, Home equity loans & lines	273,916,000	275,906,000
Consumer & other	33,789,000	32,008,000
Total	4,886,746,000	4,794,140,000
Special Mention [Member]
Commercial real estate, Term & multifamily	317,006,000	314,094,000
Commercial real estate, Construction & development	18,625,000	25,295,000
Commercial real estate, Residential development	10,021,000	13,764,000
Commercial, Term	29,983,000	17,658,000
Commercial, LOC & other	41,091,000	30,761,000
Residential, Mortgage	2,369,000	2,414,000
Residential, Home equity loans & lines	2,414,000	2,447,000
Consumer & other	267,000	595,000
Total	421,776,000	407,028,000
Substandard [Member]
Commercial real estate, Term & multifamily	144,812,000	113,405,000
Commercial real estate, Construction & development	19,591,000	51,853,000
Commercial real estate, Residential development	12,021,000	23,106,000
Commercial, Term	23,632,000	12,109,000
Commercial, LOC & other	36,158,000	42,162,000
Residential, Mortgage	2,003,000	786,000
Residential, Home equity loans & lines	556,000	125,000
Consumer & other	36,000	29,000
Total	238,809,000	243,575,000
Doubtful/Loss [Member]
Residential, Mortgage	2,286,000	2,138,000
Residential, Home equity loans & lines	567,000	107,000
Consumer & other	492,000	411,000
Total	3,345,000	2,656,000
Impaired [Member]
Commercial real estate, Term & multifamily	65,764,000	77,860,000
Commercial real estate, Construction & development	34,789,000	25,558,000
Commercial real estate, Residential development	65,911,000	83,515,000
Commercial, Term	9,121,000	7,174,000
Commercial, LOC & other	20,800,000	28,333,000
Residential, Mortgage	178,000	179,000
Total	$ 196,563,000	$ 222,619,000