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

3 Months Ended

Mar. 31, 2014

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

Summary of lending-related and other commitments

			March 31, 2014		December 31, 2013
			($ in Thousands)
Commitments to extend credit, excluding commitments to originate residential
	mortgage loans held for sale(1)(2)	$	6,235,837	$	6,367,771
Commercial letters of credit (1)			132,590		132,777
Standby letters of credit (3)			258,919		250,030

Summary of changes in the residential mortgage repurchase reserve

		For the Three
		Months Ended		For the Year Ended
		March 31, 2014		December 31, 2013
		($ in Thousands)
Balance at beginning of period	$	5,700	$	3,300
Repurchase provision expense		(638)		5,909
Charge offs		(262)		(3,509)
Balance at end of period	$	4,800	$	5,700