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

3 Months Ended

Mar. 31, 2012

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

Summary of lending-related and other commitments

			March 31, 2012		December 31, 2011
			($ in Thousands)
Commitments to extend credit, excluding commitments to originate residential
	mortgage loans held for sale(1)(2)	$	4,551,151	$	4,561,210
Commercial letters of credit (1)			48,479		47,699
Standby letters of credit (3)			313,165		320,375