Note Income taxes (Components of deferred tax assets and liabilities) (Detail) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Deferred tax assets:
Tax credits available for carryforward	$ 23,657	$ 23,657
Net operating loss and other carryforward available	838,382	837,087
Postretirement and pension benefits	82,940	83,390
Allowance for loan losses	502,058	535,255
Accelerated depreciation	7,723	7,749
FDIC-assisted transaction	92,209	95,851
Difference in outside basis from pass-through entities	17,430	20,209
Other temporary differences	32,817	32,479
Total gross deferred tax assets	1,601,867	1,641,682
Deferred tax liabilities:
Indefinite-lived intangibles	75,700	73,678
Unrealized net gain (loss) on trading and available-for-sale securities	24,617	11,040
Other temporary differences	12,508	11,688
Total gross deferred tax liabilities	112,825	96,406
Valuation allowance	496,642	496,307
Net deferred tax asset	992,400	1,048,969
PUERTO RICO
Deferred tax assets:
Tax credits available for carryforward	15,900	15,900
Net operating loss and other carryforward available	121,529	116,154
Postretirement and pension benefits	82,940	83,390
Allowance for loan losses	482,185	516,643
Accelerated depreciation	1,963	1,963
FDIC-assisted transaction	92,209	95,851
Difference in outside basis from pass-through entities	17,430	20,209
Other temporary differences	24,797	24,957
Total gross deferred tax assets	843,008	879,801
Deferred tax liabilities:
Indefinite-lived intangibles	34,914	34,081
Unrealized net gain (loss) on trading and available-for-sale securities	32,253	23,823
Other temporary differences	11,399	10,579
Total gross deferred tax liabilities	78,566	68,483
Valuation allowance	95,334	89,852
Net deferred tax asset	669,108	721,466
UNITED STATES
Deferred tax assets:
Tax credits available for carryforward	7,757	7,757
Net operating loss and other carryforward available	716,853	720,933
Postretirement and pension benefits	0	0
Allowance for loan losses	19,873	18,612
Accelerated depreciation	5,760	5,786
FDIC-assisted transaction	0	0
Difference in outside basis from pass-through entities	0	0
Other temporary differences	8,020	7,522
Total gross deferred tax assets	758,859	761,881
Deferred tax liabilities:
Indefinite-lived intangibles	40,786	39,597
Unrealized net gain (loss) on trading and available-for-sale securities	(7,636)	(12,783)
Other temporary differences	1,109	0
Total gross deferred tax liabilities	34,259	26,814
Valuation allowance	401,308	406,455
Net deferred tax asset	323,292	328,612
Deferred loans origination fees
Deferred tax assets:
Deferred income	837	1,936
Deferred loans origination fees | PUERTO RICO
Deferred tax assets:
Deferred income	2,756	3,216
Deferred loans origination fees | UNITED STATES
Deferred tax assets:
Deferred income	(1,919)	(1,280)
Deferred gain
Deferred tax assets:
Deferred income	2,515	2,551
Deferred gain | PUERTO RICO
Deferred tax assets:
Deferred income	0	0
Deferred gain | UNITED STATES
Deferred tax assets:
Deferred income	2,515	2,551
Intercompany deferred gains
Deferred tax assets:
Deferred income	1,299	1,518
Intercompany deferred gains | PUERTO RICO
Deferred tax assets:
Deferred income	1,299	1,518
Intercompany deferred gains | UNITED STATES
Deferred tax assets:
Deferred income	$ 0	$ 0