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

9 Months Ended

Sep. 30, 2014

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

Summary of lending-related and other commitments

			September 30, 2014		December 31, 2013
			($ in Thousands)
Commitments to extend credit, excluding commitments to originate residential
	mortgage loans held for sale(1)(2)	$	6,703,718	$	6,367,771
Commercial letters of credit (1)			8,705		12,034
Standby letters of credit (3)			352,445		370,773

Summary of changes in the residential mortgage repurchase reserve

		For the Nine
		Months Ended		For the Year Ended
		September 30, 2014		December 31, 2013
		($ in Thousands)
Balance at beginning of period	$	5,700	$	3,300
Repurchase provision (recovery) expense		(1,883)		5,909
Charge offs		(417)		(3,509)
Balance at end of period	$	3,400	$	5,700