Note Income taxes - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Income Taxes [Line Items]
Deferred Tax Assets Net	$ 1,031,360		$ 1,035,110
Unrecognized Tax Benefits Interest On Income Taxes Accrued	2,800		2,700
Unrecognized Tax Benefits That Would Impact Effective Tax Rate	9,200		9,000
Significant Change In Unrecognized Tax Benefits Is Reasonably Possible Amount Of Unrecorded Benefit	4,600
Recognized Tax Benefits Current Interest On Income Taxes Accrued	151	$ 145
Deferred Tax Liabilities	143,480		154,049
Deferred Tax Assets Valuation Allowance	455,940		447,824
Income Tax Expense Benefit	22,155	33,006
Popular, Inc. Holding Co.
Income Taxes [Line Items]
Income Tax Expense Benefit	0	0
Other liabilities
Income Taxes [Line Items]
Deferred Tax Liabilities	1,500		1,300
PUERTO RICO
Income Taxes [Line Items]
Deferred Tax Assets Net	680,000
Deferred Tax Liabilities	122,910		128,615
Deferred Tax Assets Valuation Allowance	74,489		67,263
Income Tax Expense Benefit	22,155	$ 33,006
UNITED STATES
Income Taxes [Line Items]
Deferred Tax Assets Net	350,000
Deferred Tax Liabilities	20,570		25,434
Deferred Tax Assets Valuation Allowance	381,451		$ 380,561
Deferred Tax Assets	$ 731,000