Fair Value Disclosures (Tables)

3 Months Ended

Mar. 31, 2018

Fair Value Disclosures [Abstract]

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

The following table summarizes financial assets and financial liabilities measured at fair value on a recurring basis as of March 31, 2018 and 2017, and December 31, 2017, respectively, segregated by the level of the valuation inputs within the fair value hierarchy utilized to measure fair value (dollars in thousands):

March 31, 2018
	Level 1 Inputs		Level 2 Inputs		Level 3 Inputs		Total Fair Value
Available-for-sale investment securities:
Obligations of U. S. government sponsored enterprises and agencies	$	—	$	50,215	$	—	$	50,215
Obligations of states and political subdivisions		—		1,320,133		—		1,320,133
Corporate bonds		—		4,971		—		4,971
Residential mortgage-backed securities		—		1,427,772		—		1,427,772
Commercial mortgage-backed securities		—		468,746		—		468,746
Other securities		4,356		—		—		4,356
Total	$	4,356	$	3,271,837	$	—	$	3,276,193
March 31, 2017
	Level 1 Inputs		Level 2 Inputs		Level 3 Inputs		Total Fair Value
Available-for-sale investment securities:
U.S. Treasury securities	$	10,619	$	—	$	—	$	10,619
Obligations of U. S. government sponsored enterprises and agencies		—		79,905		—		79,905
Obligations of states and political subdivisions		—		1,564,513		—		1,564,513
Corporate bonds		—		43,503		—		43,503
Residential mortgage-backed securities		—		991,553		—		991,553
Commercial mortgage-backed securities		—		323,758		—		323,758
Other securities		4,428		—		—		4,428
Total	$	15,047	$	3,003,232	$	—	$	3,018,279
December 31, 2017
	Level 1 Inputs		Level 2 Inputs		Level 3 Inputs		Total Fair Value
Available-for-sale investment securities:
Obligations of U. S. government sponsored enterprises and agencies		—		60,330		—		60,330
Obligations of states and political subdivisions		—		1,420,850		—		1,420,850
Corporate bonds		—		7,031		—		7,031
Residential mortgage-backed securities		—		1,219,097		—		1,219,097
Commercial mortgage-backed securities		—		375,737		—		375,737
Other securities		4,428		—		—		4,428
Total	$	4,428	$	3,083,045	$	—	$	3,087,473

Other Real Estate Owned

The following table presents other real estate owned that were re-measured subsequent to their initial transfer to other real estate owned (dollars in thousands):

	Three Months Ended March 31,
	2018		2017
Carrying value of other real estate owned prior to re-measurement	$	—	$	—
Write-downs included in gain (loss) on sale of other real estate owned		—		—
Fair value	$	—	$	—

Schedule of Estimated Fair Values and Carrying Values of All Financial Instruments

The estimated fair values and carrying values of all financial instruments under current authoritative guidance at March 31, 2018 and 2017, and December 31, 2017, were as follows (in thousands):

	March 31,								December 31,
	2018				2017				2017
	Carrying Value		Estimated Fair Value		Carrying Value		Estimated Fair Value		Carrying Value		Estimated Fair Value		Fair Value Hierarchy
Cash and due from banks	$	130,979	$	130,979	$	163,674	$	163,674	$	209,583	$	209,583		Level 1
Federal funds sold		—		—		3,840		3,840		—		—		Level 1
Interest-bearing deposits in banks		67,060		67,060		55,165		55,165		162,764		162,764		Level 1
Interest-bearing time deposits in banks		1,458		1,458		1,707		1,708		1,458		1,458		Level 2
Available-for-sale Securities		3,276,193		3,276,193		3,018,279		3,018,279		3,087,473		3,087,473		Levels 1 and 2
Held-to-maturity securities		—		—		114		116		—		—		Level 2
Loans		3,697,582		3,718,987		3,339,949		3,368,084		3,452,543		3,470,133		Level 3
Accrued interest receivable		28,631		28,631		26,639		26,639		36,081		36,081		Level 2
Deposits with stated maturities		468,078		469,000		495,720		496,782		451,255		451,255		Level 2
Deposits with no stated maturities		5,722,685		5,722,685		5,166,248		5,166,248		5,511,706		5,511,706		Level 1
Borrowings		372,155		372,155		360,264		360,264		331,000		331,000		Level 2
Accrued interest Payable		195		195		166		166		197		197		Level 2