Allowance for credit losses - Allowance Movement (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Financing Receivable, Allowance for Credit Losses
Beginning balance	$ 896,250	$ 477,708
Impact of adopting CECL		315,107
Provision (reversal of provision)	(75,779)	188,995
Initial allowance for credit losses - PCD Loans	1,356	429
Charge-offs	(48,610)	(78,683)
Recoveries	27,580	16,160
Ending balance	800,797	919,716
Off Balance Sheet Credit Loss Liability [Rollforward]
Balance at beginning of period	15,851	8,717
Impact of CECL		(5,460)
Provision	(6,282)	1,209
Balance at end of period	9,569	4,466
Construction
Financing Receivable, Allowance for Credit Losses
Beginning balance	14,237	4,840
Impact of adopting CECL		(2,923)
Provision (reversal of provision)	875	557
Initial allowance for credit losses - PCD Loans	0	0
Charge-offs	(6,619)	0
Recoveries	702	174
Ending balance	9,195	2,648
Off Balance Sheet Credit Loss Liability [Rollforward]
Balance at beginning of period	9,079	419
Impact of CECL		397
Provision	(4,931)	503
Balance at end of period	4,148	1,319
Mortgages
Financing Receivable, Allowance for Credit Losses
Beginning balance	215,716	121,108
Impact of adopting CECL		96,512
Provision (reversal of provision)	(6,723)	14,575
Initial allowance for credit losses - PCD Loans	1,356	429
Charge-offs	(10,382)	(8,315)
Recoveries	2,159	2,778
Ending balance	202,126	227,087
Off Balance Sheet Credit Loss Liability [Rollforward]
Balance at beginning of period	0	0
Impact of CECL		0
Provision	0	0
Balance at end of period	0	0
Commercial
Financing Receivable, Allowance for Credit Losses
Beginning balance	333,380	147,620
Impact of adopting CECL		91,930
Provision (reversal of provision)	(58,579)	68,046
Initial allowance for credit losses - PCD Loans	0	0
Charge-offs	(3,266)	(3,571)
Recoveries	4,684	2,992
Ending balance	276,219	307,017
Off Balance Sheet Credit Loss Liability [Rollforward]
Balance at beginning of period	6,666	830
Impact of CECL		1,611
Provision	(1,310)	647
Balance at end of period	5,356	3,088
Leasing
Financing Receivable, Allowance for Credit Losses
Beginning balance	16,863	10,768
Impact of adopting CECL		(713)
Provision (reversal of provision)	(4,058)	5,841
Initial allowance for credit losses - PCD Loans	0	0
Charge-offs	(1,058)	(3,775)
Recoveries	940	468
Ending balance	12,687	12,589
Off Balance Sheet Credit Loss Liability [Rollforward]
Balance at beginning of period	0	0
Impact of CECL		0
Provision	0	0
Balance at end of period	0	0
Consumer
Financing Receivable, Allowance for Credit Losses
Beginning balance	316,054	193,372
Impact of adopting CECL		130,301
Provision (reversal of provision)	(7,294)	99,976
Initial allowance for credit losses - PCD Loans	0	0
Charge-offs	(27,285)	(63,022)
Recoveries	19,095	9,748
Ending balance	300,570	370,375
Off Balance Sheet Credit Loss Liability [Rollforward]
Balance at beginning of period	106	7,468
Impact of CECL		(7,468)
Provision	(41)	59
Balance at end of period	65	59
Puerto Rico
Financing Receivable, Allowance for Credit Losses
Beginning balance	739,750	432,651
Impact of adopting CECL		270,368
Provision (reversal of provision)	(39,976)	113,004
Initial allowance for credit losses - PCD Loans	1,356	429
Charge-offs	(44,970)	(73,159)
Recoveries	25,496	13,642
Ending balance	681,656	756,935
Off Balance Sheet Credit Loss Liability [Rollforward]
Balance at beginning of period	9,523	8,439
Impact of CECL		(6,494)
Provision	(5,365)	210
Balance at end of period	4,158	2,155
Puerto Rico | Construction
Financing Receivable, Allowance for Credit Losses
Beginning balance	4,871	574
Impact of adopting CECL		115
Provision (reversal of provision)	1,306	(289)
Initial allowance for credit losses - PCD Loans	0	0
Charge-offs	(6,619)	0
Recoveries	702	19
Ending balance	260	419
Off Balance Sheet Credit Loss Liability [Rollforward]
Balance at beginning of period	4,610	294
Impact of CECL		(185)
Provision	(4,365)	69
Balance at end of period	245	178
Puerto Rico | Mortgages
Financing Receivable, Allowance for Credit Losses
Beginning balance	195,557	116,281
Impact of adopting CECL		86,081
Provision (reversal of provision)	(2,805)	5,547
Initial allowance for credit losses - PCD Loans	1,356	429
Charge-offs	(10,381)	(8,306)
Recoveries	2,078	2,768
Ending balance	185,805	202,800
Off Balance Sheet Credit Loss Liability [Rollforward]
Balance at beginning of period	0	0
Impact of CECL		0
Provision	0	0
Balance at end of period	0	0
Puerto Rico | Commercial
Financing Receivable, Allowance for Credit Losses
Beginning balance	225,323	131,063
Impact of adopting CECL		62,393
Provision (reversal of provision)	(29,646)	14,974
Initial allowance for credit losses - PCD Loans	0	0
Charge-offs	(2,883)	(2,994)
Recoveries	4,317	2,414
Ending balance	197,111	207,850
Off Balance Sheet Credit Loss Liability [Rollforward]
Balance at beginning of period	4,913	678
Impact of CECL		1,158
Provision	(1,000)	141
Balance at end of period	3,913	1,977
Puerto Rico | Leasing
Financing Receivable, Allowance for Credit Losses
Beginning balance	16,863	10,768
Impact of adopting CECL		(713)
Provision (reversal of provision)	(4,058)	5,841
Initial allowance for credit losses - PCD Loans	0	0
Charge-offs	(1,058)	(3,775)
Recoveries	940	468
Ending balance	12,687	12,589
Off Balance Sheet Credit Loss Liability [Rollforward]
Balance at beginning of period	0	0
Impact of CECL		0
Provision	0	0
Balance at end of period	0	0
Puerto Rico | Consumer
Financing Receivable, Allowance for Credit Losses
Beginning balance	297,136	173,965
Impact of adopting CECL		122,492
Provision (reversal of provision)	(4,773)	86,931
Initial allowance for credit losses - PCD Loans	0	0
Charge-offs	(24,029)	(58,084)
Recoveries	17,459	7,973
Ending balance	285,793	333,277
Off Balance Sheet Credit Loss Liability [Rollforward]
Balance at beginning of period	0	7,467
Impact of CECL		(7,467)
Provision	0	0
Balance at end of period	0	0
Popular U.S.
Financing Receivable, Allowance for Credit Losses
Beginning balance	156,500	45,057
Impact of adopting CECL		44,739
Provision (reversal of provision)	(35,803)	75,991
Charge-offs	(3,640)	(5,524)
Recoveries	2,084	2,518
Ending balance	119,141	162,781
Off Balance Sheet Credit Loss Liability [Rollforward]
Balance at beginning of period	6,328	278
Impact of CECL		1,034
Provision	(917)	999
Balance at end of period	5,411	2,311
Popular U.S. | Construction
Financing Receivable, Allowance for Credit Losses
Beginning balance	9,366	4,266
Impact of adopting CECL		(3,038)
Provision (reversal of provision)	(431)	846
Charge-offs	0	0
Recoveries	0	155
Ending balance	8,935	2,229
Off Balance Sheet Credit Loss Liability [Rollforward]
Balance at beginning of period	4,469	125
Impact of CECL		582
Provision	(566)	434
Balance at end of period	3,903	1,141
Popular U.S. | Mortgages
Financing Receivable, Allowance for Credit Losses
Beginning balance	20,159	4,827
Impact of adopting CECL		10,431
Provision (reversal of provision)	(3,918)	9,028
Charge-offs	(1)	(9)
Recoveries	81	10
Ending balance	16,321	24,287
Off Balance Sheet Credit Loss Liability [Rollforward]
Balance at beginning of period	0	0
Impact of CECL		0
Provision	0	0
Balance at end of period	0	0
Popular U.S. | Commercial
Financing Receivable, Allowance for Credit Losses
Beginning balance	108,057	16,557
Impact of adopting CECL		29,537
Provision (reversal of provision)	(28,933)	53,072
Charge-offs	(383)	(577)
Recoveries	367	578
Ending balance	79,108	99,167
Off Balance Sheet Credit Loss Liability [Rollforward]
Balance at beginning of period	1,753	152
Impact of CECL		453
Provision	(310)	506
Balance at end of period	1,443	1,111
Popular U.S. | Consumer
Financing Receivable, Allowance for Credit Losses
Beginning balance	18,918	19,407
Impact of adopting CECL		7,809
Provision (reversal of provision)	(2,521)	13,045
Charge-offs	(3,256)	(4,938)
Recoveries	1,636	1,775
Ending balance	14,777	37,098
Off Balance Sheet Credit Loss Liability [Rollforward]
Balance at beginning of period	106	1
Impact of CECL		(1)
Provision	(41)	59
Balance at end of period	$ 65	$ 59