Condensed Consolidating Statement of Condition (Detail) - USD ($) $ in Thousands		Jun. 30, 2018		Mar. 31, 2018	Dec. 31, 2017		Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016
Assets:
Cash And Due From Banks		$ 400,568			$ 402,857
Money market investments		8,628,442			5,255,119
Trading account debt securities, at fair value		41,637			33,926
Debt securities available-for-sale, at fair value		10,542,010			10,176,923
Debt securities held-to-maturity, at amortized cost		104,937	[1]		107,019	[2]
Equity securities (realizable value 2018 - $163,316; 2017 - $168,417)		159,017			165,103
Investment in subsidiaries		0			0
Loans held-for-sale, at lower of cost or fair value		73,859			132,395
Loans held-in-portfolio:
Loans not covered under loss-sharing agreements with the FDIC		24,752,700			24,423,427
Loans covered under loss-sharing agreements with the FDIC		0			517,274
Less - Unearned income		144,184			130,633
Allowance for loan losses		643,018		$ 640,578	623,426		$ 540,014	$ 544,496	$ 540,651
Total loans held-in-portfolio, net		23,965,498			24,186,642
FDIC loss-share asset		0			45,192
Premises and equipment, net		548,432			547,142
Accrued income receivable		165,592			213,844
Mortgage servicing assets, at fair value		164,025			168,031		188,728		196,889
Other assets		1,940,780			1,991,323
Goodwill		627,294			627,294		627,294		627,294
Other intangible assets		31,023			35,672
Total assets		47,535,177			44,277,337		41,242,669
Deposits:
Non-interest bearing		9,392,263			8,490,945
Interest bearing		29,985,298			26,962,563
Total deposits		39,377,561			35,453,508
Assets sold under agreements to repurchase		306,911			390,921
Other short-term borrowings		1,200			96,208
Notes payable		1,561,663			1,536,356
Other liabilities		998,181			1,696,439
Total liabilities		42,245,516			39,173,432
Stockholders' equity:
Preferred stock		50,160			50,160
Common stock		1,043			1,042
Surplus		4,302,946			4,298,503
Retained Earnings (Accumulated Deficit)		1,515,058			1,194,994
Treasury stock, at cost		(82,754)			(90,142)
Accumulated other comprehensive (loss) income, net of tax	[3]	(496,792)			(350,652)		(302,943)
Total stockholders' equity		5,289,661			5,103,905		$ 5,278,045		$ 5,197,957
Total liabilities and stockholders' equity		47,535,177			44,277,337
Elimination
Assets:
Cash And Due From Banks		(62,437)			(48,178)
Money market investments		(212,920)			(248,807)
Trading account debt securities, at fair value		0			0
Debt securities available-for-sale, at fair value		0			0
Debt securities held-to-maturity, at amortized cost		0			0
Equity securities (realizable value 2018 - $163,316; 2017 - $168,417)		(133)			(101)
Investment in subsidiaries		(7,029,298)			(7,140,697)
Loans held-for-sale, at lower of cost or fair value		0			0
Loans held-in-portfolio:
Loans not covered under loss-sharing agreements with the FDIC		1,654			5,955
Loans covered under loss-sharing agreements with the FDIC					0
Less - Unearned income		0			0
Allowance for loan losses		0			0
Total loans held-in-portfolio, net		1,654			5,955
FDIC loss-share asset					0
Premises and equipment, net		0			0
Accrued income receivable		(400)			(211)
Mortgage servicing assets, at fair value		0			0
Other assets		(315,604)			(17,035)
Goodwill		(1)			0
Other intangible assets		0			0
Total assets		(7,619,139)			(7,449,074)
Deposits:
Non-interest bearing		(62,437)			(48,178)
Interest bearing		(212,920)			(248,807)
Total deposits		(275,357)			(296,985)
Assets sold under agreements to repurchase		0			0
Other short-term borrowings		(4,301)			0
Notes payable		0			0
Other liabilities		(316,181)			(15,033)
Total liabilities		(595,839)			(312,018)
Stockholders' equity:
Preferred stock		0			0
Common stock		(56,309)			(56,309)
Surplus		(9,818,944)			(9,821,299)
Retained Earnings (Accumulated Deficit)		2,299,132			2,362,302
Treasury stock, at cost		(87)			(84)
Accumulated other comprehensive (loss) income, net of tax		552,908			378,334
Total stockholders' equity		(7,023,300)			(7,137,056)
Total liabilities and stockholders' equity		(7,619,139)			(7,449,074)
Non Covered Under Loss Sharing Agreements with FDIC
Loans held-in-portfolio:
Other real estate owned		142,063			169,260
Non Covered Under Loss Sharing Agreements with FDIC | Elimination
Loans held-in-portfolio:
Other real estate owned		0			0
Covered Under Loss Sharing Agreements With FDIC Member
Loans held-in-portfolio:
Loans covered under loss-sharing agreements with the FDIC	[4],[5]				517,274
Other real estate owned		0			19,595
Covered Under Loss Sharing Agreements With FDIC Member | Elimination
Loans held-in-portfolio:
Other real estate owned		0			0
Popular, Inc. Holding Co.
Assets:
Cash And Due From Banks		62,429			47,663
Money market investments		211,494			246,457
Trading account debt securities, at fair value		0			0
Debt securities available-for-sale, at fair value		0			0
Debt securities held-to-maturity, at amortized cost		8,725			8,726
Equity securities (realizable value 2018 - $163,316; 2017 - $168,417)		5,849			5,109
Investment in subsidiaries		5,385,074			5,494,410
Loans held-for-sale, at lower of cost or fair value		0			0
Loans held-in-portfolio:
Loans not covered under loss-sharing agreements with the FDIC		37,260			33,221
Loans covered under loss-sharing agreements with the FDIC					0
Less - Unearned income		0			0
Allowance for loan losses		225			266
Total loans held-in-portfolio, net		37,035			32,955
FDIC loss-share asset					0
Premises and equipment, net		3,396			3,365
Accrued income receivable		556			369
Mortgage servicing assets, at fair value		0			0
Other assets		370,895			61,319
Goodwill		0			0
Other intangible assets		6,114			6,114
Total assets		6,091,567			5,906,487
Deposits:
Non-interest bearing		0			0
Interest bearing		0			0
Total deposits		0			0
Assets sold under agreements to repurchase		0			0
Other short-term borrowings		0			0
Notes payable		738,727			737,685
Other liabilities		63,092			64,813
Total liabilities		801,819			802,498
Stockholders' equity:
Preferred stock		50,160			50,160
Common stock		1,043			1,042
Surplus		4,294,419			4,289,976
Retained Earnings (Accumulated Deficit)		1,523,585			1,203,521
Treasury stock, at cost		(82,667)			(90,058)
Accumulated other comprehensive (loss) income, net of tax		(496,792)			(350,652)
Total stockholders' equity		5,289,748			5,103,989
Total liabilities and stockholders' equity		6,091,567			5,906,487
Popular, Inc. Holding Co. | Non Covered Under Loss Sharing Agreements with FDIC
Loans held-in-portfolio:
Other real estate owned		0			0
Popular, Inc. Holding Co. | Covered Under Loss Sharing Agreements With FDIC Member
Loans held-in-portfolio:
Other real estate owned		0			0
PNA Holding Co.
Assets:
Cash And Due From Banks		0			462
Money market investments		1,920			2,807
Trading account debt securities, at fair value		0			0
Debt securities available-for-sale, at fair value		0			0
Debt securities held-to-maturity, at amortized cost		4,472			4,472
Equity securities (realizable value 2018 - $163,316; 2017 - $168,417)		20			20
Investment in subsidiaries		1,644,224			1,646,287
Loans held-for-sale, at lower of cost or fair value		0			0
Loans held-in-portfolio:
Loans not covered under loss-sharing agreements with the FDIC		0			0
Loans covered under loss-sharing agreements with the FDIC					0
Less - Unearned income		0			0
Allowance for loan losses		0			0
Total loans held-in-portfolio, net		0			0
FDIC loss-share asset					0
Premises and equipment, net		0			0
Accrued income receivable		112			112
Mortgage servicing assets, at fair value		0			0
Other assets		35,100			34,312
Goodwill		0			0
Other intangible assets		0			0
Total assets		1,685,848			1,688,472
Deposits:
Non-interest bearing		0			0
Interest bearing		0			0
Total deposits		0			0
Assets sold under agreements to repurchase		0			0
Other short-term borrowings		4,301			0
Notes payable		148,552			148,539
Other liabilities		6,308			5,276
Total liabilities		159,161			153,815
Stockholders' equity:
Preferred stock		0			0
Common stock		2			2
Surplus		4,100,893			4,100,848
Retained Earnings (Accumulated Deficit)		(2,516,565)			(2,536,707)
Treasury stock, at cost		0			0
Accumulated other comprehensive (loss) income, net of tax		(57,643)			(29,486)
Total stockholders' equity		1,526,687			1,534,657
Total liabilities and stockholders' equity		1,685,848			1,688,472
PNA Holding Co. | Non Covered Under Loss Sharing Agreements with FDIC
Loans held-in-portfolio:
Other real estate owned		0			0
PNA Holding Co. | Covered Under Loss Sharing Agreements With FDIC Member
Loans held-in-portfolio:
Other real estate owned		0			0
All other subsidiaries and eliminations
Assets:
Cash And Due From Banks		400,576			402,910
Money market investments		8,627,948			5,254,662
Trading account debt securities, at fair value		41,637			33,926
Debt securities available-for-sale, at fair value		10,542,010			10,176,923
Debt securities held-to-maturity, at amortized cost		91,740			93,821
Equity securities (realizable value 2018 - $163,316; 2017 - $168,417)		153,281			160,075
Investment in subsidiaries		0			0
Loans held-for-sale, at lower of cost or fair value		73,859			132,395
Loans held-in-portfolio:
Loans not covered under loss-sharing agreements with the FDIC		24,713,786			24,384,251
Loans covered under loss-sharing agreements with the FDIC					517,274
Less - Unearned income		144,184			130,633
Allowance for loan losses		642,793			623,160
Total loans held-in-portfolio, net		23,926,809			24,147,732
FDIC loss-share asset					45,192
Premises and equipment, net		545,036			543,777
Accrued income receivable		165,324			213,574
Mortgage servicing assets, at fair value		164,025			168,031
Other assets		1,850,389			1,912,727
Goodwill		627,295			627,294
Other intangible assets		24,909			29,558
Total assets		47,376,901			44,131,452
Deposits:
Non-interest bearing		9,454,700			8,539,123
Interest bearing		30,198,218			27,211,370
Total deposits		39,652,918			35,750,493
Assets sold under agreements to repurchase		306,911			390,921
Other short-term borrowings		1,200			96,208
Notes payable		674,384			650,132
Other liabilities		1,244,962			1,641,383
Total liabilities		41,880,375			38,529,137
Stockholders' equity:
Preferred stock		0			0
Common stock		56,307			56,307
Surplus		5,726,578			5,728,978
Retained Earnings (Accumulated Deficit)		208,906			165,878
Treasury stock, at cost		0			0
Accumulated other comprehensive (loss) income, net of tax		(495,265)			(348,848)
Total stockholders' equity		5,496,526			5,602,315
Total liabilities and stockholders' equity		47,376,901			44,131,452
All other subsidiaries and eliminations | Non Covered Under Loss Sharing Agreements with FDIC
Loans held-in-portfolio:
Other real estate owned		142,063			169,260
All other subsidiaries and eliminations | Covered Under Loss Sharing Agreements With FDIC Member
Loans held-in-portfolio:
Other real estate owned		$ 0			$ 19,595

[1] Includes $90.9 million pledged to secure public and trust deposits that the secured parties are not permitted to sell or repledge the collateral.

[2] Includes $92.8 million pledged to secure public and trust deposits that the secured parties are not permitted to sell or repledge the collateral.

[3] All amounts presented are net of tax.

[4] Covered loans accounted for under ASC Subtopic 310-30 are excluded from the above table as they are considered to be performing due to the application of the accretion method, in which these loans will accrete interest income over the remaining life of the loans using estimated cash flow analyses.

[5] Includes $279 million pledged to secure credit facilities at the FHLB which are not permitted to sell or repledge the collateral.