Note Income taxes - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Income Taxes [Line Items]
Deferred Tax Assets Net	$ 1,207,597		$ 1,207,597		$ 1,243,668
Unrecognized Tax Benefits Interest On Income Taxes Accrued	2,600		2,600		2,900
Unrecognized Tax Benefits That Would Impact Effective Tax Rate	8,500		8,500		9,000
Significant Change In Unrecognized Tax Benefits Is Reasonably Possible Amount Of Unrecorded Benefit	4,500		4,500
Unrecognized Tax Benefits Current Interest On Income Taxes Accrued	458		458		1,200
Deferred Tax Liabilities	171,110		171,110		162,149
Deferred Tax Assets Valuation Allowance	678,086		678,086		664,287
Unrecognized Tax Benefits Expected Decreases Resulting From Settlements With Taxing Authorities	505		505
Income Tax Expense Benefit	(19,966)	$ 15,839	48,772	$ 80,550
Other liabilities
Income Taxes [Line Items]
Deferred Tax Liabilities	1,400		1,400		1,400
PUERTO RICO
Income Taxes [Line Items]
Deferred Tax Assets Net	687,000		687,000
Deferred Tax Liabilities	129,648		129,648		125,001
Deferred Tax Assets Valuation Allowance	62,213		62,213		46,951
Unrecognized tax benefits	(1,185)	(4,442)	(1,185)	(4,442)
Income Tax Expense Benefit	(19,966)	15,839	48,772	80,550
UNITED STATES
Income Taxes [Line Items]
Deferred Tax Assets Net	519,000		519,000
Deferred Tax Liabilities	41,462		41,462		37,148
Deferred Tax Assets Valuation Allowance	615,873		615,873		$ 617,336
Deferred Tax Assets	1,100,000		1,100,000
Popular, Inc. Holding Co.
Income Taxes [Line Items]
Income Tax Expense Benefit	0	$ (2)	0	$ 1
Popular, Inc. Holding Co. | PUERTO RICO
Income Taxes [Line Items]
Deferred Tax Assets Valuation Allowance	$ 62,000		$ 62,000