Note Income taxes (Differences between income tax expense (benefit) applicable to income before income taxes and amount computed by applying the statutory tax rate in Puerto Rico) (Detail) - USD ($) $ in Thousands	3 Months Ended			6 Months Ended
	Jun. 30, 2018		Jun. 30, 2017	Jun. 30, 2018		Jun. 30, 2017
Amount
Income tax expense	$ (28,560)		$ 35,732	$ (6,405)		$ 68,738
PUERTO RICO
Amount
Computed income tax at statutory rates	97,977		51,464	142,234		100,585
Net benefit of net tax exempt interest income	(22,407)		(18,841)	(45,400)		(36,845)
Deferred tax asset valuation allowance	4,186		5,064	11,412		10,120
Difference in tax rates due to multiple jurisdictions	(2,238)		(831)	(5,197)		(1,790)
State and local taxes	1,718		1,585	3,081		2,864
Income tax expense	$ (28,560)		$ 35,732	$ (6,405)		$ 68,738
% of pre-tax income
Computed income tax at statutory rates	39.00%		39.00%	39.00%		39.00%
Net benefit of net tax exempt interest income	(9.00%)		(14.00%)	(12.00%)		(14.00%)
Deferred tax asset valuation allowance	2.00%		4.00%	3.00%		4.00%
Difference in tax rates due to multiple jurisdictions	(1.00%)		(1.00%)	(2.00%)		(1.00%)
State and local taxes	1.00%		1.00%	1.00%		1.00%
Income tax (benefit) expense	(11.00%)		27.00%	(2.00%)		27.00%
PUERTO RICO | Effect Of Income Subject To Preferential Tax Rate
Amount
Other	$ (103,008)	[1]	$ (3,493)	$ (106,056)	[2]	$ (6,512)
% of pre-tax income
Others	(41.00%)	[1]	(3.00%)	(29.00%)	[2]	(2.00%)
PUERTO RICO | Others
Amount
Other	$ (4,788)		$ 784	$ (6,479)		$ 316
% of pre-tax income
Others	(2.00%)		1.00%	(2.00%)		0.00%

[1] For the quarter ended June 30, 2018, includes the impact of the Tax Closing Agreement entered into in connection with the Westernbank FDIC-assisted Transaction.

[2] For the six months ended June 30, 2018, includes the impact of the Tax Closing Agreement entered into in connection with the Westernbank FDIC-assisted Transaction.