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Fair Value Measurements - Carrying Values and Fair Values of Financial Instruments (Details) - USD ($) $ in Thousands		Jun. 30, 2019	Dec. 31, 2018
ASSETS
Securities, at fair value		$ 668,588	$ 684,872
Portfolio loans, net		5,971,721	5,885,652
FHLB and other restricted stock		22,491	29,435
LIABILITIES
Junior subordinated debt securities		45,619	45,619
Carrying Value
ASSETS
Cash and due from banks, including interest-bearing deposits	[1]	122,876	155,489
Securities, at fair value	[1]	668,588	684,872
Loans held for sale	[1]	8,135	2,371
Portfolio loans, net	[1]	5,971,721	5,885,652
Bank owned life insurance	[1]	74,906	73,900
FHLB and other restricted stock	[1]	22,491	29,435
Securities held in a deferred compensation plan	[1]	5,532	4,725
Mortgage servicing rights	[1]	4,214	4,464
LIABILITIES
Deposits	[1]	5,856,700	5,673,922
Securities sold under repurchase agreements	[1]	14,154	18,383
Short-term borrowings	[1]	295,000	470,000
Long-term borrowings	[1]	69,791	70,314
Junior subordinated debt securities	[1]	45,619	45,619
Carrying Value | Interest rate swaps
ASSETS
Derivative financial assets		22,688	5,504	[1]
LIABILITIES
Derivative financial liabilities	[1]	22,620	5,340
Carrying Value | Interest rate lock commitments
ASSETS
Derivative financial assets	[1]	649	251
Carrying Value | Forward sale contracts
ASSETS
Derivative financial assets	[1]		55
Carrying Value | Level 2 | Forward sale contracts
LIABILITIES
Derivative financial liabilities		105
Fair Value Measurements
ASSETS
Cash and due from banks, including interest-bearing deposits		122,876	155,489
Securities, at fair value		668,588	684,872
Loans held for sale		8,135	2,469
Portfolio loans, net		5,836,651	5,728,843
Bank owned life insurance		74,906	73,900
FHLB and other restricted stock		22,491	29,435
Securities held in a deferred compensation plan		5,532	4,725
Mortgage servicing rights		4,728	5,181
LIABILITIES
Deposits		5,854,053	5,662,193
Securities sold under repurchase agreements		14,154	18,383
Short-term borrowings		295,000	470,000
Long-term borrowings		70,405	70,578
Junior subordinated debt securities		45,619	45,619
Fair Value Measurements | Interest rate swaps
ASSETS
Derivative financial assets		22,688	5,504
LIABILITIES
Derivative financial liabilities		22,620	5,340
Fair Value Measurements | Interest rate lock commitments
ASSETS
Derivative financial assets		649	251
Fair Value Measurements | Forward sale contracts
ASSETS
Derivative financial assets			55
LIABILITIES
Derivative financial liabilities		105
Fair Value Measurements | Level 1
ASSETS
Cash and due from banks, including interest-bearing deposits		122,876	155,489
Securities, at fair value		0	0
Loans held for sale		0	0
Portfolio loans, net		0	0
Bank owned life insurance		0	0
FHLB and other restricted stock		0	0
Securities held in a deferred compensation plan		5,532	4,725
Mortgage servicing rights		0	0
LIABILITIES
Deposits		4,508,445	4,261,884
Securities sold under repurchase agreements		14,154	18,383
Short-term borrowings		295,000	470,000
Long-term borrowings		39,334	38,610
Junior subordinated debt securities		45,619	45,619
Fair Value Measurements | Level 1 | Interest rate swaps
ASSETS
Derivative financial assets		0	0
LIABILITIES
Derivative financial liabilities		0	0
Fair Value Measurements | Level 1 | Interest rate lock commitments
ASSETS
Derivative financial assets		0	0
Fair Value Measurements | Level 1 | Forward sale contracts
ASSETS
Derivative financial assets			0
LIABILITIES
Derivative financial liabilities		0
Fair Value Measurements | Level 2
ASSETS
Cash and due from banks, including interest-bearing deposits		0	0
Securities, at fair value		668,588	684,872
Loans held for sale		0	0
Portfolio loans, net		0	0
Bank owned life insurance		74,906	73,900
FHLB and other restricted stock		0	0
Securities held in a deferred compensation plan		0	0
Mortgage servicing rights		0	0
LIABILITIES
Deposits		1,345,608	1,400,309
Securities sold under repurchase agreements		0	0
Short-term borrowings		0	0
Long-term borrowings		31,071	31,968
Junior subordinated debt securities		0	0
Fair Value Measurements | Level 2 | Interest rate swaps
ASSETS
Derivative financial assets		22,688	5,504
LIABILITIES
Derivative financial liabilities		22,620	5,340
Fair Value Measurements | Level 2 | Interest rate lock commitments
ASSETS
Derivative financial assets		649	251
Fair Value Measurements | Level 2 | Forward sale contracts
ASSETS
Derivative financial assets			55
LIABILITIES
Derivative financial liabilities		105
Fair Value Measurements | Level 3
ASSETS
Cash and due from banks, including interest-bearing deposits		0	0
Securities, at fair value		0	0
Loans held for sale		8,135	2,469
Portfolio loans, net		5,836,651	5,728,843
Bank owned life insurance		0	0
FHLB and other restricted stock		22,491	29,435
Securities held in a deferred compensation plan		0	0
Mortgage servicing rights		4,728	5,181
LIABILITIES
Deposits		0	0
Securities sold under repurchase agreements		0	0
Short-term borrowings		0	0
Long-term borrowings		0	0
Junior subordinated debt securities		0	0
Fair Value Measurements | Level 3 | Interest rate swaps
ASSETS
Derivative financial assets		0	0
LIABILITIES
Derivative financial liabilities		0	0
Fair Value Measurements | Level 3 | Interest rate lock commitments
ASSETS
Derivative financial assets		0	0
Fair Value Measurements | Level 3 | Forward sale contracts
ASSETS
Derivative financial assets			$ 0
LIABILITIES
Derivative financial liabilities		$ 0
[1] As reported in the Consolidated Balance Sheets

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