Loans Schedule of accounts, Notes, Loans and Financing Receivables (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Commercial	$ 9,116,184		$ 8,750,109	$ 8,771,329
Loans and Leases Receivable, Gross, Consumer, Mortgage	1,052,455		1,050,584	957,863
Loans and Leases Receivable, Gross, Consumer, Installment, Other	2,928,985		2,738,656	2,725,517
Loans and Leases Receivable, Gross, Consumer, Home Equity	1,356,260		1,311,932	1,274,132
Loans and Leases Receivable, Gross, Consumer, Revolving, Credit Card	151,967		148,313	142,319
Loans and Leases Receivable, Gross, Consumer, Lease Financing	319,795		239,551	188,353
Loans and Leases Receivable, Gross	14,969,627		14,300,972	14,143,423
Allowance for loan losses	(142,036)		(141,252)	(147,714)
Loans and Leases Receivable, Net Amount	14,827,591		14,159,720	13,995,709
Originated Loans and Leases Receivable Fair Value	11,458,318		10,017,722	8,984,845
FDIC Indemnification Asset	43,981		61,827	83,910
Originated Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Commercial	7,365,499		6,648,279	5,997,812
Loans and Leases Receivable, Gross, Consumer, Mortgage	580,166		529,253	462,427
Loans and Leases Receivable, Gross, Consumer, Installment, Other	2,051,587		1,727,925	1,496,663
Loans and Leases Receivable, Gross, Consumer, Home Equity	998,179		920,066	845,051
Loans and Leases Receivable, Gross, Consumer, Revolving, Credit Card	151,967		148,313	142,319
Loans and Leases Receivable, Gross, Consumer, Lease Financing	319,795		239,551	188,353
Loans and Leases Receivable, Gross	11,467,193		10,213,387	9,132,625
Allowance for loan losses	(91,950)		(96,484)	(98,645)
Loans and Leases Receivable, Net Amount	11,375,243		10,116,903	9,033,980
Acquired Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Commercial	1,457,903		1,725,970	2,267,811
Loans and Leases Receivable, Gross, Consumer, Mortgage	425,584		470,652	439,380
Loans and Leases Receivable, Gross, Consumer, Installment, Other	872,034		1,004,569	1,221,060
Loans and Leases Receivable, Gross, Consumer, Home Equity	268,266		294,424	322,111
Loans and Leases Receivable, Gross	3,023,787		3,495,615	4,250,362
Allowance for loan losses	(4,977)		(741)	0
Loans and Leases Receivable, Net Amount	3,018,810		3,494,874
Originated Loans and Leases Receivable Fair Value	3,166,228			4,250,362
Covered Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Commercial	292,782		375,860	505,706
Loans and Leases Receivable, Gross, Consumer, Mortgage	46,705		50,679	56,056
Loans and Leases Receivable, Gross, Consumer, Installment, Other	5,364		6,162	7,794
Loans and Leases Receivable, Gross, Consumer, Home Equity	89,815		97,442	106,970
Loans and Leases Receivable, Net Amount	433,538		547,943	711,367
Loans and Leases Receivable, Gross, Carrying Amount, Covered	478,647		591,970	760,436
Loans and Leases Receivable, Allowance, Covered	45,109		44,027	49,069
Level 3
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated Loans and Leases Receivable Fair Value	11,458,318		10,017,722	8,984,845
Level 3 | Acquired Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Originated Loans and Leases Receivable Fair Value	3,166,228			4,250,362
Covered Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Allowance, Covered	45,109	49,970	44,027	49,069	47,945	43,255
Covered Loans | Covered Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
FDIC Indemnification Asset	43,981
Covered Loans Loss Share Receivable			$ 61,827	$ 83,910