Acquisitions and Dispositions - Acquisitions, Narrative (Details) $ / shares in Units, $ in Thousands		12 Months Ended
	Jan. 01, 2023 USD ($) option branchOffice $ / shares shares	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Business Acquisition [Line Items]
Goodwill		$ 478,750	$ 364,263	$ 364,263
Fair value mark	$ 29,500
Assets		12,114,942	10,625,049
Loans		8,150,102	6,665,145
Deposits		10,031,599	9,227,529
Merger and acquisition expenses		13,695	5,072	16,845
Provision for loan losses		19,750	12,600	9,611
(Reversal of) provision for unfunded commitments		(1,937)	(200)	$ 5,420
Unfunded Loan Commitment
Business Acquisition [Line Items]
Provision for loan losses		$ (3,858)	(200)
Minimum
Business Acquisition [Line Items]
Identifiable intangible assets, useful life		5 years
Core Deposits | Minimum
Business Acquisition [Line Items]
Identifiable intangible assets, useful life		10 years
Grand South
Business Acquisition [Line Items]
Merger and acquisition expenses		$ 13,700
Grand South
Business Acquisition [Line Items]
Percentage of voting interest acquired	100.00%
Common stock portion, number of First Bancorp's stock for each share of acquiree common stock converted (in shares) | shares	0.91
Number of shares issued | shares	5,032,834
Common stock options converted | option	542,345
Business acquisition, equity interest issued or issuable, common stock options, converted, exercise price (in dollars per share) | $ / shares	$ 20.14
Total purchase price	$ 229,489
Price per share at acquisition date (in US dollars per share) | $ / shares	$ 42.84
Number banking locations | branchOffice	8
Goodwill	$ 114,487
Loans reclassified from fair value mark to ACL resulting from PCD loans	5,610
Other assets acquired	27,163
Liabilities assumed	1,088,197
Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Financing Receivable, Allowance For Credit Loss, Excluding Accrued Interest			$ 2,200
Allowance for credit loss, increase from acquisition, non-purchase	12,200
Grand South | Unfunded Loan Commitment
Business Acquisition [Line Items]
Provision for loan losses	$ 1,900
Grand South | Core deposit intangibles
Business Acquisition [Line Items]
Identifiable intangible assets, useful life	10 years
Useful life	41 months