FIRST BANCORP. (Holding Company Only) Financial Information - Statements of Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Income:
Interest income on money market investments	$ 92,599	$ 102,505	$ 102,922
Gain on early extinguishment of debt	0	1,605	0
Expense:
Income tax expense	92,483	94,572	142,512
Net income	298,724	302,864	305,072
Other comprehensive income (loss), net of tax	72,614	165,608	(720,779)
Comprehensive income (loss)	371,338	468,472	(415,707)
Holding Company [Member]
Income:
Interest income on money market investments	292	228	79
Gain on early extinguishment of debt	0	1,605	0
Other income	360	406	248
Total income	321,018	333,922	368,997
Expense:
Interest expense on long-term borrowings	11,986	13,535	8,253
Other non-interest expenses	1,704	1,817	1,730
Total expenses	13,690	15,352	9,983
Income before income taxes and equity in undistributed earnings of subsidiaries	307,328	318,570	359,014
Income tax expense	1	1	1
Equity in undistributed earnings of subsidiaries (distributions in excess of earnings)	(8,603)	(15,705)	(53,941)
Net income	298,724	302,864	305,072
Other comprehensive income (loss), net of tax	72,614	165,608	(720,779)
Comprehensive income (loss)	371,338	468,472	(415,707)
Holding Company [Member] | Investment In Banking Subsidiary [Member]
Income:
Dividend income	320,366	319,683	368,670
Holding Company [Member] | Non Banking Subsidiary [Member]
Income:
Dividend income	$ 0	$ 12,000	$ 0