DERIVATIVES (Tables)

12 Months Ended

Dec. 31, 2021

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Summary of Derivative Financial Instruments and Balances

The following table details the location and amounts of client derivatives and foreign exchange contracts recognized in the Consolidated Balance Sheets:

		December 31, 2021						December 31, 2020
				Estimated fair value						Estimated fair value
(Dollars in thousands)	Balance Sheet Classification	Notional amount		Gain		Loss		Notional amount		Gain		Loss
Client derivatives-instruments associated with loans
Matched interest rate swaps with borrower	Accrued interest and other assets and other liabilities	$	2,430,587	$	84,694	$	(7,508)	$	2,300,336	$	184,777	$	(107)
Matched interest rate swaps with counterparty	Accrued interest and other liabilities	2,430,587		7,508		(84,701)		2,300,336		107		(184,884)
Foreign exchange contracts
Matched foreign exchange contracts with customers	Accrued interest and other assets	6,423,085		67,988		(52,780)		3,637,509		60,366		(27,249)
Match foreign exchange contracts with counterparty	Accrued interest and other liabilities	6,399,432		52,780		(67,988)		3,637,509		27,249		(60,366)
Total		$	17,683,691	$	212,970	$	(212,977)	$	11,875,690	$	272,499	$	(272,606)

Disclosure by Type of Financial Instrument [Table Text Block]

The following table discloses the gross and net amounts of client derivatives and foreign exchange contracts recognized in the Consolidated Balance Sheets:

	December 31, 2021						December 31, 2020
(Dollars in thousands)	Gross amounts of recognized liabilities		Gross amounts offset in the Consolidated Balance Sheets		Net amounts of (assets)/liabilities presented in the Consolidated Balance Sheets		Gross amounts of recognized liabilities		Gross amounts offset in the Consolidated Balance Sheets		Net amounts of (assets)/liabilities presented in the Consolidated Balance Sheets
Client derivatives
Matched interest rate swaps	$	92,209	$	(149,647)	$	(57,438)	$	184,991	$	(385,088)	$	(200,097)
Foreign exchange contracts with counterparty	120,768		(56,443)		64,325		87,615		(17,392)		70,223
Total	$	212,977	$	(206,090)	$	6,887	$	272,606	$	(402,480)	$	(129,874)

Derivative Financial Instruments, Average Remaining Maturity and the Weighted-Average Interest Rates being Paid and Received

The following table details the derivative financial instruments, the average remaining maturities and the weighted-average interest rates being paid and received by First Financial at December 31, 2021:

(Dollars in thousands)	Notional amount		Average maturity (years)	Fair value
Client derivatives-interest rate contracts
Receive fixed, matched interest rate swaps with borrower	$	2,430,587	5.7	$	77,186
Pay fixed, matched interest rate swaps with counterparty	2,430,587		5.7	(77,193)
Client derivatives-foreign exchange contracts
Foreign exchange contracts - pay USD	6,423,085		0.6	15,208
Foreign exchange contracts - receive USD	6,399,432		0.6	(15,208)
Total client derivatives	$	17,683,691	2.0	$	(7)