Note Income taxes (Components of deferred tax assets and liabilities) (Detail) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Deferred tax assets:
Tax credits available for carryforward	$ 24,359	$ 24,048
Net operating loss and other carryforward available	859,302	823,670
Postretirement and pension benefits	82,886	85,488
Allowance for loan losses	610,198	624,170
Accelerated depreciation	8,761	8,383
FDIC-assisted transaction	108,327
Difference in outside basis from pass-through entities	28,257	30,424
Other temporary differences	34,847	31,985
Total gross deferred tax assets	1,764,417	1,635,689
Deferred tax liabilities:
FDIC-assisted transaction		60,402
Indefinite-lived intangibles	71,912	64,982
Unrealized net gain (loss) on trading and available-for-sale securities	(912)	18,403
Other temporary differences	11,580	10,262
Total gross deferred tax liabilities	82,580	154,049
Valuation allowance	498,084	447,824
Net deferred tax asset	1,183,753	1,033,816
PUERTO RICO
Deferred tax assets:
Tax credits available for carryforward	16,500	16,069
Net operating loss and other carryforward available	119,578	115,512
Postretirement and pension benefits	82,886	85,488
Allowance for loan losses	586,457	603,462
Accelerated depreciation	1,300	1,300
FDIC-assisted transaction	108,327
Difference in outside basis from pass-through entities	28,257	30,424
Other temporary differences	27,869	25,084
Total gross deferred tax assets	976,269	881,232
Deferred tax liabilities:
FDIC-assisted transaction		60,402
Indefinite-lived intangibles	33,713	31,973
Unrealized net gain (loss) on trading and available-for-sale securities	15,949	26,364
Other temporary differences	10,735	9,876
Total gross deferred tax liabilities	60,397	128,615
Valuation allowance	78,676	67,263
Net deferred tax asset	837,196	685,354
UNITED STATES
Deferred tax assets:
Tax credits available for carryforward	7,859	7,979
Net operating loss and other carryforward available	739,724	708,158
Postretirement and pension benefits	0	0
Allowance for loan losses	23,741	20,708
Accelerated depreciation	7,461	7,083
FDIC-assisted transaction	0
Difference in outside basis from pass-through entities	0	0
Other temporary differences	6,978	6,901
Total gross deferred tax assets	788,148	754,457
Deferred tax liabilities:
FDIC-assisted transaction		0
Indefinite-lived intangibles	38,199	33,009
Unrealized net gain (loss) on trading and available-for-sale securities	(16,861)	(7,961)
Other temporary differences	845	386
Total gross deferred tax liabilities	22,183	25,434
Valuation allowance	419,408	380,561
Net deferred tax asset	346,557	348,462
Deferred loans origination fees
Deferred tax assets:
Deferred income	3,235	4,627
Deferred loans origination fees | PUERTO RICO
Deferred tax assets:
Deferred income	3,583	3,669
Deferred loans origination fees | UNITED STATES
Deferred tax assets:
Deferred income	(348)	958
Deferred gain
Deferred tax assets:
Deferred income	2,733	2,670
Deferred gain | PUERTO RICO
Deferred tax assets:
Deferred income	0	0
Deferred gain | UNITED STATES
Deferred tax assets:
Deferred income	2,733	2,670
Intercompany deferred gains
Deferred tax assets:
Deferred income	1,512	224
Intercompany deferred gains | PUERTO RICO
Deferred tax assets:
Deferred income	1,512	224
Intercompany deferred gains | UNITED STATES
Deferred tax assets:
Deferred income	$ 0	$ 0