Note Commitments and contingencies (FDIC dealings section) - Additional Information (Detail) $ in Thousands	3 Months Ended			6 Months Ended
	Jun. 30, 2016 USD ($) D	Jun. 30, 2015 USD ($)	Mar. 31, 2015 USD ($)	Jun. 30, 2016 USD ($) D	Jun. 30, 2015 USD ($)	Dec. 31, 2015 USD ($)	Nov. 12, 2015 USD ($)	Apr. 13, 2015 USD ($)	Apr. 01, 2015 USD ($)	Nov. 25, 2014 USD ($)
FDIC Dealings [Line Items]
Write-off	$ 70,635	$ 108,003		$ 130,572	$ 189,818
Loans and Leases Receivable, Gross, Carrying Amount, Covered	607,170			607,170		$ 646,115
F D I C Indemnification Asset	$ 214,029			$ 214,029		310,221
True Up Payment Term | D	45			45
FDIC
FDIC Dealings [Line Items]
Business Combination Contingent Consideration Liability	$ 127,876			$ 127,876		119,745
Portfolio Sales Arbitration Filed On June 2015
FDIC Dealings [Line Items]
Loss Contingency Aggregate Claims Damages Sought	88,500
Pending Dispute With FDIC
FDIC Dealings [Line Items]
Loss Contingency Aggregate Claims Damages Sought	4,900
Banco Popular de Puerto Rico | Pending Dispute With FDIC
FDIC Dealings [Line Items]
Unreimbursed Claims Submitted to the FDIC		$ 6,900			$ 6,900
Payments Withheld By The FDIC							$ 5,500
F D I C Indemnification Asset	142,000			142,000
Covered loans
FDIC Dealings [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount, Covered	$ 607,170			$ 607,170		$ 646,115
Covered loans | Banco Popular de Puerto Rico | Pending Dispute With FDIC
FDIC Dealings [Line Items]
Loss Claim Disputed Amount										$ 66,600
Write-off			$ 53,300
F D I C Reimbursable Expenses Clawed Back									$ 1,700
Loss Contingency Increase In Damages Sought Value								$ 1,700