Commitments, Off-Balance Sheet Arrangements and Contingent Liabilities (Tables)

12 Months Ended

Dec. 31, 2011

Commitments, off-balance Sheet Arrangements, and Contingent Liabilities [Abstract]

Summary of lending-related and other commitments

		2011		2010
		($ in Thousands)
Commitments to extend credit, excluding commitments to originate residential mortgage loans held
	for sale(1)(2)	$	4,561,210	$	3,862,208
Commercial letters of credit(1)			47,699		37,872
Standby letters of credit(3)		$	320,375	$	362,275