OFG Bancorp Holding Company Only Financial Information (Balance Sheet) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Assets [Abstract]
Investment securities available-for-sale, at fair value	$ 645,797	$ 751,484
Deferred tax asset	127,421	124,200
Other Assets	64,693	80,365
Liabilities and Stockholders' Equity [Abstract]
Accrued expenses and other liabilities	86,791	95,370
Subordinated capital notes	36,083	36,083
Stockholders' Equity	945,107	920,411
Parent [Member]
Assets [Abstract]
Cash and Due From Banks Parent	24,430	22,573
Investment in bank subsidiary, equity method	941,198	920,085
Investment in nonbank subsidiaries, equity method	20,231	18,427
Due From Bank Subsidiary	22	92
Deferred tax asset	2,230	2,643
Other Assets	1,616	2,085
Total Parent Assets	989,727	965,905
Liabilities and Stockholders' Equity [Abstract]
DividendsPayableCurrent	6,504	6,501
Due to Affiliates	0	237
Accrued expenses and other liabilities	2,033	2,673
Subordinated capital notes	36,083	36,083
Total Parent Liabilities	44,620	45,494
Stockholders' Equity	945,107	920,411
Total Parent Liabilities and Stockholders' Equity	$ 989,727	$ 965,905