FIRST BANCORP. (Holding Company Only) Financial Information - Statements of Cash Flows (Detail) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Net Cash Provided By Used In Operating Activities [Abstract]
Net income		$ 93,229	$ 21,297	$ 392,287
Adjustments to reconcile net income to net cash provided by operating activities:
Gain on extinguishment of debt		(4,217)	0	0
Deferred income tax provision		23,879	80	(306,010)
Share Based Compensation		6,876	6,037	4,221
Equity in loss of unconsolidated entity		0	0	7,279
Other Than Temporary Impairment Losses Investments Portion Recognized In Earnings Net	[1]	6,687	16,517	388
Decrease in other assets		17,716	20,625	19,724
Increase Decrease In Other Operating Liabilities		(15,144)	5,891	(17,251)
Net Cash Provided By Used In Operating Activities		199,432	261,891	264,353
Net Cash Provided By Used In Investing Activities [Abstract]
Principal collected on loans		2,830,830	2,969,616	3,483,131
Proceeds from sale of available-for-sale securities		219,780	0	4,861
Net Cash Provided By Used In Investing Activities		83,194	438,979	254,733
Net Cash Provided By Used In Financing Activities [Abstract]
Repayments of junior subordinated debentures		(7,025)	0	0
Dividends paid on preferred stock		(223)	0	0
Issuance costs of common stock issued in exchange for preferred stock Series A through E		0	0	(62)
Repurchase of outstanding common stock		(1,132)	(1,173)	(946)
Net Cash Provided By Used In Financing Activities		(735,399)	(744,520)	(378,649)
Cash And Cash Equivalents Period Increase Decrease		(452,773)	(43,650)	140,437
Cash and cash equivalents at beginning of year		752,458	796,108	655,671
Cash and cash equivalents at end of year		299,685	752,458	796,108
Cash and cash equivalents include:
Money market instruments		10,094	219,473	16,961
Parent Company [Member]
Net Cash Provided By Used In Operating Activities [Abstract]
Net income		93,229	21,297	392,287
Adjustments to reconcile net income to net cash provided by operating activities:
Share Based Compensation		3,563	2,835	1,962
Equity in loss of unconsolidated entity		(58,061)	(30,641)	(401,889)
Other Than Temporary Impairment Losses Investments Portion Recognized In Earnings Net		0	0	29
Accretion Amortization Of Discounts And Premiums Loans		(11)	(7)	(3)
Decrease in other assets		802	(293)	(260)
Increase Decrease In Other Operating Liabilities		(26,685)	6,643	7,261
Net Cash Provided By Used In Operating Activities		8,620	(166)	(613)
Net Cash Provided By Used In Investing Activities [Abstract]
Principal collected on loans		50	63	38
Proceeds from sale of available-for-sale securities		0	0	6
Net Cash Provided By Used In Investing Activities		50	63	44
Net Cash Provided By Used In Financing Activities [Abstract]
Issuance costs of common stock issued in exchange for preferred stock Series A through E		0	0	(62)
Repurchase of outstanding common stock		(1,132)	(1,174)	(946)
Net Cash Provided By Used In Financing Activities		(8,380)	(1,174)	(1,008)
Cash And Cash Equivalents Period Increase Decrease		290	(1,277)	(1,577)
Cash and cash equivalents at beginning of year		35,214	36,491	38,068
Cash and cash equivalents at end of year		35,504	35,214	36,491
Cash and cash equivalents include:
Due From Banks		29,393	29,103	30,380
Money market instruments		$ 6,111	$ 6,111	$ 6,111

[1] (1) For the years ended December 31, 2016 and 2015, approximately $6.3 million and $15.9 million, respectively, of the credit impairment recognized in earnings consisted of credit losses on Puerto Rico government debt securities. The remaining impairment losses were associated with credit losses on private label MBS.