Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013		Dec. 31, 2012
Assets
Cash and due from banks	$ 569,118	[1]	$ 639,730	[2]
Overnight investments	1,354,131	[1]	443,180	[2]
Investment securities available for sale	5,161,585	[1]	5,226,228	[2]
Investment securities held to maturity	1,013	[1]	1,342	[2]
Loans held for sale	43,054	[1]	86,333	[2]
Loans and leases:
Acquired	1,188,281	[1]	1,809,235	[2]
Originated	11,884,585	[2]	11,576,115	[2]
Less allowance for loan and lease losses	237,799	[1]	319,018	[2]
Net loans and leases	12,835,067	[1]	13,066,332	[2]
Premises and equipment	868,001	[1]	882,768	[2]
Other real estate owned:
Covered under loss share agreements in other real estate owned	58,769	[1]	102,577	[2]
Not covered under loss share agreements in other real estate owned	40,338	[1]	43,513	[2]
Income earned not collected	46,110	[1]	47,666	[2]
Receivable from FDIC for loss share agreements	100,553	[1]	270,192	[1]
Goodwill	102,625	[1]	102,625	[2]
Other intangible assets	1,696	[1]	3,556	[2]
Other assets	329,292	[1]	367,610	[2]
Total assets	21,511,352	[1]	21,283,652	[2]
Liabilities
Noninterest-bearing	5,323,051	[1]	4,885,700	[2]
Interest-bearing	12,740,268	[1]	13,200,325	[2]
Total deposits	18,063,319	[1]	18,086,025	[2]
Debt, Current	604,435	[1]	568,505	[1]
Long-term obligations	510,963	[1]	444,921	[2]
Payable to FDIC for loss share agreements	107,419		101,641
Other liabilities	243,159	[1]	218,553	[2]
Total liabilities	19,529,295	[1]	19,419,645	[2]
Shareholders' Equity
Surplus	143,766	[1]	143,766	[2]
Retained earnings	1,924,217	[1]	1,792,726	[2]
Accumulated other comprehensive loss	(95,545)	[1]	(82,106)	[2]
Total shareholders' equity	1,982,057	[1]	1,864,007	[2]
Total liabilities and shareholders' equity	21,511,352	[1]	21,283,652	[2]
Class A Common Stock
Shareholders' Equity
Common stock	8,586	[1]	8,588	[2]
Class B Common Stock
Shareholders' Equity
Common stock	$ 1,033	[1]	$ 1,033	[2]

[1] Unaudited

[2] Derived from 2012 Annual Report on Form 10-K.