Fair Value (Tables)

12 Months Ended

Dec. 31, 2017

Fair Value

Schedule of recorded amount of assets and liabilities measured at fair value on a recurring basis

			Quoted Prices
			In Active		Significant
			Markets		Other		Significant
			for Identical		Observable		Unobservable
			Assets		Inputs		Inputs
(Dollars in thousands)	Fair Value		(Level 1)		(Level 2)		(Level 3)
December 31, 2017:
Assets
Derivative financial instruments	$	3,306	$	—	$	3,306	$	—
Loans held for sale		70,890		—		70,890		—
Securities available for sale:
Government-sponsored entities debt		85,509		—		85,509		—
State and municipal obligations		220,437		—		220,437		—
Mortgage-backed securities		1,340,687		—		1,340,687		—
Corporate securities		4,077		—		4,077		—
Total securities available for sale		1,650,710		—		1,650,710		—
Mortgage servicing rights		31,119		—		—		31,119
	$	1,756,025	$	—	$	1,724,906	$	31,119
Liabilities
Derivative financial instruments	$	3,248	$	—	$	3,248	$	—
December 31, 2016:
Assets
Derivative financial instruments	$	2,606	$	—	$	2,606	$	—
Loans held for sale		50,572		—		50,572		—
Securities available for sale:
Government-sponsored entities debt		84,642		—		84,642		—
State and municipal obligations		107,402		—		107,402		—
Mortgage-backed securities		803,577		—		803,577		—
Corporate securities		3,784		2,559		1,225		—
Total securities available for sale		999,405		2,559		996,846		—
Mortgage servicing rights		29,037		—		—		29,037
	$	1,081,620	$	2,559	$	1,050,024	$	29,037
Liabilities
Derivative financial instruments	$	730	$	—	$	730	$	—

Schedule of reconciliation of the beginning and ending balances of Level 3 assets and liabilities recorded at fair value on a recurring basis

(Dollars in thousands)	Assets		Liabilities
Fair value, January 1, 2017	$	29,037	$	—
Servicing assets that resulted from transfers of financial assets		6,439		—
Changes in fair value due to valuation inputs or assumptions		(595)		—
Changes in fair value due to decay		(3,762)		—
Fair value , December 31, 2017	$	31,119	$	—
Fair value, January 1, 2016	$	26,202	$	—
Servicing assets that resulted from transfers of financial assets		6,428		—
Changes in fair value due to valuation inputs or assumptions		560		—
Changes in fair value due to decay		(4,153)		—
Fair value, December 31, 2016	$	29,037	$	—

Schedule of amounts of assets and liabilities measured at fair value on a nonrecurring basis

			Quoted Prices
			In Active		Significant
			Markets		Other		Significant
			for Identical		Observable		Unobservable
			Assets		Inputs		Inputs
(Dollars in thousands)	Fair Value		(Level 1)		(Level 2)		(Level 3)
December 31, 2017:
OREO	$	11,203	$	—	$	—	$	11,203
Non-acquired impaired loans		10,495		—		—		10,495
December 31, 2016:
OREO	$	18,316	$	—	$	—	$	18,316
Non-acquired impaired loans		6,611		—		—		6,611

Quantitative Information about Level 3 Fair Value Measurements

			Weighted Average
			December 31,		December 31,
	Valuation Technique	Unobservable Input	2017		2016
Nonrecurring measurements:
Non-acquired impaired loans	Discounted appraisals	Collateral discounts	3	%	6	%
OREO	Discounted appraisals	Collateral discounts and estimated costs to sell	21	%	18	%

Schedule of estimated fair value, and related carrying amount, of the Company's financial instruments

	Carrying		Fair
(Dollars in thousands)	Amount		Value		Level 1		Level 2		Level 3
December 31, 2017
Financial assets:
Cash and cash equivalents	$	377,627	$	377,627	$	377,627	$	—	$	—
Investment securities		1,673,769		1,673,796		20,530		1,653,266		—
Loans held for sale		70,890		70,890		—		70,890		—
Loans, net of allowance for loan losses		10,575,417		10,724,264		—		—		10,724,264
Accrued interest receivable		32,727		32,727		—		7,051		25,676
Mortgage servicing rights		31,119		31,119		—		—		31,119
Interest rate swap - non-designated hedge		2,367		2,367		—		2,367		—
Other derivative financial instruments (mortgage banking related)		939		939		—		939		—
Financial liabilities:
Deposits		11,532,766		10,796,380		—		10,796,380		—
Federal funds purchased and securities sold under agreements to repurchase		286,857		286,857		—		286,857		—
Other borrowings		216,385		219,421		—		219,421		—
Accrued interest payable		2,789		2,789		—		2,789		—
Interest rate swap - non-designated hedge		2,750		2,750		—		2,750		—
Interest rate swap - cash flow hedge		246		246		—		246		—
Other derivative financial instruments (mortgage banking related)		252		252		—		252		—
Off balance sheet financial instruments:
Commitments to extend credit		—		41,319		—		41,319		—
December 31, 2016
Financial assets:
Cash and cash equivalents	$	374,448	$	374,448	$	374,448	$	—	$	—
Investment securities		1,014,981		1,015,137		12,041		1,003,096		—
Loans held for sale		50,572		50,572		—		50,572		—
Loans, net of allowance for loan losses		6,643,326		6,649,575		—		—		6,649,575
Accrued interest receivable		18,618		18,618		—		3,642		14,976
Mortgage servicing rights		29,037		29,037		—		—		29,037
Interest rate swap - non-designated hedge		203		203		—		203		—
Other derivative financial instruments (mortgage banking related)		2,403		2,403		—		2,403		—
Financial liabilities:
Deposits		7,334,423		6,935,867		—		6,935,867		—
Federal funds purchased and securities sold under agreements to repurchase		313,773		313,773		—		313,773		—
Other borrowings		55,358		54,379		—		54,379		—
Accrued interest payable		1,359		1,359		—		1,359		—
Interest rate swap - non-designated hedge		181		181		—		181		—
Interest rate swap - cash flow hedge		498		498		—		498		—
Other derivative financial instruments (mortgage banking related)		51		51		—		51		—
Off balance sheet financial instruments:
Commitments to extend credit		—		1,587		—		1,587		—