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

6 Months Ended

Jun. 30, 2013

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

Summary of lending-related and other commitments

			June 30, 2013		December 31, 2012
			($ in Thousands)
Commitments to extend credit, excluding commitments to originate residential
	mortgage loans held for sale(1)(2)	$	5,676,656	$	5,526,326
Commercial letters of credit (1)			132,802		85,689
Standby letters of credit (3)			276,110		303,705

Summary of changes in the residential mortgage repurchase reserve

		For the Six
		Months Ended		For the Year Ended
		June 30, 2013		December 31, 2012
		($ in Thousands)
Balance at beginning of period	$	3,300	$	0
Repurchase provision expense		4,018		7,109
Charge offs		(2,118)		(3,809)
Balance at end of period	$	5,200	$	3,300