Condensed Consolidating Statement of Condition (Detail) - USD ($) $ in Thousands	Mar. 31, 2018		Dec. 31, 2017		Mar. 31, 2017	Dec. 31, 2016
Assets:
Cash And Due From Banks	$ 280,077		$ 402,857
Money market investments	6,984,009		5,255,119
Trading account debt securities, at fair value	42,386		33,926
Debt securities available-for-sale, at fair value	10,420,589		10,176,923
Debt securities held-to-maturity, at amortized cost	104,817	[1]	107,019	[2]
Equity securities (realizable value 2018 - $169,127; 2017 - $168,417)	165,218		165,103
Investment in subsidiaries	0		0
Loans held-for-sale, at lower of cost or fair value	77,701		132,395
Loans held-in-portfolio:
Loans not covered under loss-sharing agreements with the FDIC	24,224,793		24,423,427
Loans covered under loss-sharing agreements with the FDIC	514,611		517,274
Less - Unearned income	136,856		130,633
Allowance for loan losses	640,578		623,426		$ 544,496	$ 540,651
Total loans held-in-portfolio, net	23,961,970		24,186,642
FDIC loss-share asset	44,469		45,192
Premises and equipment, net	544,109		547,142
Accrued income receivable	157,340		213,844
Mortgage servicing assets, at fair value	166,281		168,031		193,698	196,889
Other assets	1,978,760		1,991,323
Goodwill	627,294		627,294		627,294	627,294
Other intangible assets	33,347		35,672
Total assets	45,756,761		44,277,337		40,259,282
Deposits:
Non-interest bearing	8,698,610		8,490,945
Interest bearing	28,435,483		26,962,563
Total deposits	37,134,093		35,453,508
Assets sold under agreements to repurchase	380,061		390,921
Other short-term borrowings	186,200		96,208
Notes payable	1,564,204		1,536,356
Other liabilities	1,427,294		1,696,439
Total liabilities	40,691,852		39,173,432
Stockholders' equity:
Preferred stock	50,160		50,160
Common stock	1,043		1,042
Surplus	4,300,936		4,298,503
Retained Earnings (Accumulated Deficit)	1,261,775		1,194,994
Treasury stock, at cost	(86,167)		(90,142)
Accumulated other comprehensive (loss) income, net of tax	(462,838)		(350,652)		(319,912)
Total stockholders' equity	5,064,909		5,103,905		$ 5,190,213	$ 5,197,957
Total liabilities and stockholders' equity	45,756,761		44,277,337
Elimination
Assets:
Cash And Due From Banks	(39,850)		(48,178)
Money market investments	(218,060)		(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 - $169,127; 2017 - $168,417)	(123)		(101)
Investment in subsidiaries	(7,110,673)		(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		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		0
Premises and equipment, net	0		0
Accrued income receivable	(245)		(211)
Mortgage servicing assets, at fair value	0		0
Other assets	(15,701)		(17,035)
Goodwill	(1)		0
Other intangible assets	0		0
Total assets	(7,382,999)		(7,449,074)
Deposits:
Non-interest bearing	(39,850)		(48,178)
Interest bearing	(218,060)		(248,807)
Total deposits	(257,910)		(296,985)
Assets sold under agreements to repurchase	0		0
Other short-term borrowings	(4,301)		0
Notes payable	0		0
Other liabilities	(16,417)		(15,033)
Total liabilities	(278,628)		(312,018)
Stockholders' equity:
Preferred stock	0		0
Common stock	(56,308)		(56,309)
Surplus	(9,831,879)		(9,821,299)
Retained Earnings (Accumulated Deficit)	2,270,534		2,362,302
Treasury stock, at cost	(86)		(84)
Accumulated other comprehensive (loss) income, net of tax	513,368		378,334
Total stockholders' equity	(7,104,371)		(7,137,056)
Total liabilities and stockholders' equity	(7,382,999)		(7,449,074)
Non Covered Under Loss Sharing Agreements with FDIC
Loans held-in-portfolio:
Other real estate owned	153,061		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	514,611	[3]	517,274	[4]
Other real estate owned	15,333		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	39,389		47,663
Money market investments	217,485		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 - $169,127; 2017 - $168,417)	5,554		5,109
Investment in subsidiaries	5,470,699		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	37,389		33,221
Loans covered under loss-sharing agreements with the FDIC	0		0
Less - Unearned income	0		0
Allowance for loan losses	245		266
Total loans held-in-portfolio, net	37,144		32,955
FDIC loss-share asset	0		0
Premises and equipment, net	3,317		3,365
Accrued income receivable	403		369
Mortgage servicing assets, at fair value	0		0
Other assets	68,216		61,319
Goodwill	0		0
Other intangible assets	6,114		6,114
Total assets	5,857,046		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	738,206		737,685
Other liabilities	53,844		64,813
Total liabilities	792,050		802,498
Stockholders' equity:
Preferred stock	50,160		50,160
Common stock	1,043		1,042
Surplus	4,292,409		4,289,976
Retained Earnings (Accumulated Deficit)	1,270,303		1,203,521
Treasury stock, at cost	(86,081)		(90,058)
Accumulated other comprehensive (loss) income, net of tax	(462,838)		(350,652)
Total stockholders' equity	5,064,996		5,103,989
Total liabilities and stockholders' equity	5,857,046		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	462		462
Money market investments	1,060		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 - $169,127; 2017 - $168,417)	20		20
Investment in subsidiaries	1,639,974		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		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		0
Premises and equipment, net	0		0
Accrued income receivable	31		112
Mortgage servicing assets, at fair value	0		0
Other assets	35,317		34,312
Goodwill	0		0
Other intangible assets	0		0
Total assets	1,681,336		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	148,545		148,539
Other liabilities	2,600		5,276
Total liabilities	155,446		153,815
Stockholders' equity:
Preferred stock	0		0
Common stock	2		2
Surplus	4,100,866		4,100,848
Retained Earnings (Accumulated Deficit)	(2,523,310)		(2,536,707)
Treasury stock, at cost	0		0
Accumulated other comprehensive (loss) income, net of tax	(51,668)		(29,486)
Total stockholders' equity	1,525,890		1,534,657
Total liabilities and stockholders' equity	1,681,336		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	280,076		402,910
Money market investments	6,983,524		5,254,662
Trading account debt securities, at fair value	42,386		33,926
Debt securities available-for-sale, at fair value	10,420,589		10,176,923
Debt securities held-to-maturity, at amortized cost	91,620		93,821
Equity securities (realizable value 2018 - $169,127; 2017 - $168,417)	159,767		160,075
Investment in subsidiaries	0		0
Loans held-for-sale, at lower of cost or fair value	77,701		132,395
Loans held-in-portfolio:
Loans not covered under loss-sharing agreements with the FDIC	24,185,750		24,384,251
Loans covered under loss-sharing agreements with the FDIC	514,611		517,274
Less - Unearned income	136,856		130,633
Allowance for loan losses	640,333		623,160
Total loans held-in-portfolio, net	23,923,172		24,147,732
FDIC loss-share asset	44,469		45,192
Premises and equipment, net	540,792		543,777
Accrued income receivable	157,151		213,574
Mortgage servicing assets, at fair value	166,281		168,031
Other assets	1,890,928		1,912,727
Goodwill	627,295		627,294
Other intangible assets	27,233		29,558
Total assets	45,601,378		44,131,452
Deposits:
Non-interest bearing	8,738,460		8,539,123
Interest bearing	28,653,543		27,211,370
Total deposits	37,392,003		35,750,493
Assets sold under agreements to repurchase	380,061		390,921
Other short-term borrowings	186,200		96,208
Notes payable	677,453		650,132
Other liabilities	1,387,267		1,641,383
Total liabilities	40,022,984		38,529,137
Stockholders' equity:
Preferred stock	0		0
Common stock	56,306		56,307
Surplus	5,739,540		5,728,978
Retained Earnings (Accumulated Deficit)	244,248		165,878
Treasury stock, at cost	0		0
Accumulated other comprehensive (loss) income, net of tax	(461,700)		(348,848)
Total stockholders' equity	5,578,394		5,602,315
Total liabilities and stockholders' equity	45,601,378		44,131,452
All other subsidiaries and eliminations | Non Covered Under Loss Sharing Agreements with FDIC
Loans held-in-portfolio:
Other real estate owned	153,061		169,260
All other subsidiaries and eliminations | Covered Under Loss Sharing Agreements With FDIC Member
Loans held-in-portfolio:
Other real estate owned	$ 15,333		$ 19,595

[1] Includes $90.8 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] Includes $268 million pledged to secure credit facilities at the FHLB which are not permitted to sell or repledge the collateral.

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