Acquisitions and Dispositions - Acquisitions, Narrative (Details) $ / shares in Units, $ in Thousands			12 Months Ended
	Oct. 15, 2021 USD ($) location $ / shares shares	Sep. 01, 2020 USD ($) shares	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Business Acquisition [Line Items]
Goodwill			$ 364,263	$ 239,272	$ 234,368
Loans			6,081,715	4,731,315	4,453,466
Merger and acquisition expenses			16,845	0	192
Provision for loan losses			9,611	35,039	2,263
Provision for unfunded commitments			$ 5,420	0	$ 0
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
Core Deposits | Weighted Average
Business Acquisition [Line Items]
Identifiable intangible assets, useful life			41 months
Select
Business Acquisition [Line Items]
Option price, cash out value (in usd per share) | $ / shares	$ 18.00
Number banking locations | location	22
Merger and acquisition expenses			$ 800
Provision for loan losses			(1,300)	$ 6,200
Select
Business Acquisition [Line Items]
Common Stock Portion, number of First Bancorp's stock for each share of Select common stock converted (in shares) | shares	0.408
Number of shares issued | shares	7,070,371
Fair value of shares issued	$ 324,400
Payments for acquisition	1,400
Total purchase price	$ 325,819
Percentage of voting interest acquired	100.00%
Goodwill	$ 132,356
Loans	19,300
Loans reclassified from fair value mark to ACL resulting from PCD loans	4,895
Merger and acquisition expenses			16,800
Other assets acquired	61,020
Liabilities assumed	$ 1,621,421
Select | Adjustment for Non-PCD Provision
Business Acquisition [Line Items]
Provision for loan losses			14,100
Select | Adjustment on Initial Recording of Provision
Business Acquisition [Line Items]
Provision for unfunded commitments			$ 3,900
Magnolia Financial, Inc.
Business Acquisition [Line Items]
Number of shares issued | shares		24,096
Fair value of shares issued		$ 500
Payments for acquisition		9,500
Total purchase price		10,000
Loans acquired		14,600
Other assets acquired		500
Liabilities assumed		11,700
Goodwill deductible for tax purposes		4,900
Intangible assets deductible for tax purposes		$ 1,600
Intangible assets and goodwill, deductible for tax purposes, period		15 years