Fair Value Measurements (Tables)

6 Months Ended

Jun. 30, 2018

Fair Value Disclosures [Abstract]

Assets and Liabilities Measured at Fair Value on Recurring Basis

Assets measured at fair value on a recurring basis as of June 30, 2018 and December 31, 2017(in thousands):

	Fair Value Measurement at June 30, 2018
Description	June 30, 2018		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	$	338	$	338	$	—	$	—
U.S. Agencies		2,088		—		2,088		—
State and political subdivisions		41,308		—		41,308		—
Corporates		10,138		10,138		—		—
Trading – other		13,219		12,464		755		—
Trading securities		67,091		22,940		44,151		—
U.S. Treasury		38,090		38,090		—		—
U.S. Agencies		198		—		198		—
Mortgage-backed		3,672,956		—		3,672,956		—
State and political subdivisions		2,298,972		—		2,298,972		—
Corporates		1,468		1,468		—		—
Available for sale securities		6,011,684		39,558		5,972,126		—
Company-owned life insurance		56,770		—		56,770		—
Bank-owned life insurance		269,703		—		269,703		—
Derivatives		2,970		—		2,970		—
Total	$	6,408,218	$	62,498	$	6,345,720	$	—
Liabilities
Deferred compensation	$	53,084	$	53,084	$	—	$	—
Derivatives		7,970		—		7,970		—
Securities sold not yet purchased		16,834		—		16,834		—
Total	$	77,888	$	53,084	$	24,804	$	—

	Fair Value Measurement at December 31, 2017
Description	December 31, 2017		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	$	18	$	18	$	—	$	—
U.S. Agencies		9,976		—		9,976		—
Mortgage-backed		1,949		—		1,949		—
State and political subdivisions		27,114		—		27,114		—
Corporates		1,885		1,885		—		—
Trading – other		13,113		12,434		679		—
Trading securities		54,055		14,337		39,718		—
U.S. Treasury		38,643		38,643		—		—
U.S. Agencies		14,752		—		14,752		—
Mortgage-backed		3,649,243		—		3,649,243		—
State and political subdivisions		2,542,673		—		2,542,673		—
Corporates		13,266		13,266		—		—
Available for sale securities		6,258,577		51,909		6,206,668		—
Company-owned life insurance		53,577		—		53,577		—
Bank-owned life insurance		265,823		—		265,823		—
Derivatives		10,149		—		10,149		—
Total	$	6,642,181	$	66,246	$	6,575,935	$	—
Liabilities
Deferred compensation	$	50,963	$	50,963	$	—	$	—
Derivatives		8,906		—		8,906		—
Securities sold not yet purchased		4,130		—		4,130		—
Total	$	63,999	$	50,963	$	13,036	$	—

Assets Measured at Fair Value on Non-Recurring Basis

Assets measured at fair value on a non-recurring basis as of June 30, 2018 and December 31, 2017(in thousands):

	Fair Value Measurement at June 30, 2018 Using
Description	June 30, 2018		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 Six Months Ended June 30
Impaired loans	$	10,264	$	—	$	—	$	10,264	$	2,222
Other real estate owned		3,683		—		—		3,683		—
Total	$	13,947	$	—	$	—	$	13,947	$	2,222

	Fair Value Measurement at December 31, 2017 Using
Description	December 31, 2017		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	$	15,186	$	—	$	—	$	15,186	$	1,251
Other real estate owned		1,488		—		—		1,488		13
Total	$	16,674	$	—	$	—	$	16,674	$	1,264

Estimated Fair Value of Financial Instruments

The estimated fair value of the Company’s financial instruments at June 30, 2018 and December 31, 2017 are as follows (in thousands):

	Fair Value Measurement at June 30, 2018 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	$	563,654	$	508,224	$	55,430	$	—	$	563,654
Securities available for sale		6,011,684		39,558		5,972,126		—		6,011,684
Securities held to maturity		1,204,582		—		1,103,937		—		1,103,937
Trading securities		67,091		22,940		44,151		—		67,091
Other securities		66,547		—		66,547		—		66,547
Loans (exclusive of allowance for loan loss)		11,635,110		—		11,660,240		—		11,660,240
Derivatives		2,970		—		2,970		—		2,970
FINANCIAL LIABILITIES
Demand and savings deposits		15,466,124		15,466,124		—		—		15,466,124
Time deposits		919,954		—		919,954		—		919,954
Other borrowings		1,666,158		378,684		1,287,474		—		1,666,158
Long-term debt		78,692		—		78,984		—		78,984
Derivatives		7,970		—		7,970		—		7,970
OFF-BALANCE SHEET ARRANGEMENTS
Commitments to extend credit for loans										2,691
Commercial letters of credit										35
Standby letters of credit										1,291

	Fair Value Measurement at December 31, 2017 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	$	1,936,084	$	1,749,618	$	186,466	$	—	$	1,936,084
Securities available for sale		6,258,577		51,909		6,206,668		—		6,258,577
Securities held to maturity		1,261,014		—		1,207,447		—		1,207,447
Trading securities		54,055		14,337		39,718		—		54,055
Other securities		65,897		—		65,897		—		65,897
Loans (exclusive of allowance for loan loss)		11,281,973		—		11,318,764		—		11,318,764
Derivatives		10,149		—		10,149		—		10,149
FINANCIAL LIABILITIES
Demand and savings deposits		16,742,736		16,742,736		—		—		16,742,736
Time deposits		1,280,264		—		1,280,264		—		1,280,264
Other borrowings		1,260,704		11,334		1,249,370		—		1,260,704
Long-term debt		79,281		—		79,496		—		79,496
Derivatives		8,906		—		8,906		—		8,906
OFF-BALANCE SHEET ARRANGEMENTS
Commitments to extend credit for loans										6,654
Commercial letters of credit										136
Standby letters of credit										2,514