First Commonwealth Financial (FCF) 10-Q 9 May 14 2014 Q1 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	3 Months Ended
	Mar. 31, 2014	9-May-14
Entity Information [Line Items]	'	'
Document Type	'10-Q	'
Amendment Flag	'false	'
Document Period End Date	31-Mar-14	'
Document Fiscal Year Focus	'2014	'
Document Fiscal Period Focus	'Q1	'
Trading Symbol	'FCF	'
Entity Registrant Name	'FIRST COMMONWEALTH FINANCIAL CORP /PA/	'
Entity Central Index Key	'0000712537	'
Current Fiscal Year End Date	'--12-31	'
Entity Filer Category	'Large Accelerated Filer	'
Entity Common Stock, Shares Outstanding	'	94,033,825

Condensed_Consolidated_Stateme

Condensed Consolidated Statements of Financial Condition (Unaudited) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Assets	'	'
Cash and due from banks	$82,327	$74,427
Interest-bearing bank deposits	9,087	3,012
Securities available for sale, at fair value	1,351,039	1,318,365
Other investments	34,047	35,444
Loans:	'	'
Portfolio loans	4,252,213	4,283,833
Allowance for credit losses	-54,506	-54,225
Net loans	4,197,707	4,229,608
Premises and equipment, net	66,112	67,940
Other real estate owned	10,080	11,728
Goodwill	159,371	159,956
Amortizing intangibles, net	1,133	1,311
Bank owned life insurance	174,801	174,372
Other assets	123,693	138,698
Total assets	6,209,397	6,214,861
Deposits (all domestic):	'	'
Noninterest-bearing	966,956	912,361
Interest-bearing	3,680,861	3,691,502
Total deposits	4,647,817	4,603,863
Short-term borrowings	572,965	626,615
Subordinated debentures	72,167	72,167
Other long-term debt	144,268	144,385
Total long-term debt	216,435	216,552
Other liabilities	55,397	56,134
Total liabilities	5,492,614	5,503,164
Shareholders’ Equity	'	'
Preferred stock, $1 par value per share, 3,000,000 shares authorized, none issued	0	0
Common stock, $1 par value per share, 200,000,000 shares authorized; 105,563,455 shares issued at March 31, 2014 and December 31, 2013, and 94,223,883 and 95,245,215 shares outstanding at March 31, 2014 and December 31, 2013, respectively	105,563	105,563
Additional paid-in capital	365,469	365,333
Retained earnings	340,430	334,748
Accumulated other comprehensive loss, net	-12,492	-20,588
Treasury stock (11,339,572 and 10,318,240 shares at March 31, 2014 and December 31, 2013, respectively)	-82,187	-73,359
Total shareholders’ equity	716,783	711,697
Total liabilities and shareholders’ equity	$6,209,397	$6,214,861

Condensed_Consolidated_Stateme1

Condensed Consolidated Statements of Financial Condition (Unaudited) (Parenthetical) (USD $)	Mar. 31, 2014	Dec. 31, 2013
Preferred stock, par value (in dollars per share)	$1	$1
Preferred stock, shares authorized (in shares)	3,000,000	3,000,000
Preferred stock, shares issued (in shares)	0	0
Common stock, par value (in dollars per share)	$1	$1
Common stock, shares authorized (in shares)	200,000,000	200,000,000
Common stock, shares issued (in shares)	105,563,455	105,563,455
Common stock, shares outstanding (in shares)	94,223,883	95,245,215
Treasury stock, shares (in shares)	11,339,572	10,318,240

Condensed_Consolidated_Stateme2

Condensed Consolidated Statements of Income (Unaudited) (USD $)	3 Months Ended
In Thousands, except Share data, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Interest Income	'	'
Interest and fees on loans	$43,098	$44,614
Interest and dividends on investments:	'	'
Taxable interest	7,180	7,109
Interest exempt from federal income taxes	4	1
Dividends	222	36
Interest on bank deposits	2	1
Total interest income	50,506	51,761
Interest Expense	'	'
Interest on deposits	3,507	4,191
Interest on short-term borrowings	469	220
Interest on subordinated debentures	566	1,384
Interest on other long-term debt	373	548
Total interest expense	4,915	6,343
Net Interest Income	45,591	45,418
Provision for credit losses	3,231	4,497
Net Interest Income after Provision for Credit Losses	42,360	40,921
Noninterest Income	'	'
Net securities gains	0	4
Trust income	1,435	1,663
Service charges on deposit accounts	3,792	3,401
Insurance and retail brokerage commissions	1,395	1,417
Income from bank owned life insurance	1,369	1,428
Gain on sale of assets	1,581	275
Card related interchange income	3,366	3,188
Derivatives mark to market	-58	989
Other income	2,040	2,520
Total noninterest income	14,920	14,885
Noninterest Expense	'	'
Salaries and employee benefits	21,044	21,793
Net occupancy expense	3,506	3,635
Furniture and equipment expense	5,330	3,272
Data processing expense	1,468	1,516
Advertising and promotion expense	700	779
Pennsylvania shares tax expense	711	1,190
Intangible amortization	178	358
Collection and repossession expense	709	1,151
Other professional fees and services	1,024	969
FDIC insurance	1,049	1,050
Operational (recoveries) losses	-689	338
Conversion related expenses	354	0
Other operating expenses	4,503	5,403
Total noninterest expense	39,887	41,454
Income Before Income Taxes	17,393	14,352
Income tax provision	5,093	3,799
Net Income	$12,300	$10,553
Average Shares Outstanding (in shares)	94,543,420	99,288,738
Average Shares Outstanding Assuming Dilution (in shares)	94,568,059	99,305,414
Per Share Data:	'	'
Basic Earnings per Share (in dollars per share)	$0.13	$0.11
Diluted Earnings per Share (in dollars per share)	$0.13	$0.11
Cash Dividends Declared per Common Share (in dollars per share)	$0.07	$0.05

Condensed_Consolidated_Stateme3

Condensed Consolidated Statements of Comprehensive Income (Unaudited) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Net Income	$12,300	$10,553
Other comprehensive income (loss), before tax (expense) benefit:	'	'
Unrealized holding gains (losses) on securities arising during the period	12,457	-2,411
Less: reclassification adjustment for gains on securities included in net income	0	-4
Total other comprehensive income (loss), before tax (expense) benefit	12,457	-2,415
Income tax (expense) benefit related to items of other comprehensive income (loss)	-4,361	844
Total other comprehensive income (loss)	8,096	-1,571
Comprehensive Income	$20,396	$8,982

Condensed_Consolidated_Stateme4

Condensed Consolidated Statements of Changes in Shareholders' Equity (Unaudited) (USD $)	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss), net [Member]	Treasury Stock [Member]
In Thousands, except Share data
Beginning balance at Dec. 31, 2012	$746,007	$105,563	$365,354	$315,608	$1,259	($41,777)
Beginning balance, shares at Dec. 31, 2012	'	99,629,494	'	'	'	'
Net Income	10,553	'	'	10,553	'	'
Other comprehensive income (loss)	-1,571	'	'	'	-1,571	'
Dividends, Common Stock, Cash	-4,976	'	'	-4,976	'	'
Discount on dividend reinvestment plan purchases	-25	'	-25	'	'	'
Treasury stock acquired	-2,381	'	'	'	'	-2,381
Treasury stock acquired, shares	'	-331,374	'	'	'	'
Restricted stock, shares	'	0	'	'	'	'
Restricted stock	121	'	25	0	'	96
Ending balance at Mar. 31, 2013	747,728	105,563	365,354	321,185	-312	-44,062
Ending balance, shares at Mar. 31, 2013	'	99,298,120	'	'	'	'
Beginning balance at Dec. 31, 2013	711,697	105,563	365,333	334,748	-20,588	-73,359
Beginning balance, shares at Dec. 31, 2013	95,245,215	95,245,215	'	'	'	'
Net Income	12,300	'	'	12,300	'	'
Other comprehensive income (loss)	8,096	'	'	'	8,096	'
Dividends, Common Stock, Cash	-6,618	'	'	-6,618	'	'
Discount on dividend reinvestment plan purchases	-33	'	-33	'	'	'
Treasury stock acquired	-8,941	'	'	'	'	-8,941
Treasury stock acquired, shares	'	-1,084,958	'	'	'	'
Restricted stock, shares	'	63,626	'	'	'	'
Restricted stock	282	'	169	0	'	113
Ending balance at Mar. 31, 2014	$716,783	$105,563	$365,469	$340,430	($12,492)	($82,187)
Ending balance, shares at Mar. 31, 2014	94,223,883	94,223,883	'	'	'	'

Condensed_Consolidated_Stateme5

Condensed Consolidated Statements of Changes in Shareholders' Equity (Unaudited) (Parenthetical) (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Cash Dividends Declared per Common Share (in dollars per share)	$0.07	$0.05
Common Stock [Member]	'	'
Cash Dividends Declared per Common Share (in dollars per share)	$0.07	$0.05

Condensed_Consolidated_Stateme6

Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Operating Activities	'	'
Net Income	$12,300	$10,553
Adjustment to reconcile net income to net cash provided by operating activities:	'	'
Provision for credit losses	3,231	4,497
Deferred tax expense	2,646	2,778
Depreciation and amortization	4,310	2,397
Net gains on securities and other assets	-1,086	-1,081
Net amortization of premiums and discounts on securities	538	552
Net accretion of premiums and discounts on long term debt	-30	-29
Income from increase in cash surrender value of bank owned life insurance	-1,369	-1,428
Decrease (increase) in interest receivable	689	-258
Decrease in interest payable	-163	-826
Increase in income taxes payable	2,231	1,008
Other-net	-2,420	-5,342
Net cash provided by operating activities	20,877	12,821
Investing Activities	'	'
Proceeds from sales	0	42
Proceeds from maturities and redemptions	101,125	75,603
Purchases	-114,706	-204,505
Purchases of FHLB stock	-6,579	-2,886
Proceeds from the redemption of FHLB stock	7,976	2,756
Proceeds from bank owned life insurance	939	178
Proceeds from sale of loans	716	14,099
Proceeds from sale of other assets	4,443	1,334
Net decrease (increase) in loans	26,564	-41,343
Purchases of premises and equipment	-2,240	-2,164
Net cash provided by (used in) investing activities	18,238	-156,886
Financing Activities	'	'
Net decrease in federal funds purchased	-500	-14,800
Net decrease in other short-term borrowings	-53,149	-33,327
Net increase in deposits	43,955	153,709
Repayments of other long-term debt	-87	-123
Discount on dividend reinvestment plan purchases	-33	-25
Dividends paid	-6,618	-4,976
Purchase of treasury stock	-8,708	-3,604
Net cash (used in) provided by financing activities	-25,140	96,854
Net increase (decrease) in cash and cash equivalents	13,975	-47,211
Cash and cash equivalents at January 1	77,439	102,982
Cash and cash equivalents at March 31	$91,414	$55,771

Basis_of_Presentation

Basis of Presentation	3 Months Ended
	Mar. 31, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Basis of Presentation	'
	Basis of Presentation
	The accounting and reporting policies of First Commonwealth Financial Corporation and its subsidiaries (“First Commonwealth” or “Company”) conform with generally accepted accounting principles in the United States of America (“GAAP”). The preparation of financial statements in conformity with GAAP requires management to make estimates, assumptions and judgments that affect the amounts reported in the financial statements and accompanying notes. Actual realized amounts could differ from those estimates. In the opinion of management, the unaudited interim condensed consolidated financial statements include all adjustments (consisting of only normal recurring adjustments) necessary for a fair presentation of First Commonwealth’s financial position, results of operations, cash flows and changes in shareholders’ equity as of and for the periods presented.
	The results of operations for the three months ended March 31, 2014 are not necessarily indicative of the results that may be expected for the full year of 2014. These interim financial statements should be read in conjunction with First Commonwealth’s 2013 Annual Report on Form 10-K which is available on First Commonwealth’s website at http://www.fcbanking.com.
	For purposes of reporting cash flows, cash and cash equivalents include cash on hand, amounts due from banks, federal funds sold and interest-bearing bank deposits. Generally, federal funds are sold for one-day periods.

Supplemental_Comprehensive_Inc

Supplemental Comprehensive Income Disclosures	3 Months Ended
	Mar. 31, 2014
Supplemental Comprehensive Income Disclosures [Abstract]	'
Schedule of Amounts Recognized in Other Comprehensive Income (Loss) [Table Text Block]	'
	The following table details the change in components of OCI for the three months ended March 31:
		2014										2013
		Securities Available for Sale			Post-Retirement Obligation			Accumulated Other Comprehensive Income				Securities Available for Sale			Post-Retirement Obligation		Accumulated Other Comprehensive Income
		(dollars in thousands)
	Balance at December 31	$	(20,868	)	$	280		$	(20,588	)		$	1,121		$	138	$	1,259
	Other comprehensive income (loss) before reclassification adjustment	8,096			—			8,096				(1,568		)	—		(1,568		)
	Amounts reclassified from accumulated other comprehensive income (loss)	—			—			—				(3		)	—		(3		)
	Net other comprehensive income (loss) during the period	8,096			—			8,096				(1,571		)	—		(1,571		)
	Balance at March 31	$	(12,772	)	$	280		$	(12,492	)		$	(450	)	$	138	$	(312	)
Supplemental Comprehensive Income Disclosures	'
	Supplemental Comprehensive Income Disclosures
	The following table identifies the related tax effects allocated to each component of other comprehensive income (“OCI”) in the Condensed Consolidated Statements of Comprehensive Income. Reclassification adjustments related to securities available for sale are included in the "Net securities gains" line in the Condensed Consolidated Statements of Income. The non-credit related gains on securities not expected to be sold are included in the "Noninterest Income" section of the Condensed Consolidated Statements of Income.
		For the Three-Months Ended March 31
		2014												2013
		Pretax Amount				Tax (Expense) Benefit				Net of Tax Amount				Pretax Amount			Tax (Expense) Benefit			Net of Tax Amount
		(dollars in thousands)
	Unrealized gains (losses) on securities:
	Unrealized holding gains (losses) on securities arising during the period	$	12,457			$	(4,361	)		$	8,096			$	(2,411	)	$	843		$	(1,568	)
	Reclassification adjustment for gains on securities included in net income	—				—				—				(4		)	1			(3		)
	Total unrealized gains (losses) on securities	12,457				(4,361		)		8,096				(2,415		)	844			(1,571		)
	Total other comprehensive income (loss)	$	12,457			$	(4,361	)		$	8,096			$	(2,415	)	$	844		$	(1,571	)
	The following table details the change in components of OCI for the three months ended March 31:
		2014										2013
		Securities Available for Sale			Post-Retirement Obligation			Accumulated Other Comprehensive Income				Securities Available for Sale			Post-Retirement Obligation		Accumulated Other Comprehensive Income
		(dollars in thousands)
	Balance at December 31	$	(20,868	)	$	280		$	(20,588	)		$	1,121		$	138	$	1,259
	Other comprehensive income (loss) before reclassification adjustment	8,096			—			8,096				(1,568		)	—		(1,568		)
	Amounts reclassified from accumulated other comprehensive income (loss)	—			—			—				(3		)	—		(3		)
	Net other comprehensive income (loss) during the period	8,096			—			8,096				(1,571		)	—		(1,571		)
	Balance at March 31	$	(12,772	)	$	280		$	(12,492	)		$	(450	)	$	138	$	(312	)

Supplemental_Cash_Flow_Disclos

Supplemental Cash Flow Disclosures	3 Months Ended
	Mar. 31, 2014
Supplemental Cash Flow Information [Abstract]	'
Supplemental Cash Flow Disclosures	'
	Supplemental Cash Flow Disclosures
	The following table presents information related to cash paid during the period for interest as well as detail on non-cash investing and financing activities for the three months ended March 31:
		2014		2013
		(dollars in thousands)
	Cash paid during the period for:
	Interest	$	5,108	$	7,211
	Non-cash investing and financing activities:
	Loans transferred to other real estate owned and repossessed assets	1,292		1,207
	Loans transferred from held to maturity to held for sale	716		16,613
	Loans sold, not settled	—		2,640
	Gross increase (decrease) in market value adjustment to securities available for sale	12,459		(2,411		)
	Investments committed to purchase, not settled	2,522		—
	Unsettled treasury stock repurchases	233		—

Earnings_per_Share

Earnings per Share	3 Months Ended
	Mar. 31, 2014
Earnings Per Share [Abstract]	'
Earnings per Share	'
	Earnings per Share
	The following table summarizes the composition of the weighted-average common shares (denominator) used in the basic and diluted earnings per share computations:
		For the Three-Months Ended March 31
		2014		2013
	Weighted average common shares issued	105,563,455		105,563,455
	Average treasury stock shares	(10,876,695	)	(6,104,526	)
	Average unearned nonvested shares	(143,340	)	(170,191	)
	Weighted average common shares and common stock equivalents used to calculate basic earnings per share	94,543,420		99,288,738
	Additional common stock equivalents (nonvested stock) used to calculate diluted earnings per share	24,639		16,676
	Additional common stock equivalents (stock options) used to calculate diluted earnings per share	—		—
	Weighted average common shares and common stock equivalents used to calculate diluted earnings per share	94,568,059		99,305,414
	The following table shows the number of shares and the price per share related to common stock equivalents that were not included in the computation of diluted earnings per share for the three months ended March 31 because to do so would have been antidilutive.
		2014						2013
				Price Range					Price Range
		Shares		From		To		Shares	From		To
	Stock Options	15,000		$	14.55	$	14.55	82,041	$	9.19	$	14.55
	Restricted Stock	5,601		8.75		9.18		—	—		—

Variable_Interest_Entities

Variable Interest Entities	3 Months Ended
	Mar. 31, 2014
Variable Interest Entities [Abstract]	'
Variable Interest Entities	'
	Variable Interest Entities
	As defined by Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) 810-10, a Variable Interest Entity (“VIE”) is a corporation, partnership, trust or any other legal structure used for business purposes that either (a) does not have equity investors with voting rights or (b) has equity investors that do not provide sufficient financial resources for the entity to support its activities. Under ASC 810-10, an entity that holds a variable interest in a VIE is required to consolidate the VIE if the entity is deemed to be the primary beneficiary, which generally means it is subject to a majority of the risk of loss from the VIE’s activities, is entitled to receive a majority of the entity’s residual returns, or both.
	First Commonwealth’s VIEs are evaluated under the guidance included in FASB Accounting Standards Update (“ASU”) 2009-17. These VIEs include qualified affordable housing projects that First Commonwealth has invested in as part of its community reinvestment initiatives. We periodically assess whether or not our variable interests in the VIE, based on qualitative analysis, provide us with a controlling interest in the VIE. The analysis includes an assessment of the characteristics of the VIE. We do not have a controlling financial interest in the VIE, which would require consolidation of the VIE, as we do not have the following characteristics: (1) the power to direct the activities that most significantly impact the VIE’s economic performance; and (2) the obligation to absorb losses or the right to receive benefits from the VIE that could potentially be significant to the VIE.
	First Commonwealth’s maximum potential exposure is equal to its carrying value and is summarized in the table below:
		31-Mar-14		31-Dec-13
		(dollars in thousands)
	Low Income Housing Limited Partnership Investments	$	174	$	207

Commitments_and_Contingent_Lia

Commitments and Contingent Liabilities	3 Months Ended
	Mar. 31, 2014
Commitments and Contingencies Disclosure [Abstract]	'
Commitments and Contingent Liabilities	'
	Commitments and Contingent Liabilities
	Commitments and letters of credit
	Standby letters of credit and commercial letters of credit are conditional commitments issued by First Commonwealth to guarantee the performance of a customer to a third party. The contract or notional amount of these instruments reflects the maximum amount of future payments that First Commonwealth could be required to pay under the guarantees if there were a total default by the guaranteed parties, without consideration of possible recoveries under recourse provisions or from collateral held or pledged. In addition, many of these commitments are expected to expire without being drawn upon; therefore, the total commitment amounts do not necessarily represent future cash requirements.
	The following table identifies the notional amount of those instruments at:
		31-Mar-14		31-Dec-13
		(dollars in thousands)
	Financial instruments whose contract amounts represent credit risk:
	Commitments to extend credit	$	1,519,436	$	1,571,987
	Financial standby letters of credit	37,119		38,121
	Performance standby letters of credit	27,458		32,441
	Commercial letters of credit	—		—
	The notional amounts outstanding as of March 31, 2014 include amounts issued in 2014 of $0.1 million in financial standby letters of credit and $0.4 million in performance standby letters of credit. There were no commercial letters of credit issued during 2014. A liability of $0.1 million has been recorded as of March 31, 2014 and December 31, 2013, which represents the estimated fair value of letters of credit issued. The fair value of letters of credit is estimated based on the unrecognized portion of fees received at the time the commitment was issued.
	Unused commitments and letters of credit provide exposure to future credit loss in the event of nonperformance by the borrower or guaranteed parties. Management’s evaluation of the credit risk related to these commitments resulted in the recording of a liability of $2.8 million as of March 31, 2014 and $3.2 million as of December 31, 2013. The credit risk evaluation incorporated probability of default, loss given default and estimated utilization for the next twelve months for each loan category and the letters of credit.
	Legal proceedings
	Market Rate Savings IRA Litigation
	McGrogan v. First Commonwealth Bank was filed as a class action on January 12, 2009, in the Court of Common Pleas of Allegheny County, Pennsylvania. The action alleges that First Commonwealth Bank (the “Bank”) promised class members a minimum interest rate of 8% on its IRA Market Rate Savings Account for as long as the class members kept their money on deposit in the IRA account. The class asserted that the Bank committed fraud, breached its modified contract with the class members, and violated the Pennsylvania Unfair Trade Practice and Consumer Protection Law (UTPCPL) when it resigned as custodian of the IRA Market Rate Savings Accounts in 2008 and offered the class members a roll-over IRA account with a 3.5% interest rate. Plaintiffs sought monetary damages for the alleged breach of contract, punitive damages for the alleged fraud and Unfair Trade Practice and Consumer Protection Law violations and attorney’s fees. The court granted class certification as to the breach of modified contract claim and denied class certification as to the fraud and Pennsylvania Unfair Trade Practice and Consumer Protection Law claims. The breach of contract claim was predicated upon a letter sent to customers in 1998 which reversed an earlier decision by the Bank to reduce the rate paid on the accounts. The letter stated, in relevant part, “This letter will serve as notification that a decision has been made to re-establish the rate on your account to eight percent (8)%. This rate will be retroactive to your most recent maturity date and will continue going forward on deposits presently in the account and on annual additions.” On August 30, 2012, the Court entered an order granting the Bank’s motion for summary judgment and dismissed the class action claims. The Court found that the Bank retained the right to resign as custodian of the accounts and that the act of resigning as custodian and closing the accounts did not breach the terms of the underlying IRA contract. On appeal, the Superior Court affirmed the denial of class certification to the claims of fraud in the execution and violation of the UTPCPL. The Superior Court found that none of the other issues were ripe for appeal. Jurisdiction was returned to the Court of Common Pleas where the individual fraud and UTPCPL claims of Mr. and Mrs. McGrogan await trial.
	In December 2013, three new complaints were filed by 34 former members of the McGrogan class:
	-1	Jarrett et al. v. First Commonwealth Bank - An action filed by eight plaintiffs on December 2, 2013 in the Westmoreland County Court of Common Pleas asserting claims for fraud in the inducement, fraud in the execution, violation of the UTPCPL, breach of fiduciary duty and promissory estoppel.
	-2	Young et al. v. First Commonwealth Bank - An action filed by 12 plaintiffs on December 2, 2013 in the Westmoreland County Court of Common Pleas asserting claims for fraud in the inducement, fraud in the execution, violation of the UTPCPL, breach of fiduciary duty and promissory estoppel.
	-3	Fisanik et. al. v. First Commonwealth Bank - An action filed by 14 plaintiffs on December 9, 2013 in the Cambria County Court of Common Pleas asserting claims for fraud in the inducement, fraud in the execution, violation of the UTPCPL, and breach of fiduciary duty.
	The 36 plaintiffs who have filed individual actions held Market Rate Savings IRA balances totaling approximately $4 million at the time of the Bank’s resignation as custodian of the IRAs in 2008. The average age of the plaintiffs at that time was 62.
	At this time, the Bank believes the claims are without merit.
	Other matters
	First Commonwealth identified an error related to historical tax reporting for approximately 700-900 customers. A liability related to this error is considered probable, resulting in the establishment of an $0.8 million contingency reserve during 2013. As resolution of this issue continues, the $0.8 million reserve represents management's best estimate of liability. The contingent reserve is included in “Other liabilities” in the Condensed Consolidated Statements of Financial Condition.
	There are no other material legal proceedings to which First Commonwealth or its subsidiaries are a party, or of which their property is the subject, except proceedings which arise in the normal course of business and, in the opinion of management, will not have a material adverse effect on the consolidated operations, financial position or cash flow of First Commonwealth or its subsidiaries.

Investment_Securities

Investment Securities	3 Months Ended
	Mar. 31, 2014
Investments, Debt and Equity Securities [Abstract]	'
Investment Securities	'
	Investment Securities
	Below is an analysis of the amortized cost and estimated fair values of securities available for sale at:
		31-Mar-14									31-Dec-13
		Amortized		Gross		Gross			Estimated		Amortized		Gross		Gross			Estimated
		Cost		Unrealized		Unrealized			Fair Value		Cost		Unrealized		Unrealized			Fair Value
				Gains		Losses							Gains		Losses
		(dollars in thousands)
	Obligations of U.S. Government Agencies:
	Mortgage-Backed Securities – Residential	$	21,648	$	2,627	$	(34	)	$	24,241	$	22,639	$	2,624	$	(59	)	$	25,204
	Obligations of U.S. Government-Sponsored Enterprises:
	Mortgage-Backed Securities – Residential	1,020,102		12,977		(19,472		)	1,013,607		1,009,519		12,531		(27,163		)	994,887
	Mortgage-Backed Securities – Commercial	96		2		—			98		104		1		—			105
	Other Government-Sponsored Enterprises	269,170		3		(1,863		)	267,310		267,971		81		(1,927		)	266,125
	Obligations of States and Political Subdivisions	9,340		22		(3		)	9,359		80		—		—			80
	Corporate Securities	6,691		437		—			7,128		6,693		328		—			7,021
	Pooled Trust Preferred Collateralized Debt Obligations	42,214		—		(14,338		)	27,876		42,040		—		(18,517		)	23,523
	Total Debt Securities	1,369,261		16,068		(35,710		)	1,349,619		1,349,046		15,565		(47,666		)	1,316,945
	Equities	1,420		—		—			1,420		1,420		—		—			1,420
	Total Securities Available for Sale	$	1,370,681	$	16,068	$	(35,710	)	$	1,351,039	$	1,350,466	$	15,565	$	(47,666	)	$	1,318,365
	Mortgage backed securities include mortgage backed obligations of U.S. Government agencies and obligations of U.S. Government-sponsored enterprises. These obligations have contractual maturities ranging from less than one year to approximately 30 years with lower anticipated lives to maturity due to prepayments. All mortgage backed securities contain a certain amount of risk related to the uncertainty of prepayments of the underlying mortgages. Interest rate changes have a direct impact upon prepayment speeds, therefore First Commonwealth uses computer simulation models to test the average life and yield volatility of all mortgage backed securities under various interest rate scenarios to monitor the potential impact on earnings and interest rate risk positions.
	Expected maturities will differ from contractual maturities because issuers may have the right to call or repay obligations with or without call or prepayment penalties. Other fixed income securities within the portfolio also contain prepayment risk.
	The amortized cost and estimated fair value of debt securities available for sale at March 31, 2014, by contractual maturity, are shown below.
		Amortized		Estimated
		Cost		Fair Value
		(dollars in thousands)
	Due within 1 year	$	5,601	$	5,604
	Due after 1 but within 5 years	263,570		261,706
	Due after 5 but within 10 years	3,371		3,381
	Due after 10 years	54,873		40,982
		327,415		311,673
	Mortgage-Backed Securities (a)	1,041,846		1,037,946
	Total Debt Securities	$	1,369,261	$	1,349,619
	(a)	Mortgage Backed Securities include an amortized cost of $21.6 million and a fair value of $24.2 million for Obligations of U.S. Government agencies issued by Ginnie Mae and an amortized cost of $1,020.2 million and a fair value of $1,013.7 million for Obligations of U.S. Government-sponsored enterprises issued by Fannie Mae and Freddie Mac.
	Proceeds from sales, gross gains (losses) realized on sales, maturities and other-than-temporary impairment charges related to securities available for sale were as follows for the three months ended March 31:
		2014		2013
		(dollars in thousands)
	Proceeds from sales	$	—	$	42
	Gross gains (losses) realized:
	Sales Transactions:
	Gross gains	$	—	$	4
	Gross losses	—		—
	Net gains and impairment	$	—	$	4
	Securities available for sale with an estimated fair value of $548.4 million and $594.9 million were pledged as of March 31, 2014 and December 31, 2013, respectively, to secure public deposits and for other purposes required or permitted by law.

Impairment_of_Investment_Secur

Impairment of Investment Securities	3 Months Ended
	Mar. 31, 2014
Impairment of Investment Securities Disclosure [Abstract]	'
Impairment of Investment Securities	'
	Impairment of Investment Securities
	Securities Available for Sale
	As required by FASB ASC Topic 320, “Investments – Debt and Equity Securities,” credit related other-than-temporary impairment on debt securities is recognized in earnings while non-credit related other-than-temporary impairment on debt securities not expected to be sold is recognized in OCI. During the three months ended March 31, 2014 and 2013, no other-than-temporary impairment charges were recognized.
	First Commonwealth utilizes the specific identification method to determine the net gain or loss on debt securities and the average cost method to determine the net gain or loss on equity securities.
	We review our investment portfolio on a quarterly basis for indications of impairment. This review includes analyzing the length of time and the extent to which the fair value has been lower than the cost, the financial condition and near-term prospects of the issuer, including any specific events which may influence the operations of the issuer and whether we are more likely than not to sell the security. We evaluate whether we are more likely than not to sell debt securities based upon our investment strategy for the particular type of security and our cash flow needs, liquidity position, capital adequacy, tax position and interest rate risk position. In addition, the risk of future other-than-temporary impairment may be influenced by additional bank failures, weakness in the U.S. economy, changes in real estate values and additional interest deferrals in our pooled trust preferred collateralized debt obligations. Our pooled trust preferred collateralized debt obligations are beneficial interests in securitized financial assets within the scope of FASB ASC Topic 325, “Investments – Other,” and are therefore evaluated for other-than-temporary impairment using management’s best estimate of future cash flows. If these estimated cash flows indicate that it is probable that an adverse change in cash flows has occurred, then other-than-temporary impairment would be recognized in accordance with FASB ASC Topic 320. There is a risk that First Commonwealth will record other-than-temporary impairment charges in the future. See Note 11, “Fair Values of Assets and Liabilities,” for additional information.
	The following table presents the gross unrealized losses and estimated fair values at March 31, 2014 by investment category and time frame for which securities have been in a continuous unrealized loss position:
		Less Than 12 Months								12 Months or More							Total
		Estimated				Gross				Estimated				Gross			Estimated			Gross
		Fair Value				Unrealized				Fair Value				Unrealized			Fair Value			Unrealized
						Losses								Losses						Losses
		(dollars in thousands)
	Obligations of U.S. Government Agencies:
	Mortgage-Backed Securities – Residential	$	2,044			$	(34	)		$	—			$	—		$	2,044		$	(34	)
	Obligations of U.S. Government-Sponsored Enterprises:
	Mortgage-Backed Securities – Residential	459,224				(11,805		)		149,391				(7,667		)	608,615			(19,472		)
	Other Government-Sponsored Enterprises	237,136				(1,452		)		24,570				(411		)	261,706			(1,863		)
	Obligations of States and Political Subdivisions	2,825				(3		)		—				—			2,825			(3		)
	Pooled Trust Preferred Collateralized Debt Obligations	2,637				(57		)		25,240				(14,281		)	27,877			(14,338		)
	Total Securities Available for Sale	$	703,866			$	(13,351	)		$	199,201			$	(22,359	)	$	903,067		$	(35,710	)
	At March 31, 2014, pooled trust preferred collateralized debt obligations accounted for 40% of the unrealized losses, while fixed income securities issued by U.S. Government-sponsored enterprises comprised 60% of total unrealized losses. The unrealized losses related to U.S. Government-sponsored enterprises are the result of interest rate movements. There were no equity securities in an unrealized loss position at March 31, 2014.
	The following table presents the gross unrealized losses and estimated fair values at December 31, 2013 by investment category and time frame for which securities have been in a continuous unrealized loss position:
		Less Than 12 Months								12 Months or More							Total
		Estimated				Gross				Estimated				Gross			Estimated			Gross
		Fair Value				Unrealized				Fair Value				Unrealized			Fair Value			Unrealized
						Losses								Losses						Losses
		(dollars in thousands)
	Obligations of U.S. Government Agencies:
	Mortgage-Backed Securities – Residential	$	2,035			$	(59	)		$	—			$	—		$	2,035		$	(59	)
	Obligations of U.S. Government-Sponsored Enterprises:
	Mortgage-Backed Securities – Residential	632,231				(22,844		)		65,324				(4,319		)	697,555			(27,163		)
	Other Government-Sponsored Enterprises	183,542				(1,448		)		24,501				(479		)	208,043			(1,927		)
	Pooled Trust Preferred Collateralized Debt Obligations	2,401				(237		)		21,122				(18,280		)	23,523			(18,517		)
	Total Securities Available for Sale	$	820,209			$	(24,588	)		$	110,947			$	(23,078	)	$	931,156		$	(47,666	)
	As of March 31, 2014, our corporate securities had an amortized cost and an estimated fair value of $6.7 million and $7.1 million, respectively, and were comprised of single issue trust preferred securities issued primarily by large regional banks. As of December 31, 2013, the same portion of the portfolio had an amortized cost of $6.7 million and an estimated fair value of $7.0 million. There were no corporate securities in an unrealized loss position as of March 31, 2014 and December 31, 2013. When unrealized losses exist on these investments, management reviews each of the issuer’s asset quality, earnings trends and capital position, to determine whether issues in an unrealized loss position were other-than-temporarily impaired. All interest payments on the corporate securities are being made as contractually required.
	As of March 31, 2014, the book value of our pooled trust preferred collateralized debt obligations totaled $42.2 million with an estimated fair value of $27.9 million, which includes securities comprised of 288 banks and other financial institutions. All of our pooled securities are mezzanine tranches, four of which now have no senior class remaining in the issue. The credit rating on all of our issues are below investment grade. At the time of initial issue, the subordinated tranches ranged in size from approximately 7% to 35% of the total principal amount of the respective securities and no more than 5% of any pooled security consisted of a security issued by any one institution. As of March 31, 2014, after taking into account management’s best estimates of future interest deferrals and defaults, five of our securities had no excess subordination in the tranches we own and five of our securities had excess subordination which ranged from 8% to 56% of the current performing collateral.
	The following table provides information related to our pooled trust preferred collateralized debt obligations as of March 31, 2014:
	Deal	Class		Book				Estimated Fair				Unrealized				Moody’s/	Number		Deferrals			Excess
				Value				Value				Gain				Fitch	of		and			Subordination
												(Loss)				Ratings	Banks		Defaults			as a % of
																			as a % of			Current
																			Current			Performing
																			Collateral			Collateral
	(dollars in thousands)
	Pre TSL IV	Mezzanine		$	1,830			$	1,297			$	(533	)		B1/B	6		18.05	%		55.72	%
	Pre TSL V	Mezzanine		58				28				(30		)		C/-	3		100			—
	Pre TSL VII	Mezzanine		2,636				2,609				(27		)		Ca/C	14		54.14			—
	Pre TSL VIII	Mezzanine		1,985				1,400				(585		)		C/C	30		54.77			—
	Pre TSL IX	Mezzanine		2,313				1,390				(923		)		Caa1/C	42		28.05			7.86
	Pre TSL X	Mezzanine		1,409				1,391				(18		)		Caa3/C	46		35.07			—
	Pre TSL XII	Mezzanine		5,410				3,311				(2,099		)		Caa3/C	68		30.28			—
	Pre TSL XIII	Mezzanine		12,408				7,941				(4,467		)		Caa3/C	61		27.78			19.84
	Pre TSL XIV	Mezzanine		13,720				8,146				(5,574		)		Ca/C	58		31.9			50.44
	MMCap I	Mezzanine		445				363				(82		)		Ca/C	11		58.76			14.63
	Total			$	42,214			$	27,876			$	(14,338	)
	Lack of liquidity in the market for trust preferred collateralized debt obligations, below investment grade credit ratings and market uncertainties related to the financial industry are factors contributing to the impairment on these securities.
	All of the Company's pooled trust preferred securities are included in the non-exclusive list issued by the regulatory agencies and therefore are not considered covered funds under the Volcker Rule.
	On a quarterly basis we evaluate our debt securities for other-than-temporary impairment. During the three-months ended March 31, 2014 and 2013, there were no credit related other-than-temporary impairment charges recognized on our pooled trust preferred collateralized debt obligations. When evaluating these investments we determine a credit related portion and a non-credit related portion of other-than-temporary impairment. The credit related portion is recognized in earnings and represents the difference between book value and the present value of future cash flows. The non-credit related portion is recognized in OCI and represents the difference between the fair value of the security and the amount of credit related impairment. A discounted cash flow analysis provides the best estimate of credit related other-than-temporary impairment for these securities.
	Additional information related to the discounted cash flow analysis follows:
	Our pooled trust preferred collateralized debt obligations are measured for other-than-temporary impairment within the scope of FASB ASC Topic 325 by determining whether it is probable that an adverse change in estimated cash flows has occurred. Determining whether there has been an adverse change in estimated cash flows from the cash flows previously projected involves comparing the present value of remaining cash flows previously projected against the present value of the cash flows estimated at March 31, 2014. We consider the discounted cash flow analysis to be our primary evidence when determining whether credit related other-than-temporary impairment exists.
	Results of a discounted cash flow test are significantly affected by other variables such as the estimate of future cash flows, credit worthiness of the underlying banks and determination of probability of default of the underlying collateral. The following provides additional information for each of these variables:
	•	Estimate of Future Cash Flows – Cash flows are constructed in an INTEX cash flow model which includes each deal’s structural features. Projected cash flows include prepayment assumptions which are dependent on the issuer's asset size and coupon rate. For collateral issued by financial institutions over $15 billion in asset size with a coupon over 7%, a 100% prepayment rate is assumed. Financial institutions over $15 billion with a coupon of 7% or under are assigned a prepayment rate of 40% for two years and 2% thereafter. Financial institutions with assets between $2 billion and $15 billion with coupons over 7% are assigned a 5% prepayment rate. For financial institutions below $2 billion, if the coupon is over 10%, a prepayment rate of 5% is assumed and for all other issuers, there is no prepayment assumption incorporated into the cash flows. The modeled cash flows are then used to estimate if all the scheduled principal and interest payments of our investments will be returned.
	•	Credit Analysis – A quarterly credit evaluation is performed for each of the 288 banks comprising the collateral across the various pooled trust preferred securities. Our credit evaluation considers all evidence available to us and includes the nature of the issuer’s business, its years of operating history, corporate structure, loan composition, loan concentrations, deposit mix, asset growth rates, geographic footprint and local economic environment. Our analysis focuses on profitability, return on assets, shareholders’ equity, net interest margin, credit quality ratios, operating efficiency, capital adequacy and liquidity.
	•	Probability of Default – A probability of default is determined for each bank and is used to calculate the expected impact of future deferrals and defaults on our expected cash flows. Each bank in the collateral pool is assigned a probability of default for each year until maturity. Currently, any bank that is in default is assigned a 100% probability of default and a 0% projected recovery rate. All other banks in the pool are assigned a probability of default based on their unique credit characteristics and market indicators with a 10% projected recovery rate. For the majority of banks currently in deferral we assume the bank continues to defer and will eventually default and, therefore, a 100% probability of default is assigned. However, for some deferring collateral there is the possibility that they become current on interest or principal payments at some point in the future and in those cases a probability that the deferral will ultimately cure is assigned. The probability of default is updated quarterly. As of March 31, 2014, default probabilities for performing collateral ranged from 0.33% to 75%.
Our credit evaluation provides a basis for determining deferral and default probabilities for each underlying piece of collateral. Using the results of the credit evaluation, the next step of the process is to look at pricing of senior debt or credit default swaps for the issuer (or where such information is unavailable, for companies having similar credit profiles as the issuer). The pricing of these market indicators provides the information necessary to determine appropriate default probabilities for each bank.
In addition to the above factors, our evaluation of impairment also includes a stress test analysis which provides an estimate of excess subordination for each tranche. We stress the cash flows of each pool by increasing current default assumptions to the level of defaults which results in an adverse change in estimated cash flows. This stressed breakpoint is then used to calculate excess subordination levels for each pooled trust preferred security. The results of the stress test allow management to identify those pools that are at a greater risk for a future break in cash flows so that we can monitor banks in those pools more closely for potential deterioration of credit quality.
Our cash flow analysis as of March 31, 2014, indicates that no credit related other-than-temporary impairment has occurred on our pooled trust preferred securities during the three months ended March 31, 2014. Based upon the analysis performed by management, it is probable that five of our pooled trust preferred securities will experience principal and interest shortfalls and therefore appropriate other-than-temporary charges were recorded in prior periods. These securities are identified in the table on page 15 with 0% “Excess Subordination as a Percentage of Current Performing Collateral.” For the remaining securities listed in that table, our analysis as of March 31, 2014 indicates it is probable that we will collect all contractual principal and interest payments. For four of those securities, PreTSL IX, PreTSL XIII, PreTSL XIV and MMCap I, other-than-temporary impairment charges were recorded in prior periods, however, due to improvement in the expected cash flows of these securities, it is now probable that all contractual payments will be received.
During 2008, 2009 and 2010, other-than-temporary impairment charges were recognized on all of our pooled trust preferred securities, except for PreTSL IV. Our cash flow analysis as of March 31, 2014, for all of these impaired securities indicates that it is now probable we will collect principal and interest in excess of what was estimated at the time other-than-temporary impairment charges were recorded. This change can be attributed to improvement in the underlying collateral for these securities and has resulted in our current book value being below the present value of estimated future principal and interest payments. The excess for each bond of the present value of future cash flows over our current book value ranges from 18% to 155% and will be recognized as an adjustment to yield over the remaining life of these securities. The excess subordination recognized as an adjustment to yield are reflected in the following table as increases in cash flows expected to be collected.
The following table provides a cumulative roll forward of credit losses recognized in earnings for debt securities held and not intended to be sold:
	For the Three-Months Ended March 31
	2014				2013
	(dollars in thousands)
Balance, beginning (a)	$	27,543			$	43,274
Credit losses on debt securities for which other-than-temporary impairment was not previously recognized	—				—
Additional credit losses on debt securities for which other-than-temporary impairment was previously recognized	—				—
Increases in cash flows expected to be collected, recognized over the remaining life of the security (b)	(289		)		(283		)
Balance, ending	$	27,254			$	42,991
(a)	The beginning balance represents credit related losses included in other-than-temporary impairment charges recognized on debt securities in prior periods.
(b)	Represents the increase in cash flows recognized in interest income during the period.
In the first quarter of 2014 and 2013, no other-than-temporary impairment charges were recorded on equity securities. On a quarterly basis, management evaluates equity securities for other-than-temporary impairment by reviewing the severity and duration of decline in estimated fair value, research reports, analysts’ recommendations, credit rating changes, news stories, annual reports, regulatory filings, impact of interest rate changes and other relevant information. As of March 31, 2014 and 2013, there are no equity securities in an unrealized loss position.
Other Investments
As a member of the Federal Home Loan Bank (“FHLB”), First Commonwealth is required to purchase and hold stock in the FHLB to satisfy membership and borrowing requirements. The level of stock required to be held is dependent on the amount of First Commonwealth's mortgage related assets and outstanding borrowings with the FHLB. This stock is restricted in that it can only be sold to the FHLB or to another member institution, and all sales of FHLB stock must be at par. As a result of these restrictions, FHLB stock is unlike other investment securities insofar as there is no trading market for FHLB stock and the transfer price is determined by FHLB membership rules and not by market participants. As of March 31, 2014 and December 31, 2013, our FHLB stock totaled $34.0 million and $35.4 million, respectively and is included in “Other investments” on the Condensed Consolidated Statements of Financial Condition.
Beginning in July 2013, the FHLB began repurchasing 100% of a member's excess stock on a monthly basis. In the months prior to that in 2013, the FHLB repurchased the lessor of 5% of the members' total capital stock outstanding or its total excess capital stock on a quarterly basis. As a result, during the three months ended March 31, 2014 and 2013, $8.0 million and $2.8 million, respectively, of the stock owned by First Commonwealth was repurchased. The FHLB repurchased stock and paid dividends in 2014 and 2013, however, decisions regarding any future repurchase of excess capital stock and dividend payments will be made by the FHLB on an ongoing basis. Management reviewed the FHLB’s Form 10-K for the period ended December 31, 2013 filed with the SEC on March 13, 2014.
FHLB stock is held as a long-term investment and its value is determined based on the ultimate recoverability of the par value. First Commonwealth evaluates impairment quarterly. The decision of whether impairment exists is a matter of judgment that reflects our view of the FHLB’s long-term performance, which includes factors such as the following:
•	its operating performance;
•	the severity and duration of declines in the fair value of its net assets related to its capital stock amount;
•	its commitment to make payments required by law or regulation and the level of such payments in relation to its operating performance;
•	the impact of legislative and regulatory changes on the FHLB, and accordingly, on the members of FHLB; and
•	its liquidity and funding position.
After evaluating all of these considerations, First Commonwealth concluded that the par value of its investment in FHLB stock will be recovered. Accordingly, no impairment charge was recorded on these securities for the three months ended March 31, 2014. Our evaluation of the factors described above in future periods could result in the recognition of impairment charges on FHLB stock.

Loans_and_Allowance_for_Credit

Loans and Allowance for Credit Losses	3 Months Ended
	Mar. 31, 2014
Loans and Leases Receivable Disclosure [Abstract]	'
Loans and Allowance for Credit Losses	'
	Loans and Allowance for Credit Losses
	The following table provides outstanding balances related to each of our loan types:
		31-Mar-14				31-Dec-13
		(dollars in thousands)
	Commercial, financial, agricultural and other	$	1,017,412			$	1,021,056
	Real estate construction	95,110				93,289
	Residential real estate	1,240,169				1,262,718
	Commercial real estate	1,290,852				1,296,472
	Loans to individuals	608,670				610,298
	Total loans and leases net of unearned income	$	4,252,213			$	4,283,833
	Credit Quality Information
	As part of the on-going monitoring of credit quality within the loan portfolio, the following credit worthiness categories are used in grading our loans:
	Pass		Acceptable levels of risk exist in the relationship. Includes all loans not adversely classified as OAEM, substandard or doubtful.
	Other Assets Especially Mentioned (OAEM)		Potential weaknesses that deserve management’s close attention. The potential weaknesses may result in deterioration of the repayment prospects or weaken the Bank’s credit position at some future date. The credit risk may be relatively minor, yet constitute an undesirable risk in light of the circumstances surrounding the specific credit. No loss of principal or interest is expected.
	Substandard		Well-defined weakness or a weakness that jeopardizes the repayment of the debt. A loan may be classified as substandard as a result of deterioration of the borrower’s financial condition and repayment capacity. Loans for which repayment plans have not been met or collateral equity margins do not protect the Company may also be classified as substandard.
	Doubtful		Loans with the characteristics of substandard loans with the added characteristic that collection or liquidation in full, on the basis of presently existing facts and conditions, is highly improbable.
	The use of creditworthiness categories to grade loans permits management’s use of migration analysis to estimate a portion of credit risk. The Company’s internal creditworthiness grading system provides a measurement of credit risk based primarily on an evaluation of the borrower’s cash flow and collateral. Movements between these rating categories provides a predictive measure of credit losses and therefore assists in determining the appropriate level for the loan loss reserves. Category ratings are reviewed each quarter, at which time management analyzes the results, as well as other external statistics and factors related to loan performance. Loans that migrate towards higher risk rating levels generally have an increased risk of default, whereas loans that migrate toward lower risk ratings generally will result in a lower risk factor being applied to those related loan balances.
	The following tables represent our credit risk profile by creditworthiness:
		31-Mar-14
		Commercial, financial, agricultural and other				Real estate construction				Residential real estate				Commercial real estate				Loans to individuals				Total
		(dollars in thousands)
	Pass	$	945,063			$	83,456			$	1,225,083			$	1,242,664			$	608,491			$	4,104,757
	Non-Pass
	OAEM	23,958				8,686				3,375				30,207				1				66,227
	Substandard	48,391				2,968				11,711				17,981				178				81,229
	Doubtful	—				—				—				—				—				—
	Total Non-Pass	72,349				11,654				15,086				48,188				179				147,456
	Total	$	1,017,412			$	95,110			$	1,240,169			$	1,290,852			$	608,670			$	4,252,213
		31-Dec-13
		Commercial, financial, agricultural and other				Real estate construction				Residential real estate				Commercial real estate				Loans to individuals				Total
		(dollars in thousands)
	Pass	$	943,107			$	79,679			$	1,245,422			$	1,243,170			$	610,094			$	4,121,472
	Non-Pass
	OAEM	35,429				9,710				5,161				28,823				1				79,124
	Substandard	42,520				3,900				12,135				24,479				203				83,237
	Doubtful	—				—				—				—				—				—
	Total Non-Pass	77,949				13,610				17,296				53,302				204				162,361
	Total	$	1,021,056			$	93,289			$	1,262,718			$	1,296,472			$	610,298			$	4,283,833
	Portfolio Risks
	The credit quality of our loan portfolio can potentially represent significant risk to our earnings, capital, regulatory agency relationships, investment community reputation and shareholder returns. First Commonwealth devotes a substantial amount of resources managing this risk primarily through our credit administration department that develops and administers policies and procedures for underwriting, maintaining, monitoring and collecting activities. Credit administration is independent of lending departments and oversight is provided by the credit committee of the First Commonwealth Board of Directors.
	Criticized loans have been evaluated when determining the appropriateness of the allowance for credit losses, which we believe is adequate to absorb losses inherent to the portfolio as of March 31, 2014. However, changes in economic conditions, interest rates, borrower financial condition, delinquency trends or previously established fair values of collateral factors could significantly change those judgmental estimates.
	Risk factors associated with commercial real estate and construction related loans are monitored closely since this is an area that represents a significant portion of the loan portfolio and has experienced the most stress during the economic downturn.
	Age Analysis of Past Due Loans by Segment
	The following tables delineate the aging analysis of the recorded investments in past due loans as of March 31, 2014 and December 31, 2013. Also included in these tables are loans that are 90 days or more past due and still accruing because they are well-secured and in the process of collection.
		31-Mar-14
		30 - 59				60 - 89				90 days				Nonaccrual				Total past				Current				Total
		days				days				and								due and
		past due				past				greater								nonaccrual
						due				and still
										accruing
		(dollars in thousands)
	Commercial, financial, agricultural and other	$	971			$	490			$	300			$	28,268			$	30,029			$	987,383			$	1,017,412
	Real estate construction	40				—				—				1,698				1,738				93,372				95,110
	Residential real estate	4,265				1,004				746				10,011				16,026				1,224,143				1,240,169
	Commercial real estate	2,020				665				21				5,526				8,232				1,282,620				1,290,852
	Loans to individuals	2,094				682				1,383				177				4,336				604,334				608,670
	Total	$	9,390			$	2,841			$	2,450			$	45,680			$	60,361			$	4,191,852			$	4,252,213
		31-Dec-13
		30 - 59				60 - 89				90 days				Nonaccrual				Total past				Current				Total
		days				days				and								due and
		past due				past				greater								nonaccrual
						due				and still
										accruing
	(dollars in thousands)
Commercial, financial, agricultural and other	$	594			$	319			$	185			$	23,631			$	24,729			$	996,327			$	1,021,056
Real estate construction	—				—				—				2,567				2,567				90,722				93,289
Residential real estate	4,002				524				1,041				10,520				16,087				1,246,631				1,262,718
Commercial real estate	1,199				23				13				8,966				10,201				1,286,271				1,296,472
Loans to individuals	2,895				990				1,266				204				5,355				604,943				610,298
Total	$	8,690			$	1,856			$	2,505			$	45,888			$	58,939			$	4,224,894			$	4,283,833
Nonaccrual Loans
The previous tables summarize nonaccrual loans by loan segment. The Company generally places loans on nonaccrual status when the full and timely collection of interest or principal becomes uncertain, when part of the principal balance has been charged off and no restructuring has occurred, or the loans reach a certain number of days past due. Generally, loans 90 days or more past due are placed on nonaccrual status, except for consumer loans which are placed in nonaccrual status at 150 days past due.
When a loan is placed on nonaccrual, the accrued unpaid interest receivable is reversed against interest income and all future payments received are applied as a reduction to the loan principal. Generally, the loan is returned to accrual status when (a) all delinquent interest and principal become current under the terms of the loan agreement or (b) the loan is both well-secured and in the process of collection and collectability is no longer doubtful.
Impaired Loans
Management considers loans to be impaired when, based on current information and events, it is determined that the Company will not be able to collect all amounts due according to the loan contract, including scheduled interest payments. Determination of impairment is treated the same across all loan categories. When management identifies a loan as impaired, the impairment is measured based on the present value of expected future cash flows, discounted at the loan’s effective interest rate, except when the sole source for repayment of the loan is the operation or liquidation of collateral. When the loan is collateral dependent, the appraised value less estimated cost to sell is utilized. If management determines the value of the impaired loan is less than the recorded investment in the loan, impairment is recognized through an allowance estimate or a charge-off to the allowance. Troubled debt restructured loans on accrual status are considered to be impaired loans.
When the ultimate collectability of the total principal of an impaired loan is in doubt and the loan is on nonaccrual status, all payments are applied to principal, under the cost recovery method. When the ultimate collectability of the total principal of an impaired loan is not in doubt and the loan is on nonaccrual status, contractual interest is credited to interest income when received, under the cash basis method.
Nonperforming loans decreased $3.2 million during the three months ended March 31, 2014. Contributing to this decrease was the sale of three real estate construction loans totaling $0.7 million and the payoff of four loans totaling $6.9 million. The payoffs included a $3.1 million commercial real estate loan with a non-profit organization in western Pennsylvania, a $2.9 million commercial real estate loan to a real estate investor in western Pennsylvania, a $0.6 million commercial relationship with a western Pennsylvania glass manufacturer and a $0.3 million commercial real estate loan with a western Pennsylvania real estate investor. Additionally, charge-offs recognized during the first three months of 2014 include $0.5 million for a commercial industrial loan to a local energy company, $0.4 million for a consumer home equity loan in western Pennsylvania and $0.6 million for a commercial loan in western Pennsylvania.
Offsetting the previously noted decreases in nonperforming loans is a total of $9.6 million in loans which were moved into nonaccrual status during the three months ended March 31, 2014, the majority of which relates to an $8.0 million commercial industrial loan relationship. In addition to this, $1.1 million in consumer loans which were 150 days or more past due were moved to nonaccrual status.
The specific allowance for nonperforming loans increased by $1.7 million at March 31, 2014 compared to December 31, 2013, primarily due to the specific reserve on the previously mentioned loan which was transferred to nonaccrual status, offset by charge-offs of amounts reserved for in prior periods as well as the payoff of certain nonaccrual loans previously discussed. Unfunded commitments related to nonperforming loans were $3.4 million at March 31, 2014 and after consideration of available collateral related to these commitments, a reserve of $0.1 million was established was established for these off balance sheet exposures.
There were no loans held for sale at March 31, 2014 and December 31, 2013; however, sales of loans during the three months ended March 31, 2013 resulted in gains of $0.1 million. During the three months ended March 31, 2014 no gains were recognized on the sale of loans.
Significant nonaccrual loans as of March 31, 2014, include the following:
•	$10.9 million of commercial industrial loans to a local energy company. These loans were originated from 2008 to 2011 and were placed in nonaccrual status during the third quarter of 2013. One of these loans, totaling $2.7 million, was modified, resulting in TDR classification in the second quarter of 2012. A second of these loans, totaling $0.3 million was modified, resulting in TDR classification in the first quarter of 2013. During the three months ended March 31, 2014, chargeoffs of $0.5 million related to this relationship were recorded. A valuation of the collateral was completed during the third quarter of 2013.
•	$8.0 million commercial industrial loans to a gas drilling related business in Louisiana. These loans were originated in 2012 and placed on nonaccrual status in the first quarter of 2014.
•	$2.4 million, the remaining portion net of reserves, of a $44.1 million unsecured loan to a western Pennsylvania real estate developer. This loan was originated in 2004 and was placed on nonaccrual status in the fourth quarter of 2009. Charge-offs of $28.5 million have been recorded on this loan. In April 2014, the remaining balance of this loan was paid off.
•	$3.2 million in commercial real estate and industrial loans to a specialty metal processor in western Pennsylvania. This loan were originated in 2003 and were placed on nonaccrual status in the second quarter of 2013. The assets collateralizing this relationship as well as the appraisal for the real estate collateral were valued in the second quarter of 2013.
The following tables include the recorded investment and unpaid principal balance for impaired loans with the associated allowance amount, if applicable, as of March 31, 2014 and December 31, 2013. Also presented are the average recorded investment in impaired loans and the related amount of interest recognized while the loan was considered impaired. Average balances are calculated using month-end balances of the loans for the period reported and are included in the table below based on its period-end allowance position.
	31-Mar-14												31-Dec-13
	Recorded				Unpaid				Related				Recorded				Unpaid				Related
	investment				principal				allowance				investment				principal				allowance
					balance												balance
	(dollars in thousands)
With no related allowance recorded:
Commercial, financial, agricultural and other	$	9,788			$	10,960							$	6,752			$	7,649
Real estate construction	2,213				2,782								3,486				6,664
Residential real estate	9,864				10,741								9,333				9,952
Commercial real estate	7,348				8,423								13,606				14,719
Loans to individuals	270				297								289				307
Subtotal	29,483				33,203								33,466				39,291
With an allowance recorded:
Commercial, financial, agricultural and other	22,940				23,559				9,886				21,482				22,082				7,364
Real estate construction	638				1,780				74				414				737				94
Residential real estate	2,841				3,435				496				3,533				3,585				1,282
Commercial real estate	301				315				47				488				612				84
Loans to individuals	—				—				—				—				—				—
Subtotal	26,720				29,089				10,503				25,917				27,016				8,824
Total	$	56,203			$	62,292			$	10,503			$	59,383			$	66,307			$	8,824
	For the Three-Months Ended March 31
	2014								2013
	Average				Interest				Average				Interest
	recorded				Income				recorded				Income
	investment				Recognized				investment				Recognized
	(dollars in thousands)
With no related allowance recorded:
Commercial, financial, agricultural and other	$	10,953			$	17			$	8,592			$	51
Real estate construction	2,438				12				7,877				—
Residential real estate	9,825				49				8,516				37
Commercial real estate	9,498				33				33,978				11
Loans to individuals	271				1				247				1
Subtotal	32,985				112				59,210				100
With an allowance recorded:
Commercial, financial, agricultural and other	17,649				45				25,803				19
Real estate construction	638				—				2,685				13
Residential real estate	3,161				8				2,457				4
Commercial real estate	307				1				6,704				25
Loans to individuals	—				—				—				—
Subtotal	21,755				54				37,649				61
Total	$	54,740			$	166			$	96,859			$	161
Troubled debt restructured loans are those loans whose terms have been renegotiated to provide a reduction or deferral of principal or interest as a result of the financial difficulties experienced by the borrower, who could not obtain comparable terms from alternate financing sources.
The following table provides detail as to the total troubled debt restructured loans and total commitments outstanding on troubled debt restructured loans:
	31-Mar-14				31-Dec-13
	(dollars in thousands)
Troubled debt restructured loans
Accrual status	$	10,523			$	13,495
Nonaccrual status	12,327				16,980
Total	$	22,850			$	30,475
Commitments
Letters of credit	$	—			$	—
Unused lines of credit	709				452
Total	$	709			$	452
At March 31, 2014, troubled debt restructured loans decreased $7.6 million compared to December 31, 2013, and commitments related to troubled debt restructured loans increased $0.3 million for the same period. This decrease in loans is primarily a result of the payoff of three commercial loans totaling $6.6 million, including a $3.1 million commercial real estate loan with a non-profit organization and a $2.9 million commercial real estate loan in western Pennsylvania. The increase in unused line of credit commitments is related to two commercial borrowers.
The following tables provide detail, including specific reserves and reasons for modification, related to loans identified as troubled debt restructurings:
	For the Three-Months Ended March 31, 2014
				Type of Modification
	Number			Extend				Modify				Modify				Total				Post-				Specific
	of			Maturity				Rate				Payments				Pre-Modification				Modification				Reserve
	Contracts															Outstanding				Outstanding
																Recorded				Recorded
																Investment				Investment
	(dollars in thousands)
Commercial, financial, agricultural and other	1			$	60			$	—			$	—			$	60			$	60			$	29
Residential real estate	13			—				172				517				689				676				5
Commercial real estate	1			—				—				12				12				8				—
Loans to individuals	6			—				31				20				51				47				—
Total	21			$	60			$	203			$	549			$	812			$	791			$	34
	For the Three-Months Ended March 31, 2013
				Type of Modification
	Number			Extend				Modify				Modify				Total				Post-				Specific
	of			Maturity				Rate				Payments				Pre-Modification				Modification				Reserve
	Contracts															Outstanding				Outstanding
																Recorded				Recorded
																Investment				Investment
	(dollars in thousands)
Commercial, financial, agricultural and other	2			$	426			$	—			$	12			$	438			$	377			$	—
Residential real estate	9			7				214				514				735				677				—
Commercial real estate	1			—				244				—				244				242				—
Loans to individuals	4			—				23				4				27				25				—
Total	16			$	433			$	481			$	530			$	1,444			$	1,321			$	—
The troubled debt restructurings included in the above tables are also included in the impaired loan tables provided earlier in this note. Loans defined as modified due to a change in rate may include loans that were modified for a change in rate as well as a reamortization of the principal and an extension of the maturity. For the three months ended March 31, 2014 and 2013, $0.2 million and $0.5 million, respectively, of total rate modifications represent loans with modifications to the rate as well as payment as a result of reamortization. For both 2014 and 2013 the changes in loan balances between the pre-modification balance and the post-modification balance are due to customer payments.
A troubled debt restructuring is considered to be in default when a restructured loan is 90 days or more past due. The following table provides information related to restructured loans that were considered to default during the three months ended March 31:
	2014							2013
	Number of			Recorded				Number of			Recorded
	Contracts			Investment				Contracts			Investment
	(dollars in thousands)
Residential real estate	4			$	138			1			$	10
Loans to individuals	—			—				1			6
Total	4			$	138			2			$	16
The following tables provide detail related to the allowance for credit losses:
	For the Three-Months Ended March 31, 2014
	Commercial,				Real estate				Residential				Commercial				Loans to				Unallocated				Total
	financial,				construction				real estate				real estate				individuals
	agricultural
	and other
	(dollars in thousands)
Allowance for credit losses:
Beginning Balance	$	22,663			$	6,600			$	7,727			$	11,778			$	5,457			$	—			$	54,225
Charge-offs	(1,601		)		—				(1,095		)		(140		)		(810		)		—				(3,646		)
Recoveries	85				169				244				20				178				—				696
Provision (credit)	4,978				(555		)		(850		)		(539		)		197				—				3,231
Ending Balance	$	26,125			$	6,214			$	6,026			$	11,119			$	5,022			$	—			$	54,506
Ending balance: individually evaluated for impairment	$	9,886			$	74			$	496			$	47			$	—			$	—			$	10,503
Ending balance: collectively evaluated for impairment	16,239				6,140				5,530				11,072				5,022				—				44,003
Loans:
Ending balance	1,017,412				95,110				1,240,169				1,290,852				608,670								4,252,213
Ending balance: individually evaluated for impairment	31,730				2,797				9,103				5,773				—								49,403
Ending balance: collectively evaluated for impairment	985,682				92,313				1,231,066				1,285,079				608,670								4,202,810
	For the Three-Months Ended March 31, 2013
	Commercial,				Real estate				Residential				Commercial				Loans to				Unallocated				Total
	financial,				construction				real estate				real estate				individuals
	agricultural
	and other
	(dollars in thousands)
Allowance for credit losses:
Beginning Balance	$	19,852			$	8,928			$	5,908			$	22,441			$	4,132			$	5,926			$	67,187
Charge-offs	(538		)		(84		)		(322		)		(8,544		)		(988		)		—				(10,476		)
Recoveries	128				12				723				97				94				—				1,054
Provision (credit)	833				(1,123		)		(560		)		4,476				901				(30		)		4,497
Ending Balance	$	20,275			$	7,733			$	5,749			$	18,470			$	4,139			$	5,896			$	62,262
Ending balance: individually evaluated for impairment	$	9,846			$	503			$	1,091			$	1,249			$	—			$	—			$	12,689
Ending balance: collectively evaluated for impairment	10,429				7,230				4,658				17,221				4,139				5,896				49,573
Loans:
Ending balance	1,057,663				70,461				1,255,515				1,243,676				591,495								4,218,810
Ending balance: individually evaluated for impairment	33,322				8,917				7,813				21,369				—								71,421
Ending balance: collectively evaluated for impairment	1,024,341				61,544				1,247,702				1,222,307				591,495								4,147,389
The change in the unallocated portion of the allowance for credit losses comparing March 31, 2014 with March 31, 2013 is a result of the unallocated portion of the allowance for credit losses no longer being treated as a separate component of the allowance as of December 31, 2013. Instead it is incorporated into the reserve provided for each loan category. This portion of the allowance for credit losses reflects the qualitative or environmental factors that are likely to cause estimated credit losses to differ from historical loss experience.

Income_Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2014
Income Tax Disclosure [Abstract]	'
Income Taxes	'
	Income Taxes
	At March 31, 2014 and December 31, 2013, First Commonwealth had no material unrecognized tax benefits or accrued interest and penalties. If applicable, First Commonwealth will record interest and penalties as a component of noninterest expense. Federal and state tax years 2010 through 2012 were open for examination as of March 31, 2014.

Fair_Values_of_Assets_and_Liab

Fair Values of Assets and Liabilities	3 Months Ended
	Mar. 31, 2014
Fair Value Disclosures [Abstract]	'
Fair Values of Assets and Liabilities	'
	Fair Values of Assets and Liabilities
	FASB ASC Topic 820, “Fair Value Measurements and Disclosures” requires disclosures for non-financial assets and non-financial liabilities, except for items that are recognized or disclosed at fair value in the financial statements on a recurring basis (at least annually). All non-financial assets are included either as a separate line item on the Condensed Consolidated Statements of Financial Condition or in the “Other assets” category of the Condensed Consolidated Statements of Financial Condition. Currently, First Commonwealth does not have any non-financial liabilities to disclose.
	FASB ASC Topic 825, “Financial Instruments” permits entities to irrevocably elect to measure select financial instruments and certain other items at fair value. The unrealized gains and losses are required to be included in earnings each reporting period for the items that fair value measurement is elected. First Commonwealth has elected not to measure any existing financial instruments at fair value under FASB ASC Topic 825; however, in the future we may elect to adopt this guidance for select financial instruments.
	In accordance with FASB ASC Topic 820, First Commonwealth groups financial assets and financial liabilities measured at fair value in three levels based on the principal markets in which the assets and liabilities are transacted and the observability of the data points used to determine fair value. These levels are:
	•	Level 1 – Valuations for assets and liabilities traded in active exchange markets, such as the New York Stock Exchange (“NYSE”). Valuations are obtained from readily available pricing sources for market transactions involving identical assets or liabilities. Level 1 securities include equity holdings comprised of publicly traded bank stocks which were priced using quoted market prices.
	•	Level 2 – Valuations for assets and liabilities traded in less active dealer or broker markets. Valuations are obtained for identical or comparable assets or liabilities from alternative pricing sources with reasonable levels of price transparency. Level 2 includes Obligations of U.S. Government securities issued by Agencies and Sponsored Enterprises, Obligations of States and Political Subdivisions, corporate securities, FHLB stock, interest rate derivatives that include interest rate swaps and risk participation agreements, certain other real estate owned and certain impaired loans.
	Level 2 investment securities are valued by a recognized third party pricing service using observable inputs. The model used by the pricing service varies by asset class and incorporates available market, trade and bid information as well as cash flow information when applicable. Because many fixed-income investment securities do not trade on a daily basis, the model uses available information such as benchmark yield curves, benchmarking of like investment securities, sector groupings and matrix pricing. The model will also use processes such as an option adjusted spread to assess the impact of interest rates and to develop prepayment estimates. Market inputs normally used in the pricing model include benchmark yields, reported trades, broker/dealer quotes, issuer spreads, two-sided markets, benchmark securities, bids, offers and reference data including market research publications.
	Management validates the market values provided by the third party service by having another recognized pricing service price 100% of the securities on an annual basis and a random sample of securities each quarter, monthly monitoring of variances from prior period pricing and, on a monthly basis, evaluating pricing changes compared to expectations based on changes in the financial markets.
	Other Investments are comprised of FHLB stock whose estimated fair value is based on its par value. Additional information on FHLB stock is provided in Note 8, “Impairment of Investment Securities.”
	Interest rate derivatives are reported at an estimated fair value utilizing Level 2 inputs and are included in other assets and other liabilities and consist of interest rate swaps where there is no significant deterioration in the counterparties' (loan customers) credit risk since origination of the interest rate swap as well as interest rate caps and risk participation agreements. First Commonwealth values its interest rate swap and cap positions using a yield curve by taking market prices/rates for an appropriate set of instruments. The set of instruments currently used to determine the U.S. Dollar yield curve includes cash LIBOR rates from overnight to three months, Eurodollar futures contracts and swap rates from three years to thirty years. These yield curves determine the valuations of interest rate swaps. Interest rate derivatives are further described in Note 12, “Derivatives.”
	For purposes of potential valuation adjustments to our derivative positions, First Commonwealth evaluates the credit risk of its counterparties as well as our own credit risk. Accordingly, we have considered factors such as the likelihood of default, expected loss given default, net exposures and remaining contractual life, among other things, in determining if any fair value adjustments related to credit risk are required. We review our counterparty exposure quarterly, and when necessary, appropriate adjustments are made to reflect the exposure.
	We also utilize this approach to estimate our own credit risk on derivative liability positions. In 2014, we have not realized any losses due to a counterparty's inability to pay any uncollateralized positions.
	The estimated fair value for other real estate owned included in Level 2 is determined by either an independent market based appraisal less estimated costs to sell or an executed sales agreement.
	•	Level 3 – Valuations for assets and liabilities that are derived from other valuation methodologies, including option pricing models, discounted cash flow models and similar techniques, and not based on market exchange, dealer or broker traded transactions. If the inputs used to provide the valuation are unobservable and/or there is very little, if any, market activity for the security or similar securities, the securities would be considered Level 3 securities. Level 3 valuations incorporate certain assumptions and projections in determining the fair value assigned to such assets or liabilities. The assets included in Level 3 are pooled trust preferred collateralized debt obligations, non-marketable equity investments, certain interest rate derivatives, certain other real estate owned and certain impaired loans.
	Our pooled trust preferred collateralized debt obligations are collateralized by the trust preferred securities of individual banks, thrifts and bank holding companies in the U.S. There has been little or no active trading in these securities since 2009; therefore it was more appropriate to determine estimated fair value using a discounted cash flow analysis. Detail on our process for determining the appropriate cash flows for this analysis is provided in Note 8, “Impairment of Investment Securities.” The discount rate applied to the cash flows is determined by evaluating the current market yields for comparable corporate and structured credit products along with an evaluation of the risks associated with the cash flows of the comparable security. Due to the fact that there is no active market for the pooled trust preferred collateralized debt obligations, one key reference point is the market yield for the single issue trust preferred securities issued by banks and thrifts for which there is more activity than for the pooled securities. Adjustments are then made to reflect the credit and structural differences between these two security types.
	Management validates the fair value of the pooled trust preferred collateralized debt obligations by monitoring the performance of the underlying collateral, discussing the discount rate, cash flow assumptions and general market trends with the specialized third party and confirming changes in the underlying collateral to the trustee reports. Management’s monitoring of the underlying collateral includes deferrals of interest payments, payment defaults, cures of previously deferred interest payments, any regulatory filings or actions and general news related to the underlying collateral. Management also evaluates fair value changes compared to expectations based on changes in the interest rates used in determining the discount rate and general financial markets.
	The estimated fair value of the non-marketable equity investments included in Level 3 is based on par value.
	For interest rate derivatives included in Level 3, the fair value incorporates credit risk by considering such factors as likelihood of default and expected loss given default based on the credit quality of the underlying counterparties (loan customers).
	In accordance with ASU 2011-4, the following table provides information related to quantitative inputs and assumptions used in Level 3 fair value measurements.
		Fair Value (dollars		Valuation	Unobservable Inputs		Range /
		in thousands)		Technique			(weighted average)
	Pooled Trust Preferred Securities	$27,876		Discounted Cash Flow	Probability of default		0% - 100% (18.22%)
					Prepayment rates		0% - 100% (7.48%)
					Discount rates		5.5% - 15.5% (a)
	Equities	1,420		Par Value	N/A		N/A
	Interest Rate Swap	—		Option model	Counterparty credit risk		6.33% - 8.12% (b)
	Impaired Loans	5,848 (c)		Reserve study	Discount rate		10.00%
					Gas per MCF		$3.84 - $6.45 (d)
					Oil per BBL/d		$78.3 - $107.00 (d)
					NGL per gallon		$0.83 (d)
		113 (c)		Discounted Cash Flow	Discount Rate		9.00%
	Other Real Estate Owned	157		Internal Valuation	N/A		N/A
	(a)	incorporates spread over risk free rate related primarily to credit quality and illiquidity of securities.
	(b)	represents the range of the credit spread curve used in valuation.
	(c)	the remainder of impaired loans valued using Level 3 inputs are not included in this disclosure as the values of those loans are based on bankruptcy agreement documentation.
	(d)	unobservable inputs are defined as follows: MCF - million cubic feet; BBL/d - barrels per day; NGL - natural gas liquid.
	The significant unobservable inputs used in the fair value measurement of pooled trust preferred securities are the probability of default, discount rates and prepayment rates. Significant increases in the probability of default or discount rate used would result in a decrease in the estimated fair value of these securities while decreases in these variables would result in higher fair value measurements. In general, a change in the assumption of probability of default is accompanied by a directionally similar change in the discount rate. In most cases, increases in the prepayment rate assumptions would result in a higher estimated fair value for these securities while decreases would provide for a lower value. The direction of this change is somewhat dependent on the structure of the investment and the amount of the investment tranches senior to our position.
	The discount rate is the significant unobservable input used in the fair value measurement of impaired loans. Significant increases in this rate would result in a decrease in the estimated fair value of the loans, while a decrease in this rate would result in higher fair value measurement. Other unobservable inputs in the fair value measurement of impaired loans relate to gas, oil and natural gas prices and increases in these rates would result in an increase in the estimated fair value of the loans, while a decrease in these prices would result in a lower fair value measurement.
	The significant unobservable input used in the fair value measurement of interest rate swaps classified as Level 3 is counterparty credit risk and the resulting range of the credit spread curve used in the valuation. Higher credit risk would result in an increased credit spread, which would reduce the fair value of the interest rate swap.
	The tables below present the balances of assets and liabilities measured at fair value on a recurring basis:
		31-Mar-14
		Level 1			Level 2			Level 3			Total
		(dollars in thousands)
	Obligations of U.S. Government Agencies:
	Mortgage-Backed Securities - Residential	$	—		$	24,241		$	—		$	24,241
	Obligations of U.S. Government-Sponsored Enterprises:
	Mortgage-Backed Securities - Residential	—			1,013,607			—			1,013,607
	Mortgage-Backed Securities - Commercial	—			98			—			98
	Other Government-Sponsored Enterprises	—			267,310			—			267,310
	Obligations of States and Political Subdivisions	—			9,359			—			9,359
	Corporate Securities	—			7,128			—			7,128
	Pooled Trust Preferred Collateralized Debt Obligations	—			—			27,876			27,876
	Total Debt Securities	—			1,321,743			27,876			1,349,619
	Equities	—			—			1,420			1,420
	Total Securities Available for Sale	—			1,321,743			29,296			1,351,039
	Other Investments	—			34,047			—			34,047
	Loans held for sale	—			—			—			—
	Other Assets(a)	—			12,521			—			12,521
	Total Assets	$	—		$	1,368,311		$	29,296		$	1,397,607
	Other Liabilities(a)	$	—		$	12,497		$	—		$	12,497
	Total Liabilities	$	—		$	12,497		$	—		$	12,497
	(a)	Non-hedging interest rate derivatives
		31-Dec-13
	Level 1			Level 2			Level 3			Total
	(dollars in thousands)
Obligations of U.S. Government Agencies:
Mortgage-Backed Securities - Residential	$	—		$	25,204		$	—		$	25,204
Obligations of U.S. Government-Sponsored Enterprises:
Mortgage-Backed Securities - Residential	—			994,887			—			994,887
Mortgage-Backed Securities - Commercial	—			105			—			105
Other Government-Sponsored Enterprises	—			266,125			—			266,125
Obligations of States and Political Subdivisions	—			80			—			80
Corporate Securities	—			7,021			—			7,021
Pooled Trust Preferred Collateralized Debt Obligations	—			—			23,523			23,523
Total Debt Securities	—			1,293,422			23,523			1,316,945
Equities	—			—			1,420			1,420
Total Securities Available for Sale	—			1,293,422			24,943			1,318,365
Other Investments	—			35,444			—			35,444
Loans Held for Sale	—			—			—			—
Other Assets(a)	—			14,358			—			14,358
Total Assets	$	—		$	1,343,224		$	24,943		$	1,368,167
Other Liabilities(a)	$	—		$	14,318		$	—		$	14,318
Total Liabilities	$	—		$	14,318		$	—		$	14,318
(a)	Non-hedging interest rate derivatives
For the three months ended March 31, changes in Level 3 assets and liabilities measured at fair value on a recurring basis are summarized as follows:
	2014
	Pooled Trust			Equities			Loans			Other		Total
	Preferred						Held for			Assets
	Collateralized						Sale
	Debt
	Obligations
	(dollars in thousands)
Balance, beginning of period	$	23,523		$	1,420		$	—		$	—	$	24,943
Total gains or losses
Included in earnings	—			—			—			—		—
Included in other comprehensive income	4,743			—			—			—		4,743
Purchases, issuances, sales, and settlements
Purchases	—			—			—			—		—
Issuances	—			—			—			—		—
Sales	—			—			(716		)	—		(716		)
Settlements	(390		)	—			—			—		(390		)
Transfers into Level 3	—			—			716			—		716
Balance, end of period	$	27,876		$	1,420		$	—		$	—	$	29,296
	2013
	Pooled Trust			Equities			Loans Held for Sale			Other		Total
	Preferred									Assets
	Collateralized
	Debt
	Obligations
	(dollars in thousands)
Balance, beginning of period	$	23,373		$	1,420		$	—		$	—	$	24,793
Total gains or losses
Included in earnings	—			—			126			—		126
Included in other comprehensive income	2,391			—			—			—		2,391
Purchases, issuances, sales, and settlements
Purchases	—			—			—			—		—
Issuances	—			—			—			—		—
Sales	—			—			(16,739		)	—		(16,739		)
Settlements	(1,252		)	—			—			—		(1,252		)
Transfers into Level 3	—			—			16,613			—		16,613
Balance, end of period	$	24,512		$	1,420		$	—		$	—	$	25,932
For the three months ended March 31, 2014 and 2013, there were no transfers between fair value Levels 1 and 2. However, $0.7 million and $16.6 million of loans were transferred into Level 3 from Level 2 during the three months ended March 31, 2014 and 2013, respectively, due to the loans being transferred to a held for sale status. The loans transferred and subsequently sold related to three loans in a nonperforming relationship for which this was determined to be the appropriate exit strategy. There were no gains or losses included in earnings for the periods presented that are attributable to the change in realized gains (losses) relating to assets held at March 31, 2014 and 2013.
The tables below present the balances of assets measured at fair value on a non-recurring basis at:
	31-Mar-14
	Level 1			Level 2			Level 3			Total
	(dollars in thousands)
Impaired loans	$	—		$	32,940		$	12,759		$	45,699
Other real estate owned	—			10,601			157			10,758
Total Assets	$	—		$	43,541		$	12,916		$	56,457
	31-Dec-13
	Level 1			Level 2			Level 3			Total
	(dollars in thousands)
Impaired loans	$	—		$	36,903		$	13,656		$	50,559
Other real estate owned	—			12,752			172			12,924
Total Assets	$	—		$	49,655		$	13,828		$	63,483
The following losses were realized on the assets measured on a nonrecurring basis:
	For the Three-Months Ended March 31
	2014			2013
	(dollars in thousands)
Impaired loans	$	(3,996	)	$	(503	)
Other real estate owned	(363		)	(131		)
Total losses	$	(4,359	)	$	(634	)
Impaired loans over $0.1 million are individually reviewed to determine the amount of each loan considered to be at risk of non-collection. The fair value for impaired loans that are collateral based is determined by reviewing real property appraisals, equipment valuations, accounts receivable listings and other financial information. A discounted cash flow analysis is performed to determine fair value for impaired loans when an observable market price or a current appraisal is not available. First Commonwealth’s loan policy requires updated appraisals be obtained at least every twelve months on all impaired loans with balances of $250 thousand and over. For balances under $250 thousand, we rely on broker price opinions.
The fair value for other real estate owned determined by either an independent market based appraisal less estimated costs to sell or an executed sales agreement is classified as Level 2. The fair value for other real estate owned determined using an internal valuation is classified as Level 3. Other real estate owned has a book cost of $10.1 million as of March 31, 2014 and consisted primarily of commercial real estate properties in Pennsylvania. We review whether events and circumstances subsequent to a transfer to other real estate owned have occurred that indicate the balance of those assets may not be recoverable. If events and circumstances indicate further impairment we will record a charge to the extent that the carrying value of the assets exceed their fair values, less estimated cost to sell, as determined by valuation techniques appropriate in the circumstances.
Certain other assets and liabilities, including goodwill and core deposit intangibles, are measured at fair value on a non-recurring basis; that is, the instruments are not measured at fair value on an ongoing basis but are subject to fair value adjustments only in certain circumstances. Additional information related to goodwill is provided in Note 13, “Goodwill.” There were no other assets or liabilities measured at fair value on a non-recurring basis during the three months ended March 31, 2014.
FASB ASC 825-10, “Transition Related to FSP FAS 107-1” and APB 28-1, “Interim Disclosures about Fair Value of Financial Instruments,” requires disclosure of the fair value of financial assets and financial liabilities, including those financial assets and financial liabilities that are not measured and reported at fair value on a recurring basis or non-recurring basis. The methodologies for estimating the fair value of financial assets and financial liabilities that are measured at fair value on a recurring or non-recurring basis are as discussed above. The methodologies for other financial assets and financial liabilities are discussed below.
Cash and due from banks and interest-bearing bank deposits: The carrying amounts for cash and due from banks and interest-bearing bank deposits approximate the estimated fair values of such assets.
Securities: Fair values for securities available for sale are based on quoted market prices, if available. If quoted market prices are not available, fair values are based on quoted market prices of comparable instruments. Pooled trust preferred collateralized debt obligations values are derived from other valuation methodologies, including option pricing models, discounted cash flow models and similar techniques, and not based on market exchange, dealer or broker traded transactions. These valuations incorporate certain assumptions and projections in determining the fair value assigned to each instrument. The carrying value of other investments, which includes FHLB stock, is considered a reasonable estimate of fair value.
Loans: The fair values of all loans are estimated by discounting the estimated future cash flows using interest rates currently offered for loans with similar terms to borrowers of similar credit quality adjusted for past due and nonperforming loans, which is not an exit price under FASB ASC Topic 820, “Fair Value Measurements and Disclosures.”
Off-balance sheet instruments: Many of First Commonwealth’s off-balance sheet instruments, primarily loan commitments and standby letters of credit, are expected to expire without being drawn upon; therefore, the commitment amounts do not necessarily represent future cash requirements. FASB ASC Topic 460, “Guarantees” clarified that a guarantor is required to recognize, at the inception of a guarantee, a liability for the fair value of the obligation undertaken in issuing the guarantee. The carrying amount and fair value for standby letters of credit was $0.1 million at March 31, 2014 and December 31, 2013, respectively. See Note 6, “Commitments and Contingent Liabilities,” for additional information.
Deposit liabilities: Management estimates that the fair value of deposits is based on a market valuation of similar deposits. The carrying value of variable rate time deposit accounts and certificates of deposit approximate their fair values at the report date. Also, fair values of fixed rate time deposits for both periods are estimated by discounting the future cash flows using interest rates currently being offered and a schedule of aggregated expected maturities.
Short-term borrowings: The fair values of borrowings from the FHLB were estimated based on the estimated incremental borrowing rate for similar types of borrowings. The carrying amounts of other short-term borrowings such as federal funds purchased and securities sold under agreement to repurchase were used to approximate fair value due to the short-term nature of the borrowings.
Long-term debt and subordinated debt: The fair value of long-term debt and subordinated debt is estimated by discounting the future cash flows using First Commonwealth’s estimate of the current market rate for similar types of borrowing arrangements or an announced redemption price.
The following table presents carrying amounts and fair values of First Commonwealth’s financial instruments:
	31-Mar-14
				Fair Value Measurements Using:
	Carrying			Total			Level 1			Level 2		Level 3
	Amount
	(dollars in thousands)
Financial assets
Cash and due from banks	$	82,327		$	82,327		$	82,327		$	—	$	—
Interest-bearing deposits	9,087			9,087			9,087			—		—
Securities available for sale	1,351,039			1,351,039			—			1,321,743		29,296
Other investments	34,047			34,047			—			34,047		—
Loans	4,252,213			4,283,303			—			32,940		4,250,363
Financial liabilities
Deposits	4,647,817			4,573,324			—			4,573,324		—
Short-term borrowings	572,965			572,954			—			572,954		—
Long-term debt	144,268			145,510			—			145,510		—
Subordinated debt	72,167			61,347			—			—		61,347
	31-Dec-13
				Fair Value Measurements Using:
	Carrying			Total			Level 1			Level 2		Level 3
	Amount
	(dollars in thousands)
Financial assets
Cash and due from banks	$	74,427		$	74,427		$	74,427		$	—	$	—
Interest-bearing deposits	3,012			3,012			3,012			—		—
Securities available for sale	1,318,365			1,318,365			—			1,293,422		24,943
Other investments	35,444			35,444			—			35,444		—
Loans	4,283,833			4,321,847			—			36,903		4,284,944
Financial liabilities
Deposits	4,603,863			4,531,685			—			4,531,685		—
Short-term borrowings	626,615			626,603			—			626,603		—
Long-term debt	144,385			145,477			—			145,477		—
Subordinated debt	72,167			51,706			—			—		51,706

Derivatives

Derivatives	3 Months Ended
	Mar. 31, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
Derivatives	'
	Derivatives
	First Commonwealth is a party to interest rate derivatives that are not designated as accounting hedges. These derivatives relate to interest rate swaps that First Commonwealth enters into with customers to allow customers to convert variable rate loans to a fixed rate. First Commonwealth pays interest to the customer at a floating rate on the notional amount and receives interest from the customer at a fixed rate for the same notional amount. At the same time the interest rate swap is entered into with the customer, an offsetting interest rate swap is entered into with another financial institution. First Commonwealth pays the other financial institution interest at the same fixed rate on the same notional amount as the swap entered into with the customer, and receives interest from the financial institution for the same floating rate on the same notional amount. The changes in the fair value of the swaps offset each other, except for the credit risk of the counterparties, which is determined by taking into consideration the risk rating, probability of default and loss given default for all counterparties.
	We have eleven risk participation agreements with financial institution counterparties for interest rate swaps related to loans in which we are a participant. The risk participation agreements provide credit protection to the financial institution should the borrower fail to perform on its interest rate derivative contract with the financial institution. We have two risk participation agreements with financial institution counterparties for interest rate swaps related to loans in which we are the lead bank. The risk participation agreement provides credit protection to us should the borrower fail to perform on its interest rate derivative contract with us.
	First Commonwealth is also party to interest rate caps that are not designated as hedging instruments. These derivatives relate to contracts that First Commonwealth enters into with loan customers providing a maximum interest rate on their variable rate loan. At the same time the interest rate cap is entered into with the customer, First Commonwealth enters into an offsetting interest rate cap with another financial institution. The notional amount and maximum interest rate on both interest cap contracts are identical.
	The fee received, less the estimate of the loss for the credit exposure, was recognized in earnings at the time of the transaction.
	The following table depicts the credit value adjustment recorded related to the notional amount of derivatives outstanding as well as the notional amount of risk participation agreements participated to other banks:
		31-Mar-14			31-Dec-13
		(dollars in thousands)
	Credit value adjustment	$	19		$	77
	Notional Amount:
	Interest rate derivatives	271,391			274,718
	Interest rate caps	7,263			7,500
	Risk participation agreements	81,704			82,197
	Sold credit protection on risk participation agreements	(19,045		)	(19,161		)
	The table below presents the amount representing the change in the fair value of derivative assets and derivative liabilities attributable to credit risk included in other income on the Condensed Consolidated Statements of Income:
		For the Three-Months Ended March 31
		2014			2013
		(dollars in thousands)
	Non-hedging interest rate derivatives:
	(Decrease) increase in other income	$	(58	)	$	989

Goodwill

Goodwill	3 Months Ended
	Mar. 31, 2014
Goodwill Disclosure [Abstract]	'
Goodwill	'
	Goodwill
	FASB ASC Topic 350-20, “Intangibles – Goodwill and Other” requires an annual valuation of the fair value of a reporting unit that has goodwill and a comparison of the fair value to the book value of equity to determine whether the goodwill has been impaired. Goodwill is also required to be tested on an interim basis if an event or circumstance indicates that it is more likely than not that an impairment loss has been incurred. When triggering events or circumstances indicate goodwill testing is required, an assessment of qualitative factors can be completed before performing the two step goodwill impairment test. ASU 2011-8 provides that if an assessment of qualitative factors determines it is more likely than not that the fair value of a reporting unit exceeds its carrying amount, then the two step goodwill impairment test is not required.
	First Commonwealth is considered to be one reporting unit. The carrying amount of goodwill as of March 31, 2014 and December 31, 2013 was $159.4 million and $159.9 million, respectively. No impairment charges on goodwill or other intangible assets were incurred in 2014 or 2013. The $0.5 million decline in goodwill during the three months ended March 31, 2014 represents the amount of goodwill included in the carrying value of the investment advisory business which was sold during that period.
	We test goodwill for impairment as of November 30th each year and again at any quarter-end if any material events occur during a quarter that may affect goodwill. An assessment of qualitative factors was completed as of March 31, 2014 and indicated that it is more likely than not that the fair value of First Commonwealth exceeds its carrying amount, therefore the two step goodwill impairment test was not considered necessary. The assessment of qualitative factors incorporated the results of the Step 1 goodwill impairment test completed as of November 30, 2013 as well as macroeconomic factors, industry and market considerations, the company’s overall financial performance, and other company specific events occurring since the completion of the November 30, 2013 test.
	As of March 31, 2014, goodwill was not considered impaired; however, changing economic conditions that may adversely affect our performance, fair value of our assets and liabilities, or stock price could result in impairment, which could adversely affect earnings in future periods. Management will continue to monitor events that could impact this conclusion in the future.

New_Accounting_Pronouncements_

New Accounting Pronouncements (Notes)	3 Months Ended
	Mar. 31, 2014
Accounting Changes and Error Corrections [Abstract]	'
New Accounting Pronouncements	'
	New Accounting Pronouncements
	In January 2014, the FASB issued ASU 2014-01, "Investments - Equity Method and Joint Ventures (Topic 323)," permits reporting entities to make an accounting policy election to account for their investments in qualified affordable housing projects using the proportional amortization method if certain conditions are met. The proportional amortization method allows an entity to amortize the initial cost of the investment in proportion to the tax credits and other tax benefits received and recognizes the net investment performance in the income statement as a component of income tax expense (benefit). This amendment is effective for interim and annual periods beginning after December 15, 2014. The adoption of this ASU is not expected to have a material impact on First Commonwealth’s financial condition or results of operations.
	In January 2014, the FASB issued ASU 2014-04, "Receivables - Troubled Debt Restructurings by Creditors (Subtopic 310-40)." This amendment clarifies that an in-substance repossession or foreclosure occurs and a creditor is considered to have received physical possession of property upon either, 1. the creditor obtaining legal title to the residential real estate property upon completion of a foreclosure, or 2. the borrower conveying all interest in the residential real estate property to the creditor to satisfy that loan through completion of a deed in lieu of foreclosure or through a similar legal agreement. Interim and annual disclosure of both the amount of foreclosed residential real estate property held by the creditor and the recorded investment in consumer mortgages loans collateralized by residential real estate property that are in the process of foreclosure according to local requirements of the applicable jurisdiction are required. This amendment is effective for annual periods beginning after December 15, 2014 and for interim periods within annual periods beginning after December 15, 2015. The adoption of this ASU is not expected to have a material impact on First Commonwealth’s financial condition or results of operations.
	In April 2014, the FASB issued ASU 2014-08, “Presentation of Financial Statements (Topic 205) and Property, Plant, and Equipment (Topic 360)." This amendment changes the reporting requirements for discontinued operations. A disposal of a component of an entity or group of components of an entity is required to be reported in discontinued operations if the disposal represents a strategic shift resulting in a major effect on the entity's operations and financial results when any of the following occurs: 1. the component or group of components of an entity meets the criteria to be classified as held for sale, 2. the component or group of components of an entity is disposed of by sale, or 3. the component or group of components of an entity is disposed of other than by sale. If one of these criteria are met, the entity will present the assets and liabilities of a disposal group that includes a discontinued operation separately in the asset and liability sections of the statement of financial position for each comparative period along with additional footnote disclosure. This amendment is effective for annual periods beginning on or after December 15, 2014 and interim periods within annual periods beginning on or after December 15, 2015. The adoption of this ASU is not expected to have a material impact on First Commonwealth’s financial condition or results of operations.

Supplemental_Comprehensive_Inc1

Supplemental Comprehensive Income Disclosures (Tables)	3 Months Ended
	Mar. 31, 2014
Supplemental Comprehensive Income Disclosures [Abstract]	'
Schedule of Accumulated Other Comprehensive Income (Loss)	'
	The following table identifies the related tax effects allocated to each component of other comprehensive income (“OCI”) in the Condensed Consolidated Statements of Comprehensive Income. Reclassification adjustments related to securities available for sale are included in the "Net securities gains" line in the Condensed Consolidated Statements of Income. The non-credit related gains on securities not expected to be sold are included in the "Noninterest Income" section of the Condensed Consolidated Statements of Income.
		For the Three-Months Ended March 31
		2014												2013
		Pretax Amount				Tax (Expense) Benefit				Net of Tax Amount				Pretax Amount			Tax (Expense) Benefit			Net of Tax Amount
		(dollars in thousands)
	Unrealized gains (losses) on securities:
	Unrealized holding gains (losses) on securities arising during the period	$	12,457			$	(4,361	)		$	8,096			$	(2,411	)	$	843		$	(1,568	)
	Reclassification adjustment for gains on securities included in net income	—				—				—				(4		)	1			(3		)
	Total unrealized gains (losses) on securities	12,457				(4,361		)		8,096				(2,415		)	844			(1,571		)
	Total other comprehensive income (loss)	$	12,457			$	(4,361	)		$	8,096			$	(2,415	)	$	844		$	(1,571	)
Supplemental Comprehensive Income Disclosures	'
	The following table details the change in components of OCI for the three months ended March 31:
		2014										2013
		Securities Available for Sale			Post-Retirement Obligation			Accumulated Other Comprehensive Income				Securities Available for Sale			Post-Retirement Obligation		Accumulated Other Comprehensive Income
		(dollars in thousands)
	Balance at December 31	$	(20,868	)	$	280		$	(20,588	)		$	1,121		$	138	$	1,259
	Other comprehensive income (loss) before reclassification adjustment	8,096			—			8,096				(1,568		)	—		(1,568		)
	Amounts reclassified from accumulated other comprehensive income (loss)	—			—			—				(3		)	—		(3		)
	Net other comprehensive income (loss) during the period	8,096			—			8,096				(1,571		)	—		(1,571		)
	Balance at March 31	$	(12,772	)	$	280		$	(12,492	)		$	(450	)	$	138	$	(312	)

Supplemental_Cash_Flow_Disclos1

Supplemental Cash Flow Disclosures (Tables)	3 Months Ended
	Mar. 31, 2014
Supplemental Cash Flow Information [Abstract]	'
Schedule of Supplemental Cash Flow Disclosures	'
	The following table presents information related to cash paid during the period for interest as well as detail on non-cash investing and financing activities for the three months ended March 31:
		2014		2013
		(dollars in thousands)
	Cash paid during the period for:
	Interest	$	5,108	$	7,211
	Non-cash investing and financing activities:
	Loans transferred to other real estate owned and repossessed assets	1,292		1,207
	Loans transferred from held to maturity to held for sale	716		16,613
	Loans sold, not settled	—		2,640
	Gross increase (decrease) in market value adjustment to securities available for sale	12,459		(2,411		)
	Investments committed to purchase, not settled	2,522		—
	Unsettled treasury stock repurchases	233		—

Earnings_per_Share_Tables

Earnings per Share (Tables)	3 Months Ended
	Mar. 31, 2014
Earnings Per Share [Abstract]	'
Composition of Weighted-Average Common Shares (Denominator) Used in Basic and Diluted Earnings Per Share	'
	The following table summarizes the composition of the weighted-average common shares (denominator) used in the basic and diluted earnings per share computations:
		For the Three-Months Ended March 31
		2014		2013
	Weighted average common shares issued	105,563,455		105,563,455
	Average treasury stock shares	(10,876,695	)	(6,104,526	)
	Average unearned nonvested shares	(143,340	)	(170,191	)
	Weighted average common shares and common stock equivalents used to calculate basic earnings per share	94,543,420		99,288,738
	Additional common stock equivalents (nonvested stock) used to calculate diluted earnings per share	24,639		16,676
	Additional common stock equivalents (stock options) used to calculate diluted earnings per share	—		—
	Weighted average common shares and common stock equivalents used to calculate diluted earnings per share	94,568,059		99,305,414
Common Stock Equivalents Not Included in Computation of Diluted Earnings Per Share	'
	The following table shows the number of shares and the price per share related to common stock equivalents that were not included in the computation of diluted earnings per share for the three months ended March 31 because to do so would have been antidilutive.
		2014						2013
				Price Range					Price Range
		Shares		From		To		Shares	From		To
	Stock Options	15,000		$	14.55	$	14.55	82,041	$	9.19	$	14.55
	Restricted Stock	5,601		8.75		9.18		—	—		—

Variable_Interest_Entities_Tab

Variable Interest Entities (Tables)	3 Months Ended
	Mar. 31, 2014
Variable Interest Entities [Abstract]	'
Schedule of Maximum Potential Exposure	'
	First Commonwealth’s maximum potential exposure is equal to its carrying value and is summarized in the table below:
		31-Mar-14		31-Dec-13
		(dollars in thousands)
	Low Income Housing Limited Partnership Investments	$	174	$	207

Commitments_and_Contingent_Lia1

Commitments and Contingent Liabilities (Tables)	3 Months Ended
	Mar. 31, 2014
Commitments and Contingencies Disclosure [Abstract]	'
Notional Amount of Outstanding Commitments	'
	The following table identifies the notional amount of those instruments at:
		31-Mar-14		31-Dec-13
		(dollars in thousands)
	Financial instruments whose contract amounts represent credit risk:
	Commitments to extend credit	$	1,519,436	$	1,571,987
	Financial standby letters of credit	37,119		38,121
	Performance standby letters of credit	27,458		32,441
	Commercial letters of credit	—		—

Investment_Securities_Tables

Investment Securities (Tables)	3 Months Ended
	Mar. 31, 2014
Investments, Debt and Equity Securities [Abstract]	'
Analysis of Amortized Cost and Estimated Fair Value of Securities Available for Sale	'
	Below is an analysis of the amortized cost and estimated fair values of securities available for sale at:
		31-Mar-14									31-Dec-13
		Amortized		Gross		Gross			Estimated		Amortized		Gross		Gross			Estimated
		Cost		Unrealized		Unrealized			Fair Value		Cost		Unrealized		Unrealized			Fair Value
				Gains		Losses							Gains		Losses
		(dollars in thousands)
	Obligations of U.S. Government Agencies:
	Mortgage-Backed Securities – Residential	$	21,648	$	2,627	$	(34	)	$	24,241	$	22,639	$	2,624	$	(59	)	$	25,204
	Obligations of U.S. Government-Sponsored Enterprises:
	Mortgage-Backed Securities – Residential	1,020,102		12,977		(19,472		)	1,013,607		1,009,519		12,531		(27,163		)	994,887
	Mortgage-Backed Securities – Commercial	96		2		—			98		104		1		—			105
	Other Government-Sponsored Enterprises	269,170		3		(1,863		)	267,310		267,971		81		(1,927		)	266,125
	Obligations of States and Political Subdivisions	9,340		22		(3		)	9,359		80		—		—			80
	Corporate Securities	6,691		437		—			7,128		6,693		328		—			7,021
	Pooled Trust Preferred Collateralized Debt Obligations	42,214		—		(14,338		)	27,876		42,040		—		(18,517		)	23,523
	Total Debt Securities	1,369,261		16,068		(35,710		)	1,349,619		1,349,046		15,565		(47,666		)	1,316,945
	Equities	1,420		—		—			1,420		1,420		—		—			1,420
	Total Securities Available for Sale	$	1,370,681	$	16,068	$	(35,710	)	$	1,351,039	$	1,350,466	$	15,565	$	(47,666	)	$	1,318,365
Amortized Cost and Estimated Fair Value of Debt Securities Available for Sale	'
	he amortized cost and estimated fair value of debt securities available for sale at March 31, 2014, by contractual maturity, are shown below.
		Amortized		Estimated
		Cost		Fair Value
		(dollars in thousands)
	Due within 1 year	$	5,601	$	5,604
	Due after 1 but within 5 years	263,570		261,706
	Due after 5 but within 10 years	3,371		3,381
	Due after 10 years	54,873		40,982
		327,415		311,673
	Mortgage-Backed Securities (a)	1,041,846		1,037,946
	Total Debt Securities	$	1,369,261	$	1,349,619
	(a)	Mortgage Backed Securities include an amortized cost of $21.6 million and a fair value of $24.2 million for Obligations of U.S.
Proceeds from Sale, Gross Gains (Losses) Realized on Sales, Maturities and Other-Than-Temporary Impairment Charges Related to Securities Available for Sale	'
	Proceeds from sales, gross gains (losses) realized on sales, maturities and other-than-temporary impairment charges related to securities available for sale were as follows for the three months ended March 31:
		2014		2013
		(dollars in thousands)
	Proceeds from sales	$	—	$	42
	Gross gains (losses) realized:
	Sales Transactions:
	Gross gains	$	—	$	4
	Gross losses	—		—
	Net gains and impairment	$	—	$	4

Impairment_of_Investment_Secur1

Impairment of Investment Securities (Tables)	3 Months Ended
	Mar. 31, 2014
Impairment of Investment Securities Disclosure [Abstract]	'
Schedule of Unrealized Losses and Estimated Fair Values	'
	The following table presents the gross unrealized losses and estimated fair values at March 31, 2014 by investment category and time frame for which securities have been in a continuous unrealized loss position:
		Less Than 12 Months								12 Months or More							Total
		Estimated				Gross				Estimated				Gross			Estimated			Gross
		Fair Value				Unrealized				Fair Value				Unrealized			Fair Value			Unrealized
						Losses								Losses						Losses
		(dollars in thousands)
	Obligations of U.S. Government Agencies:
	Mortgage-Backed Securities – Residential	$	2,044			$	(34	)		$	—			$	—		$	2,044		$	(34	)
	Obligations of U.S. Government-Sponsored Enterprises:
	Mortgage-Backed Securities – Residential	459,224				(11,805		)		149,391				(7,667		)	608,615			(19,472		)
	Other Government-Sponsored Enterprises	237,136				(1,452		)		24,570				(411		)	261,706			(1,863		)
	Obligations of States and Political Subdivisions	2,825				(3		)		—				—			2,825			(3		)
	Pooled Trust Preferred Collateralized Debt Obligations	2,637				(57		)		25,240				(14,281		)	27,877			(14,338		)
	Total Securities Available for Sale	$	703,866			$	(13,351	)		$	199,201			$	(22,359	)	$	903,067		$	(35,710	)
	The following table presents the gross unrealized losses and estimated fair values at December 31, 2013 by investment category and time frame for which securities have been in a continuous unrealized loss position:
		Less Than 12 Months								12 Months or More							Total
		Estimated				Gross				Estimated				Gross			Estimated			Gross
		Fair Value				Unrealized				Fair Value				Unrealized			Fair Value			Unrealized
						Losses								Losses						Losses
		(dollars in thousands)
	Obligations of U.S. Government Agencies:
	Mortgage-Backed Securities – Residential	$	2,035			$	(59	)		$	—			$	—		$	2,035		$	(59	)
	Obligations of U.S. Government-Sponsored Enterprises:
	Mortgage-Backed Securities – Residential	632,231				(22,844		)		65,324				(4,319		)	697,555			(27,163		)
	Other Government-Sponsored Enterprises	183,542				(1,448		)		24,501				(479		)	208,043			(1,927		)
	Pooled Trust Preferred Collateralized Debt Obligations	2,401				(237		)		21,122				(18,280		)	23,523			(18,517		)
	Total Securities Available for Sale	$	820,209			$	(24,588	)		$	110,947			$	(23,078	)	$	931,156		$	(47,666	)
Pooled Trust Preferred Collateralized Debt Obligations	'
	The following table provides information related to our pooled trust preferred collateralized debt obligations as of March 31, 2014:
	Deal	Class		Book				Estimated Fair				Unrealized				Moody’s/	Number		Deferrals			Excess
				Value				Value				Gain				Fitch	of		and			Subordination
												(Loss)				Ratings	Banks		Defaults			as a % of
																			as a % of			Current
																			Current			Performing
																			Collateral			Collateral
	(dollars in thousands)
	Pre TSL IV	Mezzanine		$	1,830			$	1,297			$	(533	)		B1/B	6		18.05	%		55.72	%
	Pre TSL V	Mezzanine		58				28				(30		)		C/-	3		100			—
	Pre TSL VII	Mezzanine		2,636				2,609				(27		)		Ca/C	14		54.14			—
	Pre TSL VIII	Mezzanine		1,985				1,400				(585		)		C/C	30		54.77			—
	Pre TSL IX	Mezzanine		2,313				1,390				(923		)		Caa1/C	42		28.05			7.86
	Pre TSL X	Mezzanine		1,409				1,391				(18		)		Caa3/C	46		35.07			—
	Pre TSL XII	Mezzanine		5,410				3,311				(2,099		)		Caa3/C	68		30.28			—
	Pre TSL XIII	Mezzanine		12,408				7,941				(4,467		)		Caa3/C	61		27.78			19.84
	Pre TSL XIV	Mezzanine		13,720				8,146				(5,574		)		Ca/C	58		31.9			50.44
	MMCap I	Mezzanine		445				363				(82		)		Ca/C	11		58.76			14.63
	Total			$	42,214			$	27,876			$	(14,338	)
Cumulative Roll Forward of Credit Losses Recognized in Earnings for Debt Securities held and not Intended to be Sold	'
	The following table provides a cumulative roll forward of credit losses recognized in earnings for debt securities held and not intended to be sold:
		For the Three-Months Ended March 31
		2014				2013
		(dollars in thousands)
	Balance, beginning (a)	$	27,543			$	43,274
	Credit losses on debt securities for which other-than-temporary impairment was not previously recognized	—				—
	Additional credit losses on debt securities for which other-than-temporary impairment was previously recognized	—				—
	Increases in cash flows expected to be collected, recognized over the remaining life of the security (b)	(289		)		(283		)
	Balance, ending	$	27,254			$	42,991
	(a)	The beginning balance represents credit related losses included in other-than-temporary impairment charges recognized on debt securities in prior periods.
	(b)	Represents the increase in cash flows recognized in interest income during the period.

Loans_and_Allowance_for_Credit1

Loans and Allowance for Credit Losses (Tables)	3 Months Ended
	Mar. 31, 2014
Loans and Leases Receivable Disclosure [Abstract]	'
Outstanding Balances of Loan	'
	The following table provides outstanding balances related to each of our loan types:
		31-Mar-14				31-Dec-13
		(dollars in thousands)
	Commercial, financial, agricultural and other	$	1,017,412			$	1,021,056
	Real estate construction	95,110				93,289
	Residential real estate	1,240,169				1,262,718
	Commercial real estate	1,290,852				1,296,472
	Loans to individuals	608,670				610,298
	Total loans and leases net of unearned income	$	4,252,213			$	4,283,833
Credit Risk Profile by Creditworthiness	'
	The following tables represent our credit risk profile by creditworthiness:
		31-Mar-14
		Commercial, financial, agricultural and other				Real estate construction				Residential real estate				Commercial real estate				Loans to individuals				Total
		(dollars in thousands)
	Pass	$	945,063			$	83,456			$	1,225,083			$	1,242,664			$	608,491			$	4,104,757
	Non-Pass
	OAEM	23,958				8,686				3,375				30,207				1				66,227
	Substandard	48,391				2,968				11,711				17,981				178				81,229
	Doubtful	—				—				—				—				—				—
	Total Non-Pass	72,349				11,654				15,086				48,188				179				147,456
	Total	$	1,017,412			$	95,110			$	1,240,169			$	1,290,852			$	608,670			$	4,252,213
		31-Dec-13
		Commercial, financial, agricultural and other				Real estate construction				Residential real estate				Commercial real estate				Loans to individuals				Total
		(dollars in thousands)
	Pass	$	943,107			$	79,679			$	1,245,422			$	1,243,170			$	610,094			$	4,121,472
	Non-Pass
	OAEM	35,429				9,710				5,161				28,823				1				79,124
	Substandard	42,520				3,900				12,135				24,479				203				83,237
	Doubtful	—				—				—				—				—				—
	Total Non-Pass	77,949				13,610				17,296				53,302				204				162,361
	Total	$	1,021,056			$	93,289			$	1,262,718			$	1,296,472			$	610,298			$	4,283,833
Age Analysis of Past Due Loans by Segment	'
	The following tables delineate the aging analysis of the recorded investments in past due loans as of March 31, 2014 and December 31, 2013. Also included in these tables are loans that are 90 days or more past due and still accruing because they are well-secured and in the process of collection.
		31-Mar-14
		30 - 59				60 - 89				90 days				Nonaccrual				Total past				Current				Total
		days				days				and								due and
		past due				past				greater								nonaccrual
						due				and still
										accruing
		(dollars in thousands)
	Commercial, financial, agricultural and other	$	971			$	490			$	300			$	28,268			$	30,029			$	987,383			$	1,017,412
	Real estate construction	40				—				—				1,698				1,738				93,372				95,110
	Residential real estate	4,265				1,004				746				10,011				16,026				1,224,143				1,240,169
	Commercial real estate	2,020				665				21				5,526				8,232				1,282,620				1,290,852
	Loans to individuals	2,094				682				1,383				177				4,336				604,334				608,670
	Total	$	9,390			$	2,841			$	2,450			$	45,680			$	60,361			$	4,191,852			$	4,252,213
		31-Dec-13
		30 - 59				60 - 89				90 days				Nonaccrual				Total past				Current				Total
		days				days				and								due and
		past due				past				greater								nonaccrual
						due				and still
										accruing
		(dollars in thousands)
	Commercial, financial, agricultural and other	$	594			$	319			$	185			$	23,631			$	24,729			$	996,327			$	1,021,056
	Real estate construction	—				—				—				2,567				2,567				90,722				93,289
	Residential real estate	4,002				524				1,041				10,520				16,087				1,246,631				1,262,718
	Commercial real estate	1,199				23				13				8,966				10,201				1,286,271				1,296,472
	Loans to individuals	2,895				990				1,266				204				5,355				604,943				610,298
	Total	$	8,690			$	1,856			$	2,505			$	45,888			$	58,939			$	4,224,894			$	4,283,833
Recorded Investment and Unpaid Principal Balance for Impaired Loans with Associated Allowance	'
	The following tables include the recorded investment and unpaid principal balance for impaired loans with the associated allowance amount, if applicable, as of March 31, 2014 and December 31, 2013. Also presented are the average recorded investment in impaired loans and the related amount of interest recognized while the loan was considered impaired. Average balances are calculated using month-end balances of the loans for the period reported and are included in the table below based on its period-end allowance position.
		31-Mar-14												31-Dec-13
		Recorded				Unpaid				Related				Recorded				Unpaid				Related
		investment				principal				allowance				investment				principal				allowance
						balance												balance
		(dollars in thousands)
	With no related allowance recorded:
	Commercial, financial, agricultural and other	$	9,788			$	10,960							$	6,752			$	7,649
	Real estate construction	2,213				2,782								3,486				6,664
	Residential real estate	9,864				10,741								9,333				9,952
	Commercial real estate	7,348				8,423								13,606				14,719
	Loans to individuals	270				297								289				307
	Subtotal	29,483				33,203								33,466				39,291
	With an allowance recorded:
	Commercial, financial, agricultural and other	22,940				23,559				9,886				21,482				22,082				7,364
	Real estate construction	638				1,780				74				414				737				94
	Residential real estate	2,841				3,435				496				3,533				3,585				1,282
	Commercial real estate	301				315				47				488				612				84
	Loans to individuals	—				—				—				—				—				—
	Subtotal	26,720				29,089				10,503				25,917				27,016				8,824
	Total	$	56,203			$	62,292			$	10,503			$	59,383			$	66,307			$	8,824
		For the Three-Months Ended March 31
		2014								2013
		Average				Interest				Average				Interest
		recorded				Income				recorded				Income
		investment				Recognized				investment				Recognized
		(dollars in thousands)
	With no related allowance recorded:
	Commercial, financial, agricultural and other	$	10,953			$	17			$	8,592			$	51
	Real estate construction	2,438				12				7,877				—
	Residential real estate	9,825				49				8,516				37
	Commercial real estate	9,498				33				33,978				11
	Loans to individuals	271				1				247				1
	Subtotal	32,985				112				59,210				100
	With an allowance recorded:
	Commercial, financial, agricultural and other	17,649				45				25,803				19
	Real estate construction	638				—				2,685				13
	Residential real estate	3,161				8				2,457				4
	Commercial real estate	307				1				6,704				25
	Loans to individuals	—				—				—				—
	Subtotal	21,755				54				37,649				61
	Total	$	54,740			$	166			$	96,859			$	161
Troubled Debt Restructured Loans and Commitments	'
	The following table provides detail as to the total troubled debt restructured loans and total commitments outstanding on troubled debt restructured loans:
		31-Mar-14				31-Dec-13
		(dollars in thousands)
	Troubled debt restructured loans
	Accrual status	$	10,523			$	13,495
	Nonaccrual status	12,327				16,980
	Total	$	22,850			$	30,475
	Commitments
	Letters of credit	$	—			$	—
	Unused lines of credit	709				452
	Total	$	709			$	452
Troubled Debt Restructurings is 90 days or more past due	'
	The following tables provide detail, including specific reserves and reasons for modification, related to loans identified as troubled debt restructurings:
		For the Three-Months Ended March 31, 2014
					Type of Modification
		Number			Extend				Modify				Modify				Total				Post-				Specific
		of			Maturity				Rate				Payments				Pre-Modification				Modification				Reserve
		Contracts															Outstanding				Outstanding
																	Recorded				Recorded
																	Investment				Investment
		(dollars in thousands)
	Commercial, financial, agricultural and other	1			$	60			$	—			$	—			$	60			$	60			$	29
	Residential real estate	13			—				172				517				689				676				5
	Commercial real estate	1			—				—				12				12				8				—
	Loans to individuals	6			—				31				20				51				47				—
	Total	21			$	60			$	203			$	549			$	812			$	791			$	34
		For the Three-Months Ended March 31, 2013
					Type of Modification
		Number			Extend				Modify				Modify				Total				Post-				Specific
		of			Maturity				Rate				Payments				Pre-Modification				Modification				Reserve
		Contracts															Outstanding				Outstanding
																	Recorded				Recorded
																	Investment				Investment
		(dollars in thousands)
	Commercial, financial, agricultural and other	2			$	426			$	—			$	12			$	438			$	377			$	—
	Residential real estate	9			7				214				514				735				677				—
	Commercial real estate	1			—				244				—				244				242				—
	Loans to individuals	4			—				23				4				27				25				—
	Total	16			$	433			$	481			$	530			$	1,444			$	1,321			$	—
Troubled Debt Restructuring Identified During Period	'
	The following table provides information related to restructured loans that were considered to default during the three months ended March 31:
		2014							2013
		Number of			Recorded				Number of			Recorded
		Contracts			Investment				Contracts			Investment
		(dollars in thousands)
	Residential real estate	4			$	138			1			$	10
	Loans to individuals	—			—				1			6
	Total	4			$	138			2			$	16
Allowance for Credit Losses	'
	The following tables provide detail related to the allowance for credit losses:
		For the Three-Months Ended March 31, 2014
		Commercial,				Real estate				Residential				Commercial				Loans to				Unallocated				Total
		financial,				construction				real estate				real estate				individuals
		agricultural
		and other
		(dollars in thousands)
	Allowance for credit losses:
	Beginning Balance	$	22,663			$	6,600			$	7,727			$	11,778			$	5,457			$	—			$	54,225
	Charge-offs	(1,601		)		—				(1,095		)		(140		)		(810		)		—				(3,646		)
	Recoveries	85				169				244				20				178				—				696
	Provision (credit)	4,978				(555		)		(850		)		(539		)		197				—				3,231
	Ending Balance	$	26,125			$	6,214			$	6,026			$	11,119			$	5,022			$	—			$	54,506
	Ending balance: individually evaluated for impairment	$	9,886			$	74			$	496			$	47			$	—			$	—			$	10,503
	Ending balance: collectively evaluated for impairment	16,239				6,140				5,530				11,072				5,022				—				44,003
	Loans:
	Ending balance	1,017,412				95,110				1,240,169				1,290,852				608,670								4,252,213
	Ending balance: individually evaluated for impairment	31,730				2,797				9,103				5,773				—								49,403
	Ending balance: collectively evaluated for impairment	985,682				92,313				1,231,066				1,285,079				608,670								4,202,810
		For the Three-Months Ended March 31, 2013
		Commercial,				Real estate				Residential				Commercial				Loans to				Unallocated				Total
		financial,				construction				real estate				real estate				individuals
		agricultural
		and other
		(dollars in thousands)
	Allowance for credit losses:
	Beginning Balance	$	19,852			$	8,928			$	5,908			$	22,441			$	4,132			$	5,926			$	67,187
	Charge-offs	(538		)		(84		)		(322		)		(8,544		)		(988		)		—				(10,476		)
	Recoveries	128				12				723				97				94				—				1,054
	Provision (credit)	833				(1,123		)		(560		)		4,476				901				(30		)		4,497
	Ending Balance	$	20,275			$	7,733			$	5,749			$	18,470			$	4,139			$	5,896			$	62,262
	Ending balance: individually evaluated for impairment	$	9,846			$	503			$	1,091			$	1,249			$	—			$	—			$	12,689
	Ending balance: collectively evaluated for impairment	10,429				7,230				4,658				17,221				4,139				5,896				49,573
	Loans:
	Ending balance	1,057,663				70,461				1,255,515				1,243,676				591,495								4,218,810
	Ending balance: individually evaluated for impairment	33,322				8,917				7,813				21,369				—								71,421
	Ending balance: collectively evaluated for impairment	1,024,341				61,544				1,247,702				1,222,307				591,495								4,147,389

Fair_Values_of_Assets_and_Liab1

Fair Values of Assets and Liabilities (Tables)	3 Months Ended
	Mar. 31, 2014
Fair Value Disclosures [Abstract]	'
Fair Value Inputs, Assets, Quantitative Information	'
	In accordance with ASU 2011-4, the following table provides information related to quantitative inputs and assumptions used in Level 3 fair value measurements.
		Fair Value (dollars		Valuation	Unobservable Inputs		Range /
		in thousands)		Technique			(weighted average)
	Pooled Trust Preferred Securities	$27,876		Discounted Cash Flow	Probability of default		0% - 100% (18.22%)
					Prepayment rates		0% - 100% (7.48%)
					Discount rates		5.5% - 15.5% (a)
	Equities	1,420		Par Value	N/A		N/A
	Interest Rate Swap	—		Option model	Counterparty credit risk		6.33% - 8.12% (b)
	Impaired Loans	5,848 (c)		Reserve study	Discount rate		10.00%
					Gas per MCF		$3.84 - $6.45 (d)
					Oil per BBL/d		$78.3 - $107.00 (d)
					NGL per gallon		$0.83 (d)
		113 (c)		Discounted Cash Flow	Discount Rate		9.00%
	Other Real Estate Owned	157		Internal Valuation	N/A		N/A
	(a)	incorporates spread over risk free rate related primarily to credit quality and illiquidity of securities.
	(b)	represents the range of the credit spread curve used in valuation.
	(c)	the remainder of impaired loans valued using Level 3 inputs are not included in this disclosure as the values of those loans are based on bankruptcy agreement documentation.
	(d)	unobservable inputs are defined as follows: MCF - million cubic feet; BBL/d - barrels per day; NGL - natural gas liquid.
Schedule of Assets and Liabilities Measured at Fair Value on Recurring Basis	'
	The tables below present the balances of assets and liabilities measured at fair value on a recurring basis:
		31-Mar-14
		Level 1			Level 2			Level 3			Total
		(dollars in thousands)
	Obligations of U.S. Government Agencies:
	Mortgage-Backed Securities - Residential	$	—		$	24,241		$	—		$	24,241
	Obligations of U.S. Government-Sponsored Enterprises:
	Mortgage-Backed Securities - Residential	—			1,013,607			—			1,013,607
	Mortgage-Backed Securities - Commercial	—			98			—			98
	Other Government-Sponsored Enterprises	—			267,310			—			267,310
	Obligations of States and Political Subdivisions	—			9,359			—			9,359
	Corporate Securities	—			7,128			—			7,128
	Pooled Trust Preferred Collateralized Debt Obligations	—			—			27,876			27,876
	Total Debt Securities	—			1,321,743			27,876			1,349,619
	Equities	—			—			1,420			1,420
	Total Securities Available for Sale	—			1,321,743			29,296			1,351,039
	Other Investments	—			34,047			—			34,047
	Loans held for sale	—			—			—			—
	Other Assets(a)	—			12,521			—			12,521
	Total Assets	$	—		$	1,368,311		$	29,296		$	1,397,607
	Other Liabilities(a)	$	—		$	12,497		$	—		$	12,497
	Total Liabilities	$	—		$	12,497		$	—		$	12,497
	(a)	Non-hedging interest rate derivatives
		31-Dec-13
		Level 1			Level 2			Level 3			Total
		(dollars in thousands)
	Obligations of U.S. Government Agencies:
	Mortgage-Backed Securities - Residential	$	—		$	25,204		$	—		$	25,204
	Obligations of U.S. Government-Sponsored Enterprises:
	Mortgage-Backed Securities - Residential	—			994,887			—			994,887
	Mortgage-Backed Securities - Commercial	—			105			—			105
	Other Government-Sponsored Enterprises	—			266,125			—			266,125
	Obligations of States and Political Subdivisions	—			80			—			80
	Corporate Securities	—			7,021			—			7,021
	Pooled Trust Preferred Collateralized Debt Obligations	—			—			23,523			23,523
	Total Debt Securities	—			1,293,422			23,523			1,316,945
	Equities	—			—			1,420			1,420
	Total Securities Available for Sale	—			1,293,422			24,943			1,318,365
	Other Investments	—			35,444			—			35,444
	Loans Held for Sale	—			—			—			—
	Other Assets(a)	—			14,358			—			14,358
	Total Assets	$	—		$	1,343,224		$	24,943		$	1,368,167
	Other Liabilities(a)	$	—		$	14,318		$	—		$	14,318
	Total Liabilities	$	—		$	14,318		$	—		$	14,318
	(a)	Non-hedging interest rate derivatives
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation	'
	For the three months ended March 31, changes in Level 3 assets and liabilities measured at fair value on a recurring basis are summarized as follows:
		2014
		Pooled Trust			Equities			Loans			Other		Total
		Preferred						Held for			Assets
		Collateralized						Sale
		Debt
		Obligations
		(dollars in thousands)
	Balance, beginning of period	$	23,523		$	1,420		$	—		$	—	$	24,943
	Total gains or losses
	Included in earnings	—			—			—			—		—
	Included in other comprehensive income	4,743			—			—			—		4,743
	Purchases, issuances, sales, and settlements
	Purchases	—			—			—			—		—
	Issuances	—			—			—			—		—
	Sales	—			—			(716		)	—		(716		)
	Settlements	(390		)	—			—			—		(390		)
	Transfers into Level 3	—			—			716			—		716
	Balance, end of period	$	27,876		$	1,420		$	—		$	—	$	29,296
		2013
		Pooled Trust			Equities			Loans Held for Sale			Other		Total
		Preferred									Assets
		Collateralized
		Debt
		Obligations
		(dollars in thousands)
	Balance, beginning of period	$	23,373		$	1,420		$	—		$	—	$	24,793
	Total gains or losses
	Included in earnings	—			—			126			—		126
	Included in other comprehensive income	2,391			—			—			—		2,391
	Purchases, issuances, sales, and settlements
	Purchases	—			—			—			—		—
	Issuances	—			—			—			—		—
	Sales	—			—			(16,739		)	—		(16,739		)
	Settlements	(1,252		)	—			—			—		(1,252		)
	Transfers into Level 3	—			—			16,613			—		16,613
	Balance, end of period	$	24,512		$	1,420		$	—		$	—	$	25,932
Schedule of Assets Measured on Non-Recurring Basis	'
	The tables below present the balances of assets measured at fair value on a non-recurring basis at:
		31-Mar-14
		Level 1			Level 2			Level 3			Total
		(dollars in thousands)
	Impaired loans	$	—		$	32,940		$	12,759		$	45,699
	Other real estate owned	—			10,601			157			10,758
	Total Assets	$	—		$	43,541		$	12,916		$	56,457
		31-Dec-13
		Level 1			Level 2			Level 3			Total
		(dollars in thousands)
	Impaired loans	$	—		$	36,903		$	13,656		$	50,559
	Other real estate owned	—			12,752			172			12,924
	Total Assets	$	—		$	49,655		$	13,828		$	63,483
Losses Realized on Assets Measured on Non-Recurring Basis	'
	The following losses were realized on the assets measured on a nonrecurring basis:
		For the Three-Months Ended March 31
		2014			2013
		(dollars in thousands)
	Impaired loans	$	(3,996	)	$	(503	)
	Other real estate owned	(363		)	(131		)
	Total losses	$	(4,359	)	$	(634	)
Carrying Amounts and Fair Values of Financial Instruments	'
	The following table presents carrying amounts and fair values of First Commonwealth’s financial instruments:
		31-Mar-14
					Fair Value Measurements Using:
		Carrying			Total			Level 1			Level 2		Level 3
		Amount
		(dollars in thousands)
	Financial assets
	Cash and due from banks	$	82,327		$	82,327		$	82,327		$	—	$	—
	Interest-bearing deposits	9,087			9,087			9,087			—		—
	Securities available for sale	1,351,039			1,351,039			—			1,321,743		29,296
	Other investments	34,047			34,047			—			34,047		—
	Loans	4,252,213			4,283,303			—			32,940		4,250,363
	Financial liabilities
	Deposits	4,647,817			4,573,324			—			4,573,324		—
	Short-term borrowings	572,965			572,954			—			572,954		—
	Long-term debt	144,268			145,510			—			145,510		—
	Subordinated debt	72,167			61,347			—			—		61,347
		31-Dec-13
					Fair Value Measurements Using:
		Carrying			Total			Level 1			Level 2		Level 3
		Amount
		(dollars in thousands)
	Financial assets
	Cash and due from banks	$	74,427		$	74,427		$	74,427		$	—	$	—
	Interest-bearing deposits	3,012			3,012			3,012			—		—
	Securities available for sale	1,318,365			1,318,365			—			1,293,422		24,943
	Other investments	35,444			35,444			—			35,444		—
	Loans	4,283,833			4,321,847			—			36,903		4,284,944
	Financial liabilities
	Deposits	4,603,863			4,531,685			—			4,531,685		—
	Short-term borrowings	626,615			626,603			—			626,603		—
	Long-term debt	144,385			145,477			—			145,477		—
	Subordinated debt	72,167			51,706			—			—		51,706

Derivatives_Tables

Derivatives (Tables)	3 Months Ended
	Mar. 31, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
Credit Value Adjustment Recorded Related to Notional Amount Of Derivatives Outstanding	'
	The following table depicts the credit value adjustment recorded related to the notional amount of derivatives outstanding as well as the notional amount of risk participation agreements participated to other banks:
		31-Mar-14			31-Dec-13
		(dollars in thousands)
	Credit value adjustment	$	19		$	77
	Notional Amount:
	Interest rate derivatives	271,391			274,718
	Interest rate caps	7,263			7,500
	Risk participation agreements	81,704			82,197
	Sold credit protection on risk participation agreements	(19,045		)	(19,161		)
Schedule of Changes in Fair Value of Derivative Assets and Liabilities	'
	The table below presents the amount representing the change in the fair value of derivative assets and derivative liabilities attributable to credit risk included in other income on the Condensed Consolidated Statements of Income:
		For the Three-Months Ended March 31
		2014			2013
		(dollars in thousands)
	Non-hedging interest rate derivatives:
	(Decrease) increase in other income	$	(58	)	$	989

Supplemental_Comprehensive_Inc2

Supplemental Comprehensive Income Disclosures (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Supplemental Comprehensive Income Disclosures [Abstract]	'	'
Unrealized holding (losses) gains on securities arising during the period	$12,457	($2,411)
Reclassification adjustment for gains on securities included in net income	0	-4
Total unrealized (losses) gains on securities	12,457	-2,415
Other Comprehensive Income (Loss), Available-for-sale Securities, Tax	-4,361	844
Total other comprehensive (loss) income	12,457	-2,415
Unrealized holding (losses) gains on securities arising during the period	-4,361	843
Reclassification adjustment for gains on securities included in net income	0	1
Total other comprehensive (loss) income	-4,361	844
Other comprehensive income (loss) before reclassification adjustment	8,096	-1,568
Reclassification adjustment for gains on securities included in net income	0	-3
Total unrealized (losses) gains on securities	8,096	-1,571
Total other comprehensive (loss) income	$8,096	($1,571)

Supplemental_Comprehensive_Inc3

Supplemental Comprehensive Income Disclosures (Details 2) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Accumulated Other Comprehensive Income (Loss) [Line Items]	'	'
Accumulated Other Comprehensive Income (Loss), Beginning Balance	($20,588)	$1,259
Other comprehensive income (loss) before reclassification adjustment	8,096	-1,568
Amounts reclassified from accumulated other comprehensive income (loss)	0	-3
Total other comprehensive (loss) income	8,096	-1,571
Accumulated Other Comprehensive Income (Loss), Ending Balance	-12,492	-312
Accumulated Defined Benefit Plans Adjustment [Member]	'	'
Accumulated Other Comprehensive Income (Loss) [Line Items]	'	'
Accumulated Other Comprehensive Income (Loss), Beginning Balance	280	138
Other comprehensive income (loss) before reclassification adjustment	0	0
Amounts reclassified from accumulated other comprehensive income (loss)	0	0
Total other comprehensive (loss) income	0	0
Accumulated Other Comprehensive Income (Loss), Ending Balance	280	138
Accumulated Net Unrealized Investment Gain (Loss) [Member]	'	'
Accumulated Other Comprehensive Income (Loss) [Line Items]	'	'
Accumulated Other Comprehensive Income (Loss), Beginning Balance	-20,868	1,121
Other comprehensive income (loss) before reclassification adjustment	8,096	-1,568
Amounts reclassified from accumulated other comprehensive income (loss)	0	-3
Total other comprehensive (loss) income	8,096	-1,571
Accumulated Other Comprehensive Income (Loss), Ending Balance	($12,772)	($450)

Supplemental_Cash_Flow_Disclos2

Supplemental Cash Flow Disclosures - Non-cash Investing and Financing Activities (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Supplemental Cash Flow Information [Abstract]	'	'
Loans Transferred to Other Real Estate Owned and Repossessions	$1,292	$1,207
Cash paid during the period for:	'	'
Interest	5,108	7,211
Non-cash investing and financing activities:	'	'
Loans transferred from held to maturity to held for sale	716	16,613
Loans Sold, Not Settled	0	2,640
Gross increase (decrease) in market value adjustment to securities available for sale	12,459	-2,411
Investments committed to purchase not settled	2,522	0
Unsettled treasury stock repurchases	$233	$0

Earnings_per_Share_Composition

Earnings per Share - Composition of Weighted-Average Common Shares (Denominator) Used in Basic and Diluted Earnings Per Share (Detail)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Earnings Per Share [Abstract]	'	'
Incremental Common Shares Attributable to Call Options and Warrants	0	0
Weighted Average Number of Shares Issued, Basic	105,563,455	105,563,455
Average treasury shares (in shares)	-10,876,695	-6,104,526
Average unearned nonvested shares	-143,340	-170,191
Weighted average common shares and common stock equivalents used to calculate basic earnings per share (in shares)	94,543,420	99,288,738
Additional common stock equivalents (nonvested stock) used to calculate diluted earnings per share	24,639	16,676
Weighted average common shares and common stock equivalents used to calculate diluted earnings per share (in shares)	94,568,059	99,305,414

Earnings_per_Share_Common_Stoc

Earnings per Share - Common Stock Equivalents Not Included in Computation of Diluted Earnings Per Share (Detail) (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Stock Options [Member]	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'
Antidilutive securities excluded from computation of earnings per share (in shares)	15,000	82,041
Restricted Stock [Member]	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'
Antidilutive securities excluded from computation of earnings per share (in shares)	5,601	0
Minimum [Member] | Stock Options [Member]	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'
Antidilutive Securities Excluded from Computation of Net Income, Per Outstanding Unit, Amount	14.55	9.19
Minimum [Member] | Restricted Stock [Member]	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'
Antidilutive Securities Excluded from Computation of Net Income, Per Outstanding Unit, Amount	8.75	0
Maximum [Member] | Stock Options [Member]	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'
Antidilutive Securities Excluded from Computation of Net Income, Per Outstanding Unit, Amount	14.55	14.55
Maximum [Member] | Restricted Stock [Member]	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'
Antidilutive Securities Excluded from Computation of Net Income, Per Outstanding Unit, Amount	9.18	0

Variable_Interest_Entities_Sch

Variable Interest Entities - Schedule of Maximum Potential Exposure (Detail) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Variable Interest Entities [Abstract]	'	'
Low Income Housing Limited Partnership Investments	$174	$207

Commitments_and_Contingent_Lia2

Commitments and Contingent Liabilities - Notional Amount of Outstanding Commitments (Detail) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Commitments to extend credit [Member]	'	'
Loss Contingencies [Line Items]	'	'
Financial instrument of credit risk	$1,519,436	$1,571,987
Financial standby letters of credit [Member]	'	'
Loss Contingencies [Line Items]	'	'
Financial instrument of credit risk	37,119	38,121
Performance standby letters of credit [Member]	'	'
Loss Contingencies [Line Items]	'	'
Financial instrument of credit risk	27,458	32,441
Commercial letters of credit [Member]	'	'
Loss Contingencies [Line Items]	'	'
Financial instrument of credit risk	$0	$0

Commitments_and_Contingent_Lia3

Commitments and Contingent Liabilities - Additional Information (Detail) (USD $)	3 Months Ended
	Mar. 31, 2014	Dec. 31, 2013
	complaint
	plaintiff
Loss Contingencies [Line Items]	'	'
Notional amount of financial standby letters of credit	$141,000	'
Notional amount of performance standby letters of credit	400,000	'
Notional amount of commercial letters of credit	0	'
Financial instrument of credit risk	100,000	100,000
Number of new complaints	3	'
Loss Contingency, Number of Plaintiffs	36	'
Unused commitments and letters of credit [Member]	'	'
Loss Contingencies [Line Items]	'	'
Unfunded commitment liability	2,800,000	3,200,000
Other Matters [Member]	'	'
Loss Contingencies [Line Items]	'	'
Contingency reserve	800,000	'
Other Matters [Member] | Minimum [Member]	'	'
Loss Contingencies [Line Items]	'	'
Number of customers affected (in customers)	700	'
Other Matters [Member] | Maximum [Member]	'	'
Loss Contingencies [Line Items]	'	'
Number of customers affected (in customers)	900	'
Pending Litigation [Member]	'	'
Loss Contingencies [Line Items]	'	'
Percentage Of Interest Rate On Deposits	3.50%	'
Number of Former Plaintiffs	34	'
Specified Average Age of Plaintiffs	62	'
Jarrett [Member] | Pending Litigation [Member]	'	'
Loss Contingencies [Line Items]	'	'
Loss Contingency, Number of Plaintiffs	8	'
Young [Member] | Pending Litigation [Member]	'	'
Loss Contingencies [Line Items]	'	'
Loss Contingency, Number of Plaintiffs	12	'
Fisanik [Member] | Pending Litigation [Member]	'	'
Loss Contingencies [Line Items]	'	'
Loss Contingency, Number of Plaintiffs	14	'
Ira Market Rate For Savings Account [Member] | Pending Litigation [Member]	'	'
Loss Contingencies [Line Items]	'	'
Percentage Of Interest Rate On Deposits	8.00%	'
Market Rate Savings Balance	$4,000,000	'

Investment_Securities_Analysis

Investment Securities - Analysis of Amortized Cost and Estimated Fair Values of Securities Available for Sale (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2012	Dec. 31, 2013
Investment Securities [Line Items]	'	'	'
Amortized Cost	$1,370,681	'	$1,350,466
Gross Unrealized Gains	16,068	15,565	'
Gross Unrealized Losses	-35,710	-47,666	'
Securities available for sale, at fair value	-1,351,039	'	-1,318,365
US Government Agencies Residential Mortgage-backed Securities [Member]	'	'	'
Investment Securities [Line Items]	'	'	'
Amortized Cost	21,648	'	22,639
Gross Unrealized Gains	2,627	2,624	'
Gross Unrealized Losses	34	-59	'
Securities available for sale, at fair value	-24,241	'	-25,204
Obligations of U.S. Government-Sponsored Enterprises - Mortgage-Backed Securities - Residential [Member]	'	'	'
Investment Securities [Line Items]	'	'	'
Amortized Cost	1,020,102	'	1,009,519
Gross Unrealized Gains	12,977	12,531	'
Gross Unrealized Losses	19,472	-27,163	'
Securities available for sale, at fair value	-1,013,607	'	-994,887
Obligations of U.S. Government-Sponsored Enterprises - Mortgage-Backed Securities - Commercial [Member]	'	'	'
Investment Securities [Line Items]	'	'	'
Amortized Cost	96	'	104
Gross Unrealized Gains	2	1	'
Gross Unrealized Losses	0	0	'
Securities available for sale, at fair value	-98	'	-105
Obligations of U.S. Government-Sponsored Enterprises - Other Government-Sponsored Enterprises [Member]	'	'	'
Investment Securities [Line Items]	'	'	'
Amortized Cost	269,170	'	267,971
Gross Unrealized Gains	3	81	'
Gross Unrealized Losses	1,863	-1,927	'
Securities available for sale, at fair value	-267,310	'	-266,125
Obligations of States and Political Subdivisions [Member]	'	'	'
Investment Securities [Line Items]	'	'	'
Amortized Cost	9,340	'	80
Gross Unrealized Gains	22	0	'
Gross Unrealized Losses	3	0	'
Securities available for sale, at fair value	-9,359	'	-80
Corporate Debt Securities [Member]	'	'	'
Investment Securities [Line Items]	'	'	'
Amortized Cost	6,691	'	6,693
Gross Unrealized Gains	437	328	'
Gross Unrealized Losses	0	0	'
Securities available for sale, at fair value	-7,128	'	-7,021
Pooled Trust Preferred Collateralized Debt Obligations [Member]	'	'	'
Investment Securities [Line Items]	'	'	'
Amortized Cost	42,214	'	42,040
Gross Unrealized Gains	0	0	'
Gross Unrealized Losses	-14,338	-18,517	'
Securities available for sale, at fair value	-27,876	'	-23,523
Debt Securities [Member]	'	'	'
Investment Securities [Line Items]	'	'	'
Amortized Cost	1,369,261	'	1,349,046
Gross Unrealized Gains	16,068	15,565	'
Gross Unrealized Losses	-35,710	-47,666	'
Securities available for sale, at fair value	-1,349,619	'	-1,316,945
Equity Securities [Member]	'	'	'
Investment Securities [Line Items]	'	'	'
Amortized Cost	1,420	'	1,420
Gross Unrealized Gains	0	0	'
Gross Unrealized Losses	0	0	'
Securities available for sale, at fair value	($1,420)	'	($1,420)

Investment_Securities_Amortize

Investment Securities - Amortized Cost and Estimated Fair Value of Debt Securities Available for Sale (Detail) (USD $)	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2014		Mar. 31, 2013		Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2014
In Thousands, unless otherwise specified			Mortgage Backed Securities [Member]		Mortgage Backed Securities [Member]		US Government Agencies Residential Mortgage-backed Securities [Member]	US Government Agencies Residential Mortgage-backed Securities [Member]	Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Investment Securities [Line Items]	'	'	'		'		'	'	'
Due within one year, Amortized Cost	$5,601	'	'		'		'	'	'
Due after one but within five years, Amortized Cost	263,570	'	'		'		'	'	'
Due after five but within ten years, Amortized Cost	3,371	'	'		'		'	'	'
Due after ten years, Amortized Cost	54,873	'	'		'		'	'	'
Debt securities gross, Amortized Cost	327,415	'	'		'		'	'	'
Corporate/Mortgage-Backed Securities, Amortized cost	1,370,681	1,350,466	1,041,846	[1]	1,037,946	[1]	21,648	22,639	1,020,200
Debt Securities, Amortized Cost	1,369,261	'	'		'		'	'	'
Due within one year, Estimated Fair Value	5,604	'	'		'		'	'	'
Due after one but within five years, Estimated Fair Value	261,706	'	'		'		'	'	'
Due after five but within ten years, Estimated Fair Value	3,381	'	'		'		'	'	'
Due after ten years, Estimated Fair Value	40,982	'	'		'		'	'	'
Debt securities gross, Estimated Fair Value	311,673	'	'		'		'	'	'
Total Debt Securities, Estimated Fair Value	$1,349,619	'	'		'		'	'	'
[1]	Mortgage Backed Securities include an amortized cost of $21.6 million and a fair value of $24.2 million for Obligations of U.S.

Investment_Securities_Amortize1

Investment Securities - Amortized Cost and Estimated Fair Value of Debt Securities Available for Sale (Parenthetical) (Detail) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Investment Securities [Line Items]	'	'
Amortized Cost	$1,370,681	$1,350,466
Securities available for sale, at fair value	1,351,039	1,318,365
US Government Agencies Residential Mortgage-backed Securities [Member]	'	'
Investment Securities [Line Items]	'	'
Amortized Cost	21,648	22,639
Securities available for sale, at fair value	24,241	25,204
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]	'	'
Investment Securities [Line Items]	'	'
Amortized Cost	1,020,200	'
Securities available for sale, at fair value	$1,013,700	'

Investment_Securities_Proceeds

Investment Securities - Proceeds from Sale, Gross Gains (Losses) Realized on Sales, Maturities and Other-Than-Temporary Impairment Charges Related to Securities Available for Sale (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Investments, Debt and Equity Securities [Abstract]	'	'
Proceeds from sales	$0	$42
Sales Transactions:	'	'
Gross gains	0	4
Gross losses	0	0
Maturities and impairment	'	'
Net gains and impairment	$0	$4

Investment_Securities_Addition

Investment Securities - Additional Information (Detail) (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
Other investments	$34,047,000	'	$35,444,000
Amortized Cost	1,370,681,000	'	1,350,466,000
Available-for-sale Securities	1,351,039,000	'	1,318,365,000
Proceeds from the redemption of FHLB stock	7,976,000	2,756,000	'
Available-for-sale securities pledged as collateral	548,400,000	'	594,900,000
Corporate Debt Securities [Member]	'	'	'
Amortized Cost	6,691,000	'	6,693,000
Available-for-sale Securities	$7,128,000	'	$7,021,000

Other_Investments_Additional_I

Other Investments - Additional Information (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
Other Investments Disclosure [Abstract]	'	'	'
Other investments	$34,047	'	$35,444
Proceeds from the redemption of FHLB stock	$7,976	$2,756	'

Impairment_of_Investment_Secur2

Impairment of Investment Securities - Additional Information (Detail) (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
	Security
	Rate
	Bank
Schedule of Trading Securities and Other Trading Assets [Line Items]	'	'	'
Other than temporary impairment charges recognized	$0	$0	'
Continuous Unrealized Loss Position, Fair Value	903,067,000	'	931,156,000
Amortized Cost	1,370,681,000	'	1,350,466,000
Securities available for sale, at fair value	1,351,039,000	'	1,318,365,000
Number of banks and other financial institutions comprising the security	288	'	'
Number Of Pooled Securities with No Senior Class	4	'	'
Number of securities with no excess subordination	5	'	'
Number of Securities with Excess Subordination	5	'	'
Coupon rate	7.00%	'	'
Probability of default	100.00%	'	'
Projected recovery rate	0.00%	'	'
Probability percentage assigned to default bank subject to market indicators	10.00%	'	'
Probability percentage assigned to default bank	100.00%	'	'
Federal Home Loan Bank Stock	34,047,000	'	35,444,000
Percentage of Excess Stock to be Purchased	100.00%	'	'
Maximum Percentage Of Stock To Be Purchased	5.00%	'	'
Proceeds from Sale of Federal Reserve Bank Stock	7,976,000	2,756,000	'
Minimum [Member]	'	'	'
Schedule of Trading Securities and Other Trading Assets [Line Items]	'	'	'
Subordinated tranches range	7.00%	'	'
Total principal amount of the respective securities	5.00%	'	'
Excess subordination as a percentage of current performing collateral	8.00%	'	'
Probabilities for performing collateral range	0.33%	'	'
Excess present value of future cash flows over our current book value	18.00%	'	'
Maximum [Member]	'	'	'
Schedule of Trading Securities and Other Trading Assets [Line Items]	'	'	'
Subordinated tranches range	35.00%	'	'
Excess subordination as a percentage of current performing collateral	56.00%	'	'
Probabilities for performing collateral range	75.00%	'	'
Excess present value of future cash flows over our current book value	155.00%	'	'
Pooled Trust Preferred Collateralized Debt Obligations [Member]	'	'	'
Schedule of Trading Securities and Other Trading Assets [Line Items]	'	'	'
Percent of unrealized losses	40.00%	'	'
Continuous Unrealized Loss Position, Fair Value	27,877,000	'	23,523,000
Amortized Cost	42,214,000	'	42,040,000
Securities available for sale, at fair value	27,876,000	'	23,523,000
Trust preferred collateralized debt obligations [Member]	'	'	'
Schedule of Trading Securities and Other Trading Assets [Line Items]	'	'	'
Other than temporary impairment charges recognized	0	0	'
Percentage of Current Performing Collateral	0.00%	'	'
Corporate Debt Securities [Member]	'	'	'
Schedule of Trading Securities and Other Trading Assets [Line Items]	'	'	'
Amortized Cost	6,691,000	'	6,693,000
Securities available for sale, at fair value	7,128,000	'	7,021,000
Pooled Trust Preferred Securities [Member]	'	'	'
Schedule of Trading Securities and Other Trading Assets [Line Items]	'	'	'
Other than temporary impairment charges recognized	0	0	'
Equity Securities [Member]	'	'	'
Schedule of Trading Securities and Other Trading Assets [Line Items]	'	'	'
Other than temporary impairment charges recognized	0	0	'
Continuous Unrealized Loss Position, Fair Value	0	0	'
Amortized Cost	1,420,000	'	1,420,000
Securities available for sale, at fair value	1,420,000	'	1,420,000
Asset Size and Coupon Rate 1 [Member]	'	'	'
Schedule of Trading Securities and Other Trading Assets [Line Items]	'	'	'
Collateral issued by financial institutions	15,000,000,000	'	'
Prepayment rate	100.00%	'	'
Coupon rate	7.00%	'	'
Asset Size and Coupon Rate 2 [Member]	'	'	'
Schedule of Trading Securities and Other Trading Assets [Line Items]	'	'	'
Coupon rate	7.00%	'	'
Fair Value Inputs , Prepayment Rate Year One and Two	40.00%	'	'
Fair Value Inputs , Prepayment Rate After Year Two	2.00%	'	'
Asset Size and Coupon Rate 3 [Member]	'	'	'
Schedule of Trading Securities and Other Trading Assets [Line Items]	'	'	'
Prepayment rate	5.00%	'	'
Asset Size and Coupon Rate 3 [Member] | Minimum [Member]	'	'	'
Schedule of Trading Securities and Other Trading Assets [Line Items]	'	'	'
Collateral issued by financial institutions	2,000,000,000	'	'
Asset Size and Coupon Rate 3 [Member] | Maximum [Member]	'	'	'
Schedule of Trading Securities and Other Trading Assets [Line Items]	'	'	'
Collateral issued by financial institutions	15,000,000,000	'	'
Asset Size and Coupon Rate 4 [Member]	'	'	'
Schedule of Trading Securities and Other Trading Assets [Line Items]	'	'	'
Collateral issued by financial institutions	2,000,000,000	'	'
Prepayment rate	5.00%	'	'
Coupon rate	10.00%	'	'
Asset Size and Coupon Rate 5 [Member]	'	'	'
Schedule of Trading Securities and Other Trading Assets [Line Items]	'	'	'
Prepayment rate	0.00%	'	'
Obligations of U.S. Government-Sponsored Enterprises - Other Government-Sponsored Enterprises [Member]	'	'	'
Schedule of Trading Securities and Other Trading Assets [Line Items]	'	'	'
Percent of unrealized losses	60.00%	'	'
Reported Value Measurement [Member]	'	'	'
Schedule of Trading Securities and Other Trading Assets [Line Items]	'	'	'
Securities available for sale, at fair value	1,351,039,000	'	1,318,365,000
Federal Home Loan Bank Stock	$34,047,000	'	$35,444,000

Impairment_of_Investment_Secur3

Impairment of Investment Securities - Schedule of Unrealized Losses and Estimated Fair Values (Detail) (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
Schedule of Trading Securities and Other Trading Assets [Line Items]	'	'	'
Estimated Fair Value, Less Than 12 Months	$703,866,000	'	$820,209,000
Grous Unrealized Losses Less Than 12 Months	-13,351,000	-24,588,000	'
Estimated Fair Value, 12 Months or More	199,201,000	'	110,947,000
Gross Unrealized Losses 12 Months or More	-22,359,000	-23,078,000	'
Total Estimated Fair Value	903,067,000	'	931,156,000
Total Gross Unrealized Losses	-35,710,000	-47,666,000	'
US Government Agencies Residential Mortgage-backed Securities [Member]	'	'	'
Schedule of Trading Securities and Other Trading Assets [Line Items]	'	'	'
Estimated Fair Value, Less Than 12 Months	2,044,000	'	2,035,000
Grous Unrealized Losses Less Than 12 Months	-34,000	-59,000	'
Estimated Fair Value, 12 Months or More	0	'	0
Gross Unrealized Losses 12 Months or More	0	0	'
Total Estimated Fair Value	2,044,000	'	2,035,000
Total Gross Unrealized Losses	-34,000	-59,000	'
Obligations of U.S. Government-Sponsored Enterprises - Mortgage-Backed Securities - Residential [Member]	'	'	'
Schedule of Trading Securities and Other Trading Assets [Line Items]	'	'	'
Estimated Fair Value, Less Than 12 Months	459,224,000	'	632,231,000
Grous Unrealized Losses Less Than 12 Months	-11,805,000	-22,844,000	'
Estimated Fair Value, 12 Months or More	149,391,000	'	65,324,000
Gross Unrealized Losses 12 Months or More	-7,667,000	-4,319,000	'
Total Estimated Fair Value	608,615,000	'	697,555,000
Total Gross Unrealized Losses	-19,472,000	-27,163,000	'
Obligations of U.S. Government-Sponsored Enterprises - Other Government-Sponsored Enterprises [Member]	'	'	'
Schedule of Trading Securities and Other Trading Assets [Line Items]	'	'	'
Estimated Fair Value, Less Than 12 Months	237,136,000	'	183,542,000
Grous Unrealized Losses Less Than 12 Months	-1,452,000	-1,448,000	'
Estimated Fair Value, 12 Months or More	24,570,000	'	24,501,000
Gross Unrealized Losses 12 Months or More	-411,000	-479,000	'
Total Estimated Fair Value	261,706,000	'	208,043,000
Total Gross Unrealized Losses	-1,863,000	-1,927,000	'
Obligations of States and Political Subdivisions [Member]	'	'	'
Schedule of Trading Securities and Other Trading Assets [Line Items]	'	'	'
Estimated Fair Value, Less Than 12 Months	2,825,000	'	'
Grous Unrealized Losses Less Than 12 Months	-3,000	'	'
Estimated Fair Value, 12 Months or More	0	'	'
Gross Unrealized Losses 12 Months or More	0	'	'
Total Estimated Fair Value	2,825,000	'	'
Total Gross Unrealized Losses	-3,000	'	'
Pooled Trust Preferred Collateralized Debt Obligations [Member]	'	'	'
Schedule of Trading Securities and Other Trading Assets [Line Items]	'	'	'
Estimated Fair Value, Less Than 12 Months	2,637,000	'	2,401,000
Grous Unrealized Losses Less Than 12 Months	-57,000	-237,000	'
Estimated Fair Value, 12 Months or More	25,240,000	'	21,122,000
Gross Unrealized Losses 12 Months or More	-14,281,000	-18,280,000	'
Total Estimated Fair Value	27,877,000	'	23,523,000
Total Gross Unrealized Losses	-14,338,000	-18,517,000	'
Equity Securities [Member]	'	'	'
Schedule of Trading Securities and Other Trading Assets [Line Items]	'	'	'
Total Estimated Fair Value	$0	$0	'

Impairment_of_Investment_Secur4

Impairment of Investment Securities - Pooled Trust Preferred Collateralized Debt Obligations (Detail) (USD $)

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

In Thousands, unless otherwise specified

Pooled Trust Preferred Collateralized Debt Obligations [Member]

Pooled Trust Preferred Collateralized Debt Obligations [Member]

Pooled Trust Preferred Collateralized Debt Obligations [Member]

Pooled Trust Preferred Collateralized Debt Obligations [Member]

Pooled Trust Preferred Collateralized Debt Obligations [Member]

Pooled Trust Preferred Collateralized Debt Obligations [Member]

Pooled Trust Preferred Collateralized Debt Obligations [Member]

Pooled Trust Preferred Collateralized Debt Obligations [Member]

Pooled Trust Preferred Collateralized Debt Obligations [Member]

Pooled Trust Preferred Collateralized Debt Obligations [Member]

Pooled Trust Preferred Collateralized Debt Obligations [Member]

Mezzanine [Member]

Mezzanine [Member]

Mezzanine [Member]

Mezzanine [Member]

Mezzanine [Member]

Mezzanine [Member]

Mezzanine [Member]

Mezzanine [Member]

Mezzanine [Member]

Mezzanine [Member]

Pre TSL IV [Member]

Pre TSL V [Member]

Pre TSL VII [Member]

Pre TSL VIII [Member]

Pre TSL IX [Member]

Pre TSL X [Member]

Pre TSL XII [Member]

Pre TSL XIII [Member]

Pre TSL XIV [Member]

MMCap I [Member]

Bank

Bank

Bank

Bank

Bank

Bank

Bank

Bank

Bank

Bank

Impairment Of Investment Securities [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

Book Value

'

'

$42,214

$1,830

$58

$2,636

$1,985

$2,313

$1,409

$5,410

$12,408

$13,720

$445

Securities available for sale, at fair value

1,351,039

1,318,365

27,876

1,297

28

2,609

1,400

1,390

1,391

3,311

7,941

8,146

363

Unrealized Gain (Loss)

'

'

($14,338)

($533)

($30)

($27)

($585)

($923)

($18)

($2,099)

($4,467)

($5,574)

($82)

Debt Instrument, Credit Rating

'

'

'

'B1/B

'C/-

'Ca/C

'C/C

'Caa1/C

'Caa3/C

'Caa3/C

'Caa3/C

'Ca/C

'Ca/C

Number of Banks (in banks)

'

'

'

6

3

14

30

42

46

68

61

58

11

Deferrals and Defaults as a % of Current Collateral

'

'

'

18.05%

100.00%

54.14%

54.77%

28.05%

35.07%

30.28%

27.78%

31.90%

58.76%

Excess Subordination as a % of Current Performing Collateral

'

'

'

55.72%

0.00%

0.00%

0.00%

7.86%

0.00%

0.00%

19.84%

50.44%

14.63%

Impairment_of_Investment_Secur5

Impairment of Investment Securities - Cumulative Roll Forward of Credit Losses Recognized in Earnings for Debt Securities Held and Not Intended to be Sold (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014		Mar. 31, 2013
Impairment of Investment Securities Disclosure [Abstract]	'		'
Balance, beginning (a)	$27,543	[1]	$43,274	[1]
Credit losses on debt securities for which other-than-temporary impairment was not previously recognized	0		0
Additional credit losses on debt securities for which other-than-temporary impairment was previously recognized	0		0
Balance, ending	27,254		42,991
Other than Temporary Impairment, Credit Losses Recognized in Earnings, Reductions, Cash Flows	($289)		($283)
[1]	The beginning balance represents credit related losses included in other-than-temporary impairment charges recognized on debt securities in prior periods.

Loans_and_Allowance_for_Credit2

Loans and Allowance for Credit Losses - Outstanding Balances of Loan (Detail) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Loans and Leases Receivable, Gross	$4,252,213	$4,283,833
Commercial, financial, agricultural and other [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Loans and Leases Receivable, Gross	1,017,412	1,021,056
Real estate construction [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Loans and Leases Receivable, Gross	95,110	93,289
Residential real estate [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Loans and Leases Receivable, Gross	1,240,169	1,262,718
Commercial Real Estate [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Loans and Leases Receivable, Gross	1,290,852	1,296,472
Loans to individuals [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Loans and Leases Receivable, Gross	$608,670	$610,298

Loans_and_Allowance_for_Credit3

Loans and Allowance for Credit Losses - Additional Information (Detail) (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'	'
Increase (decrease) in nonperforming loans	($3,200,000)	'	'
Charge-offs	3,646,000	10,476,000	'
Decrease in specific allowance for nonperforming loans	-1,700,000	'	'
Unfunded commitments related to nonperforming loans	3,400,000	'	'
Off balance sheet reserve to nonperforming loans	100,000	'	'
Loans held for sale	0	'	'
Total gains or losses included in earnings	0	126,000	'
Nonaccrual	45,680,000	'	45,888,000
Recorded investment	56,203,000	'	59,383,000
Troubled debt restructured loans decreased	7,600,000	'	'
Loans to individuals [Member]	'	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'	'
Non Accrual Status Of Loans After Number Of Days Past Due	'150 days	'	'
Impaired Loans [Member]	'	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'	'
Commitments related to troubled debt restructured loans increased	300,000	'	'
Loans with modifications to rate and payment due to reamortization	200,000	475,000	'
Loans Held For Sale [Member]	'	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'	'
Total gains or losses included in earnings	0	126,000	'
Gas Drilling Related Business in Louisiana [Member] | Nonaccrual Commercial Loans [Member]	'	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'	'
Recorded investment	8,000,000	'	'
Western Pennsylvania Specialty Metal Processor [Member] | Nonaccrual Commercial Loans [Member]	'	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'	'
Nonaccrual	3,200,000	'	'
Non Accrual Loans [Member] | Local Energy Company [Member] [Member]	'	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'	'
Nonaccrual	10,900,000	'	'
Non Accrual Loans [Member] | Western Pennsylvania Real Estate Developer [Member]	'	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'	'
Nonaccrual	2,400,000	'	'
Impaired Loan Receivable, Original Balance	44,100,000	'	'
Total charge-offs recognized	28,500,000	'	'
Loans Sold [Domain]	'	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'	'
Increase (decrease) in nonperforming loans	700,000	'	'
Nonaccrual Loans Paid Off [Domain]	'	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'	'
Increase (decrease) in nonperforming loans	6,900,000	'	'
Additions to Nonperforming Loans [Domain]	'	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'	'
Increase (decrease) in nonperforming loans	9,600,000	'	'
2012 Troubled Debt Restructuring [Member] | Non Accrual Loans [Member] | Local Energy Company [Member] [Member]	'	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'	'
Nonaccrual	2,700,000	'	'
2013 Troubled Debt Restructuring [Member] | Non Accrual Loans [Member] | Local Energy Company [Member] [Member]	'	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'	'
Nonaccrual	300,000	'	'
Nonaccrual Loans Paid Off [Domain]	'	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'	'
Decrease In Troubled Debt Restructurings	6,600,000	'	'
Western Pennsylvania Reals Estate Investor [Member] | Nonaccrual Loans Paid Off [Domain]	'	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'	'
Increase (decrease) in nonperforming loans	300,000	'	'
Western Pennsylvania Non-Profit Organization [Member] | Nonaccrual Loans Paid Off [Domain]	'	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'	'
Increase (decrease) in nonperforming loans	3,100,000	'	'
Western Pennsylvania Reals Estate Manager [Member] | Nonaccrual Loans Paid Off [Domain]	'	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'	'
Increase (decrease) in nonperforming loans	2,900,000	'	'
Western Pennsylvania Glass Manufacturer [Member] [Member] | Nonaccrual Loans Paid Off [Domain]	'	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'	'
Increase (decrease) in nonperforming loans	600,000	'	'
Nonaccrual Commercial Loans [Member] | Additions to Nonperforming Loans [Domain]	'	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'	'
Increase (decrease) in nonperforming loans	8,000,000	'	'
Nonaccrual Consumer Loans [Member] | Additions to Nonperforming Loans [Domain]	'	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'	'
Increase (decrease) in nonperforming loans	1,100,000	'	'
Local Energy Company [Member] [Member] | Charge-offs [Domain]	'	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'	'
Charge-offs	500,000	'	'
Western Pennsylvania [Member] | Charge-offs [Domain]	'	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'	'
Charge-offs	600,000	'	'
Consumer Home Equity Loan [Member] | Charge-offs [Domain]	'	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'	'
Charge-offs	$400,000	'	'

Loans_and_Allowance_for_Credit4

Loans and Allowance for Credit Losses - Credit Risk Profile by Creditworthiness (Detail) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Loans and Leases Receivable, Gross	$4,252,213	$4,283,833
Pass [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Loans and Leases Receivable, Gross	4,104,757	4,121,472
OAEM [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Loans and Leases Receivable, Gross	66,227	79,124
Substandard [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Loans and Leases Receivable, Gross	81,229	83,237
Doubtful [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Loans and Leases Receivable, Gross	0	0
Total Non-Pass [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Loans and Leases Receivable, Gross	147,456	162,361
Commercial, financial, agricultural and other [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Loans and Leases Receivable, Gross	1,017,412	1,021,056
Commercial, financial, agricultural and other [Member] | Pass [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Loans and Leases Receivable, Gross	945,063	943,107
Commercial, financial, agricultural and other [Member] | OAEM [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Loans and Leases Receivable, Gross	23,958	35,429
Commercial, financial, agricultural and other [Member] | Substandard [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Loans and Leases Receivable, Gross	48,391	42,520
Commercial, financial, agricultural and other [Member] | Doubtful [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Loans and Leases Receivable, Gross	0	0
Commercial, financial, agricultural and other [Member] | Total Non-Pass [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Loans and Leases Receivable, Gross	72,349	77,949
Real estate construction [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Loans and Leases Receivable, Gross	95,110	93,289
Real estate construction [Member] | Pass [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Loans and Leases Receivable, Gross	83,456	79,679
Real estate construction [Member] | OAEM [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Loans and Leases Receivable, Gross	8,686	9,710
Real estate construction [Member] | Substandard [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Loans and Leases Receivable, Gross	2,968	3,900
Real estate construction [Member] | Doubtful [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Loans and Leases Receivable, Gross	0	0
Real estate construction [Member] | Total Non-Pass [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Loans and Leases Receivable, Gross	11,654	13,610
Residential real estate [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Loans and Leases Receivable, Gross	1,240,169	1,262,718
Residential real estate [Member] | Pass [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Loans and Leases Receivable, Gross	1,225,083	1,245,422
Residential real estate [Member] | OAEM [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Loans and Leases Receivable, Gross	3,375	5,161
Residential real estate [Member] | Substandard [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Loans and Leases Receivable, Gross	11,711	12,135
Residential real estate [Member] | Doubtful [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Loans and Leases Receivable, Gross	0	0
Residential real estate [Member] | Total Non-Pass [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Loans and Leases Receivable, Gross	15,086	17,296
Commercial Real Estate [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Loans and Leases Receivable, Gross	1,290,852	1,296,472
Commercial Real Estate [Member] | Pass [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Loans and Leases Receivable, Gross	1,242,664	1,243,170
Commercial Real Estate [Member] | OAEM [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Loans and Leases Receivable, Gross	30,207	28,823
Commercial Real Estate [Member] | Substandard [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Loans and Leases Receivable, Gross	17,981	24,479
Commercial Real Estate [Member] | Doubtful [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Loans and Leases Receivable, Gross	0	0
Commercial Real Estate [Member] | Total Non-Pass [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Loans and Leases Receivable, Gross	48,188	53,302
Loans to individuals [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Loans and Leases Receivable, Gross	608,670	610,298
Loans to individuals [Member] | Pass [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Loans and Leases Receivable, Gross	608,491	610,094
Loans to individuals [Member] | OAEM [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Loans and Leases Receivable, Gross	1	1
Loans to individuals [Member] | Substandard [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Loans and Leases Receivable, Gross	178	203
Loans to individuals [Member] | Doubtful [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Loans and Leases Receivable, Gross	0	0
Loans to individuals [Member] | Total Non-Pass [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Loans and Leases Receivable, Gross	$179	$204

Loans_and_Allowance_for_Credit5

Loans and Allowance for Credit Losses - Age Analysis of Past Due Loans by Segment (Detail) (USD $)	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2013
In Thousands, unless otherwise specified
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'	'
30 - 59 days past due	$9,390	$8,690	'
60 - 89 days past due	2,841	1,856	'
90 days and greater and still accruing	2,450	2,505	'
Nonaccrual	45,680	45,888	'
Total past due and nonaccrual	60,361	58,939	'
Current	4,191,852	4,224,894	'
Total	4,252,213	4,283,833	4,218,810
Commercial, financial, agricultural and other [Member]	'	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'	'
30 - 59 days past due	971	594	'
60 - 89 days past due	490	319	'
90 days and greater and still accruing	300	185	'
Nonaccrual	28,268	23,631	'
Total past due and nonaccrual	30,029	24,729	'
Current	987,383	996,327	'
Total	1,017,412	1,021,056	'
Real estate construction [Member]	'	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'	'
30 - 59 days past due	40	0	'
60 - 89 days past due	0	0	'
90 days and greater and still accruing	0	0	'
Nonaccrual	1,698	2,567	'
Total past due and nonaccrual	1,738	2,567	'
Current	93,372	90,722	'
Total	95,110	93,289	'
Residential real estate [Member]	'	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'	'
30 - 59 days past due	4,265	4,002	'
60 - 89 days past due	1,004	524	'
90 days and greater and still accruing	746	1,041	'
Nonaccrual	10,011	10,520	'
Total past due and nonaccrual	16,026	16,087	'
Current	1,224,143	1,246,631	'
Total	1,240,169	1,262,718	'
Commercial Real Estate [Member]	'	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'	'
30 - 59 days past due	2,020	1,199	'
60 - 89 days past due	665	23	'
90 days and greater and still accruing	21	13	'
Nonaccrual	5,526	8,966	'
Total past due and nonaccrual	8,232	10,201	'
Current	1,282,620	1,286,271	'
Total	1,290,852	1,296,472	'
Loans to individuals [Member]	'	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'	'
30 - 59 days past due	2,094	2,895	'
60 - 89 days past due	682	990	'
90 days and greater and still accruing	1,383	1,266	'
Nonaccrual	177	204	'
Total past due and nonaccrual	4,336	5,355	'
Current	604,334	604,943	'
Total	$608,670	$610,298	'

Loans_and_Allowance_for_Credit6

Loans and Allowance for Credit Losses - Recorded Investment and Unpaid Principal Balance for Impaired Loans with Associated Allowance (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
Financing Receivable, Impaired [Line Items]	'	'	'
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	$29,483	'	$33,466
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	33,203	'	39,291
Recorded investment	56,203	'	59,383
Unpaid principal balance	62,292	'	66,307
Related allowance	10,503	'	8,824
Impaired Financing Receivable, with Related Allowance, Recorded Investment	26,720	'	25,917
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	29,089	'	27,016
Average recorded investment	21,755	37,649	'
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	54	61	'
Impaired Financing Receivable, Average Recorded Investment	54,740	96,859	'
Interest Income Recognized	166	161	'
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	32,985	59,210	'
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	112	100	'
Commercial, financial, agricultural and other [Member]	'	'	'
Financing Receivable, Impaired [Line Items]	'	'	'
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	9,788	'	6,752
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	10,960	'	7,649
Related allowance	9,886	'	7,364
Impaired Financing Receivable, with Related Allowance, Recorded Investment	22,940	'	21,482
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	23,559	'	22,082
Average recorded investment	17,649	25,803	'
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	45	19	'
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	10,953	8,592	'
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	17	51	'
Real estate construction [Member]	'	'	'
Financing Receivable, Impaired [Line Items]	'	'	'
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	2,213	'	3,486
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	2,782	'	6,664
Related allowance	74	'	94
Impaired Financing Receivable, with Related Allowance, Recorded Investment	638	'	414
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	1,780	'	737
Average recorded investment	638	2,685	'
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	0	13	'
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	2,438	7,877	'
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	12	0	'
Loans to individuals [Member]	'	'	'
Financing Receivable, Impaired [Line Items]	'	'	'
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	270	'	289
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	297	'	307
Related allowance	0	'	0
Impaired Financing Receivable, with Related Allowance, Recorded Investment	0	'	0
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	0	'	0
Average recorded investment	0	0	'
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	0	0	'
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	271	247	'
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	1	1	'
Residential real estate [Member]	'	'	'
Financing Receivable, Impaired [Line Items]	'	'	'
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	9,864	'	9,333
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	10,741	'	9,952
Related allowance	496	'	1,282
Impaired Financing Receivable, with Related Allowance, Recorded Investment	2,841	'	3,533
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	3,435	'	3,585
Average recorded investment	3,161	2,457	'
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	8	4	'
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	9,825	8,516	'
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	49	37	'
Commercial Real Estate [Member]	'	'	'
Financing Receivable, Impaired [Line Items]	'	'	'
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	7,348	'	13,606
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	8,423	'	14,719
Related allowance	47	'	84
Impaired Financing Receivable, with Related Allowance, Recorded Investment	301	'	488
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	315	'	612
Average recorded investment	307	6,704	'
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	1	25	'
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	9,498	33,978	'
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	$33	$11	'

Loans_and_Allowance_for_Credit7

Loans and Allowance for Credit Losses - Troubled Debt Restructured Loans and Commitments (Detail) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Financing Receivable, Troubled Debt Restructurings [Line Items]	'	'
Financing Receivable, Modifications, Recorded Investment	$22,850	$30,475
Loans and Leases Receivable, Impaired, Commitment to Lend	709	452
Letter of Credit [Member]	'	'
Financing Receivable, Troubled Debt Restructurings [Line Items]	'	'
Loans and Leases Receivable, Impaired, Commitment to Lend	0	0
Unused lines of Credit [Member]	'	'
Financing Receivable, Troubled Debt Restructurings [Line Items]	'	'
Loans and Leases Receivable, Impaired, Commitment to Lend	709	452
Non Accrual Loans [Member]	'	'
Financing Receivable, Troubled Debt Restructurings [Line Items]	'	'
Financing Receivable, Modifications, Recorded Investment	10,523	13,495
Non Accrual Loans [Member]	'	'
Financing Receivable, Troubled Debt Restructurings [Line Items]	'	'
Financing Receivable, Modifications, Recorded Investment	$12,327	$16,980

Loans_and_Allowance_for_Credit8

Loans and Allowance for Credit Losses - Troubled Debt Restructurings Identified During Period (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
	Contract	Contract
Financing Receivable, Modifications [Line Items]	'	'
Number of Contracts	21	16
Extend Maturity	$60	$433
Modify Rate	203	481
Modify Payments	549	530
Total Pre-Modification Outstanding Recorded Investment	812	1,444
Post- Modification Outstanding Recorded Investment	791	1,321
Financing Receivable Specific Reserve	'	0
Specific Reserve	'34000	'
Commercial, financial, agricultural and other [Member]	'	'
Financing Receivable, Modifications [Line Items]	'	'
Number of Contracts	1	2
Extend Maturity	60	426
Modify Rate	0	0
Modify Payments	0	12
Total Pre-Modification Outstanding Recorded Investment	60	438
Post- Modification Outstanding Recorded Investment	60	377
Financing Receivable Specific Reserve	'	0
Specific Reserve	'29	'
Residential real estate [Member]	'	'
Financing Receivable, Modifications [Line Items]	'	'
Number of Contracts	13	9
Extend Maturity	0	7
Modify Rate	172	214
Modify Payments	517	514
Total Pre-Modification Outstanding Recorded Investment	689	735
Post- Modification Outstanding Recorded Investment	676	677
Financing Receivable Specific Reserve	'	0
Specific Reserve	'5	'
Commercial Real Estate [Member]	'	'
Financing Receivable, Modifications [Line Items]	'	'
Number of Contracts	1	1
Extend Maturity	0	0
Modify Rate	0	244
Modify Payments	12	0
Total Pre-Modification Outstanding Recorded Investment	12	244
Post- Modification Outstanding Recorded Investment	8	242
Specific Reserve	'0	'0
Loans to individuals [Member]	'	'
Financing Receivable, Modifications [Line Items]	'	'
Number of Contracts	6	4
Extend Maturity	0	0
Modify Rate	31	23
Modify Payments	20	4
Total Pre-Modification Outstanding Recorded Investment	51	27
Post- Modification Outstanding Recorded Investment	47	25
Financing Receivable Specific Reserve	'	$0
Specific Reserve	'0	'

Loans_and_Allowance_for_Credit9

Loans and Allowance for Credit Losses - Troubled Debt Restructuring is 90 Days or More Past Due (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
	Contract	Contract
Financing Receivable, Recorded Investment, Past Due [Line Items]	'	'
Number of Contracts	4	2
Recorded Investment	$138	$16
Residential real estate [Member]	'	'
Financing Receivable, Recorded Investment, Past Due [Line Items]	'	'
Number of Contracts	4	1
Recorded Investment	138	10
Loans to individuals [Member]	'	'
Financing Receivable, Recorded Investment, Past Due [Line Items]	'	'
Number of Contracts	0	1
Recorded Investment	$0	$6

Recovered_Sheet1

Loans and Allowance for Credit Losses - Allowance for Credit Losses (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
Allowance for Doubtful Accounts Receivable [Roll Forward]	'	'	'
Beginning Balance	$54,225	$67,187	'
Charge-offs	-3,646	-10,476	'
Recoveries	696	1,054	'
Provision for Loan, Lease, and Other Losses	3,231	4,497	'
Ending Balance	54,506	62,262	'
Ending balance: individually evaluated for impaired	10,503	12,689	'
Ending balance: collectively evaluated for impaired	44,003	49,573	'
Loans and Leases Receivable, Gross	4,252,213	'	4,283,833
Total	4,252,213	4,218,810	4,283,833
Ending balance: individually evaluated for impaired	49,403	71,421	'
Ending balance: collectively evaluated for impaired	4,202,810	4,147,389	'
Commercial, financial, agricultural and other [Member]	'	'	'
Allowance for Doubtful Accounts Receivable [Roll Forward]	'	'	'
Beginning Balance	22,663	19,852	'
Charge-offs	-1,601	-538	'
Recoveries	85	128	'
Provision for Loan, Lease, and Other Losses	4,978	833	'
Ending Balance	26,125	20,275	'
Ending balance: individually evaluated for impaired	9,886	9,846	'
Ending balance: collectively evaluated for impaired	16,239	10,429	'
Loans and Leases Receivable, Gross	1,017,412	'	1,021,056
Total	'	1,057,663	'
Ending balance: individually evaluated for impaired	31,730	33,322	'
Ending balance: collectively evaluated for impaired	985,682	1,024,341	'
Real estate construction [Member]	'	'	'
Allowance for Doubtful Accounts Receivable [Roll Forward]	'	'	'
Beginning Balance	6,600	8,928	'
Charge-offs	0	-84	'
Recoveries	169	12	'
Provision for Loan, Lease, and Other Losses	-555	-1,123	'
Ending Balance	6,214	7,733	'
Ending balance: individually evaluated for impaired	74	503	'
Ending balance: collectively evaluated for impaired	6,140	7,230	'
Loans and Leases Receivable, Gross	95,110	'	93,289
Total	'	70,461	'
Ending balance: individually evaluated for impaired	2,797	8,917	'
Ending balance: collectively evaluated for impaired	92,313	61,544	'
Residential real estate [Member]	'	'	'
Allowance for Doubtful Accounts Receivable [Roll Forward]	'	'	'
Beginning Balance	7,727	5,908	'
Charge-offs	-1,095	-322	'
Recoveries	244	723	'
Provision for Loan, Lease, and Other Losses	-850	-560	'
Ending Balance	6,026	5,749	'
Ending balance: individually evaluated for impaired	496	1,091	'
Ending balance: collectively evaluated for impaired	5,530	4,658	'
Loans and Leases Receivable, Gross	1,240,169	'	1,262,718
Total	'	1,255,515	'
Ending balance: individually evaluated for impaired	9,103	7,813	'
Ending balance: collectively evaluated for impaired	1,231,066	1,247,702	'
Commercial Real Estate [Member]	'	'	'
Allowance for Doubtful Accounts Receivable [Roll Forward]	'	'	'
Beginning Balance	11,778	22,441	'
Charge-offs	-140	-8,544	'
Recoveries	20	97	'
Provision for Loan, Lease, and Other Losses	-539	4,476	'
Ending Balance	11,119	18,470	'
Ending balance: individually evaluated for impaired	47	1,249	'
Ending balance: collectively evaluated for impaired	11,072	17,221	'
Loans and Leases Receivable, Gross	1,290,852	'	1,296,472
Total	'	1,243,676	'
Ending balance: individually evaluated for impaired	5,773	21,369	'
Ending balance: collectively evaluated for impaired	1,285,079	1,222,307	'
Loans to individuals [Member]	'	'	'
Allowance for Doubtful Accounts Receivable [Roll Forward]	'	'	'
Beginning Balance	5,457	4,132	'
Charge-offs	-810	-988	'
Recoveries	178	94	'
Provision for Loan, Lease, and Other Losses	197	901	'
Ending Balance	5,022	4,139	'
Ending balance: individually evaluated for impaired	0	0	'
Ending balance: collectively evaluated for impaired	5,022	4,139	'
Loans and Leases Receivable, Gross	608,670	'	610,298
Total	'	591,495	'
Ending balance: individually evaluated for impaired	0	0	'
Ending balance: collectively evaluated for impaired	608,670	591,495	'
Unallocated [Member]	'	'	'
Allowance for Doubtful Accounts Receivable [Roll Forward]	'	'	'
Beginning Balance	0	5,926	'
Charge-offs	0	0	'
Recoveries	0	0	'
Provision for Loan, Lease, and Other Losses	0	-30	'
Ending Balance	0	5,896	'
Ending balance: individually evaluated for impaired	0	0	'
Ending balance: collectively evaluated for impaired	$0	$5,896	'

Fair_Values_of_Assets_and_Liab2

Fair Values of Assets and Liabilities - Quantitative Inputs and Assumptions Used in Level 3 Fair Value Measurements (Detail) (USD $)

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Dec. 31, 2013

Pooled Trust Preferred Collateralized Debt Obligations [Member]

Pooled Trust Preferred Collateralized Debt Obligations [Member]

Pooled Trust Preferred Collateralized Debt Obligations [Member]

Pooled Trust Preferred Collateralized Debt Obligations [Member]

Pooled Trust Preferred Collateralized Debt Obligations [Member]

Interest Rate Swap [Member]

Interest Rate Swap [Member]

Interest Rate Swap [Member]

Pooled Trust Preferred Collateralized Debt Obligations [Member]

Impaired Loans [Member]

Impaired Loans [Member]

Impaired Loans [Member]

Impaired Loans [Member]

Impaired Loans [Member]

impaired Loans Valued Using a Reserve Study [Domain]

impaired Loans Valued Using a Reserve Study [Domain]

Impaired Loans Valued Using Discounted Cash Flows [Domain]

Level 3 [Member]

Level 3 [Member]

Level 3 [Member]

Level 3 [Member]

Pooled Trust Preferred Collateralized Debt Obligations [Member]

Pooled Trust Preferred Collateralized Debt Obligations [Member]

Pooled Trust Preferred Collateralized Debt Obligations [Member]

Pooled Trust Preferred Collateralized Debt Obligations [Member]

Maximum [Member]

Discounted Cash Flow [Member]

Discounted Cash Flow [Member]

Discounted Cash Flow [Member]

Discounted Cash Flow [Member]

Option model [Member]

Option model [Member]

Reserve Study [Member]

Reserve Study [Member]

Reserve Study [Member]

Reserve Study [Member]

Reserve Study [Member]

Reserve Study [Member]

Reserve Study [Member]

Equity Securities [Member]

Equity Securities [Member]

Level 3 [Member]

Level 3 [Member]

Discount rates [Member]

Maximum [Member]

Maximum [Member]

Weighted average [Member]

Weighted average [Member]

Minimum [Member]

Maximum [Member]

NGL per gallon [Member]

Minimum [Member]

Minimum [Member]

Maximum [Member]

Maximum [Member]

Weighted average [Member]

Weighted average [Member]

Probability of default [Member]

Prepayment rates [Member]

Probability of default [Member]

Prepayment rates [Member]

Counterparty credit risk [Member]

Counterparty credit risk [Member]

Gas per MCF [Member]

Oil per BBL/d [Member]

Gas per MCF [Member]

Oil per BBL/d [Member]

Discount rates [Member]

Discount rates [Member]

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Securities available for sale, at fair value

$1,351,039,000

$1,318,365,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$29,296,000

$24,943,000

$1,420,000

$1,420,000

$27,876,000

$23,523,000

$27,876,000

$23,523,000

Assets

'

'

'

'

'

'

'

0

'

'

113,000

'

'

'

'

'

5,848,000

'

'

29,296,000

24,943,000

'

'

'

'

'

'

Weighted average rate

'

'

15.50%

[1]

100.00%

100.00%

18.22%

7.48%

'

6.33%

[2]

8.12%

[2]

'

'

'

'

'

'

'

10.00%

[2]

9.00%

[2]

'

'

'

'

'

'

'

'

Fair Value Inputs Monetary

'

'

'

'

'

'

'

'

'

'

'

$0.83

[3]

$3.84

[3]

$78.30

[3]

$6.45

[3]

$107

[3]

'

'

'

'

'

'

'

'

'

'

'

[1]

(a)incorporates spread over risk free rate related primarily to credit quality and illiquidity of secu

[2]

represents the range of the credit spread curve used in valuation.

[3]

unobservable inputs are defined as follows: MCF - million cubic feet; BBL/d - barrels per day; NGL - natural gas liquid.

Fair_Values_of_Assets_and_Liab3

Fair Values of Assets and Liabilities - Schedule of Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) (USD $)	Mar. 31, 2014		Dec. 31, 2013
In Thousands, unless otherwise specified
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Securities available for sale, at fair value	$1,351,039		$1,318,365
Other investments	34,047		35,444
US Government Agencies Residential Mortgage-backed Securities [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Securities available for sale, at fair value	24,241		25,204
Obligations of U.S. Government-Sponsored Enterprises - Mortgage-Backed Securities - Residential [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Securities available for sale, at fair value	1,013,607		994,887
Obligations of U.S. Government-Sponsored Enterprises - Mortgage-Backed Securities - Commercial [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Securities available for sale, at fair value	98		105
Obligations of U.S. Government-Sponsored Enterprises - Other Government-Sponsored Enterprises [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Securities available for sale, at fair value	267,310		266,125
Obligations of States and Political Subdivisions [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Securities available for sale, at fair value	9,359		80
Corporate Debt Securities [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Securities available for sale, at fair value	7,128		7,021
Pooled Trust Preferred Collateralized Debt Obligations [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Securities available for sale, at fair value	27,876		23,523
Level 1 [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Securities available for sale, at fair value	0		0
Other investments	0		0
Loans Held for Sale	0		0
Other Assets	0		0
Total Assets	0		0
Other Liabilities	0	[1]	0	[1]
Total Liabilities	0		0
Level 1 [Member] | Debt Securities [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Securities available for sale, at fair value	0		0
Level 1 [Member] | Equity Securities [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Securities available for sale, at fair value	0		0
Level 1 [Member] | US Government Agencies Residential Mortgage-backed Securities [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Securities available for sale, at fair value	0		0
Level 1 [Member] | Obligations of U.S. Government-Sponsored Enterprises - Mortgage-Backed Securities - Residential [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Securities available for sale, at fair value	0		0
Level 1 [Member] | Obligations of U.S. Government-Sponsored Enterprises - Mortgage-Backed Securities - Commercial [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Securities available for sale, at fair value	0		0
Level 1 [Member] | Obligations of U.S. Government-Sponsored Enterprises - Other Government-Sponsored Enterprises [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Securities available for sale, at fair value	0		0
Level 1 [Member] | Obligations of States and Political Subdivisions [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Securities available for sale, at fair value	0		0
Level 1 [Member] | Corporate Debt Securities [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Securities available for sale, at fair value	0		0
Level 1 [Member] | Pooled Trust Preferred Collateralized Debt Obligations [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Securities available for sale, at fair value	0		0
Level 2 [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Securities available for sale, at fair value	1,321,743		1,293,422
Other investments	34,047		35,444
Loans Held for Sale	0		0
Other Assets	12,521		14,358
Total Assets	1,368,311		1,343,224
Other Liabilities	12,497	[1]	14,318	[1]
Total Liabilities	12,497		14,318
Level 2 [Member] | Debt Securities [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Securities available for sale, at fair value	1,321,743		1,293,422
Level 2 [Member] | Equity Securities [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Securities available for sale, at fair value	0		0
Level 2 [Member] | US Government Agencies Residential Mortgage-backed Securities [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Securities available for sale, at fair value	24,241		25,204
Level 2 [Member] | Obligations of U.S. Government-Sponsored Enterprises - Mortgage-Backed Securities - Residential [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Securities available for sale, at fair value	1,013,607		994,887
Level 2 [Member] | Obligations of U.S. Government-Sponsored Enterprises - Mortgage-Backed Securities - Commercial [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Securities available for sale, at fair value	98		105
Level 2 [Member] | Obligations of U.S. Government-Sponsored Enterprises - Other Government-Sponsored Enterprises [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Securities available for sale, at fair value	267,310		266,125
Level 2 [Member] | Obligations of States and Political Subdivisions [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Securities available for sale, at fair value	9,359		80
Level 2 [Member] | Corporate Debt Securities [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Securities available for sale, at fair value	7,128		7,021
Level 2 [Member] | Pooled Trust Preferred Collateralized Debt Obligations [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Securities available for sale, at fair value	0		0
Level 3 [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Securities available for sale, at fair value	29,296		24,943
Other investments	0		0
Loans Held for Sale	0		0
Other Assets	0		0
Total Assets	29,296		24,943
Other Liabilities	0	[1]	0	[1]
Total Liabilities	0		0
Level 3 [Member] | Debt Securities [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Securities available for sale, at fair value	27,876		23,523
Level 3 [Member] | Equity Securities [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Securities available for sale, at fair value	1,420		1,420
Level 3 [Member] | US Government Agencies Residential Mortgage-backed Securities [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Securities available for sale, at fair value	0		0
Level 3 [Member] | Obligations of U.S. Government-Sponsored Enterprises - Mortgage-Backed Securities - Residential [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Securities available for sale, at fair value	0		0
Level 3 [Member] | Obligations of U.S. Government-Sponsored Enterprises - Mortgage-Backed Securities - Commercial [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Securities available for sale, at fair value	0		0
Level 3 [Member] | Obligations of U.S. Government-Sponsored Enterprises - Other Government-Sponsored Enterprises [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Securities available for sale, at fair value	0		0
Level 3 [Member] | Obligations of States and Political Subdivisions [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Securities available for sale, at fair value	0		0
Level 3 [Member] | Corporate Debt Securities [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Securities available for sale, at fair value	0		0
Level 3 [Member] | Pooled Trust Preferred Collateralized Debt Obligations [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Securities available for sale, at fair value	27,876		23,523
Estimate of Fair Value, Fair Value Disclosure [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Securities available for sale, at fair value	1,351,039		1,318,365
Other investments	34,047		35,444
Loans Held for Sale	0		0
Other Assets	12,521		14,358
Total Assets	1,397,607		1,368,167
Other Liabilities	12,497	[1]	14,318	[1]
Total Liabilities	12,497		14,318
Estimate of Fair Value, Fair Value Disclosure [Member] | Debt Securities [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Securities available for sale, at fair value	1,349,619		1,316,945
Estimate of Fair Value, Fair Value Disclosure [Member] | Equity Securities [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Securities available for sale, at fair value	1,420		1,420
Estimate of Fair Value, Fair Value Disclosure [Member] | US Government Agencies Residential Mortgage-backed Securities [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Securities available for sale, at fair value	24,241		25,204
Estimate of Fair Value, Fair Value Disclosure [Member] | Obligations of U.S. Government-Sponsored Enterprises - Mortgage-Backed Securities - Residential [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Securities available for sale, at fair value	1,013,607		994,887
Estimate of Fair Value, Fair Value Disclosure [Member] | Obligations of U.S. Government-Sponsored Enterprises - Mortgage-Backed Securities - Commercial [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Securities available for sale, at fair value	98		105
Estimate of Fair Value, Fair Value Disclosure [Member] | Obligations of U.S. Government-Sponsored Enterprises - Other Government-Sponsored Enterprises [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Securities available for sale, at fair value	267,310		266,125
Estimate of Fair Value, Fair Value Disclosure [Member] | Obligations of States and Political Subdivisions [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Securities available for sale, at fair value	9,359		80
Estimate of Fair Value, Fair Value Disclosure [Member] | Corporate Debt Securities [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Securities available for sale, at fair value	7,128		7,021
Estimate of Fair Value, Fair Value Disclosure [Member] | Pooled Trust Preferred Collateralized Debt Obligations [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Securities available for sale, at fair value	$27,876		$23,523
[1]	Non-hedging interest rate derivatives

Fair_Values_of_Assets_and_Liab4

Fair Values of Assets and Liabilities - Schedule of Changes in Level 3 Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'
Balance, beginning of period	$24,943	$24,793
Total gains or losses included in earnings	0	126
Total gains or losses included in other comprehensive income	4,743	2,391
Purchases	0	0
Issuances	0	0
Sales	-716	-16,739
Settlements	-390	-1,252
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3	716	16,613
Balance, end of period	29,296	25,932
Pooled Trust Preferred Collateralized Debt Obligations [Member]	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'
Balance, beginning of period	23,523	23,373
Total gains or losses included in earnings	0	0
Total gains or losses included in other comprehensive income	4,743	2,391
Purchases	0	0
Issuances	0	0
Sales	0	0
Settlements	-390	-1,252
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3	0	0
Balance, end of period	27,876	24,512
Equity Securities [Member]	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'
Balance, beginning of period	1,420	1,420
Total gains or losses included in earnings	0	0
Total gains or losses included in other comprehensive income	0	0
Purchases	0	0
Issuances	0	0
Sales	0	0
Settlements	0	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3	0	0
Balance, end of period	1,420	1,420
Loans Held For Sale [Member]	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'
Balance, beginning of period	0	0
Total gains or losses included in earnings	0	126
Total gains or losses included in other comprehensive income	0	0
Purchases	0	0
Issuances	0	0
Sales	-716	-16,739
Settlements	0	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3	716	16,613
Balance, end of period	0	0
Other Assets [Member]	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'
Balance, beginning of period	0	0
Total gains or losses included in earnings	0	0
Total gains or losses included in other comprehensive income	0	0
Purchases	0	0
Issuances	0	0
Sales	0	0
Settlements	0	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3	0	0
Balance, end of period	$0	$0

Fair_Values_of_Assets_and_Liab5

Fair Values of Assets and Liabilities - Additional Information (Detail) (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]	'	'	'
Fair Value, Assets, Level 1 to Level 2 Transfers, Description	$0	$0	'
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3	716,000	16,613,000	'
Impaired loans considered to be credit risk of non-collection	100,000	'	'
Updated appraisal requirement floor	250,000	'	'
Other real estate owned	10,080,000	'	11,728,000
Financial instrument of credit risk	100,000	'	100,000
Fair Value, Assets Measured on Recurring Basis, Gain (Loss) Included in Other Income, Assets and Liabilities Continue to be held	0	0	'
Other Assets [Member]	'	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]	'	'	'
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3	0	0	'
Loans Held For Sale [Member]	'	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]	'	'	'
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3	$716,000	$16,613,000	'
Minimum [Member]	'	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]	'	'	'
Swap Rates Term Used to Determine Yield Curve	'3 years	'	'
Maximum [Member]	'	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]	'	'	'
Swap Rates Term Used to Determine Yield Curve	'30 years	'	'

Fair_Values_of_Assets_and_Liab6

Fair Values of Assets and Liabilities - Schedule of Assets Measured on Non-Recurring Basis (Detail) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Fair Value, Measurements, Nonrecurring [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Impaired loans	$45,699	$50,559
Other real estate owned	10,758	12,924
Total Assets	56,457	63,483
Level 1 [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total Assets	0	0
Level 1 [Member] | Fair Value, Measurements, Nonrecurring [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Impaired loans	0	0
Other real estate owned	0	0
Total Assets	0	0
Level 2 [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total Assets	1,368,311	1,343,224
Level 2 [Member] | Fair Value, Measurements, Nonrecurring [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Impaired loans	32,940	36,903
Other real estate owned	10,601	12,752
Total Assets	43,541	49,655
Level 3 [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total Assets	29,296	24,943
Level 3 [Member] | Fair Value, Measurements, Nonrecurring [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Impaired loans	12,759	13,656
Other real estate owned	157	172
Total Assets	$12,916	$13,828

Fair_Values_of_Assets_and_Liab7

Fair Values of Assets and Liabilities - Losses Realized on Assets Measured on Non-Recurring Basis (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Fair Value Disclosures [Abstract]	'	'
Impaired loans	($3,996)	($503)
Other real estate owned	-363	-131
Total losses	($4,359)	($634)

Fair_Values_of_Assets_and_Liab8

Fair Values of Assets and Liabilities - Carrying Amounts and Fair Values of Financial Instruments (Detail) (USD $)	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2013
In Thousands, unless otherwise specified
Fair Value Measurements Of Financial Instruments [Line Items]	'	'	'
Cash and due from banks	$82,327	$74,427	'
Interest-bearing deposits	9,087	3,012	'
Securities available for sale, at fair value	1,351,039	1,318,365	'
Other investments	34,047	35,444	'
Loans	4,252,213	4,283,833	4,218,810
Deposits	4,647,817	4,603,863	'
Short-term borrowings	572,965	626,615	'
Long-term debt	144,268	144,385	'
Subordinated debt	72,167	72,167	'
Level 1 [Member]	'	'	'
Fair Value Measurements Of Financial Instruments [Line Items]	'	'	'
Securities available for sale, at fair value	0	0	'
Other investments	0	0	'
Level 2 [Member]	'	'	'
Fair Value Measurements Of Financial Instruments [Line Items]	'	'	'
Securities available for sale, at fair value	1,321,743	1,293,422	'
Other investments	34,047	35,444	'
Level 3 [Member]	'	'	'
Fair Value Measurements Of Financial Instruments [Line Items]	'	'	'
Securities available for sale, at fair value	29,296	24,943	'
Other investments	0	0	'
Carrying Amount [Member]	'	'	'
Fair Value Measurements Of Financial Instruments [Line Items]	'	'	'
Cash and due from banks	82,327	74,427	'
Interest-bearing deposits	9,087	3,012	'
Securities available for sale, at fair value	1,351,039	1,318,365	'
Other investments	34,047	35,444	'
Loans	4,252,213	4,283,833	'
Deposits	4,647,817	4,603,863	'
Short-term borrowings	572,965	626,615	'
Long-term debt	144,268	144,385	'
Subordinated debt	72,167	72,167	'
Estimate of Fair Value, Fair Value Disclosure [Member]	'	'	'
Fair Value Measurements Of Financial Instruments [Line Items]	'	'	'
Cash and due from banks	82,327	74,427	'
Interest-bearing deposits	9,087	3,012	'
Securities available for sale, at fair value	1,351,039	1,318,365	'
Other investments	34,047	35,444	'
Loans	4,283,303	4,321,847	'
Deposits	4,573,324	4,531,685	'
Short-term borrowings	572,954	626,603	'
Long-term debt	145,510	145,477	'
Subordinated debt	61,347	51,706	'
Estimate of Fair Value, Fair Value Disclosure [Member] | Level 1 [Member]	'	'	'
Fair Value Measurements Of Financial Instruments [Line Items]	'	'	'
Cash and due from banks	82,327	74,427	'
Interest-bearing deposits	9,087	3,012	'
Securities available for sale, at fair value	0	0	'
Other investments	0	0	'
Loans	0	0	'
Deposits	0	0	'
Short-term borrowings	0	0	'
Long-term debt	0	0	'
Subordinated debt	0	0	'
Estimate of Fair Value, Fair Value Disclosure [Member] | Level 2 [Member]	'	'	'
Fair Value Measurements Of Financial Instruments [Line Items]	'	'	'
Cash and due from banks	0	0	'
Interest-bearing deposits	0	0	'
Securities available for sale, at fair value	1,321,743	1,293,422	'
Other investments	34,047	35,444	'
Loans	32,940	36,903	'
Deposits	4,573,324	4,531,685	'
Short-term borrowings	572,954	626,603	'
Long-term debt	145,510	145,477	'
Subordinated debt	0	0	'
Estimate of Fair Value, Fair Value Disclosure [Member] | Level 3 [Member]	'	'	'
Fair Value Measurements Of Financial Instruments [Line Items]	'	'	'
Cash and due from banks	0	0	'
Interest-bearing deposits	0	0	'
Securities available for sale, at fair value	29,296	24,943	'
Other investments	0	0	'
Loans	4,250,363	4,284,944	'
Deposits	0	0	'
Short-term borrowings	0	0	'
Long-term debt	0	0	'
Subordinated debt	$61,347	$51,706	'

Derivatives_Additional_Informa

Derivatives - Additional Information (Detail)	Mar. 31, 2014
	Derivatives
Risk Participation Agreements Purchased [Domain]	'
Risk participation Agreements [Line Items]	'
Number of interest rate swaps	11
Risk Participation Agreements Sold [Domain]	'
Risk participation Agreements [Line Items]	'
Number of interest rate swaps	2

Derivatives_Credit_Value_Adjus

Derivatives - Credit Value Adjustment Recorded Related to Notional Amount of Derivatives Outstanding (Detail) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Derivative [Line Items]	'	'
Derivative, Fair Value, Net	($19)	($77)
Interest Rate Swap [Member]	'	'
Derivative [Line Items]	'	'
Derivative, Notional Amount	271,391	274,718
Interest Rate Cap [Member]	'	'
Derivative [Line Items]	'	'
Derivative, Notional Amount	7,263	7,500
Credit Default Swap, Buying Protection [Member]	'	'
Derivative [Line Items]	'	'
Derivative, Notional Amount	81,704	82,197
Credit Default Swap, Selling Protection [Member]	'	'
Derivative [Line Items]	'	'
Derivative, Notional Amount	($19,045)	($19,161)

Derivatives_Schedule_of_Change

Derivatives - Schedule of Changes in Fair Value of Derivative Assets and Liabilities (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'	'
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	($58)	$989

Goodwill_Additional_Informatio

Goodwill - Additional Information (Detail) (USD $)	3 Months Ended	12 Months Ended
	Mar. 31, 2014	Dec. 31, 2013
Goodwill Disclosure [Abstract]	'	'
Goodwill	$159,371,000	$159,956,000
Impairment charges on goodwill	0	0
Goodwill, Written off Related to Sale of Business Unit	($500,000)	'