OFG BANCORP Holding Company Only Financial Information (Statement of Cash Flows) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Legal Entity [Line items]
Net (Loss) Income Attributable to Parent	$ 52,646	$ 59,186	$ (2,504)
Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract]
Amortization of investment securities premiums, net of accretion of discounts	7,865	8,540	12,109
Gain (Loss) on Sale of Securities, Net	6,896	12,207	2,572
Stock-based compensation	1,109	1,270	1,637
Stock-based compensation excess tax benefit recognized in income	(99)	0	0
Deferred income taxes, net	(3,658)	23,226	(37,329)
Net (increase) decrease in other assets	(13,675)	7,941	14,849
Net increase (decrease) in accrued expenses and other liabilities	28,431	4,344	(14,584)
Net Cash Provided by (Used in) Investing Activities [Abstract]
Maturities and redemptions of investment securities available-for-sale	105,169	145,512	238,003
Proceeds from Sale and Maturity of Available-for-sale Securities	256,996	300,483	103,831
Cash flows from financing activities:
Purchase of treasury stock	0	0	8,950
Net change in cash and cash equivalents	(25,236)	(26,270)	(36,718)
Cash and due from banks, parent	504,833
Cash and due from banks, parent	478,182	504,833
Parent [Member]
Legal Entity [Line items]
Net (Loss) Income Attributable to Parent	52,646	59,186	(2,504)
Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract]
Equity in undistributed earnings from banking subsidiary	(51,612)	(58,580)	3,804
Equity in undistributed earnings from nonbanking subsidiaries	(4,994)	(5,222)	(1,972)
Amortization of investment securities premiums, net of accretion of discounts	0	12	44
Gain (Loss) on Sale of Securities, Net	0	211	0
Other Impairments On Securities	0	0	0
Stock-based compensation	1,109	1,270	1,637
Stock-based compensation excess tax benefit recognized in income	(99)	0	0
Deferred income taxes, net	414	444	(3,088)
Net (increase) decrease in other assets	(205)	42	148
Net increase (decrease) in accrued expenses and other liabilities	(1,185)	800	(221)
Dividends from banking subsidiary	26,743	17,600	45,000
Dividends from non-banking subsidiary	4,002	6,000	0
Net cash provided by (used in) operating activities	26,819	21,763	42,848
Net Cash Provided by (Used in) Investing Activities [Abstract]
Maturities and redemptions of investment securities available-for-sale	0	702	2,013
Proceeds from Sale and Maturity of Available-for-sale Securities	0	4,888	0
Net (increase) decrease in due from bank subsidiary, net	307	317	317
Proceeds from Sale of Premises and Equipment	0	324	0
Capital contribution to banking subsidiary	788	894	1,167
Capital contribution to non-banking subsidiary	(50)	(68)	(94)
Additions to premises and equipment	(19)	(381)	(132)
Net cash procided by (used in) investing activities	(550)	4,888	937
Cash flows from financing activities:
Proceeds from (payments to) exercise of stock options and lapsed restricted units, net	0	315	204
Purchase of treasury stock	0	0	8,950
Dividends paid	24,412	24,003	31,623
Net cash provided by (used in) financing activities	(24,412)	(24,318)	(40,369)
Net change in cash and cash equivalents	1,857	2,333	3,416
Cash and due from banks, parent	22,573	20,240	16,824
Cash and due from banks, parent	$ 24,430	$ 22,573	$ 20,240