DISCLOSURES ABOUT FAIR VALUE OF FINANCIAL INSTRUMENTS (Tables)

12 Months Ended

Dec. 31, 2020

Assets and liabilities measured at fair value on a recurring basis as of December 31, 2020 and 2019 (in thousands):

	Fair Value Measurement at December 31, 2020 Using
Description	December 31, 2020		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Assets
U.S. Treasury	$	651	$	651	$	—	$	—
U.S. Agencies		1,568		—		1,568		—
Mortgage-backed		4		—		4		—
State and political subdivisions		18,545		—		18,545		—
Corporates		711		711		—		—
Trading – other		13,541		13,541		—		—
Trading securities		35,020		14,903		20,117		—
U.S. Treasury		30,740		30,740		—		—
U.S. Agencies		95,949		—		95,949		—
Mortgage-backed		5,468,181		—		5,468,181		—
State and political subdivisions		3,623,619		—		3,623,619		—
Corporates		81,199		81,199		—		—
Securities available for sale		9,299,688		111,939		9,187,749		—
Equity securities with readily determinable fair values		134,197		134,197		—		—
Company-owned life insurance		63,575		—		63,575		—
Bank-owned life insurance		387,513		—		387,513		—
Derivatives		103,554		—		103,554		—
Total	$	10,023,547	$	261,039	$	9,762,508	$	—
Liabilities
Derivatives	$	9,375	$	—	$	9,375	$	—
Securities sold not yet purchased		2,177		—		2,177		—
Total	$	11,552	$	—	$	11,552	$	—

	Fair Value Measurement at December 31, 2019 Using
Description	December 31, 2019		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Assets
U.S. Agencies	$	1,246	$	—	$	1,246	$	—
Mortgage-backed		392		—		392		—
State and political subdivisions		21,764		—		21,764		—
Corporates		5,649		5,649		—		—
Trading – other		16,567		16,567		—		—
Trading securities		45,618		22,216		23,402		—
U.S. Treasury		64,078		64,078		—		—
U.S. Agencies		93,021		—		93,021		—
Mortgage-backed		4,071,794		—		4,071,794		—
State and political subdivisions		3,029,917		—		3,029,917		—
Corporates		188,552		188,552		—		—
Securities available for sale		7,447,362		252,630		7,194,732		—
Company-owned life insurance		63,900		—		63,900		—
Bank-owned life insurance		280,709		—		280,709		—
Derivatives		55,276		—		55,276		—
Total	$	7,892,865	$	274,846	$	7,618,019	$	—
Liabilities
Derivatives	$	5,997	$	—	$	5,997	$	—
Securities sold not yet purchased		14,599		—		14,599		—
Total	$	20,596	$	—	$	20,596	$	—

Assets measured at fair value on a non-recurring basis as of December 31, 2020 and 2019 (in thousands):

			Fair Value Measurement at December 31, 2020 Using
Description	December 31, 2020		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total Gains Recognized During the Twelve Months Ended December 31
Collateral dependent assets	$	35,995	$	—	$	—	$	35,995	$	(9,389	)
Other real estate owned		2,798		—		—		2,798		(938	)
Total	$	38,793	$	—	$	—	$	38,793	$	(10,327	)

			Fair Value Measurement at December 31, 2019 Using
Description	December 31, 2019		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total Gains Recognized During the Twelve Months Ended December 31
Impaired loans	$	5,139	$	—	$	—	$	5,139	$	3,973
Other real estate owned		55		—		—		55		7
Total	$	5,194	$	—	$	—	$	5,194	$	3,980

The estimated fair value of the Company’s financial instruments at December 31, 2020 and 2019 are as follows (in thousands):

	Fair Value Measurement at December 31, 2020 Using
	Carrying Amount		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total Estimated Fair Value
FINANCIAL ASSETS
Cash and short-term investments	$	5,191,015	$	3,540,680	$	1,650,335	$	—	$	5,191,015
Securities available for sale		9,299,688		111,939		9,187,749		—		9,299,688
Securities held to maturity (exclusive of allowance for credit losses)		1,014,614		—		1,029,444		—		1,029,444
Trading securities		35,020		14,903		20,117		—		35,020
Other securities		296,053		134,197		161,856		—		296,053
Loans (exclusive of allowance for credit losses)		16,110,359		—		16,413,132		—		16,413,132
Derivatives		103,554		—		103,554		—		103,554
FINANCIAL LIABILITIES
Demand and savings deposits		26,175,156		26,175,156		—		—		26,175,156
Time deposits		876,095		—		879,841		—		879,841
Other borrowings		2,315,497		65,636		2,249,861		—		2,315,497
Long-term debt		269,595		—		299,858		—		299,858
Derivatives		9,375		—		9,375		—		9,375
OFF-BALANCE SHEET ARRANGEMENTS
Commitments to extend credit for loans										6,405
Commercial letters of credit										150
Standby letters of credit										3,365

	Fair Value Measurement at December 31, 2019 Using
	Carrying Amount		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total Estimated Fair Value
FINANCIAL ASSETS
Cash and short-term investments	$	3,276,794	$	1,701,449	$	1,575,345	$	—	$	3,276,794
Securities available for sale		7,447,362		252,630		7,194,732		—		7,447,362
Securities held to maturity		1,116,102		—		1,082,345		—		1,082,345
Trading securities		45,618		22,216		23,402		—		45,618
Other securities		108,420		—		108,420		—		108,420
Loans (exclusive of allowance for loan loss)		13,439,525		—		13,601,595		—		13,601,595
Derivatives		55,276		—		55,276		—		55,276
FINANCIAL LIABILITIES
Demand and savings deposits		20,376,880		20,376,880		—		—		20,376,880
Time deposits		1,226,364		—		1,226,646		—		1,226,646
Other borrowings		1,896,508		31,873		1,864,635		—		1,896,508
Long-term debt		70,372		—		70,713		—		70,713
Derivatives		5,997		—		5,997		—		5,997
OFF-BALANCE SHEET ARRANGEMENTS
Commitments to extend credit for loans										5,908
Commercial letters of credit										113
Standby letters of credit										2,966