Note Segment reporting (Results of Operations) (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Segment Reporting Information [Line Items]
Net Interest income (expense)	$ 393,047	$ 362,098
Provision for loan losses	71,063	40,698
Non interest Income	113,497	115,869
Amortization of intangibles	2,325	2,345
Depreciation expense	12,833	11,799
Other operating expenses	306,844	297,174
Income tax expense	22,155	33,006
Net Income (loss)	91,324	92,945
Assets	45,756,761	40,259,282	$ 44,277,337
Reportable Segment
Segment Reporting Information [Line Items]
Net Interest income (expense)	407,265	377,167
Provision for loan losses	71,084	40,698
Non interest Income	100,827	104,519
Amortization of intangibles	2,325	2,345
Depreciation expense	12,646	11,636
Other operating expenses	285,613	277,876
Income tax expense	26,936	41,218
Net Income (loss)	109,488	107,913
Assets	45,456,922	40,026,393
Intersegment Elimination
Segment Reporting Information [Line Items]
Net Interest income (expense)	4	(164)
Provision for loan losses	0	0
Non interest Income	(139)	(144)
Amortization of intangibles	0	0
Depreciation expense	0	0
Other operating expenses	(136)	(138)
Income tax expense	0	(70)
Net Income (loss)	1	(100)
Assets	(14,471)	(22,946)
Corporate
Segment Reporting Information [Line Items]
Net Interest income (expense)	(14,218)	(15,069)
Provision for loan losses	(21)	0
Non interest Income	12,948	11,427
Amortization of intangibles	0	0
Depreciation expense	187	163
Other operating expenses	22,082	19,926
Income tax expense	(5,012)	(8,423)
Net Income (loss)	(18,506)	(15,308)
Assets	5,033,543	5,004,658
Eliminations
Segment Reporting Information [Line Items]
Net Interest income (expense)	0	0
Provision for loan losses	0	0
Non interest Income	(278)	(77)
Amortization of intangibles	0	0
Depreciation expense	0	0
Other operating expenses	(851)	(628)
Income tax expense	231	211
Net Income (loss)	342	340
Assets	(4,733,704)	(4,771,769)
Banco Popular de Puerto Rico | Reportable Segment
Segment Reporting Information [Line Items]
Net Interest income (expense)	332,268	310,212
Provision for loan losses	58,469	30,118
Non interest Income	96,625	99,732
Amortization of intangibles	2,159	2,179
Depreciation expense	10,528	9,733
Other operating expenses	240,529	236,301
Income tax expense	25,847	33,998
Net Income (loss)	91,361	97,615
Assets	36,244,300	31,217,093
Banco Popular de Puerto Rico | Commercial Banking | Reportable Segment
Segment Reporting Information [Line Items]
Net Interest income (expense)	139,270	120,296
Provision for loan losses	20,693	(573)
Non interest Income	12,562	19,428
Amortization of intangibles	52	54
Depreciation expense	4,289	4,262
Other operating expenses	60,261	60,833
Income tax expense	16,875	22,076
Net Income (loss)	49,662	53,072
Assets	23,652,941	17,559,586
Banco Popular de Puerto Rico | Consumer and Retail Banking | Reportable Segment
Segment Reporting Information [Line Items]
Net Interest income (expense)	191,434	188,132
Provision for loan losses	37,776	30,691
Non interest Income	61,857	58,071
Amortization of intangibles	1,069	1,067
Depreciation expense	6,085	5,267
Other operating expenses	162,490	161,264
Income tax expense	7,457	8,983
Net Income (loss)	38,414	38,931
Assets	20,618,670	18,178,383
Banco Popular de Puerto Rico | Other Financial Services | Reportable Segment
Segment Reporting Information [Line Items]
Net Interest income (expense)	1,576	1,787
Provision for loan losses	0	0
Non interest Income	22,449	22,311
Amortization of intangibles	1,038	1,058
Depreciation expense	154	204
Other operating expenses	18,033	14,292
Income tax expense	1,515	2,939
Net Income (loss)	3,285	5,605
Assets	346,096	325,217
Banco Popular de Puerto Rico | Eliminations | Reportable Segment
Segment Reporting Information [Line Items]
Net Interest income (expense)	(12)	(3)
Provision for loan losses	0	0
Non interest Income	(243)	(78)
Amortization of intangibles	0	0
Depreciation expense	0	0
Other operating expenses	(255)	(88)
Income tax expense	0	0
Net Income (loss)	0	7
Assets	(8,373,407)	(4,846,093)
Popular Bank | Reportable Segment
Segment Reporting Information [Line Items]
Net Interest income (expense)	74,993	67,119
Provision for loan losses	12,615	10,580
Non interest Income	4,341	4,931
Amortization of intangibles	166	166
Depreciation expense	2,118	1,903
Other operating expenses	45,220	41,713
Income tax expense	1,089	7,290
Net Income (loss)	18,126	10,398
Assets	$ 9,227,093	$ 8,832,246