Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Assets
Cash and due from banks	$ 639,730	$ 590,801
Overnight investments	443,180	434,975
Investment securities available for sale (cost of $5,192,419 in 2012 and $4,029,858 in 2011)	5,226,228	4,056,423
Investment securities held to maturity (fair value of $1,448 in 2012 and $1,980 in 2011)	1,342	1,822
Loans held for sale	86,333	92,539
Loans and leases:
Covered under loss share agreements	1,809,235	2,362,152
Not covered under loss share agreements	11,576,115	11,581,637
Less: Allowance for loan and lease losses	319,018	270,144
Net loans and leases	13,066,332	13,673,645
Premises and equipment	882,768	854,476
Other real estate owned:
Covered under loss share agreements	102,577	148,599
Not covered under loss share agreements	43,513	50,399
Income earned not collected	47,666	42,216
Receivable from FDIC for loss share agreements	270,192	617,377
Goodwill	102,625	102,625
Other intangible assets	3,556	7,032
Other assets	367,610	324,369
Total assets	21,283,652	20,997,298
Deposits:
Noninterest-bearing	4,885,700	4,331,706
Interest-bearing	13,200,325	13,245,568
Total deposits	18,086,025	17,577,274
Short-term borrowings	568,505	615,222
Long-term obligations	444,921	687,599
Payable to FDIC for loss share agreements	101,641	77,866
Other liabilities	218,553	178,209
Total liabilities	19,419,645	19,136,170
Shareholders' Equity
Surplus	143,766	143,766
Retained earnings	1,792,726	1,773,652
Accumulated other comprehensive loss	(82,106)	(66,574)
Total shareholders' equity	1,864,007	1,861,128
Total liabilities and shareholders' equity	21,283,652	20,997,298
Class A Common Stock [Member]
Shareholders' Equity
Common stock	8,588	8,644
Class B Common Stock [Member]
Shareholders' Equity
Common stock	$ 1,033	$ 1,640