First Commonwealth Financial (FCF) 10-Q8 May 152015 Q1 Quarterly reportFinancial data

Company Profile

Document_and_Entity_Informatio

Document and Entity Information	3 Months Ended
Document and Entity Information	Mar. 31, 2015	8-May-15
Entity Information [Line Items]
Document Type	10-Q
Amendment Flag	FALSE
Document Period End Date	31-Mar-15
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	Q1
Trading Symbol	FCF
Entity Registrant Name	FIRST COMMONWEALTH FINANCIAL CORP /PA/
Entity Central Index Key	712537
Current Fiscal Year End Date	-19
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		88,960,268

Condensed_Consolidated_Stateme

Condensed Consolidated Statements of Financial Condition (Unaudited) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Assets
Cash and due from banks	$62,161	$72,276
Interest-bearing bank deposits	3,124	2,262
Securities available for sale, at fair value	1,269,285	1,309,819
Securities held to maturity, at amortized cost (Fair value of $30,174 at March 31, 2015)	30,253	0
Other investments	47,076	44,545
Loans held for sale	5,892	2,502
Loans:
Portfolio loans	4,437,601	4,457,308
Allowance for credit losses	-46,697	-52,051
Net loans	4,390,904	4,405,257
Premises and equipment, net	64,816	64,989
Other real estate owned	7,025	7,197
Goodwill	161,429	161,429
Amortizing intangibles, net	1,508	1,665
Bank owned life insurance	178,630	177,567
Other assets	109,739	110,777
Total assets	6,331,842	6,360,285
Deposits (all domestic):
Noninterest-bearing	1,039,929	989,027
Interest-bearing	3,253,820	3,326,484
Total deposits	4,293,749	4,315,511
Short-term borrowings	1,125,520	1,105,876
Subordinated debentures	72,167	72,167
Other long-term debt	64,324	89,459
Total long-term debt	136,491	161,626
Other liabilities	63,222	61,127
Total liabilities	5,618,982	5,644,140
Shareholdersâ€™ 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, 2015 and December 31, 2014, and 89,656,007 and 91,723,028 shares outstanding at March 31, 2015 and December 31, 2014, respectively	105,563	105,563
Additional paid-in capital	365,874	365,615
Retained earnings	360,841	353,027
Accumulated other comprehensive income (loss), net	2,702	-4,499
Treasury stock (15,907,448 and 13,840,427 shares at March 31, 2015 and December 31, 2014, respectively)	-122,120	-103,561
Total shareholdersâ€™ equity	712,860	716,145
Total liabilities and shareholdersâ€™ equity	$6,331,842	$6,360,285

Condensed_Consolidated_Stateme1

Condensed Consolidated Statements of Financial Condition (Unaudited) (Parenthetical) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, except Share data, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
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)	89,656,007	91,723,028
Treasury stock, shares (in shares)	15,907,448	13,840,427
Securities held to maturity, fair value	$30,174	$0

Condensed_Consolidated_Stateme2

Condensed Consolidated Statements of Income (Unaudited) (USD $)	3 Months Ended
In Thousands, except Share data, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Interest Income
Interest and fees on loans	$42,601	$43,098
Interest and dividends on investments:
Taxable interest	6,817	7,180
Interest exempt from federal income taxes	175	4
Dividends	1,489	222
Interest on bank deposits	3	2
Total interest income	51,085	50,506
Interest Expense
Interest on deposits	2,150	3,507
Interest on short-term borrowings	958	469
Interest on subordinated debentures	569	566
Interest on other long-term debt	236	373
Total interest expense	3,913	4,915
Net Interest Income	47,172	45,591
Provision for credit losses	1,159	3,231
Net Interest Income after Provision for Credit Losses	46,013	42,360
Noninterest Income
Net securities gains	105	0
Trust income	1,421	1,435
Service charges on deposit accounts	3,318	3,792
Insurance and retail brokerage commissions	2,195	1,395
Income from bank owned life insurance	1,354	1,369
Gain on sale of assets	663	1,581
Card related interchange income	3,418	3,366
Other income	1,717	1,982
Total noninterest income	14,191	14,920
Noninterest Expense
Salaries and employee benefits	21,892	21,044
Net occupancy expense	3,911	3,506
Furniture and equipment expense	2,680	5,330
Data processing expense	1,438	1,468
Pennsylvania shares tax expense	794	711
Intangible amortization	156	178
Collection and repossession expense	511	709
Other professional fees and services	930	1,024
FDIC insurance	1,059	1,049
Loss on sale or write-down of assets	262	435
Litigation and operational losses (recoveries)	1,000	-689
Conversion related expenses	0	354
Other operating expenses	5,221	4,768
Total noninterest expense	39,854	39,887
Income Before Income Taxes	20,350	17,393
Income tax provision	6,129	5,093
Net Income	$14,221	$12,300
Average Shares Outstanding (in shares)	90,875,724	94,543,420
Average Shares Outstanding Assuming Dilution (in shares)	90,889,035	94,568,059
Per Share Data:
Basic Earnings per Share (in dollars per share)	$0.16	$0.13
Diluted Earnings per Share (in dollars per share)	$0.16	$0.13
Cash Dividends Declared per Common Share (in dollars per share)	$0.07	$0.07

Condensed_Consolidated_Stateme3

Condensed Consolidated Statements of Comprehensive Income (Unaudited) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Net Income	$14,221	$12,300
Other comprehensive income, before tax expense:
Unrealized holding gains on securities arising during the period	9,980	12,457
Less: reclassification adjustment for gains on securities included in net income	-105	0
Unrealized holding gains on derivatives arising during the period	1,195	0
Less: reclassification adjustment for losses on derivatives included in net income	5	0
Total other comprehensive income, before tax expense	11,075	12,457
Income tax expense related to items of other comprehensive income	-3,874	-4,361
Total other comprehensive income	7,201	8,096
Comprehensive Income	$21,422	$20,396

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	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss), net [Member]	Treasury Stock [Member]
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
Net Income	12,300			12,300
Other comprehensive income (loss)	8,096				8,096
Dividends, declared (USD per share)	-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	282	0	169	0		113
Restricted stock, shares		63,626
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
Beginning balance at Dec. 31, 2014	716,145	105,563	365,615	353,027	-4,499	-103,561
Beginning balance, shares at Dec. 31, 2014	91,723,028	91,723,028
Net Income	14,221			14,221
Other comprehensive income (loss)	7,201				7,201
Dividends, declared (USD per share)	-6,407			-6,407
Treasury stock acquired	-18,874					-18,874
Treasury stock acquired, shares		-2,201,391
Restricted stock	574	0	259	0		315
Restricted stock, shares		134,370
Ending balance at Mar. 31, 2015	$712,860	$105,563	$365,874	$360,841	$2,702	($122,120)
Ending balance, shares at Mar. 31, 2015	89,656,007	89,656,007

Condensed_Consolidated_Stateme5

Condensed Consolidated Statements of Changes in Shareholders' Equity (Unaudited) (Parenthetical) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Statement of Stockholders' Equity [Abstract]
Cash Dividends Declared per Common Share (in dollars per share)	$0.07	$0.07

Condensed_Consolidated_Stateme6

Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Operating Activities
Net Income	$14,221	$12,300
Adjustment to reconcile net income to net cash provided by operating activities:
Provision for credit losses	1,159	3,231
Deferred tax expense	4,219	2,646
Depreciation and amortization	1,899	4,310
Net gains on securities and other assets	-267	-1,086
Net amortization of premiums and discounts on securities	441	538
Net accretion of premiums and discounts on long term debt	0	-30
Income from increase in cash surrender value of bank owned life insurance	-1,354	-1,369
(Increase) decrease in interest receivable	-127	689
Mortgage loans originated for sale	-15,382	0
Proceeds from sale of mortgage loans	15,472	0
Decrease in interest payable	-92	-163
Increase in income taxes payable	290	2,231
Other-net	-4,748	-2,420
Net cash provided by operating activities	15,731	20,877
Investing Activities
Payments to Acquire Held-to-maturity Securities	-29,616	0
Proceeds from maturities and redemptions	50,568	101,125
Purchases	-500	-114,706
Purchases of FHLB stock	-13,801	-6,579
Proceeds from the redemption of FHLB stock	11,270	7,976
Proceeds from bank owned life insurance	291	939
Proceeds from sale of loans	0	716
Proceeds from sale of other assets	1,008	4,443
Net decrease in loans	9,540	26,564
Purchases of premises and equipment	-1,665	-2,240
Net cash provided by investing activities	27,095	18,238
Financing Activities
Net increase (decrease) in federal funds purchased	6,000	-500
Net increase (decrease) in other short-term borrowings	13,644	-53,149
Net (decrease) increase in deposits	-21,761	43,955
Repayments of other long-term debt	-25,134	-87
Discount on dividend reinvestment plan purchases	0	-33
Dividends paid	-6,407	-6,618
Purchase of treasury stock	-18,421	-8,708
Net cash used in financing activities	-52,079	-25,140
Net (decrease) increase in cash and cash equivalents	-9,253	13,975
Cash and cash equivalents at January 1	74,538	77,439
Cash and cash equivalents at March 31	$65,285	$91,414

Basis_of_Presentation

Basis of Presentation	3 Months Ended
Basis of Presentation	Mar. 31, 2015
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 the “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, comprehensive income, 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, 2015 are not necessarily indicative of the results that may be expected for the full year of 2015. These interim financial statements should be read in conjunction with First Commonwealth’s 2014 Annual Report on Form 10-K.
	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, 2015
Supplemental Comprehensive Income Disclosures [Abstract]
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 and reclassification adjustments related to losses on derivatives are included in the "Other operating expenses" line in the Condensed Consolidated Statements of Income.


		For the Three Months Ended March 31,
		2015												2014
		Pretax Amount				Tax (Expense) Benefit				Net of Tax Amount				Pretax Amount				Tax (Expense) Benefit				Net of Tax Amount
		(dollars in thousands)
	Unrealized gains on securities:
	Unrealized holding gains on securities arising during the period	$	9,980			$	(3,491	)		$	6,489			$	12,457			$	(4,361	)		$	8,096

	Reclassification adjustment for gains on securities included in net income	(105		)		37				(68		)		—				—				—

	Total unrealized gains on securities	9,875				(3,454		)		6,421				12,457				(4,361		)		8,096

	Unrealized gains on derivatives:
	Unrealized holding gains on derivatives arising during the period	1,195				(418		)		777				—				—				—

	Reclassification adjustment for losses on derivatives included in net income	5				(2		)		3				—				—				—

	Total unrealized gains on derivatives	1,200				(420		)		780				—				—				—

	Total other comprehensive income	$	11,075			$	(3,874	)		$	7,201			$	12,457			$	(4,361	)		$	8,096






	The following table details the change in components of OCI for the three months ended March 31:


		2015													2014
		Securities Available for Sale			Post-Retirement Obligation			Derivatives			Accumulated Other Comprehensive Income				Securities Available for Sale			Post-Retirement Obligation			Derivatives			Accumulated Other Comprehensive Income
		(dollars in thousands)
	Balance at December 31	$	(4,875	)	$	300		$	76		$	(4,499	)		$	(20,868	)	$	280		$	—		$	(20,588	)

	Other comprehensive income before reclassification adjustment	6,489			—			777			7,266				8,096			—			—			8,096

	Amounts reclassified from accumulated other comprehensive (loss) income	(68		)	—			3			(65		)		—			—			—			—

	Net other comprehensive income during the period	6,421			—			780			7,201				8,096			—			—			8,096

	Balance at March 31	$	1,546		$	300		$	856		$	2,702			$	(12,772	)	$	280		$	—		$	(12,492	)

Supplemental_Cash_Flow_Disclos

Supplemental Cash Flow Disclosures	3 Months Ended
	Mar. 31, 2015
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:


		2015		2014
		(dollars in thousands)
	Cash paid during the period for:
	Interest	$	4,004	$	5,108

	Income taxes	1,500		—

	Non-cash investing and financing activities:
	Loans transferred to other real estate owned and repossessed assets	797		1,292

	Loans transferred from held to maturity to held for sale	3,011		716

	Gross increase in market value adjustment to securities available for sale	9,869		12,459

	Gross increase in market value adjustment to derivatives	1,200		—

	Investments committed to purchase, not settled	637		2,522

	Unsettled treasury stock repurchases	453		233

Earnings_per_Share

Earnings per Share	3 Months Ended
Earnings per Share	Mar. 31, 2015
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,
		2015		2014
	Weighted average common shares issued	105,563,455		105,563,455
	Weighted average common shares issued	105,563,455		105,563,455
	Average treasury stock shares	(14,503,976	)	(10,876,695	)
	Average unearned nonvested shares	(183,755	)	(143,340	)
	Weighted average common shares and common stock equivalents used to calculate basic earnings per share	90,875,724		94,543,420
		90,875,724		94,543,420
	Additional common stock equivalents (nonvested stock) used to calculate diluted earnings per share	13,311		24,639
		13,311		24,639
	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	90,889,035		94,568,059
		90,889,035		94,568,059


	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.


		2015						2014
				Price Range					Price Range
		Shares		From		To		Shares	From		To
	Stock Options	—		$	—	$	—	15,000	$	14.55	$	14.55
	Stock Options	—		$	—	$	—	15,000	$	14.55	$	14.55
	Restricted Stock	118,390		7.35		9.26		5,601	8.75		9.18
	Restricted Stock	118,390		7.35		9.26		5,601	8.75		9.18

Commitments_and_Contingent_Lia

Commitments and Contingent Liabilities	3 Months Ended
	Mar. 31, 2015
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-15		31-Dec-14
		(dollars in thousands)
	Financial instruments whose contract amounts represent credit risk:
	Commitments to extend credit	$	1,645,977	$	1,635,948

	Financial standby letters of credit	27,858		36,075

	Performance standby letters of credit	26,490		25,915

	Commercial letters of credit	2,584		2,611


	The notional amounts outstanding as of March 31, 2015 include amounts issued in 2015 of $1.5 million in performance standby letters of credit. There were no financial standby or commercial letters of credit issued during 2015. A liability of $0.2 million has been recorded as of March 31, 2015 and December 31, 2014, 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 $3.6 million as of March 31, 2015 and $3.1 million as of December 31, 2014. This liability is reflected in Other liabilities in the Condensed Consolidated Statements of Financial Condition. 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
	There are no 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, comprehensive income or cash flow of First Commonwealth or its subsidiaries.

Investment_Securities

Investment Securities	3 Months Ended
Investment Securities	Mar. 31, 2015
Investment Securities [Abstract]
Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block]	Investment Securities
	Securities Available for Sale
	Below is an analysis of the amortized cost and estimated fair values of securities available for sale at:


		31-Mar-15												31-Dec-14
		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	$	22,578		$	2,835		$	—			$	25,413	$	23,344	$	2,595	$	(3	)	$	25,936
	Mortgage-Backed Securities – Residential	$	22,578		$	2,835		$	—			$	25,413	$	23,344	$	2,595	$	(3	)	$	25,936
	Obligations of U.S. Government-Sponsored Enterprises:
	Obligations of U.S. Government-Sponsored Enterprises:
	Mortgage-Backed Securities – Residential	905,895			15,759			(6,402		)		915,252		947,635		13,076		(9,830		)	950,881
	Mortgage-Backed Securities – Residential	905,895			15,759			(6,402		)		915,252		947,635		13,076		(9,830		)	950,881
	Mortgage-Backed Securities – Commercial	65			1			—				66		72		2		—			74
	Mortgage-Backed Securities – Commercial	65			1			—				66		72		2		—			74
	Other Government-Sponsored Enterprises	260,849			180			(330		)		260,699		269,181		4		(1,308		)	267,877
	Other Government-Sponsored Enterprises	260,849			180			(330		)		260,699		269,181		4		(1,308		)	267,877
	Obligations of States and Political Subdivisions	27,060			494			(5		)		27,549		27,058		362		(43		)	27,377
	Obligations of States and Political Subdivisions	27,060			494			(5		)		27,549		27,058		362		(43		)	27,377
	Corporate Securities	6,680			572			—				7,252		6,682		573		—			7,255
	Corporate Securities	6,680			572			—				7,252		6,682		573		—			7,255
	Pooled Trust Preferred Collateralized Debt Obligations	41,868			503			(11,237		)		31,134		41,926		309		(13,236		)	28,999
	Pooled Trust Preferred Collateralized Debt Obligations	41,868			503			(11,237		)		31,134		41,926		309		(13,236		)	28,999
	Total Debt Securities	1,264,995			20,344			(17,974		)		1,267,365		1,315,898		16,921		(24,420		)	1,308,399
	Total Debt Securities	1,264,995			20,344			(17,974		)		1,267,365		1,315,898		16,921		(24,420		)	1,308,399
	Equities	1,920			—			—				1,920		1,420		—		—			1,420
	Equities	1,920			—			—				1,920		1,420		—		—			1,420
	Total Securities Available for Sale	$	1,266,915		$	20,344		$	(17,974	)		$	1,269,285	$	1,317,318	$	16,921	$	(24,420	)	$	1,309,819
	Total Securities Available for Sale	$	1,266,915		$	20,344		$	(17,974	)		$	1,269,285	$	1,317,318	$	16,921	$	(24,420	)	$	1,309,819

	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, 2015, by contractual maturity, are shown below.


		Amortized			Estimated
		Cost			Fair Value
		(dollars in thousands)
	Due within 1 year	$	6,800		$	6,798
	Due within 1 year	$	6,800		$	6,798
	Due after 1 but within 5 years	254,050			253,901
	Due after 1 but within 5 years	254,050			253,901
	Due after 5 but within 10 years	24,420			24,869
	Due after 5 but within 10 years	24,420			24,869
	Due after 10 years	51,187			41,066
	Due after 10 years	51,187			41,066
		336,457			326,634
		336,457			326,634
	Mortgage-Backed Securities (a)	928,538			940,731
	Mortgage-Backed Securities (a)	928,538			940,731
	Total Debt Securities	$	1,264,995		$	1,267,365
	Total Debt Securities	$	1,264,995		$	1,267,365


	(a)	Mortgage Backed Securities include an amortized cost of $22.6 million and a fair value of $25.4 million for Obligations of U.S. Government agencies issued by Ginnie Mae and an amortized cost of $906.0 million and a fair value of $915.3 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:


	2015			2014
	(dollars in thousands)
Proceeds from sales	$	—		$	—
Proceeds from sales	$	—		$	—
Gross gains (losses) realized:
Sales Transactions:
Gross gains	$	—		$	—
Gross gains	$	—		$	—
Gross losses	—			—
Gross losses	—			—
	—			—
	—			—
Maturities and impairment
Gross gains	105			—
Gross gains	105			—
Gross losses	—			—
Gross losses	—			—
Other-than-temporary impairment	—			—
Other-than-temporary impairment	—			—
	105			—
	105			—
Net gains and impairment	$	105		$	—
Net gains and impairment	$	105		$	—

Securities available for sale with an estimated fair value of $554.4 million and $563.2 million were pledged as of March 31, 2015 and December 31, 2014, respectively, to secure public deposits and for other purposes required or permitted by law.
Securities Held to Maturity
Below is an analysis of the amortized cost and fair values of debt securities held to maturity at March 31, 2015. There were no held to maturity securities at December 31, 2014.


	31-Mar-15
	Amortized			Gross			Gross				Estimated
	Cost			Unrealized			Unrealized				Fair Value
				Gains			Losses
	(dollars in thousands)
Obligations of U.S. Government-Sponsored Enterprises:
Mortgage-Backed Securities – Residential	$	26,315		$	—		$	(98	)		$	26,217
Mortgage-Backed Securities – Residential	$	26,315		$	—		$	(98	)		$	26,217
Obligations of States and Political Subdivisions	3,938			19			—				3,957
Obligations of States and Political Subdivisions	3,938			19			—				3,957
Total Securities Held to Maturity	$	30,253		$	19		$	(98	)		$	30,174
Total Securities Held to Maturity	$	30,253		$	19		$	(98	)		$	30,174
The amortized cost and estimated fair value of debt securities held to maturity at March 31, 2015, by contractual maturity, are shown below. Expected maturities will differ from contractual maturities because borrowers may have the right to call or repay obligations with or without call or prepayment penalties.


	Amortized			Estimated
	Cost			Fair Value
	(dollars in thousands)
Due within 1 year	$	—		$	—
Due within 1 year	$	—		$	—
Due after 1 but within 5 years	—			—
Due after 1 but within 5 years	—			—
Due after 5 but within 10 years	—			—
Due after 5 but within 10 years	—			—
Due after 10 years	3,938			3,957
Due after 10 years	3,938			3,957
	3,938			3,957
	3,938			3,957
Mortgage-Backed Securities (a)	26,315			26,217
Mortgage-Backed Securities (a)	26,315			26,217
Total Debt Securities	$	30,253		$	30,174
Total Debt Securities	$	30,253		$	30,174

(a)	Mortgage Backed Securities include an amortized cost of $26.3 million and a fair value of $26.2 million for Obligations of U.S. Government-sponsored enterprises issued by Fannie Mae and Freddie Mac.
Securities held to maturity with an amortized cost of $3.3 million were pledged as of March 31, 2015 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, 2015
Impairment of Investment Securities Disclosure [Abstract]
Impairment of Investment Securities	Impairment of Investment Securities
	Securities Available for Sale and Held to Maturity
	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, 2015 and 2014, 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 10, “Fair Values of Assets and Liabilities,” for additional information.
	The following table presents the gross unrealized losses and estimated fair values at March 31, 2015 for both available for sale and held to maturity securities 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-Sponsored Enterprises:
	Mortgage-Backed Securities – Residential	84,160				(435		)		300,792				(6,065		)		384,952				(6,500		)

	Other Government-Sponsored Enterprises	27,985				(15		)		122,833				(315		)		150,818				(330		)

	Obligations of States and Political Subdivisions	878				(5		)		—				—				878				(5		)

	Pooled Trust Preferred Collateralized Debt Obligations	—				—				26,318				(11,237		)		26,318				(11,237		)

	Total Securities	$	113,023			$	(455	)		$	449,943			$	(17,617	)		$	562,966			$	(18,072	)


	At March 31, 2015, fixed income securities issued by U.S. Government-sponsored enterprises comprised 38% of total unrealized losses due to changes in market interest rates. Pooled trust preferred collateralized debt obligations accounted for 62% of the unrealized losses due to changes in market interest rates and the illiquid market for this investment type. At March 31, 2015, there are 41 debt securities in an unrealized loss position.
	The following table presents the gross unrealized losses and estimated fair values at December 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	$	2,318			$	(3	)		$	—			$	—			$	2,318			$	(3	)

	Obligations of U.S. Government-Sponsored Enterprises:
	Mortgage-Backed Securities – Residential	111,646				(419		)		368,706				(9,411		)		480,352				(9,830		)

	Other Government-Sponsored Enterprises	112,473				(229		)		130,401				(1,079		)		242,874				(1,308		)

	Obligation of States and Political Subdivisions	3,146				(43		)		—				—				3,146				(43		)

	Pooled Trust Preferred Collateralized Debt Obligations	—				—				24,356				(13,236		)		24,356				(13,236		)

	Total Securities	$	229,583			$	(694	)		$	523,463			$	(23,726	)		$	753,046			$	(24,420	)

	As of March 31, 2015 and December 31, 2014, our corporate securities had an amortized cost and an estimated fair value of $6.7 million and $7.3 million, respectively, and were comprised of single issue trust preferred securities issued primarily by large regional banks. There were no corporate securities in an unrealized loss position as of March 31, 2015 and December 31, 2014. 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, 2015, the book value of our pooled trust preferred collateralized debt obligations totaled $41.9 million with an estimated fair value of $31.1 million, which includes securities comprised of 278 banks and other financial institutions. All of our pooled securities are mezzanine tranches, three 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, 2015, after taking into account management’s best estimates of future interest deferrals and defaults, four of our securities had no excess subordination in the tranches we own and five of our securities had excess subordination which ranged from 7% 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, 2015:


	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			$	1,324			$	(506	)		B1/BB		6			18.05	%		56	%

Pre TSL VII	Mezzanine		2,789				3,147				358				Ca/-		14			49.68			—

Pre TSL VIII	Mezzanine		1,984				1,446				(538		)		C/C		29			58.01			—

Pre TSL IX	Mezzanine		2,349				1,597				(752		)		B3/C		40			28.91			6.61

Pre TSL X	Mezzanine		1,524				1,669				145				Caa1/C		43			31.6			—

Pre TSL XII	Mezzanine		5,559				3,969				(1,590		)		B3/C		66			25.23			—

Pre TSL XIII	Mezzanine		12,525				8,870				(3,655		)		B3/C		56			25.44			20.85

Pre TSL XIV	Mezzanine		12,876				8,702				(4,174		)		Caa1/C		56			25.46			38.55

MMCap I	Mezzanine		432				410				(22		)		Ca/C		10			56.11			24.92

Total			$	41,868			$	31,134			$	(10,734	)

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, 2015 and 2014, 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, 2015. 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 278 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, 2015, 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, 2015, indicates that no credit related other-than-temporary impairment has occurred on our pooled trust preferred securities during the three months ended March 31, 2015. Based upon the analysis performed by management, it is probable that four 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, 2015 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, 2015, 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 the present value of estimated future principal and interest payments exceeding the securities current book value. The excess for each bond of the present value of future cash flows over our current book value ranges from 22% to 147% 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,
	2015				2014
	(dollars in thousands)
Balance, beginning (a)	$	26,246			$	27,543

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)	(321		)		(289		)
Reduction for debt securities called during the period	(218		)		—

Balance, ending	$	25,707			$	27,254



(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 three months of 2015 and 2014, 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, 2015 and 2014, there are no equity securities in an unrealized loss position.
Other Investments
As a member of the 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, 2015 and December 31, 2014, our FHLB stock totaled $47.1 million and $44.5 million, respectively, and is included in “Other investments” on the Condensed Consolidated Statements of Financial Condition.
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 and has concluded that the par value of its investment in FHLB stock will be recovered. Accordingly, no impairment charge was recorded on these securities during the three months ended March 31, 2015.

Loans_and_Allowance_for_Credit

Loans and Allowance for Credit Losses	3 Months Ended
	Mar. 31, 2015
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-15				31-Dec-14
		(dollars in thousands)
	Commercial, financial, agricultural and other	$	1,066,788			$	1,052,109

	Real estate construction	107,882				120,785

	Residential real estate	1,210,511				1,226,344

	Commercial real estate	1,400,276				1,405,256

	Loans to individuals	652,144				652,814

	Total loans and leases net of unearned income	$	4,437,601			$	4,457,308

	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 Company’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. Movement 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-15
		Commercial, financial, agricultural and other				Real estate construction				Residential real estate				Commercial real estate				Loans to individuals				Total
		(dollars in thousands)
	Pass	$	1,006,516			$	107,180			$	1,198,876			$	1,350,930			$	651,883			$	4,315,385

	Non-Pass
	OAEM	31,642				466				1,661				30,054				—				63,823

	Substandard	28,630				236				9,974				19,292				261				58,393

	Doubtful	—				—				—				—				—				—

	Total Non-Pass	60,272				702				11,635				49,346				261				122,216

	Total	$	1,066,788			$	107,882			$	1,210,511			$	1,400,276			$	652,144			$	4,437,601




		31-Dec-14
		Commercial, financial, agricultural and other				Real estate construction				Residential real estate				Commercial real estate				Loans to individuals				Total
		(dollars in thousands)
	Pass	$	983,357			$	112,536			$	1,214,920			$	1,353,773			$	652,596			$	4,317,182

	Non-Pass
	OAEM	32,563				8,013				2,315				29,479				—				72,370

Substandard	32,028				236				9,109				22,004				218				63,595

Doubtful	4,161				—				—				—				—				4,161

Total Non-Pass	68,752				8,249				11,424				51,483				218				140,126

Total	$	1,052,109			$	120,785			$	1,226,344			$	1,405,256			$	652,814			$	4,457,308

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, 2015. 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.
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, 2015 and December 31, 2014. 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-15
	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	$	292			$	320			$	149			$	18,654			$	19,415			$	1,047,373			$	1,066,788

Real estate construction	—				—				—				236				236				107,646				107,882

Residential real estate	3,815				1,054				2,438				7,583				14,890				1,195,621				1,210,511

Commercial real estate	1,283				124				382				6,831				8,620				1,391,656				1,400,276

Loans to individuals	2,692				612				1,276				261				4,841				647,303				652,144

Total	$	8,082			$	2,110			$	4,245			$	33,565			$	48,002			$	4,389,599			$	4,437,601




	31-Dec-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	$	2,816			$	213			$	264			$	27,007			$	30,300			$	1,021,809			$	1,052,109

Real estate construction	—				1				—				236				237				120,548				120,785

Residential real estate	5,162				1,295				1,077				7,900				15,434				1,210,910				1,226,344

Commercial real estate	1,797				122				—				7,306				9,225				1,396,031				1,405,256

Loans to individuals	3,698				1,059				1,278				218				6,253				646,561				652,814

Total	$	13,473			$	2,690			$	2,619			$	42,667			$	61,449			$	4,395,859			$	4,457,308

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.
There were $3.0 million of impaired loans held for sale at March 31, 2015. There were no impaired loans held for sale at December 31, 2014. During the three months ended March 31, 2014, $0.7 million of impaired loans were sold at carrying value. No gains were recognized on the sale of impaired loans during the three months ended March 31, 2015 and 2014.
Significant nonaccrual loans as of March 31, 2015, include the following:

•	$9.3 million relationship of commercial and real estate loans to a local water facility construction company. These loans were originated from 2009 to 2013 and were placed in nonaccrual status during the fourth quarter of 2014. A valuation of the collateral was completed during the first quarter of 2015.

•	$6.1 million relationship 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 $2.4 million, was modified, resulting in TDR classification in the second quarter of 2012. A second of these loans was modified resulting in TDR classification in the first quarter of 2013 and paid in full during the first quarter of 2015. Another portion, totaling $3.1 million, was modified resulting in a TDR classification during the fourth quarter of 2014. During the three months ended March 31, 2015, charge-offs of $3.3 million related to this relationship were recorded. A valuation of the collateral was updated during the first quarter of 2015.
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, 2015 and December 31, 2014. 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-15												31-Dec-14
	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	$	14,650			$	20,137							$	9,439			$	10,937

Real estate construction	236				479								236				476

Residential real estate	9,901				11,749								10,773				12,470

Commercial real estate	7,958				9,317								8,768				10,178

Loans to individuals	318				383								288				337

Subtotal	33,063				42,065								29,504				34,398

With an allowance recorded:
Commercial, financial, agricultural and other	10,829				10,942				3,397				24,826				25,583				9,304

Real estate construction	—				—				—				—				—				—

Residential real estate	992				1,105				165				367				380				56

Commercial real estate	1,311				1,341				267				554				554				101

Loans to individuals	—				—				—				—				—				—

Subtotal	13,132				13,388				3,829				25,747				26,517				9,461

Total	$	46,195			$	55,453			$	3,829			$	55,251			$	60,915			$	9,461




	For the Three Months Ended March 31,
	2015								2014
	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	$	19,375			$	57			$	10,953			$	17

Real estate construction	239				—				2,438				12

Residential real estate	10,155				38				9,825				49

Commercial real estate	7,711				20				9,498				33

Loans to individuals	307				1				271				1

Subtotal	37,787				116				32,985				112

With an allowance recorded:
Commercial, financial, agricultural and other	10,917				28				17,649				45

Real estate construction	—				—				638				—

Residential real estate	901				3				3,161				8

Commercial real estate	1,323				1				307				1

Loans to individuals	—				—				—				—

Subtotal	13,141				32				21,755				54

Total	$	50,928			$	148			$	54,740			$	166




Unfunded commitments related to nonperforming loans were $0.6 million at March 31, 2015 and $46 thousand at December 31, 2014. After consideration of available collateral related to these commitments, a reserve of $14 thousand was established for these off balance sheet exposures at both March 31, 2015 and December 31, 2014.

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-15				31-Dec-14
	(dollars in thousands)
Troubled debt restructured loans
Accrual status	$	12,630			$	12,584

Nonaccrual status	8,978				16,952

Total	$	21,608			$	29,536

Commitments
Unused lines of credit	$	391			$	4,120

At March 31, 2015, $3.0 million of nonaccrual loans considered to be troubled debt restructured loans are excluded from the above table as they are classified as loans held for sale.
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, 2015
				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			$	1,498			$	—			$	—			$	1,498			$	1,476			$	—

Residential real estate	5			—				252				17				269				203				—

Commercial real estate	1			—				—				464				464				449				—

Loans to individuals	1			—				—				18				18				11				—

Total	8			$	1,498			$	252			$	499			$	2,249			$	2,139			$	—




	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

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, 2015 and 2014, $0.3 million and $0.2 million, respectively, of total rate modifications represent loans with modifications to the rate as well as payment as a result of reamortization. For both 2015 and 2014 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. There were no restructured loans that were considered to default during the three months ended March 31, 2015 and 2014.















The following tables provide detail related to the allowance for credit losses:


	For the Three Months Ended March 31, 2015
	Commercial,				Real estate				Residential				Commercial				Loans to				Total
	financial,				construction				real estate				real estate				individuals
	agricultural
	and other
	(dollars in thousands)
Allowance for credit losses:
Beginning Balance	$	29,627			$	2,063			$	3,664			$	11,881			$	4,816			$	52,051

Charge-offs	(5,080		)		—				(566		)		(202		)		(1,261		)		(7,109		)

Recoveries	200				—				96				138				162				596

Provision (credit)	(341		)		(535		)		193				670				1,172				1,159

Ending Balance	$	24,406			$	1,528			$	3,387			$	12,487			$	4,889			$	46,697

Ending balance: individually evaluated for impairment	$	3,397			$	—			$	165			$	267			$	—			$	3,829

Ending balance: collectively evaluated for impairment	21,009				1,528				3,222				12,220				4,889				42,868

Loans:
Ending balance	1,066,788				107,882				1,210,511				1,400,276				652,144				4,437,601

Ending balance: individually evaluated for impairment	24,586				199				7,071				7,803				—				39,659

Ending balance: collectively evaluated for impairment	1,042,202				107,683				1,203,440				1,392,473				652,144				4,397,942




	For the Three Months Ended March 31, 2014
	Commercial,				Real estate				Residential				Commercial				Loans to				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

Income_Taxes

Income Taxes	3 Months Ended
Income Taxes	Mar. 31, 2015
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes
Income Taxes	At March 31, 2015 and December 31, 2014, 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 2011 through 2013 were open for examination as of March 31, 2015.

Fair_Values_of_Assets_and_Liab

Fair Values of Assets and Liabilities	3 Months Ended
	Mar. 31, 2015
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, loans held for sale, interest rate derivatives that include interest rate caps, 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 7, “Impairment of Investment Securities.”
	Loans held for sale include residential mortgage loans originated for sale in the secondary mortgage market as well as an impaired commercial loan for which sale was considered an appropriate exit strategy. The estimated fair value for the mortgage loans were determined on the basis of rates obtained in the respective secondary market and the estimated fair value of the commercial loan was determined by market bids obtained from potential buyers.

	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 11, “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 2015, 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 United States There has been little or no active trading in these securities since 2009; therefore, it is 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 7, “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	$31,134		Discounted Cash Flow		Probability of default		0% - 100% (17.94%)
						Prepayment rates		0% - 73.77% (5.59%)
						Discount rates		5.25% - 13.00% (a)
	Equities	1,920		Par Value		N/A		N/A
	Impaired Loans	3,299 (b)		Reserve study		Discount rate		10.00%
						Gas per MCF		$1.88 - $5.27 (c)
						Oil per BBL/d		$55.00 - $90.00 (c)
						NGL per barrel		$15.00 (c)
	Other Real Estate Owned	49		Internal Valuation		N/A		N/A


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

	(b)	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.

	(c)	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 tables below present the balances of assets and liabilities measured at fair value on a recurring basis:


		31-Mar-15
		Level 1				Level 2				Level 3			Total
		(dollars in thousands)
	Obligations of U.S. Government Agencies:
	Mortgage-Backed Securities - Residential	$	—			$	25,413			$	—		$	25,413

	Obligations of U.S. Government-Sponsored Enterprises:
	Mortgage-Backed Securities - Residential	—				915,252				—			915,252

	Mortgage-Backed Securities - Commercial	—				66				—			66

	Other Government-Sponsored Enterprises	—				260,699				—			260,699

	Obligations of States and Political Subdivisions	—				27,549				—			27,549

Corporate Securities	—				7,252				—			7,252

Pooled Trust Preferred Collateralized Debt Obligations	—				—				31,134			31,134

Total Debt Securities	—				1,236,231				31,134			1,267,365

Equities	—				—				1,920			1,920

Total Securities Available for Sale	—				1,236,231				33,054			1,269,285

Other Investments	—				47,076				—			47,076

Loans held for sale	—				5,892				—			5,892

Other Assets(a)	—				15,182				—			15,182

Total Assets	$	—			$	1,304,381			$	33,054		$	1,337,435

Other Liabilities(a)	$	—			$	13,823			$	—		$	13,823

Total Liabilities	$	—			$	13,823			$	—		$	13,823


(a)	Hedging and non-hedging interest rate derivatives



	31-Dec-14
	Level 1				Level 2				Level 3			Total
	(dollars in thousands)
Obligations of U.S. Government Agencies:
Mortgage-Backed Securities - Residential	$	—			$	25,936			$	—		$	25,936

Obligations of U.S. Government-Sponsored Enterprises:
Mortgage-Backed Securities - Residential	—				950,881				—			950,881

Mortgage-Backed Securities - Commercial	—				74				—			74

Other Government-Sponsored Enterprises	—				267,877				—			267,877

Obligations of States and Political Subdivisions	—				27,377				—			27,377

Corporate Securities	—				7,255				—			7,255

Pooled Trust Preferred Collateralized Debt Obligations	—				—				28,999			28,999

Total Debt Securities	—				1,279,400				28,999			1,308,399

Equities	—				—				1,420			1,420

Total Securities Available for Sale	—				1,279,400				30,419			1,309,819

Other Investments	—				44,545				—			44,545

Loans Held for Sale	—				2,502				—			2,502

Other Assets(a)	—				11,186				—			11,186

Total Assets	$	—			$	1,337,633			$	30,419		$	1,368,052

Other Liabilities(a)	$	—			$	10,671			$	—		$	10,671

Total Liabilities	$	—			$	10,671			$	—		$	10,671


(a)	Hedging and 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:


	2015
	Pooled Trust Preferred Collateralized Debt Obligations				Equities				Total
	(dollars in thousands)
Balance, beginning of period	$	28,999			$	1,420			$	30,419

Total gains or losses
Included in earnings	105				—				105

Included in other comprehensive income	2,620				—				2,620

Purchases, issuances, sales, and settlements
Purchases	—				500				500

Issuances	—				—				—

Sales	—				—				—

Settlements	(590		)		—				(590		)

Transfers into Level 3	—				—				—

Balance, end of period	$	31,134			$	1,920			$	33,054




	2014
	Pooled Trust Preferred Collateralized Debt Obligations				Equities				Loans Held for Sale			Total
	(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

During the three months ended March 31, 2015 and 2014, there were no transfers between fair value Levels 1 and 2. During the three months ended March 31, 2015, there were no transfers between fair value Levels 2 and 3. However, $0.7 million of loans were transferred into Level 3 from Level 2 during the three months ended March 31, 2014 due to the loans being transferred to a held for sale status. The loans transferred and subsequently sold related to three nonperforming loan relationships 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, 2015 and 2014.







The tables below present the balances of assets measured at fair value on a non-recurring basis at:


	31-Mar-15
	Level 1				Level 2				Level 3			Total
	(dollars in thousands)
Impaired loans	$	—			$	32,270			$	10,095		$	42,365

Other real estate owned	—				7,788				49			7,837

Total Assets	$	—			$	40,058			$	10,144		$	50,202



	31-Dec-14
	Level 1				Level 2				Level 3			Total
	(dollars in thousands)
Impaired loans	$	—			$	34,864			$	10,926		$	45,790

Other real estate owned	—				7,828				153			7,981

Total Assets	$	—			$	42,692			$	11,079		$	53,771

The following gains (losses) were realized on the assets measured on a nonrecurring basis:



	For the Three Months Ended March 31,
	2015				2014
	(dollars in thousands)
Impaired loans	$	(555	)		$	(3,996	)
Other real estate owned	(69		)		(363		)
Total losses	$	(624	)		$	(4,359	)
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. For real estate secured loans, 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 real estate secured loans with balances under $250 thousand, we rely on broker price opinions. For non-real estate secured assets, the Company normally relies on third party valuations specific to the collateral type.
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 $7.0 million as of March 31, 2015 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 12, “Goodwill.” There were no other assets or liabilities measured at fair value on a non-recurring basis during the three months ended March 31, 2015.
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 and held to maturity 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.”
Loans Held for Sale: The estimated fair value of loans held for sale is based on market bids obtained from potential buyers.
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 $0.2 million at March 31, 2015 and December 31, 2014, respectively. See Note 5, “Commitments and Contingent Liabilities,” for additional information.
Deposit liabilities: Estimated fair value of demand deposits, savings accounts and money market deposits is the amount payable on demand at the reporting date because of the customers’ ability to withdraw funds immediately. 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-15
					Fair Value Measurements Using:
	Carrying				Total				Level 1			Level 2			Level 3
	Amount
	(dollars in thousands)
Financial assets
Cash and due from banks	$	62,161			$	62,161			$	62,161		$	—		$	—

Interest-bearing deposits	3,124				3,124				3,124			—			—

Securities available for sale	1,269,285				1,269,285				—			1,236,231			33,054

Securities held to maturity	30,253				30,174				—			30,174			—

Other investments	47,076				47,076				—			47,076			—

Loans held for sale	5,892				5,892				—			5,892			—

Loans	4,437,601				4,465,459				—			32,270			4,433,189

Financial liabilities
Deposits	4,293,749				4,297,771				—			4,297,771			—

Short-term borrowings	1,125,520				1,125,524				—			1,125,524			—

Long-term debt	64,324				65,255				—			65,255			—

Subordinated debt	72,167				63,069				—			—			63,069




	31-Dec-14
					Fair Value Measurements Using:
	Carrying				Total				Level 1			Level 2			Level 3
	Amount
	(dollars in thousands)
Financial assets
Cash and due from banks	$	72,276			$	72,276			$	72,276		$	—		$	—

Interest-bearing deposits	2,262				2,262				2,262			—			—

Securities available for sale	1,309,819				1,309,819				—			1,279,400			30,419

Other investments	44,545				44,545				—			44,545			—

Loans held for sale	2,502				2,502				—			2,502			—

Loans	4,457,308				4,439,766				—			34,864			4,404,902

Financial liabilities
Deposits	4,315,511				4,319,997				—			4,319,997			—

Short-term borrowings	1,105,876				1,105,867				—			1,105,867			—

Long-term debt	89,459				90,319				—			90,319			—

Subordinated debt	72,167				62,815				—			—			62,815

Derivatives

Derivatives	3 Months Ended
	Mar. 31, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivatives	Derivatives
	Derivatives Not Designated as Hedging Instruments
	First Commonwealth is a party to interest rate derivatives that are not designated as hedging instruments. 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 thirteen 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 three 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.
	Derivatives Designated as Hedging Instruments
	The Company has entered four interest rate swap contracts which were designated as cash flow hedges. The interest rate swaps have a total notional amount of $200.0 million, $85.0 million with an original maturity of three years and $115.0 million with original maturity of four years. The Company's risk management objective for these hedges is to reduce its exposure to variability in expected future cash flows related to interest payments on commercial loans benchmarked to the 1-month LIBOR rate. Therefore, the interest rate swaps convert the interest payments on the first $200.0 million of 1-month LIBOR based commercial loans into fixed rate payments.
	The periodic net settlement of interest rate swaps is recorded as an adjustment to Interest and fees on loans in the Condensed Consolidated Statement of Income. For the three months ended March 31, 2015, there was a $0.4 million impact on interest income as a result of these interest rate swaps. Changes in the fair value of the effective portion of cash flow hedges are reported in OCI. When the cash flows associated with the hedged item are realized, the gain or loss included in OCI is recognized in Interest and fees on loans, the same line item in the Condensed Consolidated Statement of Income as the income on the hedged items. The cash flow hedges were highly effective at March 31, 2015, and December 31, 2014, and changes in the fair value attributed to hedge ineffectiveness were not material.
	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-15			31-Dec-14
		(dollars in thousands)
	Derivatives not Designated as Hedging Instruments
	Credit value adjustment	$	(498	)	$	(268	)
	Notional Amount:
	Interest rate derivatives	286,528			273,388

	Interest rate caps	6,375			6,656

	Risk participation agreements	109,114			113,624

	Sold credit protection on risk participation agreements	(17,827		)	(17,296		)
	Derivatives Designated as Hedging Instruments
	Fair value adjustment	1,667			472

	Notional Amount - Interest rate derivatives	200,000			100,000


	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,
		2015			2014
		(dollars in thousands)
	Non-hedging interest rate derivatives
	Decrease in other income	$	(230	)	$	(58	)
	Hedging interest rate derivatives
	Increase in interest and fees on loans	381			—

	Increase in other expense	9			—

Goodwill

Goodwill	3 Months Ended
Goodwill	Mar. 31, 2015
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.
	We consider First Commonwealth to be one reporting unit. The carrying amount of goodwill as of March 31, 2015 and December 31, 2014 was $161.4 million. No impairment charges on goodwill or other intangible assets were incurred in 2015 or 2014.
	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.
	As of March 31, 2015, goodwill was not considered impaired; however, changing economic conditions that may adversely affect our performance, fair value of our assets and liabilities, our 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
New Accounting Pronouncements (Notes)	Mar. 31, 2015
Accounting Changes and Error Corrections [Abstract]
New Accounting Pronouncements	New Accounting Pronouncements
New Accounting Pronouncements	In January 2015, the FASB issued ASU No. 2015-01, "Income Statement - Extraordinary and Unusual Items (Subtopic 225-20)," which finalizes Proposed ASU No. 2014-220, and eliminates the concept of extraordinary items from U.S. GAAP. Accordingly, this ASU eliminates FASB ASC Subtopic 225-20, "Income Statement -Extraordinary and Unusual Items", which, until now, required that an entity separately classify, present, and disclose extraordinary events and transactions. This ASU is effective for fiscal years, and interim periods within those fiscal years, 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.

Supplemental_Comprehensive_Inc1

Supplemental Comprehensive Income Disclosures (Tables)	3 Months Ended
	Mar. 31, 2015
Supplemental Comprehensive Income Disclosures [Abstract]
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 and reclassification adjustments related to losses on derivatives are included in the "Other operating expenses" line in the Condensed Consolidated Statements of Income.


		For the Three Months Ended March 31,
		2015												2014
		Pretax Amount				Tax (Expense) Benefit				Net of Tax Amount				Pretax Amount				Tax (Expense) Benefit				Net of Tax Amount
		(dollars in thousands)
	Unrealized gains on securities:
	Unrealized holding gains on securities arising during the period	$	9,980			$	(3,491	)		$	6,489			$	12,457			$	(4,361	)		$	8,096

	Reclassification adjustment for gains on securities included in net income	(105		)		37				(68		)		—				—				—

	Total unrealized gains on securities	9,875				(3,454		)		6,421				12,457				(4,361		)		8,096

	Unrealized gains on derivatives:
	Unrealized holding gains on derivatives arising during the period	1,195				(418		)		777				—				—				—

	Reclassification adjustment for losses on derivatives included in net income	5				(2		)		3				—				—				—

	Total unrealized gains on derivatives	1,200				(420		)		780				—				—				—

	Total other comprehensive income	$	11,075			$	(3,874	)		$	7,201			$	12,457			$	(4,361	)		$	8,096





Schedule of Accumulated Other Comprehensive Income (Loss)	The following table details the change in components of OCI for the three months ended March 31:


		2015													2014
		Securities Available for Sale			Post-Retirement Obligation			Derivatives			Accumulated Other Comprehensive Income				Securities Available for Sale			Post-Retirement Obligation			Derivatives			Accumulated Other Comprehensive Income
		(dollars in thousands)
	Balance at December 31	$	(4,875	)	$	300		$	76		$	(4,499	)		$	(20,868	)	$	280		$	—		$	(20,588	)

	Other comprehensive income before reclassification adjustment	6,489			—			777			7,266				8,096			—			—			8,096

	Amounts reclassified from accumulated other comprehensive (loss) income	(68		)	—			3			(65		)		—			—			—			—

	Net other comprehensive income during the period	6,421			—			780			7,201				8,096			—			—			8,096

	Balance at March 31	$	1,546		$	300		$	856		$	2,702			$	(12,772	)	$	280		$	—		$	(12,492	)

Supplemental_Cash_Flow_Disclos1

Supplemental Cash Flow Disclosures (Tables)	3 Months Ended
	Mar. 31, 2015
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:


		2015		2014
		(dollars in thousands)
	Cash paid during the period for:
	Interest	$	4,004	$	5,108

	Income taxes	1,500		—

	Non-cash investing and financing activities:
	Loans transferred to other real estate owned and repossessed assets	797		1,292

	Loans transferred from held to maturity to held for sale	3,011		716

	Gross increase in market value adjustment to securities available for sale	9,869		12,459

	Gross increase in market value adjustment to derivatives	1,200		—

	Investments committed to purchase, not settled	637		2,522

	Unsettled treasury stock repurchases	453		233

Earnings_per_Share_Tables

Earnings per Share (Tables)	3 Months Ended
Earnings per Share (Tables)	Mar. 31, 2015
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,
		2015		2014
	Weighted average common shares issued	105,563,455		105,563,455
	Weighted average common shares issued	105,563,455		105,563,455
	Average treasury stock shares	(14,503,976	)	(10,876,695	)
	Average unearned nonvested shares	(183,755	)	(143,340	)
	Weighted average common shares and common stock equivalents used to calculate basic earnings per share	90,875,724		94,543,420
		90,875,724		94,543,420
	Additional common stock equivalents (nonvested stock) used to calculate diluted earnings per share	13,311		24,639
		13,311		24,639
	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	90,889,035		94,568,059
		90,889,035		94,568,059
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.


		2015						2014
				Price Range					Price Range
		Shares		From		To		Shares	From		To
	Stock Options	—		$	—	$	—	15,000	$	14.55	$	14.55
	Stock Options	—		$	—	$	—	15,000	$	14.55	$	14.55
	Restricted Stock	118,390		7.35		9.26		5,601	8.75		9.18
	Restricted Stock	118,390		7.35		9.26		5,601	8.75		9.18

Commitments_and_Contingent_Lia1

Commitments and Contingent Liabilities (Tables)	3 Months Ended
	Mar. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Notional Amount of Outstanding Commitments	The following table identifies the notional amount of those instruments at:


		31-Mar-15		31-Dec-14
		(dollars in thousands)
	Financial instruments whose contract amounts represent credit risk:
	Commitments to extend credit	$	1,645,977	$	1,635,948

	Financial standby letters of credit	27,858		36,075

	Performance standby letters of credit	26,490		25,915

	Commercial letters of credit	2,584		2,611

Investment_Securities_Tables

Investment Securities (Tables)	3 Months Ended
Investment Securities (Tables)	Mar. 31, 2015
Investment 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-15									31-Dec-14
		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	$	22,578	$	2,835	$	—		$	25,413	$	23,344	$	2,595	$	(3	)	$	25,936
	Mortgage-Backed Securities – Residential	$	22,578	$	2,835	$	—		$	25,413	$	23,344	$	2,595	$	(3	)	$	25,936
	Obligations of U.S. Government-Sponsored Enterprises:
	Obligations of U.S. Government-Sponsored Enterprises:
	Mortgage-Backed Securities – Residential	905,895		15,759		(6,402		)	915,252		947,635		13,076		(9,830		)	950,881
	Mortgage-Backed Securities – Residential	905,895		15,759		(6,402		)	915,252		947,635		13,076		(9,830		)	950,881
	Mortgage-Backed Securities – Commercial	65		1		—			66		72		2		—			74
	Mortgage-Backed Securities – Commercial	65		1		—			66		72		2		—			74
	Other Government-Sponsored Enterprises	260,849		180		(330		)	260,699		269,181		4		(1,308		)	267,877
	Other Government-Sponsored Enterprises	260,849		180		(330		)	260,699		269,181		4		(1,308		)	267,877
	Obligations of States and Political Subdivisions	27,060		494		(5		)	27,549		27,058		362		(43		)	27,377
	Obligations of States and Political Subdivisions	27,060		494		(5		)	27,549		27,058		362		(43		)	27,377
	Corporate Securities	6,680		572		—			7,252		6,682		573		—			7,255
	Corporate Securities	6,680		572		—			7,252		6,682		573		—			7,255
	Pooled Trust Preferred Collateralized Debt Obligations	41,868		503		(11,237		)	31,134		41,926		309		(13,236		)	28,999
	Pooled Trust Preferred Collateralized Debt Obligations	41,868		503		(11,237		)	31,134		41,926		309		(13,236		)	28,999
	Total Debt Securities	1,264,995		20,344		(17,974		)	1,267,365		1,315,898		16,921		(24,420		)	1,308,399
	Total Debt Securities	1,264,995		20,344		(17,974		)	1,267,365		1,315,898		16,921		(24,420		)	1,308,399
	Equities	1,920		—		—			1,920		1,420		—		—			1,420
	Equities	1,920		—		—			1,920		1,420		—		—			1,420
	Total Securities Available for Sale	$	1,266,915	$	20,344	$	(17,974	)	$	1,269,285	$	1,317,318	$	16,921	$	(24,420	)	$	1,309,819
	Total Securities Available for Sale	$	1,266,915	$	20,344	$	(17,974	)	$	1,269,285	$	1,317,318	$	16,921	$	(24,420	)	$	1,309,819
Amortized Cost and Estimated Fair Value of Debt Securities Available for Sale	The amortized cost and estimated fair value of debt securities available for sale at March 31, 2015, by contractual maturity, are shown below.


		Amortized		Estimated
		Cost		Fair Value
		(dollars in thousands)
	Due within 1 year	$	6,800	$	6,798
	Due within 1 year	$	6,800	$	6,798
	Due after 1 but within 5 years	254,050		253,901
	Due after 1 but within 5 years	254,050		253,901
	Due after 5 but within 10 years	24,420		24,869
	Due after 5 but within 10 years	24,420		24,869
	Due after 10 years	51,187		41,066
	Due after 10 years	51,187		41,066
		336,457		326,634
		336,457		326,634
	Mortgage-Backed Securities (a)	928,538		940,731
	Mortgage-Backed Securities (a)	928,538		940,731
	Total Debt Securities	$	1,264,995	$	1,267,365
	Total Debt Securities	$	1,264,995	$	1,267,365


	(a)	Mortgage Backed Securities include an amortized cost of $22.6 million and a fair value of $25.4 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:


		2015		2014
		(dollars in thousands)
	Proceeds from sales	$	—	$	—
	Proceeds from sales	$	—	$	—
	Gross gains (losses) realized:
	Sales Transactions:
	Gross gains	$	—	$	—
	Gross gains	$	—	$	—
	Gross losses	—		—
	Gross losses	—		—
		—		—
		—		—
	Maturities and impairment
	Gross gains	105		—
	Gross gains	105		—
	Gross losses	—		—
	Gross losses	—		—
	Other-than-temporary impairment	—		—
	Other-than-temporary impairment	—		—
		105		—
		105		—
	Net gains and impairment	$	105	$	—
	Net gains and impairment	$	105	$	—

Investment_Securities_Maturity

Investment Securities Maturity of Held-to-Maturity Securities (Tables)	3 Months Ended
	Mar. 31, 2015
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity Securities [Table Text Block]	Below is an analysis of the amortized cost and fair values of debt securities held to maturity at March 31, 2015. There were no held to maturity securities at December 31, 2014.


		31-Mar-15
		Amortized		Gross		Gross			Estimated
		Cost		Unrealized		Unrealized			Fair Value
				Gains		Losses
		(dollars in thousands)
	Obligations of U.S. Government-Sponsored Enterprises:
	Mortgage-Backed Securities – Residential	$	26,315	$	—	$	(98	)	$	26,217

	Obligations of States and Political Subdivisions	3,938		19		—			3,957

	Total Securities Held to Maturity	$	30,253	$	19	$	(98	)	$	30,174

Schedule of Held-to-Maturity Securities by Maturity [Table Text Block]	The amortized cost and estimated fair value of debt securities held to maturity at March 31, 2015, by contractual maturity, are shown below. Expected maturities will differ from contractual maturities because borrowers may have the right to call or repay obligations with or without call or prepayment penalties.


		Amortized		Estimated
		Cost		Fair Value
		(dollars in thousands)
	Due within 1 year	$	—	$	—

	Due after 1 but within 5 years	—		—

	Due after 5 but within 10 years	—		—

	Due after 10 years	3,938		3,957

		3,938		3,957

	Mortgage-Backed Securities (a)	26,315		26,217

	Total Debt Securities	$	30,253	$	30,174


	(a)	Mortgage Backed Securities include an amortized cost of $26.3 million and a fair value of $26.2 million for Obligations of U.S. Government-sponsored enterprises issued by Fannie Mae and Freddie Mac.

Impairment_of_Investment_Secur1

Impairment of Investment Securities (Tables)	3 Months Ended
	Mar. 31, 2015
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, 2015 for both available for sale and held to maturity securities 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-Sponsored Enterprises:
	Mortgage-Backed Securities – Residential	84,160				(435		)		300,792				(6,065		)	384,952			(6,500		)

	Other Government-Sponsored Enterprises	27,985				(15		)		122,833				(315		)	150,818			(330		)

	Obligations of States and Political Subdivisions	878				(5		)		—				—			878			(5		)

	Pooled Trust Preferred Collateralized Debt Obligations	—				—				26,318				(11,237		)	26,318			(11,237		)

	Total Securities	$	113,023			$	(455	)		$	449,943			$	(17,617	)	$	562,966		$	(18,072	)

	The following table presents the gross unrealized losses and estimated fair values at December 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	$	2,318			$	(3	)		$	—			$	—		$	2,318		$	(3	)

	Obligations of U.S. Government-Sponsored Enterprises:
	Mortgage-Backed Securities – Residential	111,646				(419		)		368,706				(9,411		)	480,352			(9,830		)

	Other Government-Sponsored Enterprises	112,473				(229		)		130,401				(1,079		)	242,874			(1,308		)

	Obligation of States and Political Subdivisions	3,146				(43		)		—				—			3,146			(43		)

	Pooled Trust Preferred Collateralized Debt Obligations	—				—				24,356				(13,236		)	24,356			(13,236		)

	Total Securities	$	229,583			$	(694	)		$	523,463			$	(23,726	)	$	753,046		$	(24,420	)

Pooled Trust Preferred Collateralized Debt Obligations	The following table provides information related to our pooled trust preferred collateralized debt obligations as of March 31, 2015:


	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			$	1,324			$	(506	)		B1/BB	6		18.05	%		56	%

	Pre TSL VII	Mezzanine		2,789				3,147				358				Ca/-	14		49.68			—

	Pre TSL VIII	Mezzanine		1,984				1,446				(538		)		C/C	29		58.01			—

	Pre TSL IX	Mezzanine		2,349				1,597				(752		)		B3/C	40		28.91			6.61

	Pre TSL X	Mezzanine		1,524				1,669				145				Caa1/C	43		31.6			—

	Pre TSL XII	Mezzanine		5,559				3,969				(1,590		)		B3/C	66		25.23			—

	Pre TSL XIII	Mezzanine		12,525				8,870				(3,655		)		B3/C	56		25.44			20.85

	Pre TSL XIV	Mezzanine		12,876				8,702				(4,174		)		Caa1/C	56		25.46			38.55

	MMCap I	Mezzanine		432				410				(22		)		Ca/C	10		56.11			24.92

	Total			$	41,868			$	31,134			$	(10,734	)

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,
		2015				2014
		(dollars in thousands)
	Balance, beginning (a)	$	26,246			$	27,543

	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)	(321		)		(289		)
	Reduction for debt securities called during the period	(218		)		—

	Balance, ending	$	25,707			$	27,254



	(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, 2015
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-15				31-Dec-14
		(dollars in thousands)
	Commercial, financial, agricultural and other	$	1,066,788			$	1,052,109

	Real estate construction	107,882				120,785

	Residential real estate	1,210,511				1,226,344

	Commercial real estate	1,400,276				1,405,256

	Loans to individuals	652,144				652,814

	Total loans and leases net of unearned income	$	4,437,601			$	4,457,308

Credit Risk Profile by Creditworthiness	The following tables represent our credit risk profile by creditworthiness:


		31-Mar-15
		Commercial, financial, agricultural and other				Real estate construction				Residential real estate				Commercial real estate				Loans to individuals				Total
		(dollars in thousands)
	Pass	$	1,006,516			$	107,180			$	1,198,876			$	1,350,930			$	651,883			$	4,315,385

	Non-Pass
	OAEM	31,642				466				1,661				30,054				—				63,823

	Substandard	28,630				236				9,974				19,292				261				58,393

	Doubtful	—				—				—				—				—				—

	Total Non-Pass	60,272				702				11,635				49,346				261				122,216

	Total	$	1,066,788			$	107,882			$	1,210,511			$	1,400,276			$	652,144			$	4,437,601




		31-Dec-14
		Commercial, financial, agricultural and other				Real estate construction				Residential real estate				Commercial real estate				Loans to individuals				Total
		(dollars in thousands)
	Pass	$	983,357			$	112,536			$	1,214,920			$	1,353,773			$	652,596			$	4,317,182

	Non-Pass
	OAEM	32,563				8,013				2,315				29,479				—				72,370

	Substandard	32,028				236				9,109				22,004				218				63,595

	Doubtful	4,161				—				—				—				—				4,161

	Total Non-Pass	68,752				8,249				11,424				51,483				218				140,126

	Total	$	1,052,109			$	120,785			$	1,226,344			$	1,405,256			$	652,814			$	4,457,308

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, 2015 and December 31, 2014. 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-15
		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	$	292			$	320			$	149			$	18,654			$	19,415			$	1,047,373			$	1,066,788

	Real estate construction	—				—				—				236				236				107,646				107,882

	Residential real estate	3,815				1,054				2,438				7,583				14,890				1,195,621				1,210,511

	Commercial real estate	1,283				124				382				6,831				8,620				1,391,656				1,400,276

	Loans to individuals	2,692				612				1,276				261				4,841				647,303				652,144

	Total	$	8,082			$	2,110			$	4,245			$	33,565			$	48,002			$	4,389,599			$	4,437,601




		31-Dec-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	$	2,816			$	213			$	264			$	27,007			$	30,300			$	1,021,809			$	1,052,109

	Real estate construction	—				1				—				236				237				120,548				120,785

	Residential real estate	5,162				1,295				1,077				7,900				15,434				1,210,910				1,226,344

	Commercial real estate	1,797				122				—				7,306				9,225				1,396,031				1,405,256

	Loans to individuals	3,698				1,059				1,278				218				6,253				646,561				652,814

	Total	$	13,473			$	2,690			$	2,619			$	42,667			$	61,449			$	4,395,859			$	4,457,308

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, 2015 and December 31, 2014. 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-15												31-Dec-14
		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	$	14,650			$	20,137							$	9,439			$	10,937

	Real estate construction	236				479								236				476

	Residential real estate	9,901				11,749								10,773				12,470

	Commercial real estate	7,958				9,317								8,768				10,178

	Loans to individuals	318				383								288				337

	Subtotal	33,063				42,065								29,504				34,398

	With an allowance recorded:
	Commercial, financial, agricultural and other	10,829				10,942				3,397				24,826				25,583				9,304

	Real estate construction	—				—				—				—				—				—

	Residential real estate	992				1,105				165				367				380				56

	Commercial real estate	1,311				1,341				267				554				554				101

	Loans to individuals	—				—				—				—				—				—

	Subtotal	13,132				13,388				3,829				25,747				26,517				9,461

	Total	$	46,195			$	55,453			$	3,829			$	55,251			$	60,915			$	9,461




		For the Three Months Ended March 31,
		2015								2014
		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	$	19,375			$	57			$	10,953			$	17

	Real estate construction	239				—				2,438				12

	Residential real estate	10,155				38				9,825				49

	Commercial real estate	7,711				20				9,498				33

	Loans to individuals	307				1				271				1

	Subtotal	37,787				116				32,985				112

	With an allowance recorded:
	Commercial, financial, agricultural and other	10,917				28				17,649				45

	Real estate construction	—				—				638				—

Residential real estate	901				3				3,161				8

Commercial real estate	1,323				1				307				1

Loans to individuals	—				—				—				—

Subtotal	13,141				32				21,755				54

Total	$	50,928			$	148			$	54,740			$	166




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-15				31-Dec-14
		(dollars in thousands)
	Troubled debt restructured loans
	Accrual status	$	12,630			$	12,584

	Nonaccrual status	8,978				16,952

	Total	$	21,608			$	29,536

	Commitments
	Unused lines of credit	$	391			$	4,120

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, 2015
					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			$	1,498			$	—			$	—			$	1,498			$	1,476			$	—

	Residential real estate	5			—				252				17				269				203				—

	Commercial real estate	1			—				—				464				464				449				—

	Loans to individuals	1			—				—				18				18				11				—

	Total	8			$	1,498			$	252			$	499			$	2,249			$	2,139			$	—




		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







Troubled Debt Restructuring Identified During Period






Allowance for Credit Losses	The following tables provide detail related to the allowance for credit losses:


		For the Three Months Ended March 31, 2015
		Commercial,				Real estate				Residential				Commercial				Loans to				Total
		financial,				construction				real estate				real estate				individuals
		agricultural
		and other
		(dollars in thousands)
	Allowance for credit losses:
	Beginning Balance	$	29,627			$	2,063			$	3,664			$	11,881			$	4,816			$	52,051

	Charge-offs	(5,080		)		—				(566		)		(202		)		(1,261		)		(7,109		)

	Recoveries	200				—				96				138				162				596

	Provision (credit)	(341		)		(535		)		193				670				1,172				1,159

	Ending Balance	$	24,406			$	1,528			$	3,387			$	12,487			$	4,889			$	46,697

	Ending balance: individually evaluated for impairment	$	3,397			$	—			$	165			$	267			$	—			$	3,829

	Ending balance: collectively evaluated for impairment	21,009				1,528				3,222				12,220				4,889				42,868

	Loans:
	Ending balance	1,066,788				107,882				1,210,511				1,400,276				652,144				4,437,601

	Ending balance: individually evaluated for impairment	24,586				199				7,071				7,803				—				39,659

	Ending balance: collectively evaluated for impairment	1,042,202				107,683				1,203,440				1,392,473				652,144				4,397,942




		For the Three Months Ended March 31, 2014
		Commercial,				Real estate				Residential				Commercial				Loans to				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

Fair_Values_of_Assets_and_Liab1

Fair Values of Assets and Liabilities (Tables)	3 Months Ended
	Mar. 31, 2015
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	$31,134		Discounted Cash Flow		Probability of default		0% - 100% (17.94%)
						Prepayment rates		0% - 73.77% (5.59%)
						Discount rates		5.25% - 13.00% (a)
	Equities	1,920		Par Value		N/A		N/A
	Impaired Loans	3,299 (b)		Reserve study		Discount rate		10.00%
						Gas per MCF		$1.88 - $5.27 (c)
						Oil per BBL/d		$55.00 - $90.00 (c)
						NGL per barrel		$15.00 (c)
	Other Real Estate Owned	49		Internal Valuation		N/A		N/A


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

	(b)	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.

	(c)	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-15
		Level 1				Level 2				Level 3				Total
		(dollars in thousands)
	Obligations of U.S. Government Agencies:
	Mortgage-Backed Securities - Residential	$	—			$	25,413			$	—			$	25,413

	Obligations of U.S. Government-Sponsored Enterprises:
	Mortgage-Backed Securities - Residential	—				915,252				—				915,252

	Mortgage-Backed Securities - Commercial	—				66				—				66

	Other Government-Sponsored Enterprises	—				260,699				—				260,699

	Obligations of States and Political Subdivisions	—				27,549				—				27,549

	Corporate Securities	—				7,252				—				7,252

	Pooled Trust Preferred Collateralized Debt Obligations	—				—				31,134				31,134

	Total Debt Securities	—				1,236,231				31,134				1,267,365

	Equities	—				—				1,920				1,920

	Total Securities Available for Sale	—				1,236,231				33,054				1,269,285

	Other Investments	—				47,076				—				47,076

	Loans held for sale	—				5,892				—				5,892

	Other Assets(a)	—				15,182				—				15,182

	Total Assets	$	—			$	1,304,381			$	33,054			$	1,337,435

	Other Liabilities(a)	$	—			$	13,823			$	—			$	13,823

	Total Liabilities	$	—			$	13,823			$	—			$	13,823


	(a)	Hedging and non-hedging interest rate derivatives



		31-Dec-14
		Level 1				Level 2				Level 3				Total
		(dollars in thousands)
	Obligations of U.S. Government Agencies:
	Mortgage-Backed Securities - Residential	$	—			$	25,936			$	—			$	25,936

	Obligations of U.S. Government-Sponsored Enterprises:
	Mortgage-Backed Securities - Residential	—				950,881				—				950,881

	Mortgage-Backed Securities - Commercial	—				74				—				74

	Other Government-Sponsored Enterprises	—				267,877				—				267,877

	Obligations of States and Political Subdivisions	—				27,377				—				27,377

	Corporate Securities	—				7,255				—				7,255

	Pooled Trust Preferred Collateralized Debt Obligations	—				—				28,999				28,999

Total Debt Securities	—				1,279,400				28,999				1,308,399

Equities	—				—				1,420				1,420

Total Securities Available for Sale	—				1,279,400				30,419				1,309,819

Other Investments	—				44,545				—				44,545

Loans Held for Sale	—				2,502				—				2,502

Other Assets(a)	—				11,186				—				11,186

Total Assets	$	—			$	1,337,633			$	30,419			$	1,368,052

Other Liabilities(a)	$	—			$	10,671			$	—			$	10,671

Total Liabilities	$	—			$	10,671			$	—			$	10,671


(a)	Hedging and 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:


		2015
		Pooled Trust Preferred Collateralized Debt Obligations				Equities				Total
		(dollars in thousands)
	Balance, beginning of period	$	28,999			$	1,420			$	30,419

	Total gains or losses
	Included in earnings	105				—				105

	Included in other comprehensive income	2,620				—				2,620

	Purchases, issuances, sales, and settlements
	Purchases	—				500				500

	Issuances	—				—				—

	Sales	—				—				—

	Settlements	(590		)		—				(590		)

	Transfers into Level 3	—				—				—

	Balance, end of period	$	31,134			$	1,920			$	33,054




		2014
		Pooled Trust Preferred Collateralized Debt Obligations				Equities				Loans Held for Sale				Total
		(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








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-15
		Level 1				Level 2				Level 3				Total
		(dollars in thousands)
	Impaired loans	$	—			$	32,270			$	10,095			$	42,365

	Other real estate owned	—				7,788				49				7,837

	Total Assets	$	—			$	40,058			$	10,144			$	50,202



		31-Dec-14
		Level 1				Level 2				Level 3				Total
		(dollars in thousands)
	Impaired loans	$	—			$	34,864			$	10,926			$	45,790

	Other real estate owned	—				7,828				153				7,981

	Total Assets	$	—			$	42,692			$	11,079			$	53,771

Losses Realized on Assets Measured on Non-Recurring Basis	The following gains (losses) were realized on the assets measured on a nonrecurring basis:



		For the Three Months Ended March 31,
		2015				2014
		(dollars in thousands)
	Impaired loans	$	(555	)		$	(3,996	)
	Other real estate owned	(69		)		(363		)
	Total losses	$	(624	)		$	(4,359	)
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-15
						Fair Value Measurements Using:
		Carrying				Total				Level 1				Level 2			Level 3
		Amount
		(dollars in thousands)
	Financial assets
	Cash and due from banks	$	62,161			$	62,161			$	62,161			$	—		$	—

	Interest-bearing deposits	3,124				3,124				3,124				—			—

	Securities available for sale	1,269,285				1,269,285				—				1,236,231			33,054

	Securities held to maturity	30,253				30,174				—				30,174			—

	Other investments	47,076				47,076				—				47,076			—

	Loans held for sale	5,892				5,892				—				5,892			—

	Loans	4,437,601				4,465,459				—				32,270			4,433,189

	Financial liabilities
	Deposits	4,293,749				4,297,771				—				4,297,771			—

	Short-term borrowings	1,125,520				1,125,524				—				1,125,524			—

	Long-term debt	64,324				65,255				—				65,255			—

	Subordinated debt	72,167				63,069				—				—			63,069




		31-Dec-14
						Fair Value Measurements Using:
		Carrying				Total				Level 1				Level 2			Level 3
		Amount
		(dollars in thousands)
	Financial assets
	Cash and due from banks	$	72,276			$	72,276			$	72,276			$	—		$	—

	Interest-bearing deposits	2,262				2,262				2,262				—			—

	Securities available for sale	1,309,819				1,309,819				—				1,279,400			30,419

	Other investments	44,545				44,545				—				44,545			—

	Loans held for sale	2,502				2,502				—				2,502			—

	Loans	4,457,308				4,439,766				—				34,864			4,404,902

	Financial liabilities
	Deposits	4,315,511				4,319,997				—				4,319,997			—

	Short-term borrowings	1,105,876				1,105,867				—				1,105,867			—

	Long-term debt	89,459				90,319				—				90,319			—

	Subordinated debt	72,167				62,815				—				—			62,815

Derivatives_Tables

Derivatives (Tables)	3 Months Ended
	Mar. 31, 2015
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-15			31-Dec-14
		(dollars in thousands)
	Derivatives not Designated as Hedging Instruments
	Credit value adjustment	$	(498	)	$	(268	)
	Notional Amount:
	Interest rate derivatives	286,528			273,388

	Interest rate caps	6,375			6,656

	Risk participation agreements	109,114			113,624

	Sold credit protection on risk participation agreements	(17,827		)	(17,296		)
	Derivatives Designated as Hedging Instruments
	Fair value adjustment	1,667			472

	Notional Amount - Interest rate derivatives	200,000			100,000

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,
		2015			2014
		(dollars in thousands)
	Non-hedging interest rate derivatives
	Decrease in other income	$	(230	)	$	(58	)
	Hedging interest rate derivatives
	Increase in interest and fees on loans	381			—

	Increase in other expense	9			—

Supplemental_Comprehensive_Inc2

Supplemental Comprehensive Income Disclosures (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Supplemental Comprehensive Income Disclosures [Abstract]
Unrealized holding gains on securities arising during the period	$9,980	$12,457
Reclassification adjustment for gains on securities included in net income	-105	0
Total unrealized gains on securities	9,875	12,457
Unrealized holding gains on derivatives arising during the period	1,195	0
Reclassification adjustment for gains on derivatives included in net income, before Tax	5	0
Total unrealized gain on derivatives	1,200	0
Total other comprehensive (loss) income	11,075	12,457
Unrealized holding gains on securities arising during the period	-3,491	-4,361
Reclassification adjustment for gains on securities included in net income	37	0
Other Comprehensive Income (Loss), Available-for-sale Securities, Tax	-3,454	-4,361
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Tax	-418	0
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Tax	-2	0
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Tax	-420	0
Total other comprehensive (loss) income	-3,874	-4,361
Other comprehensive income (loss) before reclassification adjustment	6,489	8,096
Reclassification adjustment for gains on securities included in net income	-68	0
Total unrealized (losses) gains on securities	6,421	8,096
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax	780	0
Total other comprehensive (loss) income	$7,201	$8,096

Supplemental_Comprehensive_Inc3

Supplemental Comprehensive Income Disclosures (Details 2) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Beginning Balance	($4,499)	($20,588)
Other comprehensive income (loss) before reclassification adjustment	6,489	8,096
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	7,266	8,096
Amounts reclassified from accumulated other comprehensive income (loss)	-65	0
Total other comprehensive (loss) income	7,201	8,096
Accumulated Other Comprehensive Income (Loss), Ending Balance	2,702	-12,492
Accumulated Net Unrealized Investment Gain (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Beginning Balance	-4,875	-20,868
Other comprehensive income (loss) before reclassification adjustment	6,489	8,096
Amounts reclassified from accumulated other comprehensive income (loss)	-68	0
Total other comprehensive (loss) income	6,421	8,096
Accumulated Other Comprehensive Income (Loss), Ending Balance	1,546	-12,772
Accumulated Defined Benefit Plans Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Beginning Balance	300	280
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	300	280
Derivative [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Beginning Balance	76	0
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax	777	0
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Net of Tax	-3	0
Total other comprehensive (loss) income	780	0
Accumulated Other Comprehensive Income (Loss), Ending Balance	856	0
Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total other comprehensive (loss) income	$7,201	$8,096

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, 2015	Mar. 31, 2014
Cash paid during the period for:
Interest	$4,004	$5,108
Income Taxes Paid, Net	1,500	0
Non-cash investing and financing activities:
Loans Transferred to Other Real Estate Owned and Repossessions	797	1,292
Fair value of loans transferred from held to maturity to held for sale	3,011	716
Gross increase in market value adjustment to securities available for sale	9,869	12,459
Gross increase in market value adjustment to derivatives	1,200	0
Investments committed to purchase not settled	637	2,522
Unsettled treasury stock repurchases	$453	$233

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, 2015	Mar. 31, 2014
Earnings Per Share [Abstract]
Weighted Average Number of Shares Issued, Basic	105,563,455	105,563,455
Average treasury shares (in shares)	-14,503,976	-10,876,695
Average unearned nonvested shares	-183,755	-143,340
Weighted average common shares and common stock equivalents used to calculate basic earnings per share (in shares)	90,875,724	94,543,420
Additional common stock equivalents (nonvested stock) used to calculate diluted earnings per share	13,311	24,639
Incremental Common Shares Attributable to Call Options and Warrants	0	0
Weighted average common shares and common stock equivalents used to calculate diluted earnings per share (in shares)	90,889,035	94,568,059

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, 2015	Mar. 31, 2014
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)	0	15,000
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)	118,390	5,601
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	0	14.55
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	7.35	8.75
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	0	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	9.26	9.18

Commitments_and_Contingent_Lia2

Commitments and Contingent Liabilities - Notional Amount of Outstanding Commitments (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Commitments to extend credit [Member]
Loss Contingencies [Line Items]
Financial instrument of credit risk	$1,645,977	$1,635,948
Financial standby letters of credit [Member]
Loss Contingencies [Line Items]
Financial instrument of credit risk	27,858	36,075
Performance standby letters of credit [Member]
Loss Contingencies [Line Items]
Financial instrument of credit risk	26,490	25,915
Commercial letters of credit [Member]
Loss Contingencies [Line Items]
Financial instrument of credit risk	$2,584	$2,611

Commitments_and_Contingent_Lia3

Commitments and Contingent Liabilities - Additional Information (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014
Loss Contingencies [Line Items]
Notional Amount Of Performance Standby Letters Of Credit	$1,500,000
Notional Amount Of Commercial Letters Of Credit	0
Notional Amount Of Financial Standby Letters Of Credit	0
Financial instrument of credit risk	200,000	200,000
Unfunded commitment liability	$3,600,000	$3,100,000

Investment_Securities_Analysis

Investment Securities - Analysis of Amortized Cost and Estimated Fair Values of Securities Available for Sale (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Investment Securities [Line Items]
Amortized Cost	$1,266,915	$1,317,318
Gross Unrealized Gains	20,344	16,921
Gross Unrealized Losses	-17,974	-24,420
Securities available for sale, at fair value	1,269,285	1,309,819
US Government Agencies Residential Mortgage-backed Securities [Member]
Investment Securities [Line Items]
Amortized Cost	22,578	23,344
Gross Unrealized Gains	2,835	2,595
Gross Unrealized Losses	0	-3
Securities available for sale, at fair value	25,413	25,936
Residential Mortgage Backed Securities [Member]
Investment Securities [Line Items]
Amortized Cost	905,895	947,635
Gross Unrealized Gains	15,759	13,076
Gross Unrealized Losses	6,402	-9,830
Securities available for sale, at fair value	915,252	950,881
Obligations of U.S. Government-Sponsored Enterprises - Mortgage-Backed Securities - Commercial [Member]
Investment Securities [Line Items]
Amortized Cost	65	72
Gross Unrealized Gains	1	2
Gross Unrealized Losses	0	0
Securities available for sale, at fair value	66	74
Obligations of U.S. Government-Sponsored Enterprises - Other Government-Sponsored Enterprises [Member]
Investment Securities [Line Items]
Amortized Cost	260,849	269,181
Gross Unrealized Gains	180	4
Gross Unrealized Losses	330	-1,308
Securities available for sale, at fair value	260,699	267,877
Obligations of States and Political Subdivisions [Member]
Investment Securities [Line Items]
Amortized Cost	27,060	27,058
Gross Unrealized Gains	494	362
Gross Unrealized Losses	5	-43
Securities available for sale, at fair value	27,549	27,377
Corporate Debt Securities [Member]
Investment Securities [Line Items]
Amortized Cost	6,680	6,682
Gross Unrealized Gains	572	573
Gross Unrealized Losses	0	0
Securities available for sale, at fair value	7,252	7,255
Pooled Trust Preferred Collateralized Debt Obligations [Member]
Investment Securities [Line Items]
Amortized Cost	41,868	41,926
Gross Unrealized Gains	503	309
Gross Unrealized Losses	-11,237	-13,236
Securities available for sale, at fair value	31,134	28,999
Debt Securities [Member]
Investment Securities [Line Items]
Amortized Cost	1,264,995	1,315,898
Gross Unrealized Gains	20,344	16,921
Gross Unrealized Losses	-17,974	-24,420
Securities available for sale, at fair value	1,267,365	1,308,399
Equity Securities [Member]
Investment Securities [Line Items]
Amortized Cost	1,920	1,420
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Securities available for sale, at fair value	$1,920	$1,420

Investment_Securities_Amortize

Investment Securities - Amortized Cost and Estimated Fair Value of Debt Securities Available for Sale (Detail) (USD $)	Mar. 31, 2015		Dec. 31, 2014
In Thousands, unless otherwise specified	Mar. 31, 2015		Dec. 31, 2014
Investment Securities [Line Items]
Available-for-sale Securities, Debt Maturities, Next Twelve Months, Amortized Cost Basis	$6,800
Due within one year, Amortized Cost	336,457
Available-for-Sale Securities, Debt Maturities, Single Maturity Date, Fair Value	326,634
Available-for-sale Securities, Debt Maturities, without Single Maturity Date, Amortized Cost Basis	928,538	[1]
Due after one but within five years, Amortized Cost	254,050
Due after five but within ten years, Amortized Cost	24,420
Due after ten years, Amortized Cost	51,187
Corporate/Mortgage-Backed Securities, Amortized cost	940,731	[1]
Amortized Cost	1,266,915		1,317,318
Due within one year, Estimated Fair Value	6,798
Due after one but within five years, Estimated Fair Value	253,901
Due after five but within ten years, Estimated Fair Value	24,869
Due after ten years, Estimated Fair Value	41,066
Total Debt Securities, Estimated Fair Value	1,269,285		1,309,819
Debt Securities [Member]
Investment Securities [Line Items]
Amortized Cost	1,264,995		1,315,898
Total Debt Securities, Estimated Fair Value	1,267,365		1,308,399
US Government Agencies Residential Mortgage-backed Securities [Member]
Investment Securities [Line Items]
Amortized Cost	22,578		23,344
Total Debt Securities, Estimated Fair Value	25,413		25,936
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Investment Securities [Line Items]
Amortized Cost	906,000
Total Debt Securities, Estimated Fair Value	$915,300

[1]	Mortgage Backed Securities include an amortized cost of $22.6 million and a fair value of $25.4 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, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Investment Securities [Line Items]
Amortized Cost	$1,266,915	$1,317,318
Securities available for sale, at fair value	1,269,285	1,309,819
US Government Agencies Residential Mortgage-backed Securities [Member]
Investment Securities [Line Items]
Amortized Cost	22,578	23,344
Securities available for sale, at fair value	25,413	25,936
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Investment Securities [Line Items]
Amortized Cost	906,000
Securities available for sale, at fair value	$915,300

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, 2015	Mar. 31, 2014
Investments, Debt and Equity Securities [Abstract]
Proceeds from sales	$0	$0
Sales Transactions:
Gross gains	0	0
Gross losses	0	0
Available-for-sale Securities, Gross Realized Gain (Loss), Excluding Other than Temporary Impairments	0	0
Maturities and impairment
Gross Gains	105	0
Gross Losses	0	0
Other Than Temporary Impairment	0	0
Gain Losses Maturities And Impairment	105	0
Net gains and impairment	$105	$0

Investment_Securities_Addition

Investment Securities - Additional Information (Detail) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Investments, Debt and Equity Securities [Abstract]
Held-to-maturity Securities Pledged as Collateral	$3,300,000
Proceeds from sales	0	0
Available-for-sale securities pledged as collateral	$554,400,000		$563,200,000

Investment_Securities_Schedule

Investment Securities Schedule of Held-to-Maturity Securities (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Schedule of Held-to-maturity Securities [Line Items]
Due within 1 year	$0
Held-to-maturity Securities, Debt Maturities, Next Twelve Months, Fair Value	0
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain	19
Held-to-maturity Securities	30,253
Securities held to maturity, fair value	30,174	0
Due after 1 but within 5 years	0
Due after 5 but within 10 years	0
Held-to-maturity Securities, Debt Maturities, Year Two Through Five, Fair Value	0
Due after 10 years	3,938
Held-to-maturity Securities, Debt Maturities, after Ten Years, Fair Value	3,957
Held-to-maturity Securities, Debt Maturities, Single Maturity Date, Amortized Cost Basis	3,938
Held-to-maturity Securities, Debt Maturities, Single Maturity Date, Fair Value	3,957
Held-to-maturity Securities, Debt Maturities, without Single Maturity Date, Net Carrying Amount	26,315
Held-to-maturity Securities, Debt Maturities, without Single Maturity Date, Fair Value	26,217
Residential Mortgage Backed Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain	0
Held-to-maturity Securities	26,315
Securities held to maturity, fair value	$26,217

Investment_Securities_Held_to_

Investment Securities Held to Maturity Securities by Type (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity Securities	$30,253
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain	19
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss	-98
Securities held to maturity, fair value	30,174	0
Residential Mortgage Backed Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity Securities	26,315
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain	0
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss	-98
Securities held to maturity, fair value	26,217
Obligations of States and Political Subdivisions [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity Securities	3,938
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain	19
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss	0
Securities held to maturity, fair value	$3,957

Other_Investments_Additional_I

Other Investments - Additional Information (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Other Investments Disclosure [Abstract]
Other investments	$47,076	$44,545

Impairment_of_Investment_Secur2

Impairment of Investment Securities - Additional Information (Detail) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014	Sep. 30, 2014
Schedule of Trading Securities and Other Trading Assets [Line Items]
Other than temporary impairment charges recognized	$0	$0
Amortized Cost	1,266,915,000		1,317,318,000
Securities available for sale, at fair value	1,269,285,000		1,309,819,000
Number of banks and other financial institutions comprising the security	278
Number Of Pooled Securities with No Senior Class	3
Number of securities with no excess subordination	4
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	47,076,000		44,545,000
Investment Securities in Unrealized Loss Position, Qualitative Disclosure, Number of Positions, Total	41
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	7.00%
Probabilities for performing collateral range	0.33%
Excess present value of future cash flows over our current book value	22.00%
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	147.00%
Pooled Trust Preferred Collateralized Debt Obligations [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Percent of unrealized losses	62.00%
Amortized Cost	41,868,000		41,926,000
Securities available for sale, at fair value	31,134,000		28,999,000
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	6,680,000		6,682,000
Securities available for sale, at fair value	7,252,000		7,255,000
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	1,920,000		1,420,000
Securities available for sale, at fair value	1,920,000		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
Coupon rate	7.00%
Prepayment rate	100.00%
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
Coupon rate	10.00%
Prepayment rate	5.00%
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	38.00%
Reported Value Measurement [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Securities available for sale, at fair value	1,269,285,000		1,309,819,000
Federal Home Loan Bank Stock	$47,076,000		$44,545,000

Impairment_of_Investment_Secur3

Impairment of Investment Securities - Schedule of Unrealized Losses and Estimated Fair Values (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Schedule of Trading Securities and Other Trading Assets [Line Items]
Investment Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	$113,023	$229,583
Investment Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	455	694
Investment Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	449,943	523,463
Investment Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	17,617	23,726
Investment Securities, Continuous Unrealized Loss Position, Fair Value, Total	562,966	753,046
Investment Securities, Continuous Unrealized Loss Position, Accumulated Loss	18,072	24,420
US Government Agencies Residential Mortgage-backed Securities [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Investment Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		2,318
Investment Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		3
Investment Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		0
Investment Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		0
Investment Securities, Continuous Unrealized Loss Position, Fair Value, Total		2,318
Investment Securities, Continuous Unrealized Loss Position, Accumulated Loss		3
Residential Mortgage Backed Securities [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Investment Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	84,160	111,646
Investment Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	435	419
Investment Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	300,792	368,706
Investment Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	6,065	9,411
Investment Securities, Continuous Unrealized Loss Position, Fair Value, Total	384,952	480,352
Investment Securities, Continuous Unrealized Loss Position, Accumulated Loss	6,500	9,830
Obligations of U.S. Government-Sponsored Enterprises - Other Government-Sponsored Enterprises [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Investment Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	27,985	112,473
Investment Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	15	229
Investment Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	122,833	130,401
Investment Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	315	1,079
Investment Securities, Continuous Unrealized Loss Position, Fair Value, Total	150,818	242,874
Investment Securities, Continuous Unrealized Loss Position, Accumulated Loss	330	1,308
Obligations of States and Political Subdivisions [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Investment Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	878	3,146
Investment Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	5	43
Investment Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	0	0
Investment Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	0	0
Investment Securities, Continuous Unrealized Loss Position, Fair Value, Total	878	3,146
Investment Securities, Continuous Unrealized Loss Position, Accumulated Loss	5	43
Pooled Trust Preferred Collateralized Debt Obligations [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Investment Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	0	0
Investment Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	0	0
Investment Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	26,318	24,356
Investment Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	11,237	13,236
Investment Securities, Continuous Unrealized Loss Position, Fair Value, Total	26,318	24,356
Investment Securities, Continuous Unrealized Loss Position, Accumulated Loss	$11,237	$13,236

Impairment_of_Investment_Secur4

Impairment of Investment Securities - Pooled Trust Preferred Collateralized Debt Obligations (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
	Bank	Dec. 31, 2014
Impairment Of Investment Securities [Line Items]
Securities available for sale, at fair value	$1,269,285	$1,309,819
Unrealized Gain (Loss)	17,974	24,420
Pooled Trust Preferred Collateralized Debt Obligations [Member]
Impairment Of Investment Securities [Line Items]
Book Value	41,868
Securities available for sale, at fair value	31,134
Unrealized Gain (Loss)	-10,734
Pooled Trust Preferred Collateralized Debt Obligations [Member] \| Mezzanine [Member] \| Pre TSL IV [Member]
Impairment Of Investment Securities [Line Items]
Book Value	1,830
Securities available for sale, at fair value	1,324
Unrealized Gain (Loss)	-506
Debt Instrument, Credit Rating	B1/BB
Number of Banks (in banks)	6
Deferrals and Defaults as a % of Current Collateral	18.05%
Excess Subordination as a % of Current Performing Collateral	56.00%
Pooled Trust Preferred Collateralized Debt Obligations [Member] \| Mezzanine [Member] \| Pre TSL VII [Member]
Impairment Of Investment Securities [Line Items]
Book Value	2,789
Securities available for sale, at fair value	3,147
Unrealized Gain (Loss)	358
Debt Instrument, Credit Rating	Ca/-
Number of Banks (in banks)	14
Deferrals and Defaults as a % of Current Collateral	49.68%
Excess Subordination as a % of Current Performing Collateral	0.00%
Pooled Trust Preferred Collateralized Debt Obligations [Member] \| Mezzanine [Member] \| Pre TSL VIII [Member]
Impairment Of Investment Securities [Line Items]
Book Value	1,984
Securities available for sale, at fair value	1,446
Unrealized Gain (Loss)	-538
Debt Instrument, Credit Rating	C/C
Number of Banks (in banks)	29
Deferrals and Defaults as a % of Current Collateral	58.01%
Excess Subordination as a % of Current Performing Collateral	0.00%
Pooled Trust Preferred Collateralized Debt Obligations [Member] \| Mezzanine [Member] \| Pre TSL IX [Member]
Impairment Of Investment Securities [Line Items]
Book Value	2,349
Securities available for sale, at fair value	1,597
Unrealized Gain (Loss)	-752
Debt Instrument, Credit Rating	B3/C
Number of Banks (in banks)	40
Deferrals and Defaults as a % of Current Collateral	28.91%
Excess Subordination as a % of Current Performing Collateral	6.61%
Pooled Trust Preferred Collateralized Debt Obligations [Member] \| Mezzanine [Member] \| Pre TSL X [Member]
Impairment Of Investment Securities [Line Items]
Book Value	1,524
Securities available for sale, at fair value	1,669
Unrealized Gain (Loss)	145
Debt Instrument, Credit Rating	Caa1/C
Number of Banks (in banks)	43
Deferrals and Defaults as a % of Current Collateral	31.60%
Excess Subordination as a % of Current Performing Collateral	0.00%
Pooled Trust Preferred Collateralized Debt Obligations [Member] \| Mezzanine [Member] \| Pre TSL XII [Member]
Impairment Of Investment Securities [Line Items]
Book Value	5,559
Securities available for sale, at fair value	3,969
Unrealized Gain (Loss)	-1,590
Debt Instrument, Credit Rating	B3/C
Number of Banks (in banks)	66
Deferrals and Defaults as a % of Current Collateral	25.23%
Excess Subordination as a % of Current Performing Collateral	0.00%
Pooled Trust Preferred Collateralized Debt Obligations [Member] \| Mezzanine [Member] \| Pre TSL XIII [Member]
Impairment Of Investment Securities [Line Items]
Book Value	12,525
Securities available for sale, at fair value	8,870
Unrealized Gain (Loss)	-3,655
Debt Instrument, Credit Rating	B3/C
Number of Banks (in banks)	56
Deferrals and Defaults as a % of Current Collateral	25.44%
Excess Subordination as a % of Current Performing Collateral	20.85%
Pooled Trust Preferred Collateralized Debt Obligations [Member] \| Mezzanine [Member] \| Pre TSL XIV [Member]
Impairment Of Investment Securities [Line Items]
Book Value	12,876
Securities available for sale, at fair value	8,702
Unrealized Gain (Loss)	-4,174
Debt Instrument, Credit Rating	Caa1/C
Number of Banks (in banks)	56
Deferrals and Defaults as a % of Current Collateral	25.46%
Excess Subordination as a % of Current Performing Collateral	38.55%
Pooled Trust Preferred Collateralized Debt Obligations [Member] \| Mezzanine [Member] \| MMCap I [Member]
Impairment Of Investment Securities [Line Items]
Book Value	432
Securities available for sale, at fair value	410
Unrealized Gain (Loss)	($22)
Debt Instrument, Credit Rating	Ca/C
Number of Banks (in banks)	10
Deferrals and Defaults as a % of Current Collateral	56.11%
Excess Subordination as a % of Current Performing Collateral	24.92%

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, 2015		Mar. 31, 2014
Impairment of Investment Securities Disclosure [Abstract]
Balance, beginning (a)	$26,246	[1]	$27,543	[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	25,707		27,254
Other than Temporary Impairment, Credit Losses Recognized in Earnings, Reductions, Cash Flows	218		0
Other than Temporary Impairment, Credit Losses Recognized in Earnings, Period Increase (Decrease)	$321		$289

[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, 2015	Dec. 31, 2014	Mar. 31, 2014
In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Net of Deferred Income	$4,437,601	$4,457,308	$4,252,213
Commercial, financial, agricultural and other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Net of Deferred Income	1,066,788	1,052,109	1,017,412
Real estate construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Net of Deferred Income	107,882	120,785	95,110
Residential real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Net of Deferred Income	1,210,511	1,226,344	1,240,169
Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Net of Deferred Income	1,400,276	1,405,256	1,290,852
Loans to individuals [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Net of Deferred Income	$652,144	$652,814	$608,670

Loans_and_Allowance_for_Credit3

Loans and Allowance for Credit Losses - Additional Information (Detail) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Accounts, Notes, Loans and Financing Receivable [Line Items]
Charge-offs	$7,109,000	$3,646,000
Unfunded commitments related to nonperforming loans	600,000		0
Off balance sheet reserve to nonperforming loans	0
Loans held for sale	3,000,000		0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales	0	716,000
Total gains or losses included in earnings	105,000	0
Nonaccrual	33,565,000		42,667,000
Recorded investment	46,195,000		55,251,000
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]
Loans with modifications to rate and payment due to reamortization	300,000	200,000
Loans Held For Sale [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales		716,000
Total gains or losses included in earnings		0
Water Facility Construction [Member] \| Nonaccrual Commercial Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded investment	9,300,000
Non Accrual Loans [Member] \| Local Energy Company [Member] [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual	6,100,000
Charge-off recognized	3,300,000
2012 Troubled Debt Restructuring [Member] \| Non Accrual Loans [Member] \| Local Energy Company [Member] [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual	2,400,000
2014 Troubled Debt Restructuring [Member] \| Non Accrual Loans [Member] \| Local Energy Company [Member] [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual	$3,100,000

Loans_and_Allowance_for_Credit4

Loans and Allowance for Credit Losses - Credit Risk Profile by Creditworthiness (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014
In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Net of Deferred Income	$4,437,601	$4,457,308	$4,252,213
Pass [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Net of Deferred Income	4,315,385	4,317,182
OAEM [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Net of Deferred Income	63,823	72,370
Substandard [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Net of Deferred Income	58,393	63,595
Doubtful [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Net of Deferred Income	0	4,161
Criticized [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Net of Deferred Income	122,216	140,126
Commercial, financial, agricultural and other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Net of Deferred Income	1,066,788	1,052,109
Commercial, financial, agricultural and other [Member] \| Pass [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Net of Deferred Income	1,006,516	983,357
Commercial, financial, agricultural and other [Member] \| OAEM [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Net of Deferred Income	31,642	32,563
Commercial, financial, agricultural and other [Member] \| Substandard [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Net of Deferred Income	28,630	32,028
Commercial, financial, agricultural and other [Member] \| Doubtful [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Net of Deferred Income	0	4,161
Commercial, financial, agricultural and other [Member] \| Criticized [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Net of Deferred Income	60,272	68,752
Real estate construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Net of Deferred Income	107,882	120,785
Real estate construction [Member] \| Pass [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Net of Deferred Income	107,180	112,536
Real estate construction [Member] \| OAEM [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Net of Deferred Income	466	8,013
Real estate construction [Member] \| Substandard [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Net of Deferred Income	236	236
Real estate construction [Member] \| Doubtful [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Net of Deferred Income	0	0
Real estate construction [Member] \| Criticized [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Net of Deferred Income	702	8,249
Residential real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Net of Deferred Income	1,210,511	1,226,344
Residential real estate [Member] \| Pass [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Net of Deferred Income	1,198,876	1,214,920
Residential real estate [Member] \| OAEM [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Net of Deferred Income	1,661	2,315
Residential real estate [Member] \| Substandard [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Net of Deferred Income	9,974	9,109
Residential real estate [Member] \| Doubtful [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Net of Deferred Income	0	0
Residential real estate [Member] \| Criticized [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Net of Deferred Income	11,635	11,424
Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Net of Deferred Income	1,400,276	1,405,256
Commercial Real Estate [Member] \| Pass [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Net of Deferred Income	1,350,930	1,353,773
Commercial Real Estate [Member] \| OAEM [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Net of Deferred Income	30,054	29,479
Commercial Real Estate [Member] \| Substandard [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Net of Deferred Income	19,292	22,004
Commercial Real Estate [Member] \| Doubtful [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Net of Deferred Income	0	0
Commercial Real Estate [Member] \| Criticized [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Net of Deferred Income	49,346	51,483
Loans to individuals [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Net of Deferred Income	652,144	652,814
Loans to individuals [Member] \| Pass [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Net of Deferred Income	651,883	652,596
Loans to individuals [Member] \| OAEM [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Net of Deferred Income	0	0
Loans to individuals [Member] \| Substandard [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Net of Deferred Income	261	218
Loans to individuals [Member] \| Doubtful [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Net of Deferred Income	0	0
Loans to individuals [Member] \| Criticized [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Net of Deferred Income	$261	$218

Loans_and_Allowance_for_Credit5

Loans and Allowance for Credit Losses - Age Analysis of Past Due Loans by Segment (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014
In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual	$33,565	$42,667
Total past due and nonaccrual	48,002	61,449
Current	4,389,599	4,395,859
Total	4,437,601	4,457,308	4,252,213
Commercial, financial, agricultural and other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual	18,654	27,007
Total past due and nonaccrual	19,415	30,300
Current	1,047,373	1,021,809
Total	1,066,788	1,052,109
Real estate construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual	236	236
Total past due and nonaccrual	236	237
Current	107,646	120,548
Total	107,882	120,785
Residential real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual	7,583	7,900
Total past due and nonaccrual	14,890	15,434
Current	1,195,621	1,210,910
Total	1,210,511	1,226,344
Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual	6,831	7,306
Total past due and nonaccrual	8,620	9,225
Current	1,391,656	1,396,031
Total	1,400,276	1,405,256
Loans to individuals [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual	261	218
Total past due and nonaccrual	4,841	6,253
Current	647,303	646,561
Total	652,144	652,814
Financing Receivables, 30 to 59 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total past due and nonaccrual	8,082	13,473
Financing Receivables, 30 to 59 Days Past Due [Member] \| Commercial, financial, agricultural and other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total past due and nonaccrual	292	2,816
Financing Receivables, 30 to 59 Days Past Due [Member] \| Real estate construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total past due and nonaccrual	0	0
Financing Receivables, 30 to 59 Days Past Due [Member] \| Residential real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total past due and nonaccrual	3,815	5,162
Financing Receivables, 30 to 59 Days Past Due [Member] \| Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total past due and nonaccrual	1,283	1,797
Financing Receivables, 30 to 59 Days Past Due [Member] \| Loans to individuals [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total past due and nonaccrual	2,692	3,698
Financing Receivables, 60 to 89 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total past due and nonaccrual	2,110	2,690
Financing Receivables, 60 to 89 Days Past Due [Member] \| Commercial, financial, agricultural and other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total past due and nonaccrual	320	213
Financing Receivables, 60 to 89 Days Past Due [Member] \| Real estate construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total past due and nonaccrual	0	1
Financing Receivables, 60 to 89 Days Past Due [Member] \| Residential real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total past due and nonaccrual	1,054	1,295
Financing Receivables, 60 to 89 Days Past Due [Member] \| Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total past due and nonaccrual	124	122
Financing Receivables, 60 to 89 Days Past Due [Member] \| Loans to individuals [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total past due and nonaccrual	612	1,059
Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total past due and nonaccrual	4,245	2,619
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] \| Commercial, financial, agricultural and other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total past due and nonaccrual	149	264
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] \| Real estate construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total past due and nonaccrual	0	0
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] \| Residential real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total past due and nonaccrual	2,438	1,077
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] \| Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total past due and nonaccrual	382	0
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] \| Loans to individuals [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total past due and nonaccrual	$1,276	$1,278

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, 2015	Mar. 31, 2014	Dec. 31, 2014
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	$33,063		$29,504
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	42,065		34,398
Impaired Financing Receivable, with Related Allowance, Recorded Investment	13,132		25,747
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	13,388		26,517
Related allowance	3,829		9,461
Recorded investment	46,195		55,251
Unpaid principal balance	55,453		60,915
Average recorded investment	13,141	21,755
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	37,787	32,985
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	116	112
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	32	54
Impaired Financing Receivable, Average Recorded Investment	50,928	54,740
Interest Income Recognized	148	166
Commercial, financial, agricultural and other [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	14,650		9,439
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	20,137		10,937
Impaired Financing Receivable, with Related Allowance, Recorded Investment	10,829		24,826
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	10,942		25,583
Related allowance	3,397		9,304
Average recorded investment	10,917	17,649
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	19,375	10,953
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	57	17
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	28	45
Real estate construction [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	236		236
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	479		476
Impaired Financing Receivable, with Related Allowance, Recorded Investment	0		0
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	0		0
Related allowance	0		0
Average recorded investment	0	638
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	239	2,438
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	0	12
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	0	0
Residential real estate [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	9,901		10,773
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	11,749		12,470
Impaired Financing Receivable, with Related Allowance, Recorded Investment	992		367
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	1,105		380
Related allowance	165		56
Average recorded investment	901	3,161
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	10,155	9,825
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	38	49
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	3	8
Commercial Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	7,958		8,768
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	9,317		10,178
Impaired Financing Receivable, with Related Allowance, Recorded Investment	1,311		554
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	1,341		554
Related allowance	267		101
Average recorded investment	1,323	307
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	7,711	9,498
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	20	33
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	1	1
Loans to individuals [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	318		288
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	383		337
Impaired Financing Receivable, with Related Allowance, Recorded Investment	0		0
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	0		0
Related allowance	0		0
Average recorded investment	0	0
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	307	271
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	1	1
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	$0	$0

Loans_and_Allowance_for_Credit7

Loans and Allowance for Credit Losses - Troubled Debt Restructured Loans and Commitments (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Financing Receivable, Troubled Debt Restructurings [Line Items]
Financing Receivable, Modifications, Recorded Investment	$21,608	$29,536
Unused lines of Credit [Member]
Financing Receivable, Troubled Debt Restructurings [Line Items]
Loans and Leases Receivable, Impaired, Commitment to Lend	391	4,120
Accrual Loans [Member] [Member]
Financing Receivable, Troubled Debt Restructurings [Line Items]
Financing Receivable, Modifications, Recorded Investment	12,630	12,584
Non Accrual Loans [Member]
Financing Receivable, Troubled Debt Restructurings [Line Items]
Financing Receivable, Modifications, Recorded Investment	$8,978	$16,952

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, 2015	Mar. 31, 2014
	Contract	Contract
Financing Receivable, Modifications [Line Items]
Number of Contracts	8	21
Total Pre-Modification Outstanding Recorded Investment	$2,249	$812
Post- Modification Outstanding Recorded Investment	2,139	791
Specific Reserve	0	34
Commercial, financial, agricultural and other [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts	1	1
Total Pre-Modification Outstanding Recorded Investment	1,498	60
Post- Modification Outstanding Recorded Investment	1,476	60
Specific Reserve	0	29
Residential real estate [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts	5	13
Total Pre-Modification Outstanding Recorded Investment	269	689
Post- Modification Outstanding Recorded Investment	203	676
Specific Reserve	0	5
Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts	1	1
Total Pre-Modification Outstanding Recorded Investment	464	12
Post- Modification Outstanding Recorded Investment	449	8
Specific Reserve	0	0
Loans to individuals [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts	1	6
Total Pre-Modification Outstanding Recorded Investment	18	51
Post- Modification Outstanding Recorded Investment	11	47
Specific Reserve	0	0
Extended Maturity [Member]
Financing Receivable, Modifications [Line Items]
Total Pre-Modification Outstanding Recorded Investment	1,498	60
Extended Maturity [Member] \| Commercial, financial, agricultural and other [Member]
Financing Receivable, Modifications [Line Items]
Total Pre-Modification Outstanding Recorded Investment	1,498	60
Extended Maturity [Member] \| Residential real estate [Member]
Financing Receivable, Modifications [Line Items]
Total Pre-Modification Outstanding Recorded Investment	0	0
Extended Maturity [Member] \| Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Total Pre-Modification Outstanding Recorded Investment	0	0
Extended Maturity [Member] \| Loans to individuals [Member]
Financing Receivable, Modifications [Line Items]
Total Pre-Modification Outstanding Recorded Investment	0	0
Contractual Interest Rate Reduction [Member]
Financing Receivable, Modifications [Line Items]
Total Pre-Modification Outstanding Recorded Investment	252	203
Contractual Interest Rate Reduction [Member] \| Commercial, financial, agricultural and other [Member]
Financing Receivable, Modifications [Line Items]
Total Pre-Modification Outstanding Recorded Investment	0	0
Contractual Interest Rate Reduction [Member] \| Residential real estate [Member]
Financing Receivable, Modifications [Line Items]
Total Pre-Modification Outstanding Recorded Investment	252	172
Contractual Interest Rate Reduction [Member] \| Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Total Pre-Modification Outstanding Recorded Investment	0	0
Contractual Interest Rate Reduction [Member] \| Loans to individuals [Member]
Financing Receivable, Modifications [Line Items]
Total Pre-Modification Outstanding Recorded Investment	0	31
Contractual Payment Modification [Member]
Financing Receivable, Modifications [Line Items]
Total Pre-Modification Outstanding Recorded Investment	499	549
Contractual Payment Modification [Member] \| Commercial, financial, agricultural and other [Member]
Financing Receivable, Modifications [Line Items]
Total Pre-Modification Outstanding Recorded Investment	0	0
Contractual Payment Modification [Member] \| Residential real estate [Member]
Financing Receivable, Modifications [Line Items]
Total Pre-Modification Outstanding Recorded Investment	17	517
Contractual Payment Modification [Member] \| Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Total Pre-Modification Outstanding Recorded Investment	464	12
Contractual Payment Modification [Member] \| Loans to individuals [Member]
Financing Receivable, Modifications [Line Items]
Total Pre-Modification Outstanding Recorded Investment	$18	$20

Loans_and_Allowance_for_Credit9

Loans and Allowance for Credit Losses - Troubled Debt Restructuring is 90 Days or More Past Due (Detail)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
	Contract	Contract
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Modifications, Subsequent Default, Number of Contracts	0	0

Recovered_Sheet1

Loans and Allowance for Credit Losses - Allowance for Credit Losses (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Allowance for Doubtful Accounts Receivable [Roll Forward]
Beginning Balance	$52,051	$54,225
Charge-offs	-7,109	-3,646
Recoveries	596	696
Provision for Loan, Lease, and Other Losses	1,159	3,231
Ending Balance	46,697	54,506
Ending balance: individually evaluated for impaired	3,829	10,503
Ending balance: collectively evaluated for impaired	42,868	44,003
Total	4,437,601	4,252,213	4,457,308
Ending balance: individually evaluated for impaired	39,659	49,403
Ending balance: collectively evaluated for impaired	4,397,942	4,202,810
Commercial, financial, agricultural and other [Member]
Allowance for Doubtful Accounts Receivable [Roll Forward]
Beginning Balance	29,627	22,663
Charge-offs	-5,080	-1,601
Recoveries	200	85
Provision for Loan, Lease, and Other Losses	-341	4,978
Ending Balance	24,406	26,125
Ending balance: individually evaluated for impaired	3,397	9,886
Ending balance: collectively evaluated for impaired	21,009	16,239
Total	1,066,788	1,017,412	1,052,109
Ending balance: individually evaluated for impaired	24,586	31,730
Ending balance: collectively evaluated for impaired	1,042,202	985,682
Real estate construction [Member]
Allowance for Doubtful Accounts Receivable [Roll Forward]
Beginning Balance	2,063	6,600
Charge-offs	0	0
Recoveries	0	169
Provision for Loan, Lease, and Other Losses	-535	-555
Ending Balance	1,528	6,214
Ending balance: individually evaluated for impaired	0	74
Ending balance: collectively evaluated for impaired	1,528	6,140
Total	107,882	95,110	120,785
Ending balance: individually evaluated for impaired	199	2,797
Ending balance: collectively evaluated for impaired	107,683	92,313
Residential real estate [Member]
Allowance for Doubtful Accounts Receivable [Roll Forward]
Beginning Balance	3,664	7,727
Charge-offs	-566	-1,095
Recoveries	96	244
Provision for Loan, Lease, and Other Losses	193	-850
Ending Balance	3,387	6,026
Ending balance: individually evaluated for impaired	165	496
Ending balance: collectively evaluated for impaired	3,222	5,530
Total	1,210,511	1,240,169	1,226,344
Ending balance: individually evaluated for impaired	7,071	9,103
Ending balance: collectively evaluated for impaired	1,203,440	1,231,066
Commercial Real Estate [Member]
Allowance for Doubtful Accounts Receivable [Roll Forward]
Beginning Balance	11,881	11,778
Charge-offs	-202	-140
Recoveries	138	20
Provision for Loan, Lease, and Other Losses	670	-539
Ending Balance	12,487	11,119
Ending balance: individually evaluated for impaired	267	47
Ending balance: collectively evaluated for impaired	12,220	11,072
Total	1,400,276	1,290,852	1,405,256
Ending balance: individually evaluated for impaired	7,803	5,773
Ending balance: collectively evaluated for impaired	1,392,473	1,285,079
Loans to individuals [Member]
Allowance for Doubtful Accounts Receivable [Roll Forward]
Beginning Balance	4,816	5,457
Charge-offs	-1,261	-810
Recoveries	162	178
Provision for Loan, Lease, and Other Losses	1,172	197
Ending Balance	4,889	5,022
Ending balance: individually evaluated for impaired	0	0
Ending balance: collectively evaluated for impaired	4,889	5,022
Total	652,144	608,670	652,814
Ending balance: individually evaluated for impaired	0	0
Ending balance: collectively evaluated for impaired	$652,144	$608,670

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 $)	3 Months Ended
	Mar. 31, 2015		Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at fair value	1,269,285,000		$1,309,819,000
Assets	1,337,435,000		1,368,052,000
Pooled Trust Preferred Collateralized Debt Obligations [Member] \| Minimum [Member] \| Discount rates [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Weighted average rate	5.50%	[1]
Pooled Trust Preferred Collateralized Debt Obligations [Member] \| Maximum [Member] \| Discount rates [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Weighted average rate	14.50%	[1]
Pooled Trust Preferred Collateralized Debt Obligations [Member] \| Discounted Cash Flow [Member] \| Minimum [Member] \| Probability of default [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Weighted average rate	0.00%
Pooled Trust Preferred Collateralized Debt Obligations [Member] \| Discounted Cash Flow [Member] \| Minimum [Member] \| Prepayment rates [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Weighted average rate	0.00%
Pooled Trust Preferred Collateralized Debt Obligations [Member] \| Discounted Cash Flow [Member] \| Maximum [Member] \| Probability of default [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Weighted average rate	100.00%
Pooled Trust Preferred Collateralized Debt Obligations [Member] \| Discounted Cash Flow [Member] \| Maximum [Member] \| Prepayment rates [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Weighted average rate	100.00%
Pooled Trust Preferred Collateralized Debt Obligations [Member] \| Discounted Cash Flow [Member] \| Weighted average [Member] \| Probability of default [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Weighted average rate	17.48%
Pooled Trust Preferred Collateralized Debt Obligations [Member] \| Discounted Cash Flow [Member] \| Weighted average [Member] \| Prepayment rates [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Weighted average rate	6.35%
Equity Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at fair value	1,920,000		1,420,000
Interest Rate Swap [Member] \| Option model [Member] \| Minimum [Member] \| Counterparty credit risk [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Weighted average rate	3.74%	[2]
Interest Rate Swap [Member] \| Option model [Member] \| Maximum [Member] \| Counterparty credit risk [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Weighted average rate	6.62%	[2]
Impaired Loans [Member] \| Reserve Study [Member] \| NGL per gallon [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Inputs Monetary	0.83	[3]
Impaired Loans [Member] \| Reserve Study [Member] \| Minimum [Member] \| Gas per MCF [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Inputs Monetary	3.84	[3]
Impaired Loans [Member] \| Reserve Study [Member] \| Minimum [Member] \| Oil per BBL/d [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Inputs Monetary	83.64	[3]
Impaired Loans [Member] \| Reserve Study [Member] \| Maximum [Member] \| Gas per MCF [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Inputs Monetary	6.45	[3]
Impaired Loans [Member] \| Reserve Study [Member] \| Maximum [Member] \| Oil per BBL/d [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Inputs Monetary	107	[3]
impaired Loans Valued Using a Reserve Study [Domain]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	3,299,000
impaired Loans Valued Using a Reserve Study [Domain] \| Reserve Study [Member] \| Weighted average [Member] \| Discount rates [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Weighted average rate	10.00%
Impaired Loans Valued Using Discounted Cash Flows [Domain] \| Reserve Study [Member] \| Weighted average [Member] \| Discount rates [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Weighted average rate	9.00%
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at fair value	33,054,000		30,419,000
Assets	33,054,000		30,419,000
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	1,920,000		1,420,000
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	31,134,000		28,999,000
Pooled Trust Preferred Collateralized Debt Obligations [Member] \| Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at fair value			28,999,000
Pooled Trust Preferred Collateralized Debt Obligations [Member] \| 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	31,134,000
Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other Real Estate Owned Assets Fair Value	7,837,000		7,981,000
Assets	50,202,000		53,771,000
Fair Value, Measurements, Nonrecurring [Member] \| Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other Real Estate Owned Assets Fair Value	49,000		153,000
Assets	10,144,000		11,079,000
Fair Value, Measurements, Nonrecurring [Member] \| Level 3 [Member] \| Other Real Estate Owned [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other Real Estate Owned Assets Fair Value	49,000

[1]	incorporates spread over risk free rate related primarily to credit quality and illiquidity of securities.
[2]	.
[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 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, 2015	Mar. 31, 2014
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	$30,419	$24,943
Total gains or losses included in earnings	105	0
Total gains or losses included in other comprehensive income	2,620	4,743
Purchases	500	0
Issuances	0	0
Sales	0	-716
Settlements	-590	-390
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3	0	716
Balance, end of period	33,054	29,296
Pooled Trust Preferred Collateralized Debt Obligations [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	28,999	23,523
Total gains or losses included in earnings	105	0
Total gains or losses included in other comprehensive income	2,620	4,743
Purchases	0	0
Issuances	0	0
Sales	0	0
Settlements	-590	-390
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3	0	0
Balance, end of period	31,134	27,876
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	500	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	1,920	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
Total gains or losses included in earnings		0
Total gains or losses included in other comprehensive income		0
Purchases		0
Issuances		0
Sales		-716
Settlements		0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3		716
Balance, end of period		$0

Fair_Values_of_Assets_and_Liab4

Fair Values of Assets and Liabilities - Schedule of Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) (USD $)	Mar. 31, 2015		Dec. 31, 2014
In Thousands, unless otherwise specified	Mar. 31, 2015		Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at fair value	$1,269,285		$1,309,819
Other investments	47,076		44,545
Loans Held for Sale	5,892		2,502
Other Assets	15,182	[1]	11,186	[2]
Total Assets	1,337,435		1,368,052
Other Liabilities	13,823	[1]	10,671	[2]
Total Liabilities	13,823		10,671
Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at fair value	1,267,365		1,308,399
Equity Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at fair value	1,920		1,420
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	25,413		25,936
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	915,252		950,881
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	66		74
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	260,699		267,877
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	27,549		27,377
Corporate Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at fair value	7,252		7,255
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	31,134		28,999
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	[1]	0	[2]
Total Assets	0		0
Other Liabilities	0	[1]	0	[2]
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] \| 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 - 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	1,236,231		1,279,400
Other investments	47,076		44,545
Loans Held for Sale	5,892		2,502
Other Assets	15,182	[1]	11,186	[2]
Total Assets	1,304,381		1,337,633
Other Liabilities	13,823	[1]	10,671	[2]
Total Liabilities	13,823		10,671
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	1,236,231		1,279,400
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	25,413		25,936
Level 2 [Member] \| 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	915,252		950,881
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	66		74
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	260,699		267,877
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	27,549		27,377
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	7,252		7,255
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	33,054		30,419
Other investments	0		0
Loans Held for Sale	0		0
Other Assets	0	[1]	0	[2]
Total Assets	33,054		30,419
Other Liabilities	0	[1]	0	[2]
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	31,134		28,999
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	1,920		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] \| 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 - 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			$28,999

[1]	Hedging and non-hedging interest rate derivatives
[2]	on-hedging interest rate derivatives

Fair_Values_of_Assets_and_Liab5

Fair Values of Assets and Liabilities - Additional Information (Detail) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
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	0	716,000
Impaired loans considered to be credit risk of non-collection	100,000
Updated appraisal requirement floor	250,000
Other real estate owned	7,025,000		7,197,000
Financial instrument of credit risk	200,000		200,000
Fair Value, Assets Measured on Recurring Basis, Gain (Loss) Included in Other Income, Assets and Liabilities Continue to be held	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
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, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Assets	$1,337,435	$1,368,052
Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	42,365	45,790
Other real estate owned	7,837	7,981
Total Assets	50,202	53,771
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	1,304,381	1,337,633
Level 2 [Member] \| Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	32,270	34,864
Other real estate owned	7,788	7,828
Total Assets	40,058	42,692
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Assets	33,054	30,419
Level 3 [Member] \| Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	10,095	10,926
Other real estate owned	49	153
Total Assets	$10,144	$11,079

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, 2015	Mar. 31, 2014
Fair Value Disclosures [Abstract]
Impaired loans	($555)	($3,996)
Other real estate owned	-69	-363
Total losses	($624)	($4,359)

Fair_Values_of_Assets_and_Liab8

Fair Values of Assets and Liabilities - Carrying Amounts and Fair Values of Financial Instruments (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014
In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014
Fair Value Measurements Of Financial Instruments [Line Items]
Cash and due from banks	$62,161	$72,276
Interest-bearing deposits	3,124	2,262
Securities available for sale, at fair value	1,269,285	1,309,819
Held-to-maturity Securities	30,253
Other investments	47,076	44,545
Loans and Leases Receivable, Net of Deferred Income	4,437,601	4,457,308	4,252,213
Deposits	4,293,749	4,315,511
Short-term borrowings	1,125,520	1,105,876
Long-term debt	64,324	89,459
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	1,236,231	1,279,400
Other investments	47,076	44,545
Level 3 [Member]
Fair Value Measurements Of Financial Instruments [Line Items]
Securities available for sale, at fair value	33,054	30,419
Other investments	0	0
Carrying Amount [Member]
Fair Value Measurements Of Financial Instruments [Line Items]
Cash and due from banks	62,161	72,276
Interest-bearing deposits	3,124	2,262
Securities available for sale, at fair value	1,269,285	1,309,819
Held-to-maturity Securities	30,253
Other investments	47,076	44,545
Loans Held for sale, Amount	5,892	2,502
Loans and Leases Receivable, Net of Deferred Income	4,437,601	4,457,308
Deposits	4,293,749	4,315,511
Short-term borrowings	1,125,520	1,105,876
Long-term debt	64,324	89,459
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	62,161	72,276
Interest-bearing deposits	3,124	2,262
Securities available for sale, at fair value	1,269,285	1,309,819
Held-to-maturity Securities	30,174
Other investments	47,076	44,545
Loans Held for sale, Amount	5,892	2,502
Loans and Leases Receivable, Net of Deferred Income	4,465,459	4,439,766
Deposits	4,297,771	4,319,997
Short-term borrowings	1,125,524	1,105,867
Long-term debt	65,255	90,319
Subordinated debt	63,069	62,815
Estimate of Fair Value, Fair Value Disclosure [Member] \| Level 1 [Member]
Fair Value Measurements Of Financial Instruments [Line Items]
Cash and due from banks	62,161	72,276
Interest-bearing deposits	3,124	2,262
Securities available for sale, at fair value	0	0
Held-to-maturity Securities	0
Other investments	0	0
Loans Held for sale, Amount	0	0
Loans and Leases Receivable, Net of Deferred Income	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	1,236,231	1,279,400
Held-to-maturity Securities	30,174
Other investments	47,076	44,545
Loans Held for sale, Amount	5,892	2,502
Loans and Leases Receivable, Net of Deferred Income	32,270	34,864
Deposits	4,297,771	4,319,997
Short-term borrowings	1,125,524	1,105,867
Long-term debt	65,255	90,319
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	33,054	30,419
Held-to-maturity Securities	0
Other investments	0	0
Loans Held for sale, Amount	0	0
Loans and Leases Receivable, Net of Deferred Income	4,433,189	4,404,902
Deposits	0	0
Short-term borrowings	0	0
Long-term debt	0	0
Subordinated debt	$63,069	$62,815

Derivatives_Additional_Informa

Derivatives - Additional Information (Detail) (USD $)	3 Months Ended
Derivatives - Additional Information (Detail) (USD $)	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Risk participation Agreements [Line Items]
HedgedItemsOfCashFlowHedge	$200,000,000
Derivative Instruments Designated As Hedging Instruments Interest Income	381,000	0
Risk Participation Agreements Purchased [Domain]
Risk participation Agreements [Line Items]
Number of interest rate swaps	13
Risk Participation Agreements Sold [Domain]
Risk participation Agreements [Line Items]
Number of interest rate swaps	3
Designated as Hedging Instrument [Member]
Risk participation Agreements [Line Items]
Derivative, Notional Amount	200,000,000		100,000,000
Three Year Maturity [Member] \| Designated as Hedging Instrument [Member]
Risk participation Agreements [Line Items]
Derivative, Notional Amount	85,000,000
Four Year Maturity [Member] \| Designated as Hedging Instrument [Member]
Risk participation Agreements [Line Items]
Derivative, Notional Amount	$115,000,000

Derivatives_Credit_Value_Adjus

Derivatives - Credit Value Adjustment Recorded Related to Notional Amount of Derivatives Outstanding (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative, Fair Value, Net	($498)	($268)
Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative, Fair Value, Net	1,667	472
Derivative, Notional Amount	200,000	100,000
Interest Rate Swap [Member] \| Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative, Notional Amount	286,528	273,388
Interest Rate Cap [Member] \| Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative, Notional Amount	6,375	6,656
Credit Default Swap [Member] \| Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative, Notional Amount	109,114	113,624
Credit Default Swap, Selling Protection [Member] \| Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative, Notional Amount	($17,827)	($17,296)

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, 2015	Mar. 31, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	($230)	($58)
Derivative Instruments Designated As Hedging Instruments Interest Income	381	0
Derivative, Net Hedge Ineffectiveness Gain (Loss)	$9	$0

Goodwill_Additional_Informatio

Goodwill - Additional Information (Detail) (USD $)	3 Months Ended	12 Months Ended
Goodwill - Additional Information (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014
Goodwill Disclosure [Abstract]
Goodwill	$161,429,000	$161,429,000
Impairment charges on goodwill	$0	$0