Income taxes - Components of deferred tax assets and liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Deferred tax assets:
Tax credits available for carryforward	$ 10,544	$ 3,042
Net operating loss and other carryforward available	743,616	782,886
Postretirement and pension benefits	38,121	47,122
Allowance for credit losses	273,178	283,303
Depreciation	13,352	12,281
FDIC-assisted transaction	152,665	152,665
Lease liability	49,562	51,811
Unrealized net loss on investment securities	331,620	289,868
Difference in outside basis from pass-through entities	46,056	40,602
Mortgage servicing rights	14,085	13,711
Other temporary differences	57,304	24,937
Total gross deferred tax assets	1,730,103	1,702,228
Deferred tax liabilities:
Intangibles	136,579	135,797
Right of use assets	44,678	46,277
Deferred loan origination fees/cost	430	4,037
Loans acquired	20,430	23,353
Other temporary differences	6,824	1,531
Total gross deferred tax liabilities	208,941	210,995
Valuation allowance	513,382	540,196
Net deferred tax asset	1,007,780	951,037
PR
Deferred tax assets:
Tax credits available for carryforward	263	261
Net operating loss and other carryforward available	122,634	121,742
Postretirement and pension benefits	38,121	47,122
Allowance for credit losses	244,956	250,615
Depreciation	6,774	5,972
FDIC-assisted transaction	152,665	152,665
Lease liability	29,070	28,290
Unrealized net loss on investment securities	312,583	265,955
Difference in outside basis from pass-through entities	46,056	40,602
Mortgage servicing rights	14,085	13,711
Other temporary differences	47,679	17,122
Total gross deferred tax assets	1,014,886	944,057
Deferred tax liabilities:
Intangibles	84,635	81,174
Right of use assets	26,648	26,015
Deferred loan origination fees/cost	(1,056)	1,076
Loans acquired	20,430	23,353
Other temporary differences	6,402	1,531
Total gross deferred tax liabilities	137,059	133,149
Valuation allowance	139,347	137,863
Net deferred tax asset	738,480	673,045
US
Deferred tax assets:
Tax credits available for carryforward	10,281	2,781
Net operating loss and other carryforward available	620,982	661,144
Postretirement and pension benefits	0	0
Allowance for credit losses	28,222	32,688
Depreciation	6,578	6,309
FDIC-assisted transaction	0	0
Lease liability	20,492	23,521
Unrealized net loss on investment securities	19,037	23,913
Difference in outside basis from pass-through entities	0	0
Mortgage servicing rights	0	0
Other temporary differences	9,625	7,815
Total gross deferred tax assets	715,217	758,171
Deferred tax liabilities:
Intangibles	51,944	54,623
Right of use assets	18,030	20,262
Deferred loan origination fees/cost	1,486	2,961
Loans acquired	0	0
Other temporary differences	422	0
Total gross deferred tax liabilities	71,882	77,846
Valuation allowance	374,035	402,333
Net deferred tax asset	$ 269,300	$ 277,992

The sum of the tax effects as of the balance sheet date of the amount of excesses of tax deductions over gross income in a year which cannot be used on the tax returns in the current year but can be carried forward to reduce taxable income or income taxes payable in a future year, for which there must be sufficient tax-basis income to utilize a portion or all of the carryforward amount to realize the deferred tax asset (Includes operating loss and pension carryforwards).

No definition available.