FIRST BANCORP. (Holding Company Only) Financial Information - Statements of Cash Flows (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash flows from operating activities:
Net income	$ 201,608	$ 66,956	$ 93,229
Adjustments to reconcile net income to net cash provided by operating activities:
Stock-based compensation	5,825	7,296	6,876
Gain on extinguishment of debt	(2,316)	(1,391)	(4,217)
Net (increase) decrease in other assets	(8,906)	202	(17,716)
Net increase (decrease) in other liabilities	(1,248)	8,305	(15,144)
Net cash provided by operating activities	288,323	235,964	199,432
Cash flows from investing activities:
Principal collected on loans	2,722,311	2,504,629	2,830,830
Net cash provided by investing activities	(223,258)	(73,256)	83,194
Cash flows from financing activities:
Repayments of junior subordinated debentures	(21,434)	(5,930)	(7,025)
Repurchase of outstanding common stock	(2,827)	(2,497)	(1,132)
Dividends paid on preferred stock	2,676	2,676	223
Net cash used in financing activities	(195,257)	254,002	(735,399)
Net (decrease) increase in cash and cash equivalents	(130,192)	416,710	(452,773)
Cash and cash equivalents at beginning of year	716,395	299,685	752,458
Cash and cash equivalents at end of year	586,203	716,395	299,685
Cash and cash equivalents include:
Money market instruments	7,590	10,415	10,094
Holding Company [Member]
Cash flows from operating activities:
Net income	201,608	66,956	93,229
Adjustments to reconcile net income to net cash provided by operating activities:
Stock-based compensation	2,202	3,769	3,563
Equity in undistributed earnings of subsidiaries	(172,580)	(66,587)	(58,061)
Gain on extinguishment of debt	(2,316)	(1,391)	(4,217)
Accretion of discount on loans	(4)	(14)	(11)
Net (increase) decrease in other assets	(8,417)	(8)	802
Net increase (decrease) in other liabilities	2,890	(201)	(26,685)
Net cash provided by operating activities	23,383	2,524	8,620
Cash flows from investing activities:
Principal collected on loans	191	50	50
Net cash provided by investing activities	191	50	50
Cash flows from financing activities:
Repayments of junior subordinated debentures	(21,434)	(5,930)	(7,025)
Repurchase of outstanding common stock	(2,827)	(2,497)	(1,132)
Dividends paid on common stock	(6,517)	0	0
Dividends paid on preferred stock	(2,676)	(2,676)	(223)
Net cash used in financing activities	(33,454)	(11,103)	(8,380)
Net (decrease) increase in cash and cash equivalents	(9,880)	(8,529)	290
Cash and cash equivalents at beginning of year	26,975	35,504	35,214
Cash and cash equivalents at end of year	17,095	26,975	35,504
Cash and cash equivalents include:
Cash and due from banks	10,984	20,864	29,393
Money market instruments	$ 6,111	$ 6,111	$ 6,111