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

12 Months Ended

Dec. 31, 2014

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

Summary of lending-related and other commitments

		2014		2013
		($ in Thousands)
Commitments to extend credit, excluding commitments to originate residential mortgage loans held
	for sale(1)(2)	$	6,884,411	$	6,367,771
Commercial letters of credit(1)			9,179		12,034
Standby letters of credit(3)			353,292		370,773

Summary of changes in the residential mortgage repurchase reserve

		For the Year Ended		For the Year Ended
		December 31, 2014		December 31, 2013
		($ in Thousands)
Balance at beginning of year	$	5,737	$	3,300
Repurchase provision expense		505		1,243
Adjustments to provision expense		(2,250)		4,666
Charge offs		(734)		(3,472)
Balance at end of year	$	3,258	$	5,737