OFG BANCORP Holding Company Only Financial Information (Statement of Operations) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Parent income [Abstract]
Investment securities	$ 6,232	$ 4,125	$ 3,608
Costs And Expenses [Abstract]
Interest Expense	41,475	57,165	69,196
Income (loss) before income taxes	68,089	85,180	(20,058)
Parent [Member]
Parent income [Abstract]
Interest income	188	174	321
Gain On Sale Of Investments	0	211	0
Investment securities	4,511	4,066	4,007
Total income	4,699	4,451	4,328
Costs And Expenses [Abstract]
Interest Expense	1,556	1,370	1,222
Operating expenses	6,700	7,179	6,866
Total expenses	8,256	8,549	8,088
Income (loss) before income taxes	(3,557)	(4,098)	(3,760)
Parent Income (Loss) Tax Expense (Benefit)	403	518	(3,088)
(Loss) income before changes in undistributed earnings of subsidiaries	(3,960)	(4,616)	(672)
Bank Subsidiary	51,612	58,580	(3,804)
Nonbank Subsidiaries	4,994	5,222	1,972
Net income (loss)	$ 52,646	$ 59,186	$ (2,504)