Loans, Allowance for Loan and Lease Losses, and Reserve for Off-Balance Sheet Credit Commitments (Detail 3) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Changes in Accretable Yield for Acquired Impaired Loans
Balance at the beginning of the period	$ 168,469	$ 219,018
Accretion	(28,131)	(36,067)
Reclassification from nonaccretable difference	19,545	25,636
Disposals and other	(23,239)	(28,628)
Balance at the end of the period	$ 136,644	$ 179,959
Charge off of consumer loans, delinquency period for overdrafts, low end of range	60 days
Charge off of consumer loans, delinquency period for secured consumer loans	180 days