Note Guarantees (Other Guarantees) - Additional Information (Detail) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Guarantor Obligations [Line Items]
Funds Advanced To Investors Under Servicing Agreements	$ 87,577	$ 107,299
Debt Securities Payable | Popular, Inc. Holding Co.
Guarantor Obligations [Line Items]
Guarantees, unamortized balance of the obligations	149,000	149,000
Financial Standby Letter Of Credit
Guarantor Obligations [Line Items]
Guarantees, unamortized balance of the obligations	400	300
Guarantee Type, Other | Capital securities (trust preferred securities) | Popular, Inc. Holding Co.
Guarantor Obligations [Line Items]
Guarantees, unamortized balance of the obligations	$ 427,000	$ 427,000