Fair Value Measurements - Carrying Values and Fair Values of Financial Instruments (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
ASSETS
Securities available-for-sale	$ 509,425	$ 452,266
FHLB and other restricted stock	13,629	15,315
LIABILITIES
Junior subordinated debt securities	45,619	90,619	90,619
Carrying Value [Member]
ASSETS
Cash and due from banks, including interest-bearing deposits	108,356	337,711
Securities available-for-sale	509,425	452,266
Loans held for sale	2,136	22,499
Portfolio loans, net of unearned income	3,566,199	3,346,622
Bank owned life insurance	60,480	58,619
FHLB and other restricted stock	13,629	15,315
Trading securities held in a Rabbi Trust	2,864	2,223
Mortgage servicing rights	2,919	2,106
LIABILITIES
Deposits	3,672,308	3,638,428
Securities sold under repurchase agreements	33,847	62,582
Short-term borrowings	140,000	75,000
Long-term borrowings	21,810	34,101
Junior subordinated debt securities	45,619	90,619
Carrying Value [Member] | Interest Rate Swaps [Member]
ASSETS
Derivative financial assets	13,698	23,748
LIABILITIES
Derivative financial liabilities	13,647	23,522
Carrying Value [Member] | Interest Rate Lock Commitments [Member]
ASSETS
Derivative financial assets	85	467
Carrying Value [Member] | Forward Sale Contracts [Member]
ASSETS
Derivative financial assets	34
LIABILITIES
Derivative financial liabilities		48
Fair Value Measurements [Member]
ASSETS
Cash and due from banks, including interest-bearing deposits	108,356	337,711
Securities available-for-sale	509,425	452,266
Loans held for sale	2,139	22,601
Portfolio loans, net of unearned income	3,538,072	3,347,602
Bank owned life insurance	60,480	58,619
FHLB and other restricted stock	13,629	15,315
Trading securities held in a Rabbi Trust	2,864	2,223
Mortgage servicing rights	3,143	2,106
LIABILITIES
Deposits	3,673,624	3,643,683
Securities sold under repurchase agreements	33,847	62,582
Short-term borrowings	140,000	75,000
Long-term borrowings	22,924	36,235
Junior subordinated debt securities	45,619	90,619
Fair Value Measurements [Member] | Level 1 [Member]
ASSETS
Cash and due from banks, including interest-bearing deposits	108,356	337,711
Securities available-for-sale	202	140
Trading securities held in a Rabbi Trust	2,864	2,223
Fair Value Measurements [Member] | Level 2 [Member]
ASSETS
Securities available-for-sale	509,223	451,826
Bank owned life insurance	60,480	58,619
Fair Value Measurements [Member] | Level 3 [Member]
ASSETS
Securities available-for-sale		300
Loans held for sale	2,139	22,601
Portfolio loans, net of unearned income	3,538,072	3,347,602
FHLB and other restricted stock	13,629	15,315
Mortgage servicing rights	3,143	2,106
LIABILITIES
Deposits	3,673,624	3,643,683
Securities sold under repurchase agreements	33,847	62,582
Short-term borrowings	140,000	75,000
Long-term borrowings	22,924	36,235
Junior subordinated debt securities	45,619	90,619
Fair Value Measurements [Member] | Interest Rate Swaps [Member]
ASSETS
Derivative financial assets	13,698	23,748
LIABILITIES
Derivative financial liabilities	13,647	23,522
Fair Value Measurements [Member] | Interest Rate Swaps [Member] | Level 2 [Member]
ASSETS
Derivative financial assets	13,698	23,748
LIABILITIES
Derivative financial liabilities	13,647	23,522
Fair Value Measurements [Member] | Interest Rate Lock Commitments [Member]
ASSETS
Derivative financial assets	85	467
Fair Value Measurements [Member] | Interest Rate Lock Commitments [Member] | Level 2 [Member]
ASSETS
Derivative financial assets	85	467
Fair Value Measurements [Member] | Forward Sale Contracts [Member]
ASSETS
Derivative financial assets	34
LIABILITIES
Derivative financial liabilities		48
Fair Value Measurements [Member] | Forward Sale Contracts [Member] | Level 2 [Member]
ASSETS
Derivative financial assets	34
LIABILITIES
Derivative financial liabilities		$ 48