Segment reporting - Results of Operations (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Segment Reporting Information
Net Interest income (expense)	$ 476,991	$ 451,469	$ 1,424,270	$ 1,258,652
Provision (reversal) for loan losses	36,539	54,387	118,555	185,504
Non interest Income	142,712	151,021	417,468	499,327
Amortization of intangibles	2,399	2,324	7,082	6,973
Depreciation expense	14,204	13,508	42,928	39,083
Other operating expenses	359,872	349,605	1,036,900	979,051
Income tax expense (benefit)	41,370	42,018	131,923	35,613
Net income (loss)	165,319	140,648	504,350	511,755
Segment assets	52,480,415	47,919,428	52,480,415	47,919,428	$ 47,604,577
Reportable Segment
Segment Reporting Information
Net Interest income (expense)	486,577	464,720	1,452,891	1,300,181
Provision (reversal) for loan losses	36,541	54,421	118,298	185,579
Non interest Income	130,681	141,151	385,914	467,167
Amortization of intangibles	2,375	2,324	7,009	6,973
Depreciation expense	14,018	13,320	42,369	38,535
Other operating expenses	361,295	326,267	1,039,498	912,470
Income tax expense (benefit)	41,502	49,860	132,941	56,847
Net income (loss)	161,527	159,679	498,690	566,944
Segment assets	52,161,404	47,615,136	52,161,404	47,615,136
Intersegment Elimination
Segment Reporting Information
Net Interest income (expense)	4	3	(53)	5
Provision (reversal) for loan losses	0	0	0	0
Non interest Income	(140)	(141)	(421)	(420)
Amortization of intangibles	0	0	0	0
Depreciation expense	0	0	0	0
Other operating expenses	(136)	(136)	(409)	(409)
Income tax expense (benefit)	0	0	0	0
Net income (loss)	0	(2)	(65)	(6)
Segment assets	(14,414)	(112,222)	(14,414)	(112,222)
Corporate
Segment Reporting Information
Net Interest income (expense)	(9,586)	(13,251)	(28,621)	(41,529)
Provision (reversal) for loan losses	(2)	(34)	257	(75)
Non interest Income	12,137	9,960	33,537	33,698
Amortization of intangibles	24	0	73	0
Depreciation expense	186	188	559	548
Other operating expenses	(647)	23,995	(233)	68,766
Income tax expense (benefit)	(392)	(8,070)	(1,158)	(21,505)
Net income (loss)	3,382	(19,370)	5,418	(55,565)
Segment assets	5,134,608	5,478,884	5,134,608	5,478,884
Eliminations
Segment Reporting Information
Net Interest income (expense)	0	0	0	0
Provision (reversal) for loan losses	0	0	0	0
Non interest Income	(106)	(90)	(1,983)	(1,538)
Amortization of intangibles	0	0	0	0
Depreciation expense	0	0	0	0
Other operating expenses	(776)	(657)	(2,365)	(2,185)
Income tax expense (benefit)	260	228	140	271
Net income (loss)	410	339	242	376
Segment assets	(4,815,597)	(5,174,592)	(4,815,597)	(5,174,592)
Banco Popular de Puerto Rico | Reportable Segment
Segment Reporting Information
Net Interest income (expense)	412,182	388,533	1,231,088	1,073,522
Provision (reversal) for loan losses	34,481	51,911	94,651	154,805
Non interest Income	124,868	135,762	369,026	452,577
Amortization of intangibles	2,208	2,157	6,510	6,474
Depreciation expense	11,972	11,135	36,154	32,069
Other operating expenses	309,815	282,124	887,941	777,574
Income tax expense (benefit)	35,286	39,421	117,413	41,088
Net income (loss)	143,288	137,547	457,445	514,089
Segment assets	42,080,292	38,338,571	42,080,292	38,338,571
Banco Popular de Puerto Rico | Reportable Segment | Commercial Banking
Segment Reporting Information
Net Interest income (expense)	160,038	145,397	464,441	430,341
Provision (reversal) for loan losses	(23,619)	25,580	(22,756)	56,027
Non interest Income	25,196	23,630	74,481	60,122
Amortization of intangibles	50	50	147	153
Depreciation expense	5,064	4,697	14,615	13,327
Other operating expenses	82,817	78,628	229,767	199,528
Income tax expense (benefit)	29,340	11,068	88,353	52,640
Net income (loss)	91,582	49,004	228,796	168,788
Segment assets	35,590,229	28,247,478	35,590,229	28,247,478
Banco Popular de Puerto Rico | Reportable Segment | Consumer and Retail Banking
Segment Reporting Information
Net Interest income (expense)	250,944	241,920	762,913	639,149
Provision (reversal) for loan losses	58,100	26,331	117,407	98,778
Non interest Income	75,854	88,866	220,064	220,690
Amortization of intangibles	1,072	1,069	3,218	3,209
Depreciation expense	6,753	6,287	21,071	18,284
Other operating expenses	210,753	183,626	611,348	518,147
Income tax expense (benefit)	2,649	27,436	19,878	46,625
Net income (loss)	47,471	86,037	210,055	174,796
Segment assets	23,714,260	22,672,941	23,714,260	22,672,941
Banco Popular de Puerto Rico | Reportable Segment | Other Financial Services
Segment Reporting Information
Net Interest income (expense)	1,212	1,232	3,857	4,066
Provision (reversal) for loan losses	0	0	0	0
Non interest Income	24,545	23,663	76,733	69,876
Amortization of intangibles	1,086	1,038	3,145	3,112
Depreciation expense	155	151	468	458
Other operating expenses	16,986	20,279	49,076	52,679
Income tax expense (benefit)	3,297	917	9,182	5,711
Net income (loss)	4,233	2,510	18,719	11,982
Segment assets	379,126	336,311	379,126	336,311
Banco Popular de Puerto Rico | Reportable Segment | Eliminations
Segment Reporting Information
Net Interest income (expense)	(12)	(16)	(123)	(34)
Provision (reversal) for loan losses	0	0	0	0
Non interest Income	(727)	(397)	(2,252)	101,889
Amortization of intangibles	0	0	0	0
Depreciation expense	0	0	0	0
Other operating expenses	(741)	(409)	(2,250)	7,220
Income tax expense (benefit)	0	0	0	(63,888)
Net income (loss)	2	(4)	(125)	158,523
Segment assets	(17,603,323)	(12,918,159)	(17,603,323)	(12,918,159)
PB | Reportable Segment
Segment Reporting Information
Net Interest income (expense)	74,391	76,184	221,856	226,654
Provision (reversal) for loan losses	2,060	2,510	23,647	30,774
Non interest Income	5,953	5,530	17,309	15,010
Amortization of intangibles	167	167	499	499
Depreciation expense	2,046	2,185	6,215	6,466
Other operating expenses	51,616	44,279	151,966	135,305
Income tax expense (benefit)	6,216	10,439	15,528	15,759
Net income (loss)	18,239	22,134	41,310	52,861
Segment assets	$ 10,095,526	$ 9,388,787	$ 10,095,526	$ 9,388,787