Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2017

Financial Assets and Financial Liabilities Measured at Fair Value on a Recurring Basis

The following tables summarize financial assets and financial liabilities measured at fair value on a recurring basis as of December 31, 2017 and 2016, segregated by the level of the valuation inputs within the fair value hierarchy utilized to measure fair value:



	Level 1 Inputs		Level 2 Inputs		Level 3 Inputs		Total Fair Value
2017
Securities available for sale:
U.S. Treasury	$	3,445,153	$	—	$	—	$	3,445,153
Residential mortgage-backed securities	—		665,086		—		665,086
States and political subdivisions	—		6,336,209		—		6,336,209
Other	—		42,561		—		42,561
Trading account securities:
U.S. Treasury	19,210		—		—		19,210
States and political subdivisions	—		1,888		—		1,888
Derivative assets:
Interest rate swaps, caps and floors	—		20,022		—		20,022
Commodity swaps and options	—		14,408		1,233		15,641
Foreign currency forward contracts	415		—		—		415
Derivative liabilities:
Interest rate swaps, caps and floors	—		18,754		—		18,754
Commodity swaps and options	—		15,327		—		15,327
Foreign currency forward contracts	239		—		—		239
2016
Securities available for sale:
U.S. Treasury	$	4,019,731	$	—	$	—	$	4,019,731
Residential mortgage-backed securities	—		785,167		—		785,167
States and political subdivisions	—		5,355,885		—		5,355,885
Other	—		42,494		—		42,494
Trading account securities:
U.S. Treasury	16,594		—		—		16,594
States and political subdivisions	—		109		—		109
Derivative assets:
Interest rate swaps, caps and floors	—		29,059		—		29,059
Commodity swaps and options	—		6,179		—		6,179
Foreign currency forward contracts	29		—		—		29
Derivative liabilities:
Interest rate swaps, caps and floors	—		29,968		—		29,968
Commodity swaps and options	—		5,963		—		5,963
Foreign currency forward contracts	33		—		—		33

Impaired Loans Remeasured and Reported at Fair Value of Underlying Collateral

The following table presents impaired loans that were remeasured and reported at fair value through a specific valuation allowance allocation of the allowance for loan losses based upon the fair value of the underlying collateral:



	2017			2016			2015
Carrying value of impaired loans before allocations	$	75,435		$	33,626		$	14,921
Specific valuation allowance allocations	(19,533		)	(3,961		)	(2,765		)
Fair value	$	55,902		$	29,665		$	12,156

Foreclosed Assets Remeasured and Reported at Fair Value

The following table presents foreclosed assets that were remeasured and reported at fair value:



	2017			2016			2015
Foreclosed assets remeasured at initial recognition:
Carrying value of foreclosed assets prior to remeasurement	$	279		$	756		$	1,102
Charge-offs recognized in the allowance for loan losses	—			(3		)	(169		)
Fair value	$	279		$	753		$	933
Foreclosed assets remeasured subsequent to initial recognition:
Carrying value of foreclosed assets prior to remeasurement	$	89		$	492		$	205
Write-downs included in other non-interest expense	(16		)	(217		)	(36		)
Fair value	$	73		$	275		$	169

Estimated Fair Values of Financial Instruments

The estimated fair values of financial instruments that are reported at amortized cost in our consolidated balance sheets, segregated by the level of valuation inputs within the fair value hierarchy utilized to measure fair value, were as follows:



	December 31, 2017				December 31, 2016
	Carrying Amount		Estimated Fair Value		Carrying Amount		Estimated Fair Value
Financial assets:
Level 2 inputs:
Cash and cash equivalents	$	5,053,047	$	5,053,047	$	4,141,445	$	4,141,445
Securities held to maturity	1,432,098		1,455,791		2,250,460		2,262,747
Cash surrender value of life insurance policies	180,477		180,477		177,884		177,884
Accrued interest receivable	167,508		167,508		156,714		156,714
Level 3 inputs:
Loans, net	12,990,301		12,981,165		11,822,347		11,903,956
Financial liabilities:
Level 2 inputs:
Deposits	26,872,389		26,866,676		25,811,575		25,812,039
Federal funds purchased and repurchase agreements	1,147,824		1,147,824		976,992		976,992
Junior subordinated deferrable interest debentures	136,184		137,115		136,127		137,115
Subordinated notes payable and other borrowings	98,552		105,311		99,990		100,000
Accrued interest payable	3,358		3,358		1,204		1,204