Outstanding Commitments to Extend Credit and Letters of Credit (Details) (Reserve for Off-balance Sheet Activities [Member], USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Valuation allowances and Reserves, Balance	$ 475,576	$ 520,485
Commerical mortgage and construction
Valuation allowances and Reserves, Balance	275,308	333,060
Home Equity [Member]
Valuation allowances and Reserves, Balance	1,019,470	946,637
Commercial Real Estate Other Receivable [Member]
Valuation allowances and Reserves, Balance	2,508,754	2,501,127
Total commitments to extend credit [Member]
Valuation allowances and Reserves, Balance	3,803,532	3,780,824
Standby letters of credit [Member]
Valuation allowances and Reserves, Balance	444,019	489,097
Commercial letters of credit [Member]
Valuation allowances and Reserves, Balance	31,557	31,388
Residential Mortgage [Member]
Valuation allowances and Reserves, Balance	$ (1,500)	$ (3,300)