Northwest Bancshares (NWBI) 10-K 29 Feb 16 2015 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Feb. 12, 2016	Jun. 30, 2015
Document and Entity Information
Entity Registrant Name	Northwest Bancshares, Inc.
Entity Central Index Key	1,471,265
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-K
Document Period End Date	Dec. 31, 2015
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity Common Stock, Shares Outstanding		101,775,187
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$ 1,215

CONSOLIDATED STATEMENTS OF FINA

CONSOLIDATED STATEMENTS OF FINANCIAL CONDITION - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Assets
Cash and cash equivalents	$ 92,263	$ 87,401
Interest-earning deposits in other financial institutions	74,510	152,671
Federal funds sold and other short-term investments	635	634
Marketable securities available-for-sale (amortized cost of $868,956 and $906,702)	874,405	912,371
Marketable securities held-to-maturity (fair value of $32,552 and $106,292)	31,689	103,695
Loans receivable, net of allowance for loan losses of $62,672 and $67,518	7,159,449	5,922,373
Accrued interest receivable	21,072	18,623
Real estate owned, net	8,725	16,759
Federal Home Loan Bank stock, at cost	40,903	33,293
Premises and equipment, net	154,351	143,909
Bank owned life insurance	168,509	144,362
Goodwill	261,736	175,323
Other intangible assets	8,982	3,033
Other assets	54,670	60,586
Total assets	8,951,899	7,775,033
Liabilities:
Deposits	6,612,581	5,632,542
Borrowed funds	975,007	888,109
Advances by borrowers for taxes and insurance	33,735	30,507
Accrued interest payable	1,993	936
Other liabilities	54,207	57,198
Junior subordinated deferrable interest debentures held by trusts that issued guaranteed capital debt securities	111,213	103,094
Total liabilities	7,788,736	6,712,386
Shareholders’ equity:
Preferred stock, $0.01 par value: 50,000,000 authorized, no shares issued	0	0
Common stock, $0.01 par value: 500,000,000 shares authorized, 101,871,737 and 94,721,453 shares issued, respectively	1,019	947
Paid-in capital	717,603	626,134
Retained earnings	489,292	481,577
Unallocated common stock of employee stock ownership plan	(20,216)	(21,641)
Accumulated other comprehensive loss	(24,535)	(24,370)
Total shareholders' equity	1,163,163	1,062,647
Total liabilities and shareholders’ equity	$ 8,951,899	$ 7,775,033

CONSOLIDATED STATEMENTS OF FIN3

CONSOLIDATED STATEMENTS OF FINANCIAL CONDITION (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Statement of Financial Position [Abstract]
Marketable securities available-for-sale, amortized cost	$ 868,956	$ 906,702
Marketable securities held-to-maturity, fair value	32,552	106,292
Allowance for loan losses	$ 62,672	$ 67,518
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized	50,000,000	50,000,000
Preferred stock, shares issued	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	500,000,000	500,000,000
Common stock, shares issued	101,871,737	94,721,453

CONSOLIDATED STATEMENTS OF INCO

CONSOLIDATED STATEMENTS OF INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Interest income:
Loans receivable	$ 298,665	$ 282,050	$ 286,977
Mortgage-backed securities	8,823	10,320	12,818
Taxable investment securities	4,520	4,130	4,021
Tax-free investment securities	4,313	6,281	7,817
FHLB dividends	2,828	1,809	371
Interest-earning deposits	431	837	1,093
Total interest income	319,580	305,427	313,097
Interest expense:
Deposits	24,055	25,322	29,279
Borrowed funds	32,272	31,265	31,883
Total interest expense	56,327	56,587	61,162
Net interest income	263,253	248,840	251,935
Provision for loan losses	9,712	20,314	18,519
Net interest income after provision for loan losses	253,541	228,526	233,416
Noninterest income:
Impairment losses on securities	0	0	(713)
Gain on sale of investments, net	1,037	4,930	6,118
Service charges and fees	38,362	36,383	35,884
Trust and other financial services income	12,342	12,369	9,330
Insurance commission income	9,526	8,760	8,635
Loss on real estate owned, net	(1,989)	(967)	(3,186)
Income from bank owned life insurance	4,338	4,191	5,197
Mortgage banking income	933	1,022	1,623
Other operating income	4,287	4,078	3,588
Total noninterest income	68,836	70,766	66,476
Noninterest expense:
Compensation and employee benefits	119,818	115,967	112,190
Premises and occupancy costs	24,641	23,455	23,182
Office operations	15,584	14,721	14,454
Processing expenses	30,780	26,671	25,548
Professional services	6,906	7,661	6,267
Amortization of other intangible assets	1,688	1,323	1,210
Marketing expenses	8,499	8,213	6,284
Real estate owned expense	2,070	2,140	2,437
Federal deposit insurance premiums	5,109	5,193	5,600
Acquisition expense	9,751	394	0
Other expenses	9,031	9,797	9,962
Total noninterest expense	233,877	215,535	207,134
Income before income taxes	88,500	83,757	92,758
Provision for income taxes:
Federal	24,010	19,656	23,177
State	3,950	2,139	3,022
Total provision for income taxes	27,960	21,795	26,199
Net income	$ 60,540	$ 61,962	$ 66,559
Basic earnings per share (in dollars per share)	$ 0.64	$ 0.68	$ 0.73
Diluted earnings per share (in dollars per share)	$ 0.64	$ 0.67	$ 0.73

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Statement of Comprehensive Income [Abstract]
Net Income	$ 60,540	$ 61,962	$ 66,559
Net unrealized holding gains on marketable securities:
Unrealized holding gains/ (losses), net of tax of $(204), $(5,787) and $10,551, respectively	315	9,042	(16,544)
Other-than-temporary impairment on securities included in net income, net of tax of $0, $0 and $(278), respectively	0	0	435
Reclassification adjustment for gains included in net income, net of tax of $289, $1,501 and $1,904, respectively	(451)	(2,348)	(2,977)
Net unrealized holding gains/ (losses) on marketable securities	(136)	6,694	(19,086)
Change in fair value of interest rate swaps, net of tax of $(699), $(618) and $(1,714), respectively	1,299	1,146	3,181
Defined benefit plans:
Net (loss)/ gain, net of tax of $(57), $12,080 and $(10,716), respectively	90	(18,892)	17,002
Amortization of prior service costs, net of tax of $905, $905 and $812, respectively	(1,418)	(1,418)	(1,509)
Net (loss)/ gain on defined benefit plans	(1,328)	(20,310)	15,493
Other comprehensive loss	(165)	(12,470)	(412)
Total comprehensive income	$ 60,375	$ 49,492	$ 66,147

CONSOLIDATED STATEMENTS OF COM6

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Statement of Comprehensive Income [Abstract]
Unrealized holding gains/(losses), tax	$ (204)	$ (5,787)	$ 10,551
Other-than-temporary impairment on securities included in net income, tax	0	0	(278)
Reclassification adjustment for gains included in net income, tax	289	1,501	1,904
Change in fair value of interest rate swaps, tax	(699)	(618)	(1,714)
Net gain/(loss), tax	(57)	12,080	(10,716)
Amortization of prior service costs included in net income, tax	$ 905	$ 905	$ 812

CONSOLIDATED STATEMENTS OF CHAN

CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Stock	Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Income/ (Loss)	Unallocated Common Stock of ESOP
Balance at Dec. 31, 2012	$ 1,127,032	$ 937	$ 613,249	$ 548,859	$ (11,488)	$ (24,525)
Comprehensive income:
Net Income	66,559			66,559
Other comprehensive loss, net of tax of $234, $8,081, and $559 for the year ended December 31, 2015, 2014 and 2013, respectively	(412)				(412)
Total comprehensive income	66,147			66,559	(412)
Exercise of stock options	6,618	7	6,611
Share repurchases	(4,459)	(4)	(4,455)
Stock-based compensation expense including tax benefits of $332, $945, and $635 for the year ended December 31, 2015, 2014 and 2013, respectively	5,718	3	4,273			1,442
Dividends paid ($0.56, $1.62, and $0.50 per share for the year ended December 31, 2015, 2014 and 2013, respectively)	(45,871)			(45,871)
Balance at Dec. 31, 2013	1,155,185	943	619,678	569,547	(11,900)	(23,083)
Comprehensive income:
Net Income	61,962			61,962
Other comprehensive loss, net of tax of $234, $8,081, and $559 for the year ended December 31, 2015, 2014 and 2013, respectively	(12,470)				(12,470)
Total comprehensive income	49,492			61,962	(12,470)
Exercise of stock options	6,519	6	6,513
Share repurchases	(5,273)	(4)	(5,269)
Stock-based compensation expense including tax benefits of $332, $945, and $635 for the year ended December 31, 2015, 2014 and 2013, respectively	6,656	2	5,212			1,442
Dividends paid ($0.56, $1.62, and $0.50 per share for the year ended December 31, 2015, 2014 and 2013, respectively)	(149,932)			(149,932)
Balance at Dec. 31, 2014	1,062,647	947	626,134	481,577	(24,370)	(21,641)
Comprehensive income:
Net Income	60,540			60,540
Other comprehensive loss, net of tax of $234, $8,081, and $559 for the year ended December 31, 2015, 2014 and 2013, respectively	(165)				(165)
Total comprehensive income	60,375			60,540	(165)
Shares issued to acquire LNB Bancorp, Inc.	90,608	70	90,538
Exercise of stock options	4,303	5	4,298
Share repurchases	(7,847)	(6)	(7,841)
Stock-based compensation expense including tax benefits of $332, $945, and $635 for the year ended December 31, 2015, 2014 and 2013, respectively	5,902	3	4,474			1,425
Dividends paid ($0.56, $1.62, and $0.50 per share for the year ended December 31, 2015, 2014 and 2013, respectively)	(52,825)			(52,825)
Balance at Dec. 31, 2015	$ 1,163,163	$ 1,019	$ 717,603	$ 489,292	$ (24,535)	$ (20,216)

CONSOLIDATED STATEMENTS OF CHA8

CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Statement of Stockholders' Equity [Abstract]
Other comprehensive income, tax	$ 234	$ 8,081	$ 559
Stock-based compensation expense, tax benefits	$ 332	$ 945	$ 635
Dividends paid, per share (in dollars per share)	$ 0.56	$ 1.62	$ 0.5

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Operating activities:
Net Income	$ 60,540	$ 61,962	$ 66,559
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for loan losses	9,712	20,314	18,519
Net gain on sale of assets	(921)	(5,236)	(6,061)
Net depreciation, amortization and accretion	8,958	9,868	8,952
Decrease in other assets	37,969	9,241	12,057
Increase/ (decrease) in other liabilities	(18,998)	(22,857)	2,890
Net amortization of premium on marketable securities	1,149	383	298
Noncash compensation expense related to stock benefit plans	5,570	5,711	5,083
Noncash impairment losses on investment securities	0	0	713
Noncash impairment of real estate owned	2,923	2,318	4,158
Deferred income tax expense/ (benefit)	6,290	8,595	1,262
Origination of loans held for sale	(2,504)	(1,042)	(36,773)
Proceeds from sale of loans held for sale	2,514	1,315	52,550
Net cash provided by operating activities	113,202	90,572	130,207
Investing activities:
Purchase of marketable securities available-for-sale	(59,980)	(49,996)	(234,965)
Proceeds from maturities and principal reductions of marketable securities held-to-maturity	72,265	17,673	33,764
Proceeds from maturities and principal reductions of marketable securities available-for-sale	280,277	162,007	255,064
Proceeds from sale of marketable securities available-for-sale	1,246	7,910	16,003
Loan originations	(2,319,800)	(1,944,677)	(2,072,797)
Proceeds from loan maturities and principal reductions	2,000,712	1,730,603	1,924,179
(Purchases)/ redemptions of Federal Home Loan Bank stock	(3,770)	10,422	3,119
Proceeds from sale of real estate owned	13,961	10,216	18,036
Sale of real estate owned for investment, net	608	607	814
Purchase of premises and equipment	(13,223)	(9,968)	(19,367)
Acquisitions, net of cash received	(61,108)	(2,792)	0
Net cash used in investing activities	(88,812)	(67,995)	(76,150)
Financing activities:
Decrease in deposits, net	(60,236)	(36,337)	(95,721)
Proceeds from long-term borrowings	135,000	0	30,000
Repayments of long-term borrowings	(172,552)	(52)	(68)
Net increase/ (decrease) in short-term borrowings	61,281	6,516	(8,334)
Increase in advances by borrowers for taxes and insurance	2,975	3,838	3,344
Redemption of Junior subordinated debentures	(8,119)	0	0
Share repurchases	(7,847)	(5,273)	(4,459)
Cash dividends paid on common stock	(52,825)	(149,932)	(45,871)
Proceeds from stock options exercised	4,303	6,519	6,618
Excess tax benefit from stock-based compensation	332	945	635
Net cash used in financing activities	(97,688)	(173,776)	(113,856)
Net decrease in cash and cash equivalents	(73,298)	(151,199)	(59,799)
Cash and cash equivalents at beginning of period	240,706	391,905	451,704
Net decrease in cash and cash equivalents	(73,298)	(151,199)	(59,799)
Cash and cash equivalents at end of period	167,408	240,706	391,905
Cash and cash equivalents:
Total cash and cash equivalents	240,706	391,905	451,704
Cash paid during the period for:
Interest on deposits and borrowings (including interest credited to deposit accounts of $21,949, $22,783 and $26,326, respectively)	55,270	56,539	61,162
Income taxes	16,719	26,042	22,881
Business acquisitions:
Fair value of assets acquired	1,160,190	2,798	0
Net cash paid	(61,108)	(2,792)	0
Liabilities assumed	1,099,082	6	0
Loan foreclosures and repossessions	7,633	10,820	14,529
Sale of real estate owned financed by the Company	$ 2,264	$ 486	$ 943

CONSOLIDATED STATEMENTS OF CA10

CONSOLIDATED STATEMENTS OF CASH FLOWS (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Statement of Cash Flows [Abstract]
Interest on deposits and borrowings, interest credited to deposit accounts	$ 21,949	$ 22,783	$ 26,326

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies (a) Nature of Operations Northwest Bancshares, Inc., a Maryland corporation headquartered in Warren, Pennsylvania, the federal savings and loan holding company for its wholly owned subsidiary, Northwest Bank. Northwest Bank, a Pennsylvania chartered savings bank, offers personal and business deposit and loan products as well as investment management and insurance services through its 181 banking locations in Pennsylvania, New York, Ohio and Maryland. Northwest Bank, through its subsidiary Northwest Consumer Discount Company, also offers personal loan products through 51 consumer finance offices in Pennsylvania. (b) Principles of Consolidation The consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries after elimination of all intercompany accounts and transactions. (c) Cash and Cash Equivalents For purposes of the statement of cash flows, cash and cash equivalents include cash and amounts due from banks, interest-bearing deposits in other financial institutions, federal funds sold, and other short-term investments with original maturities of three months or less. (d) Investment Securities We classify marketable securities at the time of purchase as held-to-maturity, available-for-sale, or trading securities. Securities for which management has the intent and ability to hold until maturity are classified as held-to-maturity and are carried at cost, adjusted for amortization of premiums and accretion of discounts on a level yield basis (amortized cost). If it is management’s intent at the time of purchase to hold securities for an indefinite period of time and/or to use such securities as part of its asset/liability management strategy, the securities are classified as available-for-sale and are carried at fair value, with unrealized gains and losses reported as accumulated other comprehensive income/ (loss), a separate component of shareholders’ equity, net of tax. Securities classified as available-for-sale include securities that may be sold in response to changes in interest rates, resultant prepayment risk, or other market factors. Securities that are bought and held principally for the purpose of selling them in the near term are classified as trading and are reported at fair value, with changes in fair value included in earnings. The cost of securities sold is determined on a specific identification basis. We held no securities classified as trading at or for the years ended December 31, 2015 and 2014 . On at least a quarterly basis, we review our investments for other-than-temporary impairment (“OTTI”). An investment security is deemed impaired if the fair value of the investment is less than its amortized cost. If an investment security is determined to be impaired, we evaluate whether the decline in value is other-than-temporary. We consider whether or not we expect to receive all of the contractual cash flows from the investment security based on factors that include, but are not limited to the credit worthiness of the issuer and the historical and projected performance of the underlying collateral. Also, we may evaluate the business and financial outlook of the issuer, as well as broader economic performance indicators. We consider both our intent to sell and the likelihood that we will not have to sell the investment securities before recovery of their cost basis during our evaluation. Impairment that is deemed credit related is recognized in earnings while impairment deemed noncredit related is recorded in accumulated other comprehensive income, if we do not intend to sell nor it is not likely we will be required to sell the investment security. If we intend to sell the investment security or if it’s more likely than not that we will be required to sell the investment security, the entire impairment is recorded in earnings. Federal law requires a member institution of the Federal Home Loan Bank (FHLB) system to hold stock of its district FHLB according to a predetermined formula. This stock is recorded at cost. Quarterly, we evaluate our investment in the FHLB of Pittsburgh for impairment. We evaluate recent and long-term operating performance, liquidity, funding and capital positions, stock repurchase history, dividend history and impact of legislative and regulatory changes. Based on our most recent evaluation, we have determined that no impairment write-downs are currently required. (e) Loans Receivable Our loan portfolio segments consist of Personal Banking and Business Banking loans. Personal Banking loans include the following classes: residential mortgage loans, home equity loans and other consumer loans. Business Banking loans include the following classes: commercial real estate loans and commercial loans. All classes of originated loans are carried at their unpaid principal balance net of any deferred origination fees or costs and the allowance for estimated loan losses. Interest income on loans is credited to income as earned. Interest earned on loans for which no payments were received during the month is accrued at month end. Accrued interest on loans more than 90 days delinquent is reversed and such loans are placed on nonaccrual status. All loans are placed on nonaccrual status when principal or interest is 90 days or more delinquent or when there is reasonable doubt that interest or principal will not be collected in accordance with the contractual terms. Interest receipts on all nonaccrual and impaired loans are recognized as interest revenue when it has been determined that all principal and interest will be collected or are applied to principal when collectability of principal is in doubt. Nonaccrual loans generally are restored to an accrual basis when principal and interest become current and a period of performance has been established in accordance with the contractual terms, typically six months . A loan is considered to be a troubled debt restructured loan (TDR) when the restructuring constitutes a concession and the borrower is experiencing financial difficulties. TDRs may include modifications of terms of loans, receipts of assets from borrowers in partial or full satisfaction of loans, or a combination thereof. TDRs are impaired loans. A modified loan is determined to be a TDR based on the contractual terms as specified by the original loan agreement or the most recent modification. Once classified a TDR, a loan is removed from such classification under three circumstances: (1) the loan is paid off, (2) the loan is charged off, or (3) if, at the beginning of the current fiscal year, the loan has performed in accordance with the modified terms for a minimum of six consecutive months and at the time of modification the loan’s interest rate represented a then current market interest rate for a loan of similar risk. Loan delinquency is measured based on the number of days since the payment due date. Past due status is measured using the loan’s contractual maturity date. Loan fees and certain direct loan origination costs are deferred and the net deferred fee or cost is then recognized using the level-yield method over the contractual life of the loan as an adjustment to interest income. We identify certain residential mortgage loans which will be sold prior to maturity, as loans held for sale. These loans are recorded at the lower of amortized cost or fair value less estimated cost to sell. At December 31, 2015 and 2014 , there were no residential mortgage loans classified as held for sale. Acquired loans are recorded at fair value with no carryover of the related allowance for loan losses. Determining the fair value of the loans involves estimating the amount and timing of principal and interest cash flows expected to be collected on the loans and discounting those cash flows at a market rate of interest. The excess of cash flows expected at acquisition over the estimated fair value is referred to as the accretable discount and is recognized into interest income over the remaining life of the loan. The difference between contractually required payments at acquisition and the cash flows expected to be collected at acquisition is referred to as the nonaccretable discount. The nonaccretable discount represents estimated future credit losses expected to be incurred over the life of the loan. Subsequent decreases to the expected cash flows require us to evaluate the need for an allowance for loan losses. Subsequent improvements in expected cash flows result in the reversal of a corresponding amount of the nonaccretable discount which we then reclassify as accretable discount that is recognized into interest income over the remaining life of the loan using the interest method. Charge-offs of the principal amount on acquired loans would be first applied to the nonaccretable discount portion of the fair value adjustment. Acquired loans that met the criteria for nonaccrual of interest prior to the acquisition may be considered performing upon acquisition, regardless of whether the customer is contractually delinquent, if we can reasonably estimate the timing and amount of the expected cash flows on such loans and if we expect to fully collect the new carrying value of the loans. As such, we may no longer consider the loan to be nonaccrual or nonperforming and may accrue interest on these loans, including the impact of any accretable discount. We have determined that we can reasonably estimate future cash flows on our current portfolio of acquired loans that are past due 90 days or more and on which we are accruing interest and we expect to fully collect the carrying value of the loans. (f) Allowance for Loan Losses and Provision for Loan Losses Provisions for estimated loan losses and the amount of the allowance for loan losses are based on losses inherent in the loan portfolio that are both probable and can be reasonably estimated at the date of the financial statements. We consider a loan to be impaired when it is probable that we will be unable to collect all amounts due according to the contractual terms of the loan agreement. In evaluating whether a loan is impaired, we consider not only the amount that we expect to collect but also the timing of collection. Generally, if a delay in payment is insignificant (e.g., less than 30 days ), a loan is not deemed to be impaired. Business Banking loans greater than or equal to $1.0 million are reviewed to determine if they should be individually evaluated for impairment. Smaller balance, homogeneous loans (e.g., primarily residential mortgage, home equity and consumer loans) are evaluated collectively for impairment. When a loan is considered to be impaired, the amount of impairment is measured based on the present value of expected future cash flows discounted at the loan’s effective interest rate, the loan’s market price, or fair value of the collateral, less estimated cost to sell, if the loan is collateral dependent. Impairment losses are included in the allowance for loan losses. Impaired loans are charged-off or charged down when we believe that the ultimate collectability of a loan is not likely or the collateral value no longer supports the carrying value of the loan. Interest income on non-performing loans is recognized using the cash basis method. For non-performing loans interest collected is credited to income in the period of recovery or applied to reduce principal if there is sufficient doubt about the collectability of principal. The allowance for loan losses is shown as a valuation allowance to loans. The accounting policy for the determination of the adequacy of the allowance by portfolio segment requires us to make numerous complex and subjective estimates and assumptions relating to amounts which are inherently uncertain. The allowance for loan losses is maintained to absorb losses inherent in the loan portfolio as of the balance sheet date. The methodology used to determine the allowance for loan losses is designed to provide procedural discipline in assessing the appropriateness of the allowance for loan losses. Losses are charged against and recoveries are added to the allowance for loan losses. For Business Banking loans the allowance for loan losses consists of: • An allowance for impaired loans; • An allowance for homogenous loans based on historical losses; and • An allowance for homogenous loans based on environmental factors. The allowance for impaired loans is based on individual analysis of all nonperforming loans greater than or equal to $1.0 million . The allowance is measured by the difference between the recorded value of impaired loans and their impaired value. The impaired value is either the present value of the expected future cash flows from the borrower, the market value of the loan, or the fair value of the collateral, less estimated cost to sell. The allowance for homogeneous loans based on historical factors is a rolling three -year average of actual losses incurred, adjusted for a loss realization period (the period of time from the event of loss to loss realization), applied to homogenous pools of loans categorized by similar risk characteristics, not including loans evaluated individually for impairment. The allowance for homogeneous loans based on environmental factors augments the historical loss factors for changes in: economic conditions, lending policies and procedures, the nature and volume of the loan portfolio, management, delinquency trends, loan administration, collateral values, concentrations of credit, and other external factors including legal and regulatory factors. For Personal Banking loans the allowance for loan losses consists of: • An allowance for loans 90 days or more delinquent; • An allowance for homogenous loans based on historical losses; and • An allowance for homogenous loans based on environmental factors. The allowance for loans 90 days or more delinquent is based on the loss history of loans that have become 90 days or more delinquent. We apply a historical loss factor to homogeneous pools of loans that are 90 days or more delinquent. The allowance for homogeneous loans based on historical losses is a rolling three -year average of actual losses incurred, adjusted for a loss realization period, applied to homogenous pools of loans categorized by similar risk characteristics, not including loans that are 90 days or more delinquent. The allocation of the allowance for loan losses is inherently judgmental, and the entire allowance for loan losses is available to absorb loan losses regardless of the nature of the loss. Personal Banking loans are charged-off or charged down when they become 180 days delinquent, unless the borrower has filed for bankruptcy. Business Banking loans are charged-off or charged down when, in our opinion, they are no longer collectible or when it has been determined that the collateral value no longer supports the carrying value of the loan, for loans that are collateral dependent. We have not made any material changes to our methodology for the calculation of the allowance for loan losses during the current year. (g) Real Estate Owned Real estate owned is comprised of property either acquired through foreclosure or voluntarily conveyed by borrowers. These assets are recorded on the date acquired at the lower of the loan balance or fair value of the collateral, less estimated disposition costs, with the fair value being determined by an appraisal. Any initial write-down is charged to the allowance for loan losses. Subsequently, foreclosed assets are valued at the lower of the amount recorded at acquisition date or the current fair value, less estimated disposition costs. Any subsequent write-down or gains or losses realized from the disposition of such property are credited or charged to noninterest income. (h) Premises and Equipment Premises and equipment are carried at cost, less accumulated depreciation and amortization. Depreciation is accumulated on a straight-line basis over the estimated useful lives of the related assets. Estimated lives range from three to 39 years . Amortization of leasehold improvements is accumulated on a straight-line basis over the terms of the related leases or the useful lives of the related assets, whichever is shorter. (i) Goodwill Goodwill is generated from the premium paid for an acquisition and is allocated to reporting units, which are either the Company’s reportable segments or one level below. Goodwill is not subject to amortization but is tested for impairment at least annually and possibly more frequently if certain events occur or changes in circumstances arise. Impairment testing requires that the fair value of each reporting unit be compared to its carrying amount, including goodwill. Reporting units are identified based upon analyzing each individual operating segment. A reporting unit is defined as a distinct, separately identifiable component of an operating segment for which complete, discrete financial information is available that management regularly reviews. Determining the fair value of a reporting unit requires a high degree of subjective management judgment, including developing cash flow projections, selecting appropriate discount rates, identifying relevant market comparables, incorporating general economic and market conditions and selecting an appropriate control premium. The selection and weighting of the various fair value techniques may result in a higher or lower fair value. Judgment is applied in determining the weightings that are most representative of fair value. We conducted our annual goodwill impairment assessment as of June 30 th through the assistance of an independent third party. We valued each reporting unit by using a weighted average of four valuation methodologies; comparable transaction approach, control premium approach, public market peers approach and discounted cash flow approach. Declines in fair value could result in impairment being identified. At June 30, 2015 and 2014, we did not identify any individual reporting unit where the fair value was less than the carrying value and no other events have occurred since that date that would warrant an updated valuation. Future changes in the economic environment or the operations of the operating units could cause changes to the variables used, which could give rise to declines in the estimated fair value of the reporting units. There were no changes in our operations that would cause us to update the goodwill impairment tests performed as of June 30, 2015 and 2014. Accordingly, we have determined that goodwill is not impaired as of December 31, 2015 and 2014 . (j) Core Deposit Intangibles and Other Identifiable Intangibles Through the assistance of an independent third party, we analyze and prepare a core deposit study for all bank acquisitions or other identifiable intangible asset study, such as customer lists, for all non-bank acquisitions. The core deposit study reflects the cumulative present value benefit of acquiring deposits versus an alternative source of funding. The other identifiable intangible asset study reflects the cumulative present value benefit of acquiring the income stream from an existing customer base versus developing new business relationships. Based upon analysis, the amount of the premium related to the core deposits or other identifiable intangibles of the business purchased is calculated along with the estimated life of the intangible. The intangible, which is recorded in other intangible assets, is then amortized to expense on an accelerated basis over an approximate life of 7 years . (k) Bank-Owned Life Insurance We own insurance on the lives of a certain group of key employees and directors. The policies were purchased to help offset the increase in the costs of various fringe benefit plans, including healthcare, as well as the directors deferred compensation plan. The cash surrender value of these policies is included as an asset on the consolidated statements of financial condition, and any increases in the cash surrender value are recorded as tax-free noninterest income on the consolidated statements of income. In the event of the death of an insured individual under these policies, after distribution to the insured’s beneficiaries, if any, we receive a tax-free death benefit, which is recorded as noninterest income. (l) Deposits Interest on deposits is accrued and charged to expense monthly and is paid or credited in accordance with the terms of the accounts. (m) Pension Plans We maintain multiple noncontributory defined benefit pension plans for substantially all of our employees. The net periodic pension cost has been calculated using service cost, interest cost, expected returns on plan assets and net amortization. (n) Income Taxes We join with our wholly owned subsidiaries in filing a consolidated federal income tax return. In accordance with an intercompany tax allocation agreement, the applicable federal income tax expense or benefit is allocated to each subsidiary based upon taxable income or loss calculated on a separate company basis. Each subsidiary is responsible for payment of its own federal income tax liability or receives reimbursement of federal income tax benefit. In addition, deferred taxes are calculated and maintained on a separate company basis. We account for income taxes under the asset and liability method. The objective of the asset and liability method is to establish deferred tax assets and liabilities for temporary differences between the financial reporting and tax basis of our assets and liabilities based on the tax rates expected to be in effect when such amounts are realized or settled. (o) Stock-Related Compensation We determine the fair value of each option award, estimated on the grant date, using the Black-Scholes-Merton option-pricing model. The Black-Scholes-Merton option-pricing model uses variables including; expected volatilities, expected term, risk-free discount rate and annual rate of quarterly dividends. Expected volatilities are based on historical volatility of the Company’s stock. The expected terms are based upon actual exercise and forfeiture experience of previous option grants. The risk-free rate is based on yields on U.S. Treasury securities of a similar maturity to the expected term of the options. During the year ended December 31, 2015 , we awarded 600,570 stock options to employees and 64,800 stock options to directors. Option awards are generally granted with an exercise price equal to the closing market price of the Company’s stock on the day before the grant date. The options granted in 2015 vest over a ten -year period, with the first vesting occurring on the grant date. New shares are issued when options are exercised. During the year ended December 31, 2015 , we awarded 282,050 common shares to employees and 24,300 common shares to directors. The common share awards granted in 2015 vest over a ten -year period, with the first vesting occurring on the grant date. During the year ended December 31, 2015 we awarded 126,280 common shares to eligible employees from our employee stock ownership plan (“ESOP”). For additional information regarding grants of stock options and common shares and ESOP distributions see Note 15. Stock-based employee compensation expense related to common share awards of $3.0 million , $3.0 million and $2.4 million was included in income before income taxes during the years ended December 31, 2015 , 2014 and 2013 , respectively. The effect on net income for the years ended December 31, 2015 , 2014 and 2013 was a reduction of $1.8 million , $1.8 million and $1.6 million , respectively. Total compensation expense for unvested stock options of $4.3 million has yet to be recognized as of December 31, 2015 . The weighted average period over which this remaining stock option expense will be recognized is approximately 4.23 years . The fair value of each option grant is estimated on the date of grant using the Black-Scholes-Merton option-pricing model with the following weighted average assumptions: (1) dividend yields ranging from 1.6% to 5.1% based on historical dividends and market prices; (2) expected volatility of 17% to 33% based on historical volatility; (3) risk-free interest rates ranging from 1.7% to 6.5% ; and (4) expected lives of seven to nine years based on previous grants. (p) Segment Reporting We have 2 reportable segments, Community Banking and Consumer Finance. See note 22 for related disclosures. (q) Derivative financial instruments — interest rate swaps We recognize all derivative financial instruments as either assets or liabilities in the balance sheet and measure those instruments at fair value. The accounting for changes in the fair value of a derivative depends on the intended use of the derivative and the resulting designation. An entity that elects to use hedge accounting is required, at inception, to establish the method it will use for assessing the effectiveness of the hedging derivative and the measurement approach for determining the ineffective aspect of the hedge. Those methods must be consistent with our approach to managing risk. We utilize interest rate swap agreements as part of the management of interest rate risk to hedge the interest rate risk on our trust preferred debentures. Amounts receivable or payable are recognized as accrued under the terms of the agreements and the differential is recorded as an adjustment to interest expense. The interest rate swaps are designated as cash flow hedges, with the effective portion of the derivative’s unrealized gain or loss recorded as a component of other comprehensive income. The ineffective portion of the unrealized gain or loss, if any, would be recorded in other expense. See note 23 for related disclosures. (r) Off-Balance-Sheet Instruments In the normal course of business, we extend credit in the form of loan commitments, undisbursed lines of credit, and standby letters of credit. These off-balance-sheet instruments involve, to various degrees, elements of credit and interest rate risk not reported in the consolidated statement of financial condition. We utilize the same underwriting standards for these instruments as other extensions of credit. (s) Use of Estimates The preparation of financial statements, in conformity with accounting principles generally accepted in the United States of America, requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amount of revenues and expenses during the reporting period. The estimates and assumptions that we deem important to our financial statements relate to the allowance for loan losses, the accounting treatment and valuation of our investment securities portfolio, the analysis of the carrying value of goodwill and income taxes. These estimates and assumptions are based on management’s best estimates and judgment and we evaluate them using historical experience and other factors, including the current economic environment. We adjust our estimates and assumptions when facts and circumstances dictate. As future events cannot be determined, actual results could differ significantly from our estimates. (t) Reclassification of Prior Years’ Statements Certain items previously reported have been reclassified to conform with the current year’s reporting format.

Recent Accounting Pronouncement

Recent Accounting Pronouncements	12 Months Ended
	Dec. 31, 2015
Accounting Changes and Error Corrections [Abstract]
Recent Accounting Pronouncements	Recent Accounting Pronouncements In May 2014 the FASB issued ASU 2014-09, “Revenue from Contracts with Customers”. This guidance supersedes the revenue recognition requirements in Topic 605, Revenue Recognition, and most industry-specific guidance. The core principle of this guidance requires an entity to recognize revenue upon the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services and provides five steps to be analyzed to accomplish the core principle. This guidance is effective retrospectively for annual reporting periods beginning after December 15, 2017, including interim periods within those years and early adoption is not permitted. We are currently evaluating the impact this standard will have on our results of operations and financial position. In June 2014 the FASB issued ASU 2014-12, “Compensation—Stock Compensation”. This guidance requires that a performance target that affects vesting and that could be achieved after the requisite service period be treated as a performance condition. Specifically, if the performance target becomes probable of being achieved before the end of the requisite service period, the remaining unrecognized compensation cost should be recognized prospectively over the remaining requisite service period. Further, the total amount of compensation cost recognized during and after the requisite service period should reflect the number of awards that are expected to vest and should be adjusted to reflect those awards that ultimately vest. This guidance is effective for annual periods beginning after December 15, 2015, including interim periods within those years and early adoption is permitted. We do not expect that this standard will have a material impact on our results of operations or financial position. In February 2015 the FASB issued ASU 2015-02, “Consolidation” . This guidance amends existing standards regarding the evaluation of certain legal entities and their consolidation in the financial statements. The amendments modify the evaluation of whether limited partnerships and similar legal entities are variable interest entities or voting interest entities and eliminate the presumption that a general partner should consolidate a limited partnership. The amendments also affect the consolidation analysis of reporting entities that are involved with variable interest entities and provide a scope exception from consolidation guidance for reporting entities with interests in legal entities that are required to comply with or operate in accordance with requirements that are similar to those in Rule 2a-7 of the Investment Company Act of 1940 for registered money market funds. This guidance is effective for annual periods beginning after December 15, 2015, including interim periods within those years and early adoption is permitted. We do not expect that this standard will have a material impact on our results of operations or financial position. In September 2015 the FASB issued ASU 2015-16, “ Simplifying the Accounting for Measurement-Period Adjustments ”. This guidance eliminates the requirement to retrospectively adjust the financial statements for measurement-period adjustments that occur in periods after a business combination is consummated. This guidance is effective for annual periods beginning after December 15, 2015, including interim periods within those years and early adoption is permitted. We do not expect that this standard will have a material impact on our results of operations or financial position.

Acquisition

Acquisition	12 Months Ended
	Dec. 31, 2015
Business Combinations [Abstract]
Acquisition	Acquisition On August 14, 2015, the Company acquired LNB Bancorp, Inc. (“LNB”), the parent company of The Lorain National Bank, for total consideration of $181.0 million , and thereby acquired LNB’s 21 branch locations in the Ohio counties of Lorain, Cuyahoga and Summit. The acquisition of LNB enables the Company to expand its northeastern Ohio presence, improve its core deposit base, and add additional scale in its banking operations. The result of LNB’s operations are included in the Consolidated Statements of Income from the date of acquisition. Under the terms of the merger agreement, each outstanding share of LNB stock was converted into the right to receive either 1.461 shares of common stock of the Company, or $18.70 in cash. As a result, LNB stockholders received 7,056,074 shares of Company common stock, valued at $90.6 million , based on the $12.84 closing price of the Company’s stock on August 14, 2015, and cash consideration of $90.4 million . The following table shows the consideration paid, the assets acquired, and the liabilities assumed that were recorded at fair value on the date of acquisition: Consideration paid: Northwest Bancshares, Inc. common stock issued $ 90,608 Cash paid to LNB Bancorp, Inc. stockholders 90,350 Total consideration paid 180,958 Recognized amounts of identifiable assets acquired and (liabilities assumed), at fair value Cash and cash equivalents 29,680 Investment securities available for sale 184,169 Loans 928,101 Federal Home Loan Bank stock 3,840 Premises and equipment 12,374 Core deposit intangible 7,375 Other assets 45,698 Deposits (1) (1,033,992 ) Borrowings (63,169 ) Other liabilities (19,356 ) Total indentifiable net assets 94,720 Goodwill $ 86,238 (1) Subsequent to the September 30, 2015 reporting period, we adjusted deposits by $17.4 million for trust account deposits maintained by LNB. This adjustment had no impact on goodwill. We estimated the fair value of loans acquired from LNB by utilizing a methodology wherein similar loans were aggregated into pools. Cash flows for each pool were determined by estimating future credit losses and the rate of prepayments. Projected monthly cash flows were then discounted to present value based on a market rate for similar loans. There was no carryover of LNB’s allowance for loan losses associated with the loans we acquired as the loans were initially recorded at fair value. The following table shows information related to the purchased credit impaired LNB loan portfolio as of August 14, 2015: Contractually required principal and interest at acquisition $ 41,175 Contractual cash flows not expected to be collected (nonaccretable discount) (19,900 ) Expected cash flows at acquisition 21,275 Interest component of expected cash flows (accretable discount) (1,672 ) Fair value of purchased credit impaired loans $ 19,603 The core deposit intangible asset is being amortized over its estimated useful life of approximately seven years utilizing an accelerated method. The goodwill, which is not amortized for book purposes, was assigned to our Community Banking segment and is not deductible for tax purposes. The fair values of savings and transaction deposit accounts acquired from LNB were assumed to approximate the carrying value as these accounts have no stated maturity and are payable on demand. Certificates of deposit were valued by projecting out the expected cash flows based on the contractual terms of the certificates of deposit. These cash flows were discounted based on a market rate for a certificate of deposit with a corresponding maturity. Direct costs related to the LNB acquisition were expensed as incurred and amounted to $9.8 million for the year ended December 31, 2015. Technology and communications termination costs comprised more than half of these expenses, which also included professional services, marketing and advertising, severance costs, and other noninterest expenses.

Marketable Securities

Marketable Securities	12 Months Ended
	Dec. 31, 2015
Investments, Debt and Equity Securities [Abstract]
Marketable Securities	Marketable Securities Marketable securities available-for-sale at December 31, 2015 are as follows: Amortized cost Gross unrealized holding gains Gross unrealized holding losses Fair value Debt issued by the U.S. government and agencies: Due in one year or less $ 11 — — 11 Debt issued by government sponsored enterprises: 15500 3 -48 15.45 Due in one year or less 15,500 3 (48 ) 15,455 Due after one year through five years 257,463 298 (1,395 ) 256,366 Due after five years through ten years 12,721 14 (23 ) 12,712 Due after ten years 9,815 135 (43 ) 9,907 Equity securities 1,400 500 (6 ) 1,894 Municipal securities: Due in one year or less 1,684 8 — 1,692 Due after one year through five years 14,327 117 (4 ) 14,440 Due after five years through ten years 12,400 323 — 12,723 Due after ten years 52,286 1,727 — 54,013 Corporate debt issues: Due after ten years 14,463 2,417 (405 ) 16,475 Residential mortgage-backed securities: Fixed rate pass-through 118,266 2,480 (420 ) 120,326 Variable rate pass-through 54,292 2,616 (7 ) 56,901 Fixed rate non-agency CMOs 2,519 230 — 2,749 Fixed rate agency CMOs 215,719 389 (3,881 ) 212,227 Variable rate agency CMOs 86,090 476 (52 ) 86,514 Total residential mortgage-backed securities 476,886 6,191 (4,360 ) 478,717 Total marketable securities available-for-sale $ 868,956 11,733 (6,284 ) 874,405 Marketable securities held to maturity at December 31, 2015 are as follows: Amortized cost Gross unrealized holding gains Gross unrealized holding losses Fair value Municipal securities: Due after five years through ten years $ 274 1 — 275 Due after ten years 6,336 239 — 6,575 Residential mortgage-backed securities: Fixed rate pass-through 6,458 351 — 6,809 Variable rate pass-through 3,618 41 — 3,659 Fixed rate agency CMOs 14,033 219 — 14,252 Variable rate agency CMOs 970 12 — 982 Total residential mortgage-backed securities 25,079 623 — 25,702 Total marketable securities held-to-maturity $ 31,689 863 — 32,552 Marketable securities available-for-sale at December 31, 2014 are as follows: Amortized cost Gross unrealized holding gains Gross unrealized holding losses Fair value Debt issued by the U.S. government and agencies: Due in one year or less $ 25 — — 25 Debt issued by government sponsored enterprises: Due after one year through five years 310,172 287 (2,672 ) 307,787 Due after five years through ten years 25,746 — (28 ) 25,718 Equity securities 2,591 682 (116 ) 3,157 Municipal securities: Due in one year or less 810 15 — 825 Due after one year through five years 7,878 132 — 8,010 Due after five years through ten years 6,965 115 — 7,080 Due after ten years 51,839 2,391 — 54,230 Corporate debt issues: Due after ten years 18,267 2,579 (419 ) 20,427 Residential mortgage-backed securities: Fixed rate pass-through 72,852 3,149 (124 ) 75,877 Variable rate pass-through 66,140 3,466 (8 ) 69,598 Fixed rate non-agency CMOs 3,162 246 — 3,408 Fixed rate agency CMOs 226,413 685 (5,331 ) 221,767 Variable rate agency CMOs 113,842 657 (37 ) 114,462 Total residential mortgage-backed securities 482,409 8,203 (5,500 ) 485,112 Total marketable securities available-for-sale $ 906,702 14,404 (8,735 ) 912,371 Marketable securities held to maturity at December 31, 2014 are as follows: Amortized cost Gross unrealized holding gains Gross unrealized holding losses Fair value Municipal securities: Due after five years through ten years $ 10,207 141 — 10,348 Due after ten years 56,545 1,314 — 57,859 Residential mortgage-backed securities: Fixed rate pass-through 8,236 477 — 8,713 Variable rate pass-through 4,273 122 — 4,395 Fixed rate agency CMOs 23,382 531 — 23,913 Variable rate agency CMOs 1,052 12 — 1,064 Total residential mortgage-backed securities 36,943 1,142 — 38,085 Total marketable securities held-to-maturity $ 103,695 2,597 — 106,292 The following table presents information regarding the issuers and the carrying values of our mortgage-backed securities at December 31, 2015 and 2014 : December 31, 2015 2014 Residential mortgage backed securities: FNMA $ 234,204 230,051 GNMA 48,283 54,422 FHLMC 209,788 223,479 SBA 8,166 10,052 Other (including non-agency) 3,355 4,051 Total residential mortgage-backed securities $ 503,796 522,055 Marketable securities having a carrying value of $331.8 million at December 31, 2015 , were pledged under collateral agreements. During the year ended December 31, 2015 , we sold marketable securities classified as available-for-sale for $1.2 million , with gross realized gains of $121,000 and gross realized losses of $67,000 . During the year ended December 31, 2014 , we sold marketable securities classified as available-for-sale for $7.9 million , with gross realized gains of $4.4 million and gross realized losses of $0 . During the year ended December 31, 2013 , we sold marketable securities classified as available-for-sale for $16.0 million with gross realized gains of $5.8 million and gross realized losses of $0 . During the years ended December 31, 2015 , 2014 and 2013 , we recognized non-cash credit related other-than-temporary-impairment in our investment portfolio resulting in write-downs of $0 , $0 and $713,000 , respectively. The following table shows the fair value and gross unrealized losses on investment securities, aggregated by investment category and length of time that the individual securities have been in a continuous unrealized loss position at December 31, 2015 : Less than 12 months 12 months or more Total Unrealized Unrealized Unrealized Fair value loss Fair value loss Fair value loss U.S. government and agencies $ 143,751 (723 ) 92,961 (786 ) 236,712 (1,509 ) Corporate debt issues — — 2,021 (405 ) 2,021 (405 ) Equity securities 544 (6 ) — — 544 (6 ) Municipal securities 7,505 (4 ) — 7,505 (4 ) Residential mortgage-backed securities - agency 122,109 (598 ) 149,889 (3,762 ) 271,998 (4,360 ) Total temporarily impaired securities $ 273,909 (1,331 ) 244,871 (4,953 ) 518,780 (6,284 ) The following table shows the fair value and gross unrealized losses on investment securities, aggregated by investment category and length of time that the individual securities have been in a continuous unrealized loss position at December 31, 2014 : Less than 12 months 12 months or more Total Unrealized Unrealized Unrealized Fair value loss Fair value loss Fair value loss U.S. government and agencies $ 28,878 (67 ) 244,828 (2,633 ) 273,706 (2,700 ) Corporate debt issues — — 2,003 (419 ) 2,003 (419 ) Equity securities 506 (116 ) — — 506 (116 ) Residential mortgage-backed securities - agency 20,832 (79 ) 195,505 (5,421 ) 216,337 (5,500 ) Total temporarily impaired securities $ 50,216 (262 ) 442,336 (8,473 ) 492,552 (8,735 ) We perform an assessment to determine whether there have been any events or economic circumstances that indicate a security which has an unrealized loss is impaired other-than-temporarily. The assessment considers many factors including the severity and duration of the impairment; recent events specific to the issuer or industry; and for debt securities, external credit ratings, underlying collateral position and recent downgrades. For asset backed securities, we evaluate current characteristics of each security such as delinquency and foreclosure levels, credit enhancement and projected losses and coverage. It is possible that the underlying collateral of these securities will perform worse than current expectations, which may lead to adverse changes in cash flows on these securities and potential future losses. Events that may trigger material declines in fair values for these securities in the future would be, but are not limited to: deterioration of credit metrics, significantly higher levels of default and severity of loss on the underlying collateral, deteriorating credit enhancement and loss coverage ratios, or further illiquidity. For debt securities, credit related other-than-temporary impairment is recognized in earnings, while noncredit related other-than-temporary impairment on securities not expected to be sold, or otherwise disposed of, is recognized in other comprehensive income. We assert that we do not have the intent to sell these securities and it is more likely than not that we will not have to sell these securities before a recovery of our cost basis. For these reasons, we consider the unrealized losses to be temporary impairment losses. There are approximately 148 positions that are temporarily impaired at December 31, 2015 . The aggregate carrying amount of cost-method investments, including both held-to-maturity and available-for-sale, at December 31, 2015 was $907.0 million , of which all were evaluated for impairment. The following table sets forth the categories of investment securities as of December 31, 2015 on which other-than-temporary impairment charges have been recorded in earnings: Total Accumulated Category Amortized cost Fair value Unrealized gain impairment charges Freddie Mac preferred shares $ 1 10 9 (119 ) Trust preferred investments 11,137 13,437 2,300 (7,942 ) Non-agency CMOs 2,258 2,484 226 (494 ) Total $ 13,396 15,931 2,535 (8,555 ) The table below shows a cumulative roll forward of credit related impairment losses recognized in earnings for debt securities held and not intended to be sold: December 31, 2015 2014 Beginning balance as of January 1, (1) $ 8,894 10,342 Credit losses on debt securities for which other-than-temporary impairment was not previously recognized — — Reduction for losses realized during the year (98 ) (1,448 ) Reduction for securities called realized during the year (360 ) — Additional credit losses on debt securities for which other-than-temporary impairment was previously recognized — — Ending balance as of December 31, $ 8,436 8,894 (1) The beginning balance represents credit losses included in other-than-temporary impairment charges recognized on debt securities in prior periods.

Loans Receivable and Allowance

Loans Receivable and Allowance for Loan Losses	12 Months Ended
	Dec. 31, 2015
Receivables [Abstract]
Loans Receivable and Allowance for Loan Losses	Loans Receivable and Allowance for Loan Losses Loans receivable at December 31, 2015 and 2014 are summarized in the table below: December 31, 2015 December 31, Originated Acquired Total 2014 Personal Banking: Residential mortgage loans $ 2,695,561 45,716 2,741,277 2,526,240 Home equity loans 1,055,907 131,199 1,187,106 1,066,131 Other consumer loans 307,961 202,656 510,617 242,744 Total Personal Banking 4,059,429 379,571 4,439,000 3,835,115 Business Banking: Commercial real estate loans 2,094,710 429,564 2,524,274 1,874,944 Commercial loans 372,540 65,175 437,715 419,525 Total Business Banking 2,467,250 494,739 2,961,989 2,294,469 Total loans receivable, gross 6,526,679 874,310 7,400,989 6,129,584 Deferred loan costs 14,806 5,259 20,065 6,095 Allowance for loan losses (60,970 ) (1,702 ) (62,672 ) (67,518 ) Undisbursed loan proceeds: Residential mortgage loans (10,778 ) — (10,778 ) (10,879 ) Commercial real estate loans (159,553 ) (13,287 ) (172,840 ) (73,760 ) Commercial loans (11,132 ) (4,183 ) (15,315 ) (61,149 ) Total loans receivable, net $ 6,299,052 860,397 7,159,449 5,922,373 As of December 31, 2015 , 2014 and 2013 , we serviced loans for others approximating $776.0 million , $734.9 million and $851.4 million , respectively. These loans serviced for others are not our assets and are not included in our financial statements. As of December 31, 2015 and 2014 , approximately 65% and 76% , respectively, of our loan portfolio was secured by properties located in Pennsylvania. We do not believe we have significant concentrations of credit risk to any one group of borrowers given our underwriting and collateral requirements. Loans receivable as of December 31, 2015 and 2014 include $2.417 billion and $1.876 billion , respectively, of adjustable rate loans and $4.984 billion and $4.254 billion , respectively, of fixed rate loans. Acquired loans were initially measured at fair value and subsequently accounted for under either Accounting Standards Codification (“ASC”) Topic 310-30 or ASC Topic 310-20. The following table provides information related to the outstanding principal balance and related carrying value of acquired loans for the dates indicated: December 31, 2015 Acquired loans evaluated individually for future credit losses: Outstanding principal balance $ 21,069 Carrying value 16,867 Acquired loans evaluated collectively for future credit losses: Outstanding principal balance 848,194 Carrying value 839,973 Total acquired loans: Outstanding principal balance 869,263 Carrying value 856,840 The following table provides information related to the changes in the accretable discount, which includes income recognized from contractual cash flows for the dates indicated: Total Balance at December 31, 2014 $ — LNB Bancorp, Inc. acquisition 1,672 Accretion (377 ) Net reclassification from nonaccretable yield 724 Balance at December 31, 2015 $ 2,019 The following table provides information related to purchased credit impaired loans by portfolio segment and by class of financing receivable at and for the year ended December 31, 2015: Carrying value Outstanding principal balance Related impairment reserve Average recorded investment in impaired loans Interest income/ accretion recognized Personal Banking: Residental mortgage loans $ 1,981 2,910 14 2,083 41 Home equity loans 2,084 3,455 6 2,222 51 Other consumer loans 267 492 2 305 18 Total Personal Banking 4,332 6,857 22 4,610 110 Business Banking: Commercial real estate loans 12,288 13,946 353 12,867 249 Commercial loans 247 266 — 335 18 Total Business Banking 12,535 14,212 353 13,202 267 Total $ 16,867 21,069 375 17,812 377 The following table provides information related to changes in the allowance for losses on loans receivable for the year ended December 31, 2015 : Balance Provision Charge-offs Recoveries Balance Originated loans: Personal Banking: Residential mortgage loans $ 4,692 (96 ) (1,057 ) 264 5,581 Home equity loans 3,941 693 (1,716 ) 414 4,550 Other consumer loans 7,488 7,985 (8,073 ) 1,458 6,118 Total Personal Banking 16,121 8,582 (10,846 ) 2,136 16,249 Business Banking: Commercial real estate loans 32,348 540 (5,741 ) 4,160 33,389 Commercial loans 12,501 2,768 (7,814 ) 4,032 13,515 Total Business Banking 44,849 3,308 (13,555 ) 8,192 46,904 Unallocated (1) — (4,365 ) — — 4,365 Total originated loans 60,970 7,525 (24,401 ) 10,328 67,518 Acquired loans: Personal Banking: Residential mortgage loans 18 47 (69 ) 40 — Home equity loans 101 247 (708 ) 562 — Other consumer loans 110 188 (201 ) 123 — Total Personal Banking 229 482 (978 ) 725 — Business Banking: Commercial real estate loans 1,439 1,545 (585 ) 479 — Commercial loans 34 160 (369 ) 243 — Total Business Banking 1,473 1,705 (954 ) 722 — Total acquired loans 1,702 2,187 (1,932 ) 1,447 — Total $ 62,672 9,712 (26,333 ) 11,775 67,518 (1) Due to enhancements in our allowance for loan losses process we allocated the previously unallocated allowance using both qualitative and quantitative factors. The following table provides information related to changes in the allowance for losses on loans receivable for the year ended December 31, 2014: Balance Provision Charge-offs Recoveries Balance Personal Banking: Residential mortgage loans $ 5,581 (556 ) (2,181 ) 443 7,875 Home equity loans 4,550 (1,106 ) (1,783 ) 194 7,245 Other consumer loans 6,118 5,864 (6,423 ) 1,190 5,487 Total Personal Banking 16,249 4,202 (10,387 ) 1,827 20,607 Business Banking: Commercial real estate loans 33,389 4,417 (8,422 ) 2,195 35,199 Commercial loans 13,515 11,992 (11,936 ) 2,579 10,880 Total Business Banking 46,904 16,409 (20,358 ) 4,774 46,079 Unallocated 4,365 (297 ) — — 4,662 Total $ 67,518 20,314 (30,745 ) 6,601 71,348 The following table provides information related to changes in the allowance for losses on loans receivable for the year ended December 31, 2013 : Balance Provision Charge-offs Recoveries Balance Personal Banking: Residential mortgage loans $ 7,875 1,954 (2,501 ) 420 8,002 Home equity loans 7,245 932 (2,239 ) 258 8,294 Other consumer loans 5,487 5,304 (6,055 ) 1,082 5,156 Total Personal Banking 20,607 8,190 (10,795 ) 1,760 21,452 Business Banking: Commercial real estate loans 35,199 8,347 (10,042 ) 2,305 34,589 Commercial loans 10,880 1,346 (5,007 ) 1,389 13,152 Total Business Banking 46,079 9,693 (15,049 ) 3,694 47,741 Unallocated 4,662 636 — — 4,026 Total $ 71,348 18,519 (25,844 ) 5,454 73,219 While we use available information to provide for losses, future additions to the allowance may be necessary based on changes in economic conditions. In addition, various regulatory agencies, as an integral part of their examination process, periodically review our allowance for loan losses. Such agencies may require us to recognize additions to the allowance based on their judgments about information available to them at the time of their examination. Management believes, to the best of their knowledge, that all known losses as of the balance sheet dates have been recorded. The following table provides information related to the loan portfolio by portfolio segment and by class of financing receivable as of December 31, 2015 : Recorded investment in loans receivable Allowance for loan losses Recorded investment in loans on nonaccrual (1) Recorded investment in loans 90 days or more past maturity and still accruing TDRs (1) Allowance for TDRs Additional commitments to customers with loans classified as TDRs Personal Banking: Residential mortgage loans $ 2,740,892 4,710 19,772 4 6,360 1,189 — Home equity loans 1,187,106 4,042 7,522 — 2,298 605 — Other consumer loans 520,289 7,598 3,452 976 — — — Total Personal Banking 4,448,287 16,350 30,746 980 8,658 1,794 — Business Banking: Commercial real estate loans 2,351,434 33,787 33,421 206 31,970 2,257 241 Commercial loans 422,400 12,535 7,495 148 10,487 631 79 Total Business Banking 2,773,834 46,322 40,916 354 42,457 2,888 320 Total $ 7,222,121 62,672 71,662 1,334 51,115 4,682 320 (1) Includes $21.1 million of nonaccrual TDRs. The following table provides information related to the loan portfolio by portfolio segment and by class of financing receivable as of December 31, 2014 : Recorded investment in loans receivable Allowance for loan losses Recorded investment in loans on nonaccrual (1) Recorded TDRs (1) Allowance for TDRs Additional commitments to customers with loans classified as TDRs Personal Banking: Residential mortgage loans $ 2,521,456 5,581 21,194 8 6,574 1,133 — Home equity loans 1,066,131 4,550 9,569 — 2,412 229 — Other consumer loans 242,744 6,118 2,820 206 — — — Total Personal Banking 3,830,331 16,249 33,583 214 8,986 1,362 — Business Banking: Commercial real estate loans 1,801,184 33,389 38,647 — 41,917 4,938 449 Commercial loans 358,376 13,515 7,578 21 10,885 1,095 814 Total Business Banking 2,159,560 46,904 46,225 21 52,802 6,033 1,263 Total $ 5,989,891 63,153 79,808 235 61,788 7,395 1,263 (1) Includes $24.5 million of nonaccrual TDRs. A loan is considered to be impaired, when, based on current information and events it is probable that we will be unable to collect all amounts due according to the contractual terms of the loan agreement including both contractual principal and interest payments. This includes non-accrual loans, loans more than 90 days delinquent and still accruing interest, loans for which we perform an impairment review and TDRs. Impairment is measured using one of three methods: (1) the present value of expected future cash flows discounted at the loan’s effective interest rate; (2) the loan’s observable market price; or (3) the fair value of collateral if the loan is collateral dependent, less costs of sale or disposition. If the measure of the impaired loan is less than the recorded investment in the loan, a specific allowance is allocated for the impairment. The following table provides information related to the composition of impaired loans by portfolio segment and by class of financing receivable at and for the year ended December 31, 2015 : Nonaccrual loans 90 or more days delinquent Nonaccrual loans less than 90 days delinquent Loans less than 90 days delinquent reviewed for impairment TDRs less than 90 days delinquent not included elsewhere Total impaired loans Average recorded investment in impaired loans Interest income recognized on impaired loans Personal Banking: Residential mortgage loans $ 15,810 3,962 — 5,086 24,858 24,554 944 Home equity loans 5,650 1,872 — 1,847 9,369 9,644 497 Other consumer loans 2,900 552 — — 3,452 2,977 101 Total Personal Banking 24,360 6,386 — 6,933 37,679 37,175 1,542 Business Banking: Commercial real estate loans 16,449 16,972 16,121 16,467 66,009 77,166 3,226 Commercial loans 2,459 5,036 2,014 4,654 14,163 16,187 694 Total Business Banking 18,908 22,008 18,135 21,121 80,172 93,353 3,920 Total $ 43,268 28,394 18,135 28,054 117,851 130,528 5,462 The following table provides information related to the composition of impaired loans by portfolio segment and by class of financing receivable at and for the year ended December 31, 2014 : Nonaccrual loans 90 or more days delinquent Nonaccrual loans less than 90 days delinquent Loans less than 90 days delinquent reviewed for impairment TDRs less than 90 days delinquent not included elsewhere Total impaired loans Average recorded investment in impaired loans Interest income recognized on impaired loans Personal Banking: Residential mortgage loans $ 17,696 3,498 — 5,845 27,039 28,227 817 Home equity loans 6,606 2,963 — 1,706 11,275 11,753 485 Other consumer loans 2,450 370 — — 2,820 2,383 66 Total Personal Banking 26,752 6,831 — 7,551 41,134 42,363 1,368 Business Banking: Commercial real estate loans 11,099 27,548 26,400 12,128 74,337 90,187 3,589 Commercial loans 3,475 4,103 5,266 6,026 21,708 27,088 914 Total Business Banking 14,574 31,651 31,666 18,154 96,045 117,275 4,503 Total $ 41,326 38,482 31,666 25,705 137,179 159,638 5,871 The following table provides information related to the composition of impaired loans by portfolio segment and by class of financing receivable at and for the year ended December 31, 2013 : Nonaccrual loans 90 or more days delinquent Nonaccrual loans less than 90 days delinquent Loans less than 90 days delinquent reviewed for impairment TDRs less than 90 days delinquent not included elsewhere Total impaired loans Average recorded investment in impaired loans Interest income recognized on impaired loans Personal Banking: Residential mortgage loans $ 24,625 2,652 — 3,372 30,649 29,994 723 Home equity loans 8,344 1,519 — 1,810 11,673 10,828 383 Other consumer loans 2,057 200 — — 2,257 1,976 44 Total Personal Banking 35,026 4,371 — 5,182 44,579 42,798 1,150 Business Banking: Commercial real estate loans 18,433 23,370 39,199 13,060 94,062 90,912 3,678 Commercial loans 4,298 21,723 5,219 3,963 35,203 41,303 1,127 Total Business Banking 22,731 45,093 44,418 17,023 129,265 132,215 4,805 Total $ 57,757 49,464 44,418 22,205 173,844 175,013 5,955 The following table provides information related to the evaluation of impaired loans by portfolio segment and by class of financing receivable as of and for the year ended December 31, 2015 : Loans collectively evaluated for impairment Loans individually evaluated for impairment Loans individually evaluated for impairment for which there is a related impairment reserve Related impairment reserve Loans individually evaluated for impairment for which there is no related reserve Personal Banking: Residential mortgage loans $ 2,733,741 7,151 7,151 1,189 — Home equity loans 1,184,808 2,298 2,298 605 — Other consumer loans 520,159 130 130 50 — Total Personal Banking 4,438,708 9,579 9,579 1,844 — Business Banking: Commercial real estate loans 2,297,599 53,835 35,937 2,675 17,898 Commercial loans 411,342 11,058 7,673 489 3,385 Total Business Banking 2,708,941 64,893 43,610 3,164 21,283 Total $ 7,147,649 74,472 53,189 5,008 21,283 The following table provides information related to the evaluation of impaired loans by portfolio segment and by class of financing receivable as of and for the year ended December 31, 2014 : Loans collectively evaluated for impairment Loans individually evaluated for impairment Loans individually evaluated for impairment for which there is a related impairment reserve Related impairment reserve Loans individually evaluated for impairment for which there is no related reserve Personal Banking: Residential mortgage loans $ 2,514,060 7,396 7,396 1,116 — Home equity loans 1,063,741 2,390 2,390 246 — Other consumer loans 242,678 66 66 1 — Total Personal Banking 3,820,479 9,852 9,852 1,363 — Business Banking: Commercial real estate loans 1,734,864 66,320 42,869 6,189 23,451 Commercial loans 343,416 14,960 10,938 1,378 4,022 Total Business Banking 2,078,280 81,280 53,807 7,567 27,473 Total $ 5,898,759 91,132 63,659 8,930 27,473 Our loan portfolios include certain loans that have been modified in a troubled debt restructuring (TDR), where economic concessions have been granted to borrowers who have experienced financial difficulties. These concessions typically result from our loss mitigation activities and could include: extending the note’s maturity date, permitting interest only payments, reducing the interest rate to a rate lower than current market rates for new debt with similar risk, reducing the principal payment, principal forbearance or other actions. These concessions are applicable to all loan segments and classes. Certain TDRs are classified as nonperforming at the time of restructuring and typically are returned to performing status after considering the borrower’s sustained repayment performance for a reasonable period of at least six consecutive months. When we modify loans in a TDR, we evaluate any possible impairment similar to other impaired loans based on the present value of expected future cash flows, discounted at the contractual interest rate of the original loan agreement, the loan’s observable market price or the current fair value of the collateral, less selling costs, for collateral dependent loans. If we determine that the value of the modified loan is less than the recorded investment in the loan (net of previous charge-offs, deferred loan fees or costs and unamortized premium or discount), impairment is recognized through an allowance estimate or a charge-off to the allowance. In periods subsequent to modification, we evaluate all TDRs, including those that have payment defaults, for possible impairment, using ASC 310-10. As a result, loans modified in a TDR may have the financial effect of increasing the specific allowance associated with the loan. Loans modified in a TDR are closely monitored for delinquency as an early indicator of possible future default. If loans modified in a TDR subsequently default, we evaluate the loan for possible further impairment. The allowance may be increased, adjustments may be made in the allocation of the allowance, partial charge-offs may be taken to further write-down the carrying value of the loan, or the loan may be charged-off completely. The following table provides a roll forward of troubled debt restructurings for the periods indicated: For the years ended December 31, 2015 2014 Number of contracts Amount Number of contracts Amount Beginning TDR balance: 248 $ 61,788 262 $ 79,166 New TDRs 26 8,537 46 9,460 Re-modified TDRs 3 6,386 11 3,672 Net paydowns (13,270 ) (15,825 ) Charge-offs: Residential mortgage loans — — — — Home equity loans 4 (159 ) 1 (130 ) Commercial real estate loans 4 (179 ) 10 (898 ) Commercial loans 2 (387 ) 10 (8,305 ) Paid-off loans: Residential mortgage loans 2 (109 ) — — Home equity loans 5 (194 ) 5 (103 ) Commercial real estate loans 15 (9,208 ) 10 (1,471 ) Commercial loans 14 (1,728 ) 24 (3,778 ) Transferred to real estate owned Commercial real estate loans 1 (362 ) — — Ending TDR balance: 227 $ 51,115 248 $ 61,788 Accruing TDRs $ 29,997 $ 37,329 Non-accrual TDRs 21,118 24,459 The following table provides information related to troubled debt restructurings (including re-modified TDRs) by portfolio segment and by class of financing receivable during the year ended December 31, 2015 : Number of contracts Recorded investment at the time of modification Current recorded investment Current allowance Troubled debt restructurings: Personal Banking: Residential mortgage loans 6 $ 364 357 21 Home equity loans 3 101 97 21 Other consumer loans — — — — Total Personal Banking 9 465 454 42 Business Banking: Commercial real estate loans 11 12,258 12,243 1,047 Commercial loans 9 2,200 2,184 156 Total Business Banking 20 14,458 14,427 1,203 Total 29 $ 14,923 14,881 1,245 At December 31, 2015, no TDRs that were modified in the previous twelve months had subsequently defaulted. The following table provides information related to troubled debt restructurings (including re-modified TDRs) by portfolio segment and by class of financing receivable during the year ended December 31, 2014 : Number of contracts Recorded investment at the time of modification Current recorded investment Current allowance Troubled debt restructurings: Personal Banking: Residential mortgage loans 17 $ 2,802 2,690 210 Home equity loans 6 570 507 1 Other consumer loans — — — — Total Personal Banking 23 3,372 3,197 211 Business Banking: Commercial real estate loans 11 2,010 1,793 202 Commercial loans 23 7,750 6,818 1,491 Total Business Banking 34 9,760 8,611 1,693 Total 57 $ 13,132 11,808 1,904 Number of contracts Recorded investment at the time of modification Current recorded investment Current allowance Troubled debt restructurings modified within the previous twelve months that have subsequently defaulted: Personal Banking: Residential mortgage loans 1 $ 78 77 — Home equity loans 1 360 331 1 Other consumer loans — — — — Total Personal Banking 2 438 408 1 Business Banking: Commercial real estate loans 1 12 5 1 Commercial loans 1 50 64 6 Total Business Banking 2 62 69 7 Total 4 $ 500 477 8 The following table provides information related to troubled debt restructurings (including re-modified TDRs) by portfolio segment and by class of financing receivable during the year ended December 31, 2013 : Number of contracts Recorded investment at the time of modification Current recorded investment Current allowance Troubled debt restructurings: Personal Banking: Residential mortgage loans 4 $ 374 319 50 Home equity loans 12 656 692 118 Other consumer loans — — — — Total Personal Banking 16 1,030 1,011 168 Business Banking: Commercial real estate loans 58 16,760 11,196 781 Commercial loans 47 13,321 12,754 162 Total Business Banking 105 30,081 23,950 943 Total 121 $ 31,111 24,961 1,111 Number of contracts Recorded investment at the time of modification Current recorded investment Current allowance Troubled debt restructurings modified within the previous twelve months that have subsequently defaulted: Personal Banking: Residential mortgage loans 1 $ 70 70 — Home equity loans — — — — Other consumer loans — — — — Total Personal Banking 1 70 70 — Business Banking: Commercial real estate loans 4 798 752 33 Commercial loans 1 23 8 1 Total Business Banking 5 821 760 34 Total 6 $ 891 830 34 The following table provides information for troubled debt restructurings (including re-modified TDRs) by type of modification, by portfolio segment and class of financing receivable during the year ended December 31, 2015 : Number of Type of modification contracts Rate Payment Maturity date Other Total Personal Banking: Residential mortgage loans 6 $ 71 — 110 176 357 Home equity loans 3 96 — 1 — 97 Other consumer loans — — — — — — Total Personal Banking 9 167 — 111 176 454 Business Banking: Commercial real estate loans 11 174 — 11,961 108 12,243 Commercial loans 9 — — 1,264 920 2,184 Total Business Banking 20 174 — 13,225 1,028 14,427 Total 29 $ 341 — 13,336 1,204 14,881 The following table provides information for troubled debt restructurings (including re-modified TDRs) by type of modification, by portfolio segment and class of financing receivable during the year ended December 31, 2014 : Number of Type of modification contracts Rate Payment Maturity date Other Total Personal Banking: Residential mortgage loans 17 $ — 108 2,582 — 2,690 Home equity loans 6 — 138 369 — 507 Other consumer loans — — — — — — Total Personal Banking 23 — 246 2,951 — 3,197 Business Banking: Commercial real estate loans 11 — — 1,312 481 1,793 Commercial loans 23 498 1,638 4,093 589 6,818 Total Business Banking 34 498 1,638 5,405 1,070 8,611 Total 57 $ 498 1,884 8,356 1,070 11,808 The following table provides information related to re-modified troubled debt restructurings by portfolio segment and by class of financing receivable for the year ended December 31, 2015 : Number of re- modified Type of re-modification TDRs Rate Payment Maturity date Other Total Personal Banking: Residential mortgage loans 1 $ — — — 45 45 Home equity loans 1 83 — — — 83 Other consumer loans — — — — — — Total Personal Banking 2 83 — — 45 128 Business Banking: Commercial real estate loans 1 — — 6,256 — 6,256 Commercial loans — — — — — — Total Business Banking 1 — — 6,256 — 6,256 Total 3 $ 83 — 6,256 45 6,384 The following table provides information related to re-modified troubled debt restructurings by portfolio segment and by class of financing receivable for the year ended December 31, 2014 : Number of re- modified Type of re-modification TDRs Rate Payment Maturity date Other Total Personal Banking: Residential mortgage loans 1 $ — — 76 — 76 Home equity loans — — — — — — Other consumer loans — — — — — — Total Personal Banking 1 — — 76 — 76 Business Banking: Commercial real estate loans 5 — — 119 115 234 Commercial loans 5 — — 3,230 55 3,285 Total Business Banking 10 — — 3,349 170 3,519 Total 11 $ — — 3,425 170 3,595 The following table provides information related to loan delinquencies as of December 31, 2015 : 30-59 days delinquent 60-89 days delinquent 90 days or greater delinquent Total delinquency Current Total loans 90 days or greater delinquent and accruing (1) Originated loans Personal Banking: Residential mortgage loans $ 25,503 7,541 15,564 48,608 2,646,568 2,695,176 — Home equity loans 4,870 1,836 5,251 11,957 1,043,950 1,055,907 — Other consumer loans 6,092 2,340 2,857 11,289 301,085 312,374 — Total Personal Banking 36,465 11,717 23,672 71,854 3,991,603 4,063,457 — Business Banking: Commercial real estate loans 22,212 6,875 14,942 44,029 1,891,128 1,935,157 — Commercial loans 1,703 598 2,449 4,750 356,658 361,408 — Total Business Banking 23,915 7,473 17,391 48,779 2,247,786 2,296,565 — Total originated loans 60,380 19,190 41,063 120,633 6,239,389 6,360,022 — Acquired loans Personal Banking: Residential mortgage loans 440 249 786 1,475 44,241 45,716 540 Home equity loans 936 642 861 2,439 128,760 131,199 462 Other consumer loans 1,009 181 69 1,259 206,656 207,915 26 Total Personal Banking 2,385 1,072 1,716 5,173 379,657 384,830 1,028 Business Banking: Commercial real estate loans 2,665 1,353 4,089 8,107 408,170 416,277 2,582 Commercial loans 1,165 — 150 1,315 59,677 60,992 140 Total Business Banking 3,830 1,353 4,239 9,422 467,847 477,269 2,722 Total acquired loans 6,215 2,425 5,955 14,595 847,504 862,099 3,750 Total loans $ 66,595 21,615 47,018 135,228 7,086,893 7,222,121 3,750 (1) Represents acquired loans that were originally recorded at fair value upon acquisition. These loans are considered to be accruing because we can reasonably estimate future cash flows on and expect to fully collect the carrying value of these loans. Therefore, we are accreting the difference between the carrying value and their expected cash flows into interest income. The following table provides information related to loan delinquencies as of December 31, 2014 : 30-59 days delinquent 60-89 days delinquent 90 days or greater delinquent Total delinquency Current Total loans Personal Banking: Residential mortgage loans $ 27,443 6,970 17,696 52,109 2,469,347 2,521,456 Home equity loans 5,752 1,672 6,606 14,030 1,052,101 1,066,131 Other consumer loans 5,572 2,435 2,450 10,457 232,287 242,744 Total Personal Banking 38,767 11,077 26,752 76,596 3,753,735 3,830,331 Business Banking: Commercial real estate loans 4,956 2,038 11,099 18,093 1,783,091 1,801,184 Commercial loans 2,262 209 3,475 5,946 352,430 358,376 Total Business Banking 7,218 2,247 14,574 24,039 2,135,521 2,159,560 Total loans $ 45,985 13,324 41,326 100,635 5,889,256 5,989,891 Credit quality indicators: We categorize loans into risk categories based on relevant information about the ability of borrowers to service their debt such as: current financial information, historical payment experience, credit documentation, public information, and current economic trends, among other factors. We analyze business loans individually by classifying the loans by credit risk. Credit relationships greater than or equal to $1.0 million classified as special mention or substandard are reviewed quarterly for further deterioration or improvement to determine if the loan is appropriately classified. We use the following definitions for risk ratings other than pass: Special mention — Loans designated as special mention have specific, well-defined risk issues, which create a high level of uncertainty regarding the long-term viability of the business. Loans in this class are considered to have high-risk characteristics. A special mention loan exhibits material negative financial trends due to company-specific or systemic conditions. If these potential weaknesses are not mitigated, they threaten the borrower’s capacity to meet its debt obligations. Special mention loans still demonstrate sufficient financial flexibility to react to and positively address the root cause of the adverse financial trends without significant deviations from their current business strategy. Their potential weaknesses deserve our close attention and warrant enhanced monitoring. Substandard — Loans classified as substandard are inadequately protected by the current net worth and payment capacity of the obligor or of the collateral pledged, if any. Loans so classified have a well-defined weakness or weaknesses that jeopardize the liquidation of the debt. They are characterized by the distinct possibility that we will sustain some loss if the deficiencies are not corrected. Doubtful — Loans classified as doubtful have all the weaknesses inherent in those classified as substandard. In addition, those weaknesses make collection or liquidation in full highly questionable and improbable. A loan classified as doubtful exhibits discernible loss potential, but a complete loss seems very unlikely. The possibility of a loss on a doubtful loan is high, but because of certain important and reasonably specific pending factors that may strengthen the loan, its classification as an estimated loss is deferred until a more exact status can be determined. Loss — Loans classified as loss are considered uncollectible and of such value that the continuance as a loan is not warranted. A loss classification does not mean that the loan has no recovery or salvage value; instead, it means that it is not practical or desirable to defer writing off all or a portion of a basically worthless loan even though partial recovery may be affected in the future. The following table sets forth information about credit quality indicators as of December 31, 2015 : Pass Special mention Substandard Doubtful Loss Total Originated loans Personal Banking: Residential mortgage loans $ 2,680,562 — 13,274 — 1,340 2,695,176 Home equity loans 1,048,397 — 7,510 — — 1,055,907 Other consumer loans 309,900 — 2,474 — — 312,374 Total Personal Banking 4,038,859 — 23,258 — 1,340 4,063,457 Business Banking: Commercial real estate loans 1,778,140 46,518 110,384 115 — 1,935,157 Commercial loans 299,455 23,023 37,820 1,110 — 361,408 Total Business Banking 2,077,595 69,541 148,204 1,225 — 2,296,565 Total originated loans 6,116,454 69,541 171,462 1,225 1,340 6,360,022 Acquired loans Personal Banking: Residential mortgage loans 44,930 — 786 — — 45,716 Home equity loans 130,338 — 861 — — 131,199 Other consumer loans 207,846 — 69 — — 207,915 Total Personal Banking 383,114 — 1,716 — — 384,830 Business Banking: Commercial real estate loans 392,811 6,872 16,594 — — 416,277 Commercial loans 59,948 707 337 — — 60,992 Total Business Banking 452,759 7,579 16,931 — — 477,269 Total acquired loans 835,873 7,579 18,647 — — 862,099 Total loans $ 6,952,327 77,120 190,109 1,225 1,340 7,222,121 The following table sets forth information about credit quality indicators as of December 31, 2014 : Pass Special mention Substandard Doubtful Loss Total Personal Banking: Residential mortgage loans $ 2,507,269 — 12,763 — 1,424 2,521,456 Home equity loans 1,059,525 — 6,606 — — 1,066,131 Other consumer loans 240,947 — 1,797 — — 242,744 Total Personal Banking 3,807,741 — 21,166 — 1,424 3,830,331 Business Banking: Commercial real estate loans 1,618,269 36,908 145,502 505 — 1,801,184 Commercial loans 286,234 23,690 46,280 2,172 — 358,376 Total Business Banking 1,904,503 60,598 191,782 2,677 — 2,159,560 Total loans $ 5,712,244 60,598 212,948 2,677 1,424 5,989,891 Our exposure to credit loss in the event of nonperformance by the other party to off-balance-sheet financial instruments is represented by the contract amount of the financial instrument. We use the same credit policies in making commitments for off-balance-sheet financial instruments as we do for on-balance-sheet instruments. Financial instruments with off-balance-sheet risk as of December 31, 2015 and 2014 are presented in the following table: December 31, 2015 2014 Loan commitments $ 186,731 186,637 Undisbursed lines of credit 562,284 428,649 Standby letters of credit 32,719 23,564 Total $ 781,734 638,850 Commitments to extend credit are agreements to lend to a customer as long as there is no violation of any condition established in the contract. Commitments generally have fixed expiration dates or other termination clauses and may require payment of a fee. We evaluate each customer’s creditworthiness on a case-by-case basis. The amount of collateral we obtain upon extension of credit is based on management’s credit evaluation of the counterparty. Collateral held varies but generally may include cash, marketable securities, real estate and other property. Outstanding loan commitments at December 31, 2015 , for fixed rate loans, were $81.8 million . The interest rates on these commitments approximate market rates at December 31, 2015 . Outstanding loan commitments at December 31, 2015 for adjustable rate loans were $104.9 million . The fair values of these commitments are affected by fluctuations in market rates of interest. We issue standby letters of credit in the norma

Accrued Interest Receivable

Accrued Interest Receivable	12 Months Ended
	Dec. 31, 2015
Accrued Interest Receivable
Accrued Interest Receivable	Accrued Interest Receivable Accrued interest receivable as of December 31, 2015 and 2014 is presented in the following table: December 31, 2015 2014 Investment securities $ 1,852 2,229 Mortgage-backed securities 960 875 Loans receivable 18,260 15,519 $ 21,072 18,623

Federal Home Loan Bank Stock

Federal Home Loan Bank Stock	12 Months Ended
	Dec. 31, 2015
Federal Home Loan Bank Stock Disclosure [Abstract]
Federal Home Loan Bank Stock	Federal Home Loan Bank Stock Northwest Bank is a member of the Federal Home Loan Bank system. As a member, we are required to maintain an investment in the capital stock of the FHLB of Pittsburgh in accordance with their 2015 Capital Plan, at cost, in two subclasses based on the following ranges: Membership stock purchase (Subclass B-1) ranging from 0.05 % to 1.0 % of the member asset value as defined by the FHLB, currently at 0.10 %; and Activity-based stock purchase (Subclass B-2) ranging from 2.0 % to 6.0 % of outstanding advances, currently at 4.0 %; 0.0 % to 6.0 % of acquired member assets, currently at 0.0 %; 0.0 % to 4.0 % of certain letters of credit, currently at 0.75 %; and 0.0 % to 6.0 % of outstanding advance commitments settling more than 30 days after trade, currently at 4.0 %. We received dividends on capital stock during the years ended December 31, 2015 and 2014 of $2.8 million and $1.8 million , respectively. Future dividends may be established at different rates for the two subclasses of capital stock.

Premises and Equipment

Premises and Equipment	12 Months Ended
	Dec. 31, 2015
Property, Plant and Equipment [Abstract]
Premises and Equipment	Premises and Equipment Premises and equipment at December 31, 2015 and 2014 are summarized by major classification in the following table: December 31, 2015 2014 Land and land improvements $ 23,257 20,084 Office buildings and improvements 153,003 150,745 Furniture, fixtures and equipment 115,576 116,975 Leasehold improvements 19,239 12,312 Total, at cost 311,075 300,116 Less accumulated depreciation and amortization (156,724 ) (156,207 ) Premises and equipment, net $ 154,351 143,909 Depreciation and amortization expense for the years ended December 31, 2015 , 2014 and 2013 was $13.3 million , $12.0 million and $11.9 million , respectively. Premises used by certain of our offices are occupied under formal operating lease arrangements. The leases expire on various dates through 2027. Minimum annual rentals by fiscal year are summarized in the following table: 2016 $ 4,553 2017 3,493 2018 2,572 2019 1,620 2020 1,329 Thereafter 3,388 Total $ 16,955 Rental expense for the years ended December 31, 2015 , 2014 and 2013 was $4.6 million , $4.4 million and $4.2 million , respectively.

Goodwill and Other Intangible A

Goodwill and Other Intangible Assets	12 Months Ended
	Dec. 31, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Other Intangible Assets	Goodwill and Other Intangible Assets The following table provides information for intangible assets subject to amortization for the years ended December 31, 2015 and 2014 : December 31, 2015 2014 Amortizable intangible assets: Core deposit intangibles — gross $ 30,578 30,578 Acquisitions 7,375 — Less: accumulated amortization (31,192 ) (30,578 ) Core deposit intangibles — net $ 6,761 — Customer and Contract intangible assets — gross 8,234 6,197 Acquisitions 262 2,037 Less: accumulated amortization (6,275 ) (5,201 ) Customer and Contract intangible assets — net $ 2,221 3,033 The following information shows the actual aggregate amortization expense for the years ended December 31, 2015 , 2014 and 2013 as well as the estimated aggregate amortization expense, based upon current levels of intangible assets, for each of the five succeeding fiscal years: For the year ended December 31, 2013 $ 1,210 For the year ended December 31, 2014 1,323 For the year ended December 31, 2015 1,688 For the year ending December 31, 2016 2,591 For the year ending December 31, 2017 2,090 For the year ending December 31, 2018 1,658 For the year ending December 31, 2019 1,226 For the year ending December 31, 2020 794 The following table provides information for the changes in the carrying amount of goodwill: Community Banks Consumer Finance Total Balance at December 31, 2013 $ 173,031 1,613 174,644 Goodwill acquired 679 — 679 Balance at December 31, 2014 173,710 1,613 175,323 Goodwill acquired 86,413 — 86,413 Balance at December 31, 2015 $ 260,123 1,613 261,736 We have determined that goodwill is not impaired as of December 31, 2015 and 2014 . There were no changes in our operations that would cause us to update the goodwill impairment test performed as of June 30, 2015 .

Deposits

Deposits	12 Months Ended
	Dec. 31, 2015
Deposits [Abstract]
Deposits	Deposits Deposit balances at December 31, 2015 and 2014 are shown in the table below: December 31, 2015 2014 Savings deposits $ 1,386,017 1,209,287 Interest-bearing demand deposits 1,080,086 874,623 Noninterest-bearing demand deposits 1,177,256 891,248 Money market demand accounts 1,274,504 1,179,070 Time deposits 1,694,718 1,478,314 Total deposits $ 6,612,581 5,632,542 The aggregate amount of time deposits with a minimum denomination of $100,000 at December 31, 2015 and 2014 was $518.7 million and $351.9 million , respectively. Generally, deposits in excess of $250,000 are not federally insured. At December 31, 2015 , we had $1.327 billion of deposits in accounts exceeding $250,000 . The following table summarizes the contractual maturity of time deposits at December 31, 2015 and 2014 : December 31, 2015 2014 Due within 12 months $ 929,351 647,699 Due between 12 and 24 months 448,497 392,484 Due between 24 and 36 months 205,635 319,995 Due between 36 and 48 months 21,414 92,527 Due between 48 and 60 months 78,796 15,307 After 60 months 11,025 10,302 Total time deposits $ 1,694,718 1,478,314 The following table summarizes the interest expense incurred on the respective deposits for the years ended December 31, 2015 , 2014 and 2013 : Years ended December 31, 2015 2014 2013 Savings deposits $ 3,387 3,286 3,595 Interest-bearing demand deposits 568 587 576 Money market demand accounts 3,222 3,174 3,042 Time deposits 16,878 18,275 22,066 Total interest expense $ 24,055 25,322 29,279

Borrowed Funds

Borrowed Funds	12 Months Ended
	Dec. 31, 2015
Debt Disclosure [Abstract]
Borrowed Funds	Borrowed Funds Borrowed funds at December 31, 2015 and 2014 are presented in the following table: December 31, 2015 2014 Amount Average rate Amount Average rate Term notes payable to the FHLB of Pittsburgh: Due within one year $ 145,343 3.24 % 110,000 2.53 % Due between one and two years 125,000 3.68 % 145,395 3.24 % Due between two and three years 140,000 3.73 % 125,000 3.68 % Due between three and four years 125,000 4.32 % 125,000 4.03 % Due between four and five years 95,000 3.65 % 125,000 4.32 % Due between five and ten years 120,000 3.68 % 95,000 3.75 % 750,343 725,395 Revolving line of credit, FHLB of Pittsburgh 106,000 0.43 % — — Collateralized borrowings, due within one year 118,664 0.22 % 162,714 0.27 % Total borrowed funds $ 975,007 888,109 Borrowings from the FHLB of Pittsburgh are secured by our residential first mortgage and other qualifying loans. Certain of these borrowings are subject to restrictions or penalties in the event of prepayment. The revolving line of credit with the FHLB of Pittsburgh carries a commitment of $150.0 million . The rate is adjusted daily by the FHLB of Pittsburgh, and any borrowings on this line may be repaid at any time without penalty. The collateralized borrowings are collateralized by various securities held in safekeeping by the FHLB of Pittsburgh. The market value of these securities exceeds the value of the collateralized borrowings. The average amount of collateralized borrowings outstanding in the years ended December 31, 2015 , 2014 and 2013 was $144.7 million , $155.7 million and $150.1 million , respectively. The maximum amount of collateralized borrowings outstanding during the years ended December 31, 2015 , 2014 and 2013 was $166.4 million , $174.2 million and $171.8 million , respectively.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes Total income tax was allocated for the years ended December 31, 2015 , 2014 and 2013 as follows: Years ended December 31, 2015 2014 2013 Income before income taxes $ 27,960 21,795 26,199 Shareholders’ equity for unrealized (loss)/ gain on securities available-for-sale (85 ) 4,286 (12,177 ) Shareholders’ equity for tax benefit for excess of fair value above cost of stock benefit plans (332 ) (945 ) (635 ) Shareholders’ equity for pension adjustment (848 ) (12,985 ) 9,904 Shareholders’ equity for swap fair value adjustment 699 618 1,714 Unallocated income tax $ 27,394 12,769 25,005 Income tax expense applicable to income before taxes consists of: Years ended December 31, 2015 2014 2013 Current $ 21,670 13,200 24,937 Deferred 6,290 8,595 1,262 Total income tax expense $ 27,960 21,795 26,199 A reconciliation of the expected federal statutory income tax rate to the effective rate, expressed as a percentage of pretax income for the years ended December 31, 2015 , 2014 and 2013 , is as follows: Years ended December 31, 2015 2014 2013 Expected tax rate 35.0 % 35.0 % 35.0 % Tax-exempt interest income (3.0 )% (4.1 )% (4.3 )% State income tax, net of federal benefit 2.9 % 1.7 % 2.1 % Bank-owned life insurance (1.7 )% (1.8 )% (1.9 )% Dividends on stock plans (0.8 )% (4.0 )% (1.1 )% Low income housing and historic tax credits (1.4 )% (0.9 )% (1.6 )% Non-deductible acquisition expense 0.5 % — % — % Other 0.1 % 0.1 % 0.1 % Effective tax rate 31.6 % 26.0 % 28.3 % The tax effects of temporary differences that give rise to significant portions of the deferred tax assets and deferred tax liabilities at December 31, 2015 and 2014 are presented below: December 31, 2015 2014 Deferred tax assets: Deferred fee income $ 189 193 Deferred compensation expense 3,717 3,688 Bad debts 19,478 19,851 Accrued postretirement benefit cost 644 724 Stock benefit plans 1,626 1,523 Writedown of investment securities 2,994 3,155 Accrued expenses 228 105 Pension and postretirement benefits 16,035 15,187 Unrealized loss on the fair value of derivatives 1,496 2,195 Purchase accounting 2,236 — Other 325 361 Total deferred tax assets 48,968 46,982 Deferred tax liabilities: Pension expense 7,557 4,487 Marketable securities available for sale 2,122 2,207 Purchase accounting — 1,842 Intangible assets 23,003 20,324 Mortgage servicing rights 120 313 Fixed assets 8,731 8,038 Other 460 475 Total deferred tax liabilities 41,993 37,686 Net deferred tax asset $ 6,975 9,296 As a result of the LNB acquisition, deferred tax liabilities were increased by $ 3.7 million related to acquisition accounting tax adjustments, net of deferred tax assets carried over from LNB. We have determined that no valuation allowance is necessary for the deferred tax assets because it is more likely than not that these assets will be realized through carry-back to taxable income in prior years, future reversals of existing temporary differences, and through future taxable income. We will continue to review the criteria related to the recognition of deferred tax assets on a regular basis. Under provisions of the Internal Revenue Code (“IRC”), Northwest has approximately $9.4 million in acquired federal net operating losses which have been fully utilized in the 2015 tax year through carryback on LNB's 2013 and 2014 tax returns. This is expected to result in a $ 3.2 million refund. We utilize a comprehensive model to recognize, measure, present and disclose in our financial statements uncertain tax positions that the company has taken or expects to take on a tax return. At December 31, 2015 , there were no unrecognized tax benefits that, if recognized, would favorably affect the effective income tax rate. We recognize interest accrued and penalties (if any) related to unrecognized tax benefits in income tax expense. During the year ended December 31, 2015 , we did not accrue any interest. At December 31, 2015 , we had no amount accrued for interest or the payment of penalties. We are subject to routine audits of our tax returns by the Internal Revenue Service ("IRS") as well as all states in which we conduct business. We are subject to audit by the Internal Revenue Service for the tax periods ended December 31, 2015 , 2014 , 2013 and 2012 and subject to audit by any state in which we conduct business for the tax periods ended December 31, 2015 , 2014 , 2013 and 2012 . We are currently under audit by the State of New York for the 2011 - 2013 tax years, as well as a 2013 tax year IRS audit for the LNB tax return filed prior to the acquisition. The results of these audits are not yet determinable.

Shareholders' Equity

Shareholders' Equity	12 Months Ended
	Dec. 31, 2015
Stockholders' Equity Note [Abstract]
Shareholders' Equity	Shareholders’ Equity Retained earnings are partially restricted in connection with regulations related to the insurance of deposit accounts, which requires Northwest to maintain certain statutory reserves. Northwest may not pay dividends on or repurchase any of its common stock if the effect thereof would reduce retained earnings below the level of adequate capitalization as defined by federal and state regulators. In tax years prior to fiscal 1997, Northwest was permitted, under the IRC, to deduct an annual addition to a reserve for bad debts in determining taxable income, subject to certain limitations. Bad debt deductions for income tax purposes are included in taxable income of later years only if the bad debt reserve is used subsequently for purposes other than to absorb bad debt losses. Because Northwest does not intend to use the reserve for purposes other than to absorb losses, no deferred income taxes have been provided prior to fiscal 1987. Retained earnings at December 31, 2015 and 2014 include approximately $39.1 million representing such bad debt deductions for which no deferred income taxes have been provided.

Earnings Per Share

Earnings Per Share	12 Months Ended
	Dec. 31, 2015
Earnings Per Share [Abstract]
Earnings Per Share	Earnings Per Share Basic earnings per common share (EPS) is computed by dividing net income available to common shareholders by the weighted average number of common shares outstanding for the period, without considering any dilutive items. Diluted EPS reflects the potential dilution that could occur if securities or other contracts to issue common stock were exercised or converted into common stock or resulted in the issuance of common stock that then shared in our earnings. For the year December 31, 2015 , there were 524,250 options outstanding with a weighted average exercise price of $13.15 per share that were excluded in the computation of diluted earnings per share because the stock options’ exercise price was greater than the average market price of the common shares of $12.64 . All stock options outstanding during the year ended December 31, 2014 were included in the computation of diluted earnings per share because the stock options’ exercise price was less than the average market price of the common shares of $13.34 . All stock options outstanding during the year ended December 31, 2013 were included in the computation of diluted earnings per share because the stock options exercise price was less than the average market price of the common shares of $13.25 . The computation of basic and diluted earnings per share for the years ended December 31, 2015 , 2014 and 2013 follows: Years ended December 31, 2015 2014 2013 Net income available to common shareholders $ 60,540 61,962 66,559 Weighted average common shares outstanding 94,314,420 91,535,298 90,626,324 Dilutive potential shares due to effect of stock options 515,369 739,699 844,489 Total weighted average common shares and dilutive potential shares 94,829,789 92,274,997 91,470,813 Basic earnings per share (1) $ 0.64 0.68 0.73 Diluted earnings per share (1) $ 0.64 0.67 0.73 (1) Not in thousands.

Employee Benefit Plans

Employee Benefit Plans	12 Months Ended
	Dec. 31, 2015
Compensation and Retirement Disclosure [Abstract]
Employee Benefit Plans	Employee Benefit Plans (a) Pension Plans We maintain noncontributory defined benefit pension plans covering substantially all employees and members of our board of directors. Retirement benefits are based on certain compensation levels, age, and length of service. Contributions are based on an actuarially determined amount to fund not only benefits attributed to service to date but also for those expected to be earned in the future. In addition, we have an unfunded Supplemental Executive Retirement Plan (“SERP”) to compensate those executive participants eligible for the defined benefit pension plan whose benefits are limited by Section 415 of the IRC. We also sponsor a retirement savings plan in which substantially all employees participate. We provide a matching contribution of 50% of each employee’s contribution to a maximum of 6% of the employee’s compensation. Total expense for all retirement plans, including defined benefit pension plans, was approximately $4.6 million , $1.0 million and $4.1 million , for the years ended December 31, 2015 , 2014 and 2013 , respectively. Components of net periodic pension cost and other amounts recognized in other comprehensive income: The following table sets forth the net periodic pension cost for the defined benefit pension plans for the years ended December 31, 2015 , 2014 and 2013 : Years ended December 31, 2015 2014 2013 Service cost $ 5,721 4,138 4,551 Interest cost 6,125 5,827 5,203 Expected return on plan assets (10,371 ) (9,663 ) (8,551 ) Net amortization and deferral 1,375 (897 ) 1,356 Net periodic pension (benefit)/ cost $ 2,850 (595 ) 2,559 The following table sets forth other changes in the defined benefit pension plans’ plan assets and benefit obligations recognized in other comprehensive income: Years ended December 31, 2015 2014 2013 Net loss/ (gain) $ (420 ) 30,779 (27,568 ) Prior service cost/ (credit) — — (14 ) Amortization of prior service cost 2,323 2,322 2,321 Total recognized in other comprehensive income $ 1,903 33,101 (25,261 ) Total recognized in net periodic pension cost and other comprehensive income/ (loss) $ 4,753 32,506 (22,702 ) The estimated net loss and prior service credit for the defined benefit pension plan that will be amortized from accumulated other comprehensive income into net periodic cost over the next year is $3.6 million and $(2.3) million , respectively. The following table sets forth information for the defined benefit pension plans’ funded status at December 31, 2015 and 2014 : December 31, 2015 2014 Change in benefit obligation: Benefit obligation at beginning of year $ 159,587 121,767 Service cost 5,721 4,138 Interest cost 6,125 5,827 Acquisition 5,662 — Actuarial (gain)/ loss (1) (9,357 ) 31,722 Benefits paid (5,605 ) (3,867 ) Benefit obligation at end of year $ 162,133 159,587 Change in plan assets: Fair value of plan assets at beginning of year 140,183 130,491 Actual return on plan assets (2,264 ) 9,181 Employer contributions 6,460 4,378 Acquisition 4,881 — Benefits paid (5,605 ) (3,867 ) Fair value of plan assets at end of period $ 143,655 140,183 Funded status at end of year $ (18,478 ) (19,404 ) (1) The change in actuarial (gain)/ loss is due to a decrease in the discount rate as well as updates to the RP-2014 with MMP-2007 adjustments Mortality Table. The following table sets forth the assumptions used to develop the net periodic pension cost: Years ended December 31, 2015 2014 2013 Discount rate 3.89 % 4.86 % 4.06 % Expected long-term rate of return on assets 7.50 % 7.50 % 7.50 % Rate of increase in compensation levels 3.00 % 3.00 % 3.00 % The following table sets forth the assumptions used to determine benefit obligations at the end of each period: Years ended December 31, 2015 2014 2013 Discount rate 4.25 % 3.89 % 4.86 % Expected long-term rate of return on assets 7.00 % 7.50 % 7.50 % Rate of increase in compensation levels 3.00 % 3.00 % 3.00 % The expected long-term rate of return on assets is based on the expected return of each of the asset categories, weighted based on the median of the target allocation for each category. We use the Citigroup Pension Liability Index rates matching the duration of our benefit payments as of the measurement date to determine the discount rate. The accumulated benefit obligation for the funded defined benefit pension plan was $155.9 million , $153.9 million and $116.8 million at December 31, 2015 , 2014 and 2013 , respectively. The accumulated benefit obligation for all unfunded defined benefit plans was $6.3 million , $5.6 million and $5.0 million at December 31, 2015 , 2014 and 2013 , respectively. The following table sets forth certain information related to our pension plans: December 31, 2015 2014 Projected benefit obligation $ 162,133 159,587 Accumulated benefit obligation 162,133 159,587 Fair value of plan assets 143,655 140,183 We anticipate making a contribution to our defined benefit pension plan of $4.0 million to $8.0 million during the year ending December 31, 2016 . The investment policy as established by the Plan Administrative Committee, to be followed by the Trustee, is to invest assets based on the target allocations shown in the table below. To meet target allocation ranges set forth by the Plan Administrative Committee, periodically, the assets are reallocated by the Trustee. The investment policy is reviewed periodically to determine if the policy should be changed. Pension assets are conservatively invested with the goal of providing market or better returns with below market risks. Assets are invested in a balanced portfolio composed primarily of equities, fixed income, and cash or cash equivalent investments. The Trustee tries to maintain an approximate asset mix position of 30% to 60% equities and 20% to 50% bonds. A maximum of 10% may be invested in any one stock, including the stock of Northwest Bancshares, Inc. The objective of holding equity securities is to provide capital appreciation consistent with the ownership of the common stocks of medium to large companies. Acceptable bond investments are direct or agency obligations of the U.S. Government or investment grade corporate bonds. The average maturity of the bond portfolio shall not exceed 10 years . The following table sets forth the weighted average asset allocation of defined benefit plans: Target December 31, Allocation 2015 2014 Debt securities 20 – 50% 20 % 20 % Equity securities 30 – 60% 69 % 71 % Other 5 – 50% 11 % 9 % Total 100 % 100 % All of the assets held by the defined benefit pension plan are measured and recorded at estimated fair value on our balance sheet on a recurring basis as Level 1 assets, as defined by the fair value hierarchy defined in note 16. The following table sets forth the pension plan assets as of December 31, 2015 and 2014 : December 31, 2015 2014 Mutual funds — debt $ 28,316 27,635 Mutual funds — equity 98,517 99,009 Cash and cash equivalents 16,822 13,539 The benefits expected to be paid in each year from 2016 to 2020 are $4.5 million , $4.7 million , $5.0 million , $5.5 million and $5.8 million , respectively. The aggregate benefits expected to be paid in the five years from 2021 to 2025 are $34.9 million . The expected benefits to be paid are based on the same assumptions used to measure our benefit obligations at December 31, 2015 and include estimated future employee service. (b) Postretirement Healthcare Plan In addition to pension benefits, we provide postretirement healthcare benefits for certain employees who were employed as of October 1, 1993 and were at least 55 years of age on that date. We use the accrual method of accounting for postretirement benefits other than pensions. Components of net periodic benefit cost and other amounts recognized in other comprehensive income: The following table sets forth the net periodic benefit cost for the postretirement healthcare benefits plan for the years ended December 31, 2015 , 2014 and 2013 : Years ended December 31, 2015 2014 2013 Service cost $ — — — Interest cost 58 65 63 Amortization of net loss 60 48 53 Net period benefit cost $ 118 113 116 The following table sets forth other changes in the postretirement healthcare plan’s plan assets and benefit obligations recognized in other comprehensive income: Years ended December 31, 2015 2014 2013 Net loss/ (gain) $ 273 195 (136 ) Total recognized in other comprehensive income $ 273 195 (136 ) Total recognized in net periodic benefit cost and other comprehensive income $ 391 308 (20 ) The estimated net loss for the postretirement healthcare benefit plan that will be amortized from accumulated other comprehensive income into net periodic benefit cost over the next year is $90,000 . The following table sets forth the funded status of the postretirement healthcare benefit plan at December 31, 2015 and 2014 : December 31, 2015 2014 Change in benefit obligation: Benefit obligation at beginning of year $ 1,565 1,425 Service cost — — Interest cost 58 65 Actuarial loss 333 243 Benefits paid (219 ) (168 ) Benefit obligation at end of year $ 1,737 1,565 Change in plan assets: Fair value of plan assets at beginning of year — — Employer contributions 219 168 Benefits paid (219 ) (168 ) Fair value of plan assets at end of year $ — — Funded status at year end $ (1,737 ) (1,565 ) The assumptions used to develop the preceding information for postretirement healthcare benefits are as follows: Years ended December 31, 2015 2014 2013 Discount rate 3.89 % 4.86 % 4.06 % Monthly cost of healthcare insurance per beneficiary (1) $ 470 384 351 Annual rate of increase in healthcare costs 4.00 % 4.00 % 4.00 % (1) Not in thousands If the assumed rate of increase in healthcare costs was increased by one percentage point to 5% from the level of 4% presented above, the interest cost component of net periodic postretirement healthcare benefit cost would increase by $10,000 and the accumulated postretirement benefit obligation for healthcare benefits would increase by $74,000 . The following table sets forth information for plans with an accumulated benefit obligation in excess of plan assets: December 31, 2015 2014 Projected benefit obligation $ 1,737 1,565 Accumulated benefit obligation 1,737 1,565 Fair value of plan assets — — (c) Employee Stock Ownership Plan We have a leveraged employee stock ownership plan (ESOP) for employees who have attained age 21 and who have completed a 12 -month period of employment during which they worked at least 1000 hours. Northwest is expected to make annual cash contributions to the ESOP until 2029 when the loan matures. At December 31, 2015, the loan balance was $21.7 million . ESOP compensation expense was $335,000 , $3.0 million and $1.7 million for the years ended December 31, 2015 , 2014 and 2013 , respectively. Shares of common stock are held by the ESOP and are allocated to eligible participants annually based upon a percentage of each participant’s eligible compensation. Shares are scheduled for release as the loan is repaid based on the interest method. The amortization schedule calls for 126,280 shares to be released each December 31. At December 31, 2015 , 1,767,930 shares of common stock remained unallocated. The fair value of unallocated common stock held by the ESOP at December 31, 2015 was $23.7 million . Compensation expense related to the ESOP is recognized at an amount equal to the number of common shares committed to be released by the ESOP to participants’ accounts multiplied by the average fair value of the common stock during the reporting period. The difference between the fair value of the shares of the common stock committed to be allocated by the ESOP to participants’ accounts for the period and the average cost of those common shares is recorded as an adjustment to either additional paid-in capital or retained earnings. (d) Common Stock Awards On April 20, 2011, we established the Northwest Bancshares, Inc. 2011 Equity Incentive Plan with 2,806,233 common shares authorized. On May 15, 2013, we awarded employees 240,700 common shares and outside directors 29,700 common shares with a grant date fair value of $12.55 per share (total market value of $3.4 million at issuance). On May 21, 2014, we awarded employees 251,030 common shares and outside directors 21,600 common shares with a grant date fair value of $13.22 per share (total market value of $3.6 million at issuance). On May 20, 2015, we awarded employees 282,050 common shares and outside directors 24,300 common shares with a grant date fair value of $12.31 per share (total market value of $3.8 million at issuance). Total common shares forfeited from the 2011 plan were 259,778 , of which, 77,718 shares were forfeited during the year ended December 31, 2015 . Forfeited shares may be awarded to other eligible recipients in future grants until the plan termination date in 2021. Common shares vest over a 10 -year period with the first vesting occurring on the grant date. As of December 31, 2015 , 30% of the 2013 issuances have vested, 20% of the 2014 issuances have vested and 10% of the 2015 issuances have vested. Once shares have vested, they are no longer restricted. Compensation expense, in the amount of the fair market value of the common stock at the date of the grant, will be recognized pro rata over the periods in which the shares vest. While restricted, the recipients are entitled to all shareholder rights, except that the shares may not be sold, pledged, or otherwise disposed of and are required to be held in a trust. (e) Stock Option Plans On April 20, 2011, we established the Northwest Bancshares, Inc. 2011 Equity Incentive Plan, which authorizes the granting of 7,015,583 stock options. On May 15, 2013, we granted employees 511,100 stock options and outside directors 79,200 stock options with an exercise price of $12.44 per share. On May 21, 2014, we granted employees 534,950 stock options and outside directors 57,600 stock options with an exercise price of $13.15 per share. On May 19, 2015, we granted employees 600,570 stock options and outside directors 64,800 stock options with an exercise price of $12.37 per share. Awarded stock options vest over a ten -year period with the first vesting occurring on the grant date with a ten year exercise period from the grant date. The following table summarizes the activity in our option plans during the years ended December 31, 2015 , 2014 and 2013 (amounts in this table are not in thousands): Years ended December 31, 2015 2014 2013 Number Weighted average exercise price Number Weighted average exercise price Number Weighted average exercise price Balance at beginning of year 6,402,407 $ 11.65 6,816,294 $ 11.46 7,044,753 $ 11.21 Granted (1) 665,370 12.37 592,550 13.15 590,300 12.44 Exercised (2) (474,253 ) 10.27 (745,419 ) 10.86 (727,415 ) 10.13 Forfeited (3) (287,028 ) 12.26 (261,018 ) 11.71 (91,344 ) 11.82 Balance at end of year 6,306,496 $ 11.81 6,402,407 $ 11.65 6,816,294 $ 11.46 Exercisable at end of year 3,431,113 $ 11.42 3,333,942 $ 11.20 2,916,621 $ 10.97 (1) Weighted average fair value of options at grant date: $1.14 , $1.45 and $1.03 , respectively. (2) The total intrinsic value of options exercised was $1.2 million , $2.3 million and $2.7 million , respectively. (3) Includes 7,007 options that expired without being exercised for the year ended December 31, 2015. The aggregate intrinsic value of all options expected to vest and fully vested options at December 31, 2015 is $6.8 million and $3.2 million , respectively. The following table summarizes the number of options outstanding, number of options exercisable, and weighted average remaining life of all option grants as of December 31, 2015 : Exercise Exercise Exercise Exercise Exercise Exercise Exercise Options outstanding: Number of options 315,487 331,882 50,110 270,543 422,500 232,858 465,493 Weighted average remaining contract life (years) 3.25 3.00 0.25 2.25 4.25 1.25 6.50 Options exercisable: Number of options 267,521 331,882 50,110 270,543 314,379 232,858 202,129 Weighted average remaining term - vested (years) 3.25 3.00 0.25 2.25 4.25 1.25 6.50 Exercise Exercise Exercise Exercise Exercise Exercise Exercise Total Options outstanding: Number of options 481,795 21,500 2,050,609 628,734 506,235 4,500 524,250 6,306,496 Weighted average remaining contract life (years) 5.25 5.50 5.50 9.50 7.50 1.50 8.50 5.72 Options exercisable: Number of options 305,141 8,644 1,095,267 66,551 172,272 4,500 109,316 3,431,113 Weighted average remaining term - vested (years) 5.25 5.50 5.50 9.50 7.50 1.50 8.50 4.23

Disclosures About Fair Value of

Disclosures About Fair Value of Financial Instruments	12 Months Ended
	Dec. 31, 2015
Fair Value Disclosures [Abstract]
Disclosures About Fair Value of Financial Instruments	Disclosures About Fair Value of Financial Instruments We are required to disclose fair value information about financial instruments whether or not recognized in the consolidated statement of financial condition. Fair value information of certain financial instruments and all nonfinancial instruments is not required to be disclosed. Accordingly, the aggregate fair value amounts presented do not represent the underlying value of the Company. Financial assets and liabilities recognized or disclosed at fair value on a recurring basis and certain financial assets and liabilities on a non-recurring basis are accounted for using a three-level hierarchy of valuation techniques based on whether the inputs to those valuation techniques are observable or unobservable. This hierarchy gives the highest priority to quoted prices with readily available independent data in active markets for identical assets or liabilities (Level 1) and the lowest priority to unobservable market inputs (Level 3). When various inputs for measurement fall within different levels of the fair value hierarchy, the lowest level input that has a significant impact on fair value measurement is used. Financial assets and liabilities are categorized based upon the following characteristics or inputs to the valuation techniques: • Level 1 — Financial assets and liabilities for which inputs are observable and are obtained from reliable quoted prices for identical assets or liabilities in actively traded markets. This is the most reliable fair value measurement and includes, for example, active exchange-traded equity securities. • Level 2 — Financial assets and liabilities for which values are based on quoted prices in markets that are not active or for which values are based on similar assets or liabilities that are actively traded. Level 2 also includes pricing models in which the inputs are corroborated by market data, for example, matrix pricing. • Level 3 — Financial assets and liabilities for which values are based on prices or valuation techniques that require inputs that are both unobservable and significant to the overall fair value measurement. Level 3 inputs include the following: • Quotes from brokers or other external sources that are not considered binding; • Quotes from brokers or other external sources where it cannot be determined that market participants would in fact transact for the asset or liability at the quoted price; • Quotes and other information from brokers or other external sources where the inputs are not deemed observable. We are responsible for the valuation process and as part of this process may use data from outside sources in establishing fair value. We perform due diligence to understand the inputs used or how the data was calculated or derived. We also corroborate the reasonableness of external inputs in the valuation process. The carrying amounts reported in the consolidated statement of financial condition approximate fair value for the following financial instruments: cash on hand, interest-earning deposits in other institutions, federal funds sold and other short-term investments, accrued interest receivable, accrued interest payable, and marketable securities available-for-sale. Marketable Securities Where available, market values are based on quoted market prices, dealer quotes, and prices obtained from independent pricing services. Debt securities — available for sale - Generally, debt securities are valued using pricing for similar securities, recently executed transactions and other pricing models utilizing observable inputs. The valuation for most debt securities is classified as Level 2. Securities within Level 2 include corporate bonds, municipal bonds, mortgage-backed securities and US government obligations. Certain debt securities which were AAA rated at purchase do not have an active market and as such we have used an alternative method to determine the fair value of these securities. The fair value has been determined using a discounted cash flow model using market assumptions, which generally include cash flow, collateral and other market assumptions. As such, securities which otherwise would have been classified as level 2 securities if an active market for those assets or similar assets existed are included herein as level 3 assets. Other debt securities, pooled trust preferred securities rated below AA at purchase, have a fair value based on a discounted cash flow model using similar assumptions to those noted above and accordingly are classified as level 3 assets. Equity securities — available for sale - Level 1 securities include publicly traded securities valued using quoted market prices. We consider the financial condition of the issuer to determine if the securities have indicators of impairment. Debt securities — held to maturity — The fair value of debt securities held to maturity is determined in the same manner as debt securities available for sale. Loans Receivable Loans with comparable characteristics including collateral and re-pricing structures are segregated for valuation purposes. Each loan pool is separately valued utilizing a discounted cash flow analysis. Projected monthly cash flows are discounted to present value using a market rate for comparable loans, which is not considered an exit price. Characteristics of comparable loans include remaining term, coupon interest, and estimated prepayment speeds. Delinquent loans are separately evaluated given the impact delinquency has on the projected future cash flow of the loan including the approximate discount or market rate, which is not considered an exit price. FHLB Stock Due to the restrictions placed on the transferability of FHLB stock it is not practical to determine the fair value. Deposit Liabilities The estimated fair value of deposits with no stated maturity, which includes demand deposits, money market, and other savings accounts, is the amount payable on demand. Although market premiums paid for depository institutions reflect an additional value for these low-cost deposits, adjusting fair value for any value expected to be derived from retaining those deposits for a future period of time or from the benefit that results from the ability to fund interest-earning assets with these deposit liabilities is prohibited. The fair value estimates of deposit liabilities do not include the benefit that results from the low-cost funding provided by these deposits compared to the cost of borrowing funds in the market. Fair values for time deposits are estimated using a discounted cash flow calculation that applies contractual cost currently being offered in the existing portfolio to current market rates being offered locally for deposits of similar remaining maturities. The valuation adjustment for the portfolio consists of the present value of the difference of these two cash flows, discounted at the assumed market rate of the corresponding maturity. Borrowed Funds Fixed rate advances are valued by comparing their contractual cost to the prevailing market cost. The carrying amount of repurchase agreements approximates fair value. Junior Subordinated Debentures The fair value of junior subordinated debentures is calculated using the discounted cash flows at the prevailing rate of interest. Cash flow hedges — Interest rate swap agreements (“swaps”) The fair value of the swaps is the amount we would have expected to pay to terminate the agreements and is based upon the present value of the expected future cash flows using the LIBOR swap curve, the basis for the underlying interest rate. Off-Balance Sheet Financial Instruments These financial instruments generally are not sold or traded, and estimated fair values are not readily available. However, the fair value of commitments to extend credit and standby letters of credit is estimated using the fees currently charged to enter into similar agreements. Commitments to extend credit are generally short-term in nature and, if drawn upon, are issued under current market terms. At December 31, 2015 and 2014 , there was no significant unrealized appreciation or depreciation on these financial instruments. The following table sets forth the carrying amount and estimated fair value of our financial instruments included in the consolidated statement of financial condition at December 31, 2015 and 2014 : December 31, 2015 Carrying Estimated amount fair value Level 1 Level 2 Level 3 Financial assets: Cash and cash equivalents $ 167,408 167,408 167,408 — — Securities available-for-sale 874,405 874,405 1,894 863,556 8,955 Securities held-to-maturity 31,689 32,552 — 32,552 — Loans receivable, net 7,159,449 7,482,431 — — 7,482,431 Accrued interest receivable 21,072 21,072 21,072 — — FHLB Stock 40,903 40,903 — — — Total financial assets $ 8,294,926 8,618,771 190,374 896,108 7,491,386 Financial liabilities: Savings and checking accounts $ 4,917,863 4,917,863 4,917,863 — — Time deposits 1,694,718 1,710,388 — — 1,710,388 Borrowed funds 975,007 998,527 118,664 — 879,863 Junior subordinated debentures 111,213 115,268 — — 115,268 Cash flow hedges - swaps 4,276 4,276 — 4,276 — Accrued interest payable 1,993 1,993 1,993 — — Total financial liabilities $ 7,705,070 7,748,315 5,038,520 4,276 2,705,519 December 31, 2014 Carrying Estimated amount fair value Level 1 Level 2 Level 3 Financial assets: Cash and cash equivalents $ 240,706 240,706 240,706 — — Securities available-for-sale 912,371 912,371 3,157 898,617 10,597 Securities held-to-maturity 103,695 106,292 — 106,292 — Loans receivable, net 5,922,373 6,240,079 — — 6,240,079 Accrued interest receivable 18,623 18,623 18,623 — — FHLB Stock 33,293 33,293 — — — Total financial assets $ 7,231,061 7,551,364 262,486 1,004,909 6,250,676 Financial liabilities: Savings and checking accounts $ 4,154,228 4,154,228 4,154,228 — — Time deposits 1,478,314 1,498,539 — — 1,498,539 Borrowed funds 888,109 919,612 162,714 — 756,898 Junior subordinated debentures 103,094 109,435 — — 109,435 Cash flow hedges - swaps 6,273 6,273 — 6,273 — Accrued interest payable 936 936 936 — — Total financial liabilities $ 6,630,954 6,689,023 4,317,878 6,273 2,364,872 Fair value estimates are made at a point-in-time, based on relevant market data and information about the instrument. The preceding methods and assumptions were used in estimating the fair value of financial instruments at December 31, 2015 and 2014 . There were no transfers of financial instruments between Level 1 and Level 2 during the years ended December 31, 2015 and 2014 . The following table represents assets and liabilities measured at fair value on a recurring basis as of December 31, 2015 : Level 1 Level 2 Level 3 Total at fair value Equity securities $ 1,894 — — 1,894 Debt securities: U.S. government and agencies — 11 — 11 Government sponsored enterprises — 294,440 — 294,440 States and political subdivisions — 82,868 — 82,868 Corporate — 7,520 8,955 16,475 Total debt securities — 384,839 8,955 393,794 Residential mortgage-backed securities: GNMA — 27,082 — 27,082 FNMA — 99,170 — 99,170 FHLMC — 50,369 — 50,369 Non-agency — 606 — 606 Collateralized mortgage obligations: GNMA — 10,669 — 10,669 FNMA — 122,528 — 122,528 FHLMC — 157,378 — 157,378 SBA — 8,166 — 8,166 Non-agency — 2,749 — 2,749 Total mortgage-backed securities — 478,717 — 478,717 Interest rate swaps — (4,276 ) — (4,276 ) Total assets and liabilities $ 1,894 859,280 8,955 870,129 The following table represents assets and liabilities measured at fair value on a recurring basis as of December 31, 2014 : Level 1 Level 2 Level 3 Total at fair value Equity securities $ 3,157 — — 3,157 Debt securities: U.S. government and agencies — 25 — 25 Government sponsored enterprises — 333,505 — 333,505 States and political subdivisions — 70,145 — 70,145 Corporate — 9,830 10,597 20,427 Total debt securities — 413,505 10,597 424,102 Residential mortgage-backed securities: GNMA — 29,216 — 29,216 FNMA — 73,497 — 73,497 FHLMC — 42,119 — 42,119 Non-agency — 643 — 643 Collateralized mortgage obligations: GNMA — 8,329 — 8,329 FNMA — 139,150 — 139,150 FHLMC — 178,698 — 178,698 SBA — 10,052 — 10,052 Non-agency — 3,408 — 3,408 Total mortgage-backed securities — 485,112 — 485,112 Interest rate swaps — (6,273 ) — (6,273 ) Total assets and liabilities $ 3,157 892,344 10,597 906,098 The table below presents a reconciliation of all assets and liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3) for the year ended December 31, 2015 and 2014 : December 31, 2015 2014 Equity Debt Equity Debt securities securities securities securities Beginning balance January 1, $ — 10,597 — 12,251 Total net realized investment gains/ (losses) and net change in unrealized appreciation/ (depreciation): Included in net income as OTTI — — — — Included in other comprehensive income — (502 ) — (1,549 ) Purchases — — — — Sales/ calls — (1,140 ) — (105 ) Transfers into Level 3 — — — — Transfers out of Level 3 — — — — Ending balance December 31, $ — 8,955 — 10,597 Certain assets and liabilities are measured at fair value on a nonrecurring basis after initial recognition such as loans held for sale, loans measured for impairment, real estate owned, and mortgage servicing rights. The following table represents the fair market measurement for only those nonrecurring assets that had a fair market value below the carrying amount as of December 31, 2015 : Level 1 Level 2 Level 3 Total assets at fair value Loans evaluated for impairment $ — — 48,181 48,181 Real estate owned — — 8,725 8,725 Total assets $ — — 56,906 56,906 The following table represents the fair market measurement for only those nonrecurring assets that had a fair market value below the carrying amount as of December 31, 2014 : Level 1 Level 2 Level 3 Total assets at fair value Loans evaluated for impairment $ — — 54,729 54,729 Real estate owned — — 16,759 16,759 Total assets $ — — 71,488 71,488 Loans measured for impairment — A loan is considered to be impaired as described in note 1 (f). We classify impaired loans as nonrecurring Level 3. Real estate owned — Real estate owned is comprised of property acquired through foreclosure or voluntarily conveyed by borrowers. These assets are recorded on the date acquired at the lower of the related loan balance or fair value, less estimated disposition costs, with the fair value being determined by appraisal. Subsequently, foreclosed assets are valued at the lower of the amount recorded at acquisition date or fair value, less estimated disposition costs. We classify real estate owned as nonrecurring Level 3. The following table presents additional quantitative information about assets measured at fair value on a recurring and nonrecurring basis and for which we have utilized Level 3 inputs to determine fair value at December 31, 2015 : Fair value Valuation techniques Significant unobservable inputs Range (weighted average) Debt securities $ 8,955 Discounted cash Discount margin 0.35% to 2.10% (0.69)% flow Default rates 1.00% Prepayment speeds 1.00% annually Loans measured for impairment 48,181 Appraisal Estimated costs to sell 10% value (1) Discounted cash Discount rate 3.75% to 6.50% (5.13%) flow Real estate owned 8,725 Appraisal Estimated costs to sell 10% value (1) (1) Fair value is generally determined through independent appraisals of the underlying collateral, which may include Level 3 inputs that are not identifiable, or by using the discounted cash flow method if the loan is not collateral dependent. The significant unobservable inputs used in the fair value measurement of our debt securities are discount margins, default rates and prepayment speeds. Significant increases in any of those rates would result in a significantly lower fair value measurement.

Regulatory Capital Requirements

Regulatory Capital Requirements	12 Months Ended
	Dec. 31, 2015
Regulatory Capital Requirements [Abstract]
Regulatory Capital Requirements	Regulatory Capital Requirements Our banking subsidiary is subject to various regulatory capital requirements administered by the federal and state banking agencies. Failure to meet minimum capital requirements can initiate certain mandatory — and possibly additional discretionary — actions by the regulators that, if undertaken, could have a direct material effect on our financial statements. Under capital adequacy guidelines and the regulatory framework for prompt corrective action, specific capital guidelines that involve quantitative measures of assets, liabilities, and certain off-balance sheet items as calculated under regulatory accounting practices must be met. The capital amounts and classification are also subject to qualitative judgments by the regulators about components, risk weightings, and other factors. In July 2013, the FDIC and the other federal regulatory agencies issued a final rule that revised their leverage and risk-based capital requirements and the method for calculating risk-weighted assets to make them consistent with agreements that were reached by the Basel Committee on Banking Supervision and certain provisions of the Dodd-Frank Act. Among other things, the rule establishes a new Common Equity Tier I (“CET1”) minimum capital requirement (4.5% of risk-weighted assets) and increases the minimum Tier 1 capital to risk-based assets requirement (from 4% to 6% of risk-weighted assets). The rule limits an organization's capital distributions and certain discretionary bonus payments if the organization does not hold a "capital conservation buffer" consisting of 2.5% of CET1 capital to risk-weighted assets in addition to the amount necessary to meet its minimum risk-based capital requirements. The final rule became effective for Northwest on January 1, 2015. The capital conservation buffer requirement will be phased in beginning January 1, 2016 and ending January 1, 2019, when the full capital conservation buffer requirement will be effective. The final rule also officially implements these consolidated capital requirements for savings and loan holding companies, such as the Company, effective January 1, 2015. Quantitative measures established by regulation to ensure capital adequacy require our banking subsidiary to maintain minimum amounts and ratios (set forth in the table below) of total, Tier 1, and CET1 capital (as defined in the regulations) to risk-weighted assets (as defined) and of Tier I capital to average assets (as defined). As of December 31, 2015 and 2014 , our banking subsidiary exceeded all capital adequacy requirements to which they were subject. As of December 15, 2015, the most recent notification from the FDIC categorized Northwest Bank as “well capitalized” under the regulatory framework for prompt corrective action. To be categorized as “well capitalized,” the bank must maintain total risk-based, Tier 1 risk-based, CET 1 risk-based, and Tier 1 leverage ratios as set forth in the table. There are no conditions or events since that notification that management believes have changed the bank’s categories. The actual, required, and well capitalized levels as of December 31, 2015 and 2014 were as follows: At December 31, 2015 Minimum capital Well capitalized Actual requirements requirements Amount Ratio Amount Ratio Amount Ratio Total capital (to risk weighted assets) Northwest Bancshares, Inc. $ 1,102,468 16.63 % 530,257 8.00 % 662,821 10.00 % Northwest Bank 1,006,230 15.20 % 529,498 8.00 % 661,872 10.00 % Tier 1 capital (to risk weighted assets) Northwest Bancshares, Inc. 1,039,574 15.68 % 397,693 6.00 % 530,257 8.00 % Northwest Bank 943,554 14.26 % 397,123 6.00 % 529,498 8.00 % CET 1 capital (to risk weighted assets) Northwest Bancshares, Inc. 931,699 14.06 % 298,269 4.50 % 430,834 6.50 % Northwest Bank 943,554 14.26 % 297,843 4.50 % 430,217 6.50 % Tier 1 capital (leverage) (to total assets) Northwest Bancshares, Inc. 1,039,574 11.96 % 347,582 4.00 % 434,477 5.00 % Northwest Bank 943,554 10.87 % 347,063 4.00 % 433,829 5.00 % At December 31, 2014 Minimum capital Well capitalized Actual requirements (1) requirements (1) Amount Ratio Amount Ratio Amount Ratio Total capital (to risk weighted assts) Northwest Bancshares, Inc. $ 1,062,802 20.29 % — — % — — % Northwest Bank 945,652 18.09 % 418,104 8.00 % 522,629 10.00 % Tier 1 capital (to risk weighted assets) Northwest Bancshares, Inc. 997,049 19.04 % — — % — — % Northwest Bank 880,290 16.84 % 209,052 4.00 % 313,578 6.00 % Tier 1 capital (leverage) (to total assets) Northwest Bancshares, Inc. 997,049 12.80 % — — % — — % Northwest Bank 880,290 11.55 % 304,883 4.00 % 381,104 5.00 % (1) The Federal Reserve did not yet have formal capital requirements established for Savings and Loan holding companies.

Contingent Liabilities

Contingent Liabilities	12 Months Ended
	Dec. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Contingent Liabilities	Contingent Liabilities We and our subsidiaries are subject to a number of asserted and unasserted claims encountered in the normal course of business. Management believes that the aggregate liability, if any, that may result from such potential litigation will not have a material adverse effect on our financial statements. However, we cannot presently determine whether or not any claims against us will have a material adverse effect on our results of operations in any future reporting period.

Legal Proceedings

Legal Proceedings	12 Months Ended
	Dec. 31, 2015
Legal Proceedings
Legal Proceedings	Legal Proceedings We establish accruals for legal proceedings when information related to the loss contingencies represented by those matters indicates both that a loss is probable and that the amount of loss can be reasonably estimated. As of December 31, 2015 we have not accrued for legal proceedings based on our analysis of currently available information which is subject to significant judgment and a variety of assumptions and uncertainties. Any such accruals are adjusted thereafter as appropriate to reflect changes in circumstances. Due to the inherent subjectivity of assessments and unpredictability of outcomes of legal proceedings, any amounts accrued may not represent the ultimate loss to us from legal proceedings.

Components of Accumulated Other

Components of Accumulated Other Comprehensive Income	12 Months Ended
	Dec. 31, 2015
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Components of Accumulated Other Comprehensive Income	Components of Accumulated Other Comprehensive Income The following table sets forth the components of accumulated other comprehensive income as of December 31, 2015 and 2014 : December 31, 2015 2014 Unrealized gain on marketable securities available-for-sale $ 3,325 3,461 Fair value of interest rate swaps (2,779 ) (4,078 ) Defined benefit pension plans (25,081 ) (23,753 ) Accumulated other comprehensive income $ (24,535 ) (24,370 ) The following table shows the changes in accumulated other comprehensive income by component for the year ended December 31, 2015 : Unrealized gains and losses on securities available-for- sale Change in fair value of interest rate swaps Change in defined benefit pension plans Total Balance as of January 1, $ 3,461 (4,078 ) (23,753 ) (24,370 ) Other comprehensive income/ (loss) before reclassification adjustments 315 1,299 (2,203 ) (589 ) Amounts reclassified from accumulated other comprehensive income (1), (2) (451 ) — 875 424 Net other comprehensive income/ (loss) (136 ) 1,299 (1,328 ) (165 ) Balance as of December 31, $ 3,325 (2,779 ) (25,081 ) (24,535 ) (1) Consists of realized gains on securities (gain on sales of investments, net) of $740 , net of tax (income tax expense) of $(289) . (2) Consists of amortization of prior service cost (compensation and employee benefits) of $2,323 and amortization of net loss (compensation and employee benefits) of $(3,758) , net of tax (income tax expense) of $560 . See note 15. The following table shows the changes in accumulated other comprehensive income by component for the year ended December 31, 2014 : Unrealized gains and losses on securities available-for- sale Change in fair value of interest rate swaps Change in defined benefit pension plans Total Balance as of January 1, $ (3,233 ) (5,224 ) (3,443 ) (11,900 ) Other comprehensive income/ (loss) before reclassification adjustments 9,042 1,146 (19,792 ) (9,604 ) Amounts reclassified from accumulated other comprehensive income (1), (2) (2,348 ) — (518 ) (2,866 ) Net other comprehensive income/ (loss) 6,694 1,146 (20,310 ) (12,470 ) Balance as of December 31, $ 3,461 (4,078 ) (23,753 ) (24,370 ) (1) Consists of realized gains on securities (gain on sales of investments, net) of $3,849 and other-than-temporary-impairment losses (net impairment losses) of $0 , net of tax (income tax expense) of $(1,501) . (2) Consists of amortization of prior service cost (compensation and employee benefits) of $2,323 and amortization of net loss (compensation and employee benefits) of $(1,473) , net of tax (income tax expense) of $(332) . See note 15. The following table shows the changes in accumulated other comprehensive income by component for the year ended December 31, 2013 : Unrealized gains and losses on securities available-for- sale Change in fair value of interest rate swaps Change in defined benefit pension plans Total Balance as of January 1, $ 15,853 (8,405 ) (18,936 ) (11,488 ) Other comprehensive income/ (loss) before reclassification adjustments (16,544 ) 3,181 14,577 1,214 Amounts reclassified from accumulated other comprehensive income (1), (2) (2,542 ) — 916 (1,626 ) Net other comprehensive income/ (loss) (19,086 ) 3,181 15,493 (412 ) Balance as of December 31, $ (3,233 ) (5,224 ) (3,443 ) (11,900 ) (1) Consists of realized losses on securities (gain on sales of investments, net) of 4,881 and other-than-temporary-impairment losses (net impairment losses) of $(713) , net of tax (income tax expense) of $1,626 . (2) Consists of amortization of prior service cost (compensation and employee benefits) of $2,321 and amortization of net loss (compensation and employee benefits) of $(3,730) , net of tax (income tax expense) of $493 . See note 15.

Parent Company Only Financial S

Parent Company Only Financial Statements - Condensed	12 Months Ended
	Dec. 31, 2015
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Parent Company Only Financial Statements - Condensed	Parent Company Only Financial Statements - Condensed Statements of Financial Condition December 31, 2015 2014 Assets Cash and cash equivalents $ 91,056 110,699 Marketable securities available-for-sale 1,884 3,144 Investment in bank subsidiary 1,182,308 1,054,204 Other assets 3,547 4,109 Total assets $ 1,278,795 1,172,156 Liabilities and Shareholders’ Equity Liabilities: Debentures payable $ 111,213 103,094 Other liabilities 4,419 6,415 Total liabilities 115,632 109,509 Shareholders’ equity 1,163,163 1,062,647 Total liabilities and shareholders’ equity $ 1,278,795 1,172,156 Statements of Income Years ended December 31, 2015 2014 2013 Income: Interest income $ 1,258 1,248 1,467 Other income 659 3,424 5,961 Dividends from bank subsidiary 135,000 66,183 — Undistributed earnings from equity investment in bank subsidiary (70,854 ) (3,261 ) 66,003 Total income 66,063 67,594 73,431 Expense: Compensation and benefits 1,061 962 1,024 Other expense 1,356 572 234 Interest expense 4,926 4,691 5,444 Total expense 7,343 6,225 6,702 Income before income taxes 58,720 61,369 66,729 Federal and state income taxes (1,820 ) (593 ) 170 Net income $ 60,540 61,962 66,559 Statements of Cash Flows Years ended December 31, 2015 2014 2013 Operating activities: Net income $ 60,540 61,962 66,559 Adjustments to reconcile net income to net cash provided by operating activities: Undistributed earnings of subsidiary 70,854 3,261 (66,183 ) Noncash stock benefit plan compensation expense 5,654 5,714 5,083 Gain on sale of marketable securities (54 ) (2,768 ) (5,139 ) Net change in other assets and liabilities (5,824 ) (2,352 ) (4,147 ) Net cash provided by/ (used in) operating activities 131,170 65,817 (3,827 ) Investing activities: Net sale of marketable securities 1,192 2,658 7,200 Acquisition, net of cash received (89,398 ) — — Net cash provided by/ (used in) investing activities (88,206 ) 2,658 7,200 Financing activities: Cash dividends paid (52,825 ) (149,932 ) (45,871 ) Share repurchases (7,847 ) (5,273 ) (4,459 ) Repayment of loan to ESOP 1,549 1,190 1,152 Redemption of junior subordinated debt (8,119 ) — — Excess tax benefit from stock-based compensation 332 945 635 Proceeds from options exercised 4,303 6,519 6,618 Net cash used in financing activities (62,607 ) (146,551 ) (41,925 ) Net decrease in cash and cash equivalents $ (19,643 ) (78,076 ) (38,552 ) Cash and cash equivalents at beginning of year 110,699 188,775 227,327 Net decrease in cash and cash equivalents (19,643 ) (78,076 ) (38,552 ) Cash and cash equivalents at end of year $ 91,056 110,699 188,775

Business Segments

Business Segments	12 Months Ended
	Dec. 31, 2015
Segment Reporting [Abstract]
Business Segments	Business Segments We have identified two reportable business segments based upon the operating approach currently used by management. The Community Banking segment includes our savings bank subsidiary, Northwest Bank, as well as the subsidiaries of the savings bank that provide similar products and services. The bank is a community-oriented institution that offers a full array of personal and business deposit and loan products, including mortgage, consumer, and commercial loans as well as trust, investment management, actuarial and benefit plan administration, and brokerage services typically offered by a full service financial institution. The Consumer Finance segment is comprised of Northwest Consumer Discount Company, a subsidiary of Northwest Bank. This subsidiary compliments the services of the bank by offering personal installment loans for a variety of consumer and real estate products. This activity is funded primarily through its intercompany borrowing relationship with Allegheny Services, Inc. Net income is primarily used by management to measure segment performance. The following tables provide financial information for these segments. The All Other column represents the parent company, other nonbank subsidiaries, and elimination entries necessary to reconcile to the consolidated amounts presented in the financial statements. At or for the year ended Community Banking Consumer Finance All Other (1) Consolidated External interest income $ 300,746 17,978 856 319,580 Intersegment interest income 2,393 — (2,393 ) — Interest expense 51,895 2,393 2,039 56,327 Provision for loan losses 7,429 2,283 — 9,712 Noninterest income 67,167 1,555 114 68,836 Noninterest expense 219,793 12,120 1,964 233,877 Income tax expense/ (benefit) 28,642 1,138 (1,820 ) 27,960 Net income $ 62,547 1,599 (3,606 ) 60,540 Total assets $ 8,827,574 110,670 13,655 8,951,899 At or for the year ended Community Banking Consumer Finance All Other (1) Consolidated External interest income $ 285,635 18,789 1,003 305,427 Intersegment interest income 2,406 — (2,406 ) — Interest expense 52,291 2,406 1,890 56,587 Provision for loan losses 17,500 2,814 — 20,314 Noninterest income 66,431 1,517 2,818 70,766 Noninterest expense 202,489 11,968 1,078 215,535 Income tax expense 21,097 1,291 (593 ) 21,795 Net income $ 61,095 1,827 (960 ) 61,962 Total assets $ 7,650,665 107,216 17,152 7,775,033 At or for the year ended Community Banking Consumer Finance All Other (1) Consolidated External interest income $ 291,253 20,648 1,196 313,097 Intersegment interest income 2,691 — (2,691 ) — Interest expense 56,282 2,691 2,189 61,162 Provision for loan losses 15,206 3,313 — 18,519 Noninterest income 59,616 1,647 5,213 66,476 Noninterest expense 194,028 12,303 803 207,134 Income tax expense/ (benefit) 24,330 1,699 170 26,199 Net income $ 63,714 2,289 556 66,559 Total assets $ 7,745,433 109,249 25,177 7,879,859 (1) Eliminations consist of intercompany interest income and interest expense.

Guaranteed Preferred Beneficial

Guaranteed Preferred Beneficial Interests in Company’s Junior Subordinated Deferrable Interest Debentures (Trust-Preferred Securities) and Interest Rate Swap Agreements	12 Months Ended
	Dec. 31, 2015
Guaranteed Preferred Beneficial Interests in Company's Junior Subordinated Deferrable Interest Debentures (Trust-Preferred Securities) and Interest Rate Swap Agreements
Guaranteed Preferred Beneficial Interests in Company’s Junior Subordinated Deferrable Interest Debentures (Trust-Preferred Securities) and Interest Rate Swap Agreements	Guaranteed Preferred Beneficial Interests in Company’s Junior Subordinated Deferrable Interest Debentures (Trust-Preferred Securities) and Interest Rate Swap Agreements We have two legacy statutory business trusts: Northwest Bancorp Capital Trust III, a Delaware statutory business trust, and Northwest Bancorp Statutory Trust IV, a Connecticut statutory business trust (the Trusts). The trusts exist solely to issue preferred securities to third parties for cash, issue common securities to the Company in exchange for capitalization of the Trusts, invest the proceeds from the sale of trust securities in an equivalent amount of debentures of the Company, and engage in other activities that are incidental to those previously listed. The Trusts are not consolidated. Northwest Bancorp Capital Trust III issued 50,000 cumulative trust preferred securities in a private transaction to a pooled investment vehicle on December 5, 2005 (liquidation value of $1,000 per preferred security or $50,000,000 ) with a stated maturity of December 30, 2035 and a floating rate of interest, which is reset quarterly, equal to three-month LIBOR plus 1.38% . Northwest Bancorp Statutory Trust IV issued 50,000 cumulative trust preferred securities in a private transaction to a pooled investment vehicle on December 15, 2005 (liquidation value of $1,000 per preferred security or $50,000,000 ) with a stated maturity of December 15, 2035 and a floating rate of interest, which is reset quarterly, equal to three-month LIBOR plus 1.38% . As the shareholders of the trust preferred securities are the primary beneficiaries of the Trusts, the Trusts are not consolidated in our financial statements. The Trusts have invested the proceeds of the offerings in junior subordinated deferrable interest debentures issued by the Company. The structure of these debentures mirrors the structure of the trust-preferred securities. Northwest Bancorp Capital Trust III holds $51,547,000 of the Company’s junior subordinated debentures due December 30, 2035 with a floating rate of interest, reset quarterly, of three-month LIBOR plus 1.38% . The rate in effect at December 31, 2015 was 1.98% . Northwest Bancorp Statutory Trust IV holds $51,547,000 of the Company’s junior subordinated debentures due December 15, 2035 with a floating rate of interest, reset quarterly, of three-month LIBOR plus 1.38% . The rate in effect at December 31, 2015 was 1.89% . Cash distributions on the trust securities are made on a quarterly basis to the extent interest on the debentures is received by the Trusts. We have the right to defer payment of interest on the subordinated debentures at any time, or from time-to-time, for periods not exceeding 5 years . If interest payments on the subordinated debentures are deferred, the distributions on the trust securities also are deferred. To date there have been no interest deferrals. Interest on the subordinated debentures and distributions on the trust securities is cumulative. Our obligation constitutes a full, irrevocable, and unconditional guarantee on a subordinated basis of the obligations of the trust under the preferred securities. The Trusts must redeem the preferred securities when the debentures are paid at maturity or upon an earlier redemption of the debentures to the extent the debentures are redeemed. All or part of the debentures may be redeemed at any time. Also, the debentures may be redeemed at any time if existing laws or regulations, or the interpretation or application of these laws or regulations, change causing: • the interest on the debentures to no longer be deductible by the Company for federal income tax purposes; • the trust to become subject to federal income tax or to certain other taxes or governmental charges; • the trust to register as an investment company; and • the preferred securities do not qualify as Tier I capital. We may, at any time, dissolve any of the Trusts and distribute the debentures to the trust security holders, subject to receipt of any required regulatory approval(s). As a result of the LNB acquisition we acquired two statutory business trusts: LNB Trust I and LNB Trust II, both Delaware statutory business trusts. The outstanding stock issued by LNB Trust I was redeemed on December 15, 2015. At December 31, 2015, LNB Trust II had 7,875 cumulative trust preferred securities outstanding (liquidation value of $1,000 per preferred security or $7,875,000 ) with a stated maturity of June 15, 2037. These securities carry a fixed interest rate of 6.64% through June 15, 2017, then becomes a floating interest rate, which is reset quarterly, equal to three-month LIBOR plus 1.48% . LNB Trust II invested the proceeds of the offerings in junior subordinated deferrable interest debentures acquired by the Company. The structure of these debentures mirrors the structure of the trust-preferred securities. LNB Trust II holds $8,119,000 of junior subordinated debentures. These subordinated debentures are the sole assets of the Trust. Cash distributions on the trust securities are made on a quarterly basis to the extent interest on the debentures is received by the Trust. We are currently a counterparty to two interest rate swap agreements (swaps), designating the swaps as cash flow hedges. The swaps are intended to protect against the variability of cash flows associated with Northwest Bancorp Capital Trust III and Northwest bancorp Capital Trust IV. The first swap modifies the re-pricing characteristics of Northwest Bancorp Capital Trust III, wherein for a 10 years period expiring in September 2018, the Company receives interest of three-month LIBOR from a counterparty and pays a fixed rate of 4.61% to the same counterparty calculated on a notional amount of $25.0 million . The second swap modifies the re-pricing characteristics of Northwest Bancorp Capital Trust IV, wherein for a ten year period expiring in September 2018, the Company receives interest of three-month LIBOR from a counterparty and pays a fixed rate of 4.09% to the same counterparty calculated on a notional amount of $25.0 million . The swap agreements were entered into with a counterparty that met our credit standards and the agreements contain collateral provisions protecting the at-risk party. We believe that the credit risk inherent in the contracts is not significant. At December 31, 2015 , $4.7 million of cash was pledged as collateral to the counterparty. At December 31, 2015 , the fair value of the swap agreements was $( 4.3 ) million and was the amount we would have expected to pay if the contracts were terminated. At December 31, 2015 , there was no material hedge ineffectiveness for any of the swaps discussed above. December 31, Liability Derivatives (Included in Other Liabilities) 2015 2014 Cash flow hedges — swaps: Fair value $ 4,276 6,273 Notional amount 50,000 75,000 Collateral posted 4,705 6,805 The following table sets forth a summary of guaranteed capital debt securities and junior subordinated deferrable interest debentures held by the trusts as of December 31, 2015 and 2014 : Capital Debt December 31, Securities 2015 2014 Northwest Bancorp Capital Trust III $ 50,000 51,547 51,547 Northwest Bancorp Statutory Trust IV 50,000 51,547 51,547 LNB Trust II 7,875 8,119 — Total $ 107,875 111,213 103,094

Selected Quarterly Financial Da

Selected Quarterly Financial Data - Unaudited	12 Months Ended
	Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Selected Quarterly Financial Data - Unaudited	Selected Quarterly Financial Data - Unaudited Three months ended March 31 June 30 September 30 December 31 (In thousands, except per share data) 2015: Interest income $ 76,880 75,970 81,091 85,639 Interest expense 13,899 13,792 14,150 14,486 Net interest income 62,981 62,178 66,941 71,153 Provision for loan losses 900 1,050 3,167 4,595 Noninterest income 14,625 16,525 18,140 19,546 Noninterest expenses 53,711 55,135 63,804 61,227 Income before income taxes 22,995 22,518 18,110 24,877 Income tax expense 6,825 7,213 5,238 8,684 Net income $ 16,170 15,305 12,872 16,193 Basic earnings per share $ 0.18 0.17 0.14 0.16 Diluted earnings per share $ 0.18 0.17 0.13 0.16 Three months ended March 31 June 30 September 30 December 31 (In thousands, except per share data) 2014: Interest income $ 75,326 76,987 76,528 76,586 Interest expense 14,204 14,214 14,187 13,982 Net interest income 61,122 62,773 62,341 62,604 Provision for loan losses 7,485 8,285 3,466 1,078 Noninterest income 19,381 16,427 17,737 17,221 Noninterest expenses 53,163 53,806 53,354 55,212 Income before income taxes 19,855 17,109 23,258 23,535 Income tax expense 5,244 4,435 5,926 6,190 Net income $ 14,611 12,674 17,332 17,345 Basic earnings per share $ 0.16 0.14 0.19 0.19 Diluted earnings per share $ 0.16 0.14 0.19 0.19 Three months ended March 31 June 30 September 30 December 31 (In thousands, except per share data) 2013: Interest income $ 79,475 78,723 77,850 77,049 Interest expense 15,645 15,436 15,276 14,805 Net interest income 63,830 63,287 62,574 62,244 Provision for loan losses 7,158 5,405 4,992 964 Noninterest income 16,341 13,379 15,989 20,767 Noninterest expenses 51,471 52,806 50,277 52,580 Income before income taxes 21,542 18,455 23,294 29,467 Income tax expense 6,357 5,020 5,727 9,095 Net income $ 15,185 13,435 17,567 20,372 Basic earnings per share $ 0.17 0.15 0.19 0.22 Diluted earnings per share $ 0.17 0.15 0.19 0.22

Subsequent Events - Unaudited

Subsequent Events - Unaudited	12 Months Ended
	Dec. 31, 2015
Subsequent Events [Abstract]
Subsequent Events - Unaudited	Subsequent Events - Unaudited The Company announced plans to optimize its office network. In recent years, the Company has invested heavily in alternative delivery channels such as online and mobile banking, depository ATMs, and automated telephone banking which enables customers to transact business outside of the branch and beyond normal business hours. As a result, the number of transactions conducted in offices has significantly decreased over the past several years and has created an opportunity to improve operating efficiency. Based on these changes in customer preferences, the Company expects by mid-year 2016 to consolidate 24 of its offices into nearby locations and convert two full-service offices into drive-up only facilities. Expenses associated with these changes are expected to be approximately $ 5.0 million, which will be incurred during the first half of 2016, and the annual reduction in pre-tax operating expenses beginning in 2017 is expected to be between $ 5.0 million and $ 6.0 million.

Summary of Significant Accoun36

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of Operations	Nature of Operations Northwest Bancshares, Inc., a Maryland corporation headquartered in Warren, Pennsylvania, the federal savings and loan holding company for its wholly owned subsidiary, Northwest Bank. Northwest Bank, a Pennsylvania chartered savings bank, offers personal and business deposit and loan products as well as investment management and insurance services through its 181 banking locations in Pennsylvania, New York, Ohio and Maryland. Northwest Bank, through its subsidiary Northwest Consumer Discount Company, also offers personal loan products through 51 consumer finance offices in Pennsylvania.
Principles of Consolidation	Principles of Consolidation The consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries after elimination of all intercompany accounts and transactions.
Cash and Cash Equivalents	Cash and Cash Equivalents For purposes of the statement of cash flows, cash and cash equivalents include cash and amounts due from banks, interest-bearing deposits in other financial institutions, federal funds sold, and other short-term investments with original maturities of three months or less.
Investment Securities	Investment Securities We classify marketable securities at the time of purchase as held-to-maturity, available-for-sale, or trading securities. Securities for which management has the intent and ability to hold until maturity are classified as held-to-maturity and are carried at cost, adjusted for amortization of premiums and accretion of discounts on a level yield basis (amortized cost). If it is management’s intent at the time of purchase to hold securities for an indefinite period of time and/or to use such securities as part of its asset/liability management strategy, the securities are classified as available-for-sale and are carried at fair value, with unrealized gains and losses reported as accumulated other comprehensive income/ (loss), a separate component of shareholders’ equity, net of tax. Securities classified as available-for-sale include securities that may be sold in response to changes in interest rates, resultant prepayment risk, or other market factors. Securities that are bought and held principally for the purpose of selling them in the near term are classified as trading and are reported at fair value, with changes in fair value included in earnings. The cost of securities sold is determined on a specific identification basis. We held no securities classified as trading at or for the years ended December 31, 2015 and 2014 . On at least a quarterly basis, we review our investments for other-than-temporary impairment (“OTTI”). An investment security is deemed impaired if the fair value of the investment is less than its amortized cost. If an investment security is determined to be impaired, we evaluate whether the decline in value is other-than-temporary. We consider whether or not we expect to receive all of the contractual cash flows from the investment security based on factors that include, but are not limited to the credit worthiness of the issuer and the historical and projected performance of the underlying collateral. Also, we may evaluate the business and financial outlook of the issuer, as well as broader economic performance indicators. We consider both our intent to sell and the likelihood that we will not have to sell the investment securities before recovery of their cost basis during our evaluation. Impairment that is deemed credit related is recognized in earnings while impairment deemed noncredit related is recorded in accumulated other comprehensive income, if we do not intend to sell nor it is not likely we will be required to sell the investment security. If we intend to sell the investment security or if it’s more likely than not that we will be required to sell the investment security, the entire impairment is recorded in earnings. Federal law requires a member institution of the Federal Home Loan Bank (FHLB) system to hold stock of its district FHLB according to a predetermined formula. This stock is recorded at cost. Quarterly, we evaluate our investment in the FHLB of Pittsburgh for impairment. We evaluate recent and long-term operating performance, liquidity, funding and capital positions, stock repurchase history, dividend history and impact of legislative and regulatory changes. Based on our most recent evaluation, we have determined that no impairment write-downs are currently required.
Loans Receivable	Loans Receivable Our loan portfolio segments consist of Personal Banking and Business Banking loans. Personal Banking loans include the following classes: residential mortgage loans, home equity loans and other consumer loans. Business Banking loans include the following classes: commercial real estate loans and commercial loans. All classes of originated loans are carried at their unpaid principal balance net of any deferred origination fees or costs and the allowance for estimated loan losses. Interest income on loans is credited to income as earned. Interest earned on loans for which no payments were received during the month is accrued at month end. Accrued interest on loans more than 90 days delinquent is reversed and such loans are placed on nonaccrual status. All loans are placed on nonaccrual status when principal or interest is 90 days or more delinquent or when there is reasonable doubt that interest or principal will not be collected in accordance with the contractual terms. Interest receipts on all nonaccrual and impaired loans are recognized as interest revenue when it has been determined that all principal and interest will be collected or are applied to principal when collectability of principal is in doubt. Nonaccrual loans generally are restored to an accrual basis when principal and interest become current and a period of performance has been established in accordance with the contractual terms, typically six months . A loan is considered to be a troubled debt restructured loan (TDR) when the restructuring constitutes a concession and the borrower is experiencing financial difficulties. TDRs may include modifications of terms of loans, receipts of assets from borrowers in partial or full satisfaction of loans, or a combination thereof. TDRs are impaired loans. A modified loan is determined to be a TDR based on the contractual terms as specified by the original loan agreement or the most recent modification. Once classified a TDR, a loan is removed from such classification under three circumstances: (1) the loan is paid off, (2) the loan is charged off, or (3) if, at the beginning of the current fiscal year, the loan has performed in accordance with the modified terms for a minimum of six consecutive months and at the time of modification the loan’s interest rate represented a then current market interest rate for a loan of similar risk. Loan delinquency is measured based on the number of days since the payment due date. Past due status is measured using the loan’s contractual maturity date. Loan fees and certain direct loan origination costs are deferred and the net deferred fee or cost is then recognized using the level-yield method over the contractual life of the loan as an adjustment to interest income. We identify certain residential mortgage loans which will be sold prior to maturity, as loans held for sale. These loans are recorded at the lower of amortized cost or fair value less estimated cost to sell. At December 31, 2015 and 2014 , there were no residential mortgage loans classified as held for sale. Acquired loans are recorded at fair value with no carryover of the related allowance for loan losses. Determining the fair value of the loans involves estimating the amount and timing of principal and interest cash flows expected to be collected on the loans and discounting those cash flows at a market rate of interest. The excess of cash flows expected at acquisition over the estimated fair value is referred to as the accretable discount and is recognized into interest income over the remaining life of the loan. The difference between contractually required payments at acquisition and the cash flows expected to be collected at acquisition is referred to as the nonaccretable discount. The nonaccretable discount represents estimated future credit losses expected to be incurred over the life of the loan. Subsequent decreases to the expected cash flows require us to evaluate the need for an allowance for loan losses. Subsequent improvements in expected cash flows result in the reversal of a corresponding amount of the nonaccretable discount which we then reclassify as accretable discount that is recognized into interest income over the remaining life of the loan using the interest method. Charge-offs of the principal amount on acquired loans would be first applied to the nonaccretable discount portion of the fair value adjustment. Acquired loans that met the criteria for nonaccrual of interest prior to the acquisition may be considered performing upon acquisition, regardless of whether the customer is contractually delinquent, if we can reasonably estimate the timing and amount of the expected cash flows on such loans and if we expect to fully collect the new carrying value of the loans. As such, we may no longer consider the loan to be nonaccrual or nonperforming and may accrue interest on these loans, including the impact of any accretable discount. We have determined that we can reasonably estimate future cash flows on our current portfolio of acquired loans that are past due 90 days or more and on which we are accruing interest and we expect to fully collect the carrying value of the loans.
Allowance for Loan Losses and Provision for Loan Losses	Allowance for Loan Losses and Provision for Loan Losses Provisions for estimated loan losses and the amount of the allowance for loan losses are based on losses inherent in the loan portfolio that are both probable and can be reasonably estimated at the date of the financial statements. We consider a loan to be impaired when it is probable that we will be unable to collect all amounts due according to the contractual terms of the loan agreement. In evaluating whether a loan is impaired, we consider not only the amount that we expect to collect but also the timing of collection. Generally, if a delay in payment is insignificant (e.g., less than 30 days ), a loan is not deemed to be impaired. Business Banking loans greater than or equal to $1.0 million are reviewed to determine if they should be individually evaluated for impairment. Smaller balance, homogeneous loans (e.g., primarily residential mortgage, home equity and consumer loans) are evaluated collectively for impairment. When a loan is considered to be impaired, the amount of impairment is measured based on the present value of expected future cash flows discounted at the loan’s effective interest rate, the loan’s market price, or fair value of the collateral, less estimated cost to sell, if the loan is collateral dependent. Impairment losses are included in the allowance for loan losses. Impaired loans are charged-off or charged down when we believe that the ultimate collectability of a loan is not likely or the collateral value no longer supports the carrying value of the loan. Interest income on non-performing loans is recognized using the cash basis method. For non-performing loans interest collected is credited to income in the period of recovery or applied to reduce principal if there is sufficient doubt about the collectability of principal. The allowance for loan losses is shown as a valuation allowance to loans. The accounting policy for the determination of the adequacy of the allowance by portfolio segment requires us to make numerous complex and subjective estimates and assumptions relating to amounts which are inherently uncertain. The allowance for loan losses is maintained to absorb losses inherent in the loan portfolio as of the balance sheet date. The methodology used to determine the allowance for loan losses is designed to provide procedural discipline in assessing the appropriateness of the allowance for loan losses. Losses are charged against and recoveries are added to the allowance for loan losses. For Business Banking loans the allowance for loan losses consists of: • An allowance for impaired loans; • An allowance for homogenous loans based on historical losses; and • An allowance for homogenous loans based on environmental factors. The allowance for impaired loans is based on individual analysis of all nonperforming loans greater than or equal to $1.0 million . The allowance is measured by the difference between the recorded value of impaired loans and their impaired value. The impaired value is either the present value of the expected future cash flows from the borrower, the market value of the loan, or the fair value of the collateral, less estimated cost to sell. The allowance for homogeneous loans based on historical factors is a rolling three -year average of actual losses incurred, adjusted for a loss realization period (the period of time from the event of loss to loss realization), applied to homogenous pools of loans categorized by similar risk characteristics, not including loans evaluated individually for impairment. The allowance for homogeneous loans based on environmental factors augments the historical loss factors for changes in: economic conditions, lending policies and procedures, the nature and volume of the loan portfolio, management, delinquency trends, loan administration, collateral values, concentrations of credit, and other external factors including legal and regulatory factors. For Personal Banking loans the allowance for loan losses consists of: • An allowance for loans 90 days or more delinquent; • An allowance for homogenous loans based on historical losses; and • An allowance for homogenous loans based on environmental factors. The allowance for loans 90 days or more delinquent is based on the loss history of loans that have become 90 days or more delinquent. We apply a historical loss factor to homogeneous pools of loans that are 90 days or more delinquent. The allowance for homogeneous loans based on historical losses is a rolling three -year average of actual losses incurred, adjusted for a loss realization period, applied to homogenous pools of loans categorized by similar risk characteristics, not including loans that are 90 days or more delinquent. The allocation of the allowance for loan losses is inherently judgmental, and the entire allowance for loan losses is available to absorb loan losses regardless of the nature of the loss. Personal Banking loans are charged-off or charged down when they become 180 days delinquent, unless the borrower has filed for bankruptcy. Business Banking loans are charged-off or charged down when, in our opinion, they are no longer collectible or when it has been determined that the collateral value no longer supports the carrying value of the loan, for loans that are collateral dependent. We have not made any material changes to our methodology for the calculation of the allowance for loan losses during the current year.
Real Estate Owned	Real Estate Owned Real estate owned is comprised of property either acquired through foreclosure or voluntarily conveyed by borrowers. These assets are recorded on the date acquired at the lower of the loan balance or fair value of the collateral, less estimated disposition costs, with the fair value being determined by an appraisal. Any initial write-down is charged to the allowance for loan losses. Subsequently, foreclosed assets are valued at the lower of the amount recorded at acquisition date or the current fair value, less estimated disposition costs. Any subsequent write-down or gains or losses realized from the disposition of such property are credited or charged to noninterest income.
Premises and Equipment	Premises and Equipment Premises and equipment are carried at cost, less accumulated depreciation and amortization. Depreciation is accumulated on a straight-line basis over the estimated useful lives of the related assets. Estimated lives range from three to 39 years . Amortization of leasehold improvements is accumulated on a straight-line basis over the terms of the related leases or the useful lives of the related assets, whichever is shorter.
Goodwill	Goodwill Goodwill is generated from the premium paid for an acquisition and is allocated to reporting units, which are either the Company’s reportable segments or one level below. Goodwill is not subject to amortization but is tested for impairment at least annually and possibly more frequently if certain events occur or changes in circumstances arise. Impairment testing requires that the fair value of each reporting unit be compared to its carrying amount, including goodwill. Reporting units are identified based upon analyzing each individual operating segment. A reporting unit is defined as a distinct, separately identifiable component of an operating segment for which complete, discrete financial information is available that management regularly reviews. Determining the fair value of a reporting unit requires a high degree of subjective management judgment, including developing cash flow projections, selecting appropriate discount rates, identifying relevant market comparables, incorporating general economic and market conditions and selecting an appropriate control premium. The selection and weighting of the various fair value techniques may result in a higher or lower fair value. Judgment is applied in determining the weightings that are most representative of fair value. We conducted our annual goodwill impairment assessment as of June 30 th through the assistance of an independent third party. We valued each reporting unit by using a weighted average of four valuation methodologies; comparable transaction approach, control premium approach, public market peers approach and discounted cash flow approach. Declines in fair value could result in impairment being identified. At June 30, 2015 and 2014, we did not identify any individual reporting unit where the fair value was less than the carrying value and no other events have occurred since that date that would warrant an updated valuation. Future changes in the economic environment or the operations of the operating units could cause changes to the variables used, which could give rise to declines in the estimated fair value of the reporting units. There were no changes in our operations that would cause us to update the goodwill impairment tests performed as of June 30, 2015 and 2014. Accordingly, we have determined that goodwill is not impaired as of December 31, 2015 and 2014 .
Core Deposit Intangibles and Other Identifiable Intangibles	Core Deposit Intangibles and Other Identifiable Intangibles Through the assistance of an independent third party, we analyze and prepare a core deposit study for all bank acquisitions or other identifiable intangible asset study, such as customer lists, for all non-bank acquisitions. The core deposit study reflects the cumulative present value benefit of acquiring deposits versus an alternative source of funding. The other identifiable intangible asset study reflects the cumulative present value benefit of acquiring the income stream from an existing customer base versus developing new business relationships. Based upon analysis, the amount of the premium related to the core deposits or other identifiable intangibles of the business purchased is calculated along with the estimated life of the intangible. The intangible, which is recorded in other intangible assets, is then amortized to expense on an accelerated basis over an approximate life of 7 years .
Bank-Owned Life Insurance	Bank-Owned Life Insurance We own insurance on the lives of a certain group of key employees and directors. The policies were purchased to help offset the increase in the costs of various fringe benefit plans, including healthcare, as well as the directors deferred compensation plan. The cash surrender value of these policies is included as an asset on the consolidated statements of financial condition, and any increases in the cash surrender value are recorded as tax-free noninterest income on the consolidated statements of income. In the event of the death of an insured individual under these policies, after distribution to the insured’s beneficiaries, if any, we receive a tax-free death benefit, which is recorded as noninterest income.
Deposits	Deposits Interest on deposits is accrued and charged to expense monthly and is paid or credited in accordance with the terms of the accounts.
Pension Plans	Pension Plans We maintain multiple noncontributory defined benefit pension plans for substantially all of our employees. The net periodic pension cost has been calculated using service cost, interest cost, expected returns on plan assets and net amortization.
Income Taxes	Income Taxes We join with our wholly owned subsidiaries in filing a consolidated federal income tax return. In accordance with an intercompany tax allocation agreement, the applicable federal income tax expense or benefit is allocated to each subsidiary based upon taxable income or loss calculated on a separate company basis. Each subsidiary is responsible for payment of its own federal income tax liability or receives reimbursement of federal income tax benefit. In addition, deferred taxes are calculated and maintained on a separate company basis. We account for income taxes under the asset and liability method. The objective of the asset and liability method is to establish deferred tax assets and liabilities for temporary differences between the financial reporting and tax basis of our assets and liabilities based on the tax rates expected to be in effect when such amounts are realized or settled.
Stock-Related Compensation	Stock-Related Compensation We determine the fair value of each option award, estimated on the grant date, using the Black-Scholes-Merton option-pricing model. The Black-Scholes-Merton option-pricing model uses variables including; expected volatilities, expected term, risk-free discount rate and annual rate of quarterly dividends. Expected volatilities are based on historical volatility of the Company’s stock. The expected terms are based upon actual exercise and forfeiture experience of previous option grants. The risk-free rate is based on yields on U.S. Treasury securities of a similar maturity to the expected term of the options. During the year ended December 31, 2015 , we awarded 600,570 stock options to employees and 64,800 stock options to directors. Option awards are generally granted with an exercise price equal to the closing market price of the Company’s stock on the day before the grant date. The options granted in 2015 vest over a ten -year period, with the first vesting occurring on the grant date. New shares are issued when options are exercised. During the year ended December 31, 2015 , we awarded 282,050 common shares to employees and 24,300 common shares to directors. The common share awards granted in 2015 vest over a ten -year period, with the first vesting occurring on the grant date. During the year ended December 31, 2015 we awarded 126,280 common shares to eligible employees from our employee stock ownership plan (“ESOP”). For additional information regarding grants of stock options and common shares and ESOP distributions see Note 15. Stock-based employee compensation expense related to common share awards of $3.0 million , $3.0 million and $2.4 million was included in income before income taxes during the years ended December 31, 2015 , 2014 and 2013 , respectively. The effect on net income for the years ended December 31, 2015 , 2014 and 2013 was a reduction of $1.8 million , $1.8 million and $1.6 million , respectively. Total compensation expense for unvested stock options of $4.3 million has yet to be recognized as of December 31, 2015 . The weighted average period over which this remaining stock option expense will be recognized is approximately 4.23 years . The fair value of each option grant is estimated on the date of grant using the Black-Scholes-Merton option-pricing model with the following weighted average assumptions: (1) dividend yields ranging from 1.6% to 5.1% based on historical dividends and market prices; (2) expected volatility of 17% to 33% based on historical volatility; (3) risk-free interest rates ranging from 1.7% to 6.5% ; and (4) expected lives of seven to nine years based on previous grants.
Segment Reporting	Segment Reporting We have 2 reportable segments, Community Banking and Consumer Finance. See note 22 for related disclosures.
Derivative financial instruments - interest rate swaps	Derivative financial instruments — interest rate swaps We recognize all derivative financial instruments as either assets or liabilities in the balance sheet and measure those instruments at fair value. The accounting for changes in the fair value of a derivative depends on the intended use of the derivative and the resulting designation. An entity that elects to use hedge accounting is required, at inception, to establish the method it will use for assessing the effectiveness of the hedging derivative and the measurement approach for determining the ineffective aspect of the hedge. Those methods must be consistent with our approach to managing risk. We utilize interest rate swap agreements as part of the management of interest rate risk to hedge the interest rate risk on our trust preferred debentures. Amounts receivable or payable are recognized as accrued under the terms of the agreements and the differential is recorded as an adjustment to interest expense. The interest rate swaps are designated as cash flow hedges, with the effective portion of the derivative’s unrealized gain or loss recorded as a component of other comprehensive income. The ineffective portion of the unrealized gain or loss, if any, would be recorded in other expense. See note 23 for related disclosures.
Off-Balance-Sheet Instruments	Off-Balance-Sheet Instruments In the normal course of business, we extend credit in the form of loan commitments, undisbursed lines of credit, and standby letters of credit. These off-balance-sheet instruments involve, to various degrees, elements of credit and interest rate risk not reported in the consolidated statement of financial condition. We utilize the same underwriting standards for these instruments as other extensions of credit.
Use of Estimates	Use of Estimates The preparation of financial statements, in conformity with accounting principles generally accepted in the United States of America, requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amount of revenues and expenses during the reporting period. The estimates and assumptions that we deem important to our financial statements relate to the allowance for loan losses, the accounting treatment and valuation of our investment securities portfolio, the analysis of the carrying value of goodwill and income taxes. These estimates and assumptions are based on management’s best estimates and judgment and we evaluate them using historical experience and other factors, including the current economic environment. We adjust our estimates and assumptions when facts and circumstances dictate. As future events cannot be determined, actual results could differ significantly from our estimates.
Reclassification of Prior Years' Statements	Reclassification of Prior Years’ Statements Certain items previously reported have been reclassified to conform with the current year’s reporting format.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In May 2014 the FASB issued ASU 2014-09, “Revenue from Contracts with Customers”. This guidance supersedes the revenue recognition requirements in Topic 605, Revenue Recognition, and most industry-specific guidance. The core principle of this guidance requires an entity to recognize revenue upon the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services and provides five steps to be analyzed to accomplish the core principle. This guidance is effective retrospectively for annual reporting periods beginning after December 15, 2017, including interim periods within those years and early adoption is not permitted. We are currently evaluating the impact this standard will have on our results of operations and financial position. In June 2014 the FASB issued ASU 2014-12, “Compensation—Stock Compensation”. This guidance requires that a performance target that affects vesting and that could be achieved after the requisite service period be treated as a performance condition. Specifically, if the performance target becomes probable of being achieved before the end of the requisite service period, the remaining unrecognized compensation cost should be recognized prospectively over the remaining requisite service period. Further, the total amount of compensation cost recognized during and after the requisite service period should reflect the number of awards that are expected to vest and should be adjusted to reflect those awards that ultimately vest. This guidance is effective for annual periods beginning after December 15, 2015, including interim periods within those years and early adoption is permitted. We do not expect that this standard will have a material impact on our results of operations or financial position. In February 2015 the FASB issued ASU 2015-02, “Consolidation” . This guidance amends existing standards regarding the evaluation of certain legal entities and their consolidation in the financial statements. The amendments modify the evaluation of whether limited partnerships and similar legal entities are variable interest entities or voting interest entities and eliminate the presumption that a general partner should consolidate a limited partnership. The amendments also affect the consolidation analysis of reporting entities that are involved with variable interest entities and provide a scope exception from consolidation guidance for reporting entities with interests in legal entities that are required to comply with or operate in accordance with requirements that are similar to those in Rule 2a-7 of the Investment Company Act of 1940 for registered money market funds. This guidance is effective for annual periods beginning after December 15, 2015, including interim periods within those years and early adoption is permitted. We do not expect that this standard will have a material impact on our results of operations or financial position. In September 2015 the FASB issued ASU 2015-16, “ Simplifying the Accounting for Measurement-Period Adjustments ”. This guidance eliminates the requirement to retrospectively adjust the financial statements for measurement-period adjustments that occur in periods after a business combination is consummated. This guidance is effective for annual periods beginning after December 15, 2015, including interim periods within those years and early adoption is permitted. We do not expect that this standard will have a material impact on our results of operations or financial position.

Acquisition (Tables)

Acquisition (Tables)	12 Months Ended
	Dec. 31, 2015
Business Combinations [Abstract]
Schedule of the consideration paid, the assets acquired, and the liabilities assumed that were recorded at fair value on the date of acquisition	The following table shows the consideration paid, the assets acquired, and the liabilities assumed that were recorded at fair value on the date of acquisition: Consideration paid: Northwest Bancshares, Inc. common stock issued $ 90,608 Cash paid to LNB Bancorp, Inc. stockholders 90,350 Total consideration paid 180,958 Recognized amounts of identifiable assets acquired and (liabilities assumed), at fair value Cash and cash equivalents 29,680 Investment securities available for sale 184,169 Loans 928,101 Federal Home Loan Bank stock 3,840 Premises and equipment 12,374 Core deposit intangible 7,375 Other assets 45,698 Deposits (1) (1,033,992 ) Borrowings (63,169 ) Other liabilities (19,356 ) Total indentifiable net assets 94,720 Goodwill $ 86,238 (1) Subsequent to the September 30, 2015 reporting period, we adjusted deposits by $17.4 million for trust account deposits maintained by LNB. This adjustment had no impact on goodwill.
Schedule of acquired loan portfolio	The following table shows information related to the purchased credit impaired LNB loan portfolio as of August 14, 2015: Contractually required principal and interest at acquisition $ 41,175 Contractual cash flows not expected to be collected (nonaccretable discount) (19,900 ) Expected cash flows at acquisition 21,275 Interest component of expected cash flows (accretable discount) (1,672 ) Fair value of purchased credit impaired loans $ 19,603

Marketable Securities (Tables)

Marketable Securities (Tables)	12 Months Ended
	Dec. 31, 2015
Investments, Debt and Equity Securities [Abstract]
Schedule of the portfolio of investment securities available-for-sale	Marketable securities available-for-sale at December 31, 2015 are as follows: Amortized cost Gross unrealized holding gains Gross unrealized holding losses Fair value Debt issued by the U.S. government and agencies: Due in one year or less $ 11 — — 11 Debt issued by government sponsored enterprises: 15500 3 -48 15.45 Due in one year or less 15,500 3 (48 ) 15,455 Due after one year through five years 257,463 298 (1,395 ) 256,366 Due after five years through ten years 12,721 14 (23 ) 12,712 Due after ten years 9,815 135 (43 ) 9,907 Equity securities 1,400 500 (6 ) 1,894 Municipal securities: Due in one year or less 1,684 8 — 1,692 Due after one year through five years 14,327 117 (4 ) 14,440 Due after five years through ten years 12,400 323 — 12,723 Due after ten years 52,286 1,727 — 54,013 Corporate debt issues: Due after ten years 14,463 2,417 (405 ) 16,475 Residential mortgage-backed securities: Fixed rate pass-through 118,266 2,480 (420 ) 120,326 Variable rate pass-through 54,292 2,616 (7 ) 56,901 Fixed rate non-agency CMOs 2,519 230 — 2,749 Fixed rate agency CMOs 215,719 389 (3,881 ) 212,227 Variable rate agency CMOs 86,090 476 (52 ) 86,514 Total residential mortgage-backed securities 476,886 6,191 (4,360 ) 478,717 Total marketable securities available-for-sale $ 868,956 11,733 (6,284 ) 874,405 Marketable securities available-for-sale at December 31, 2014 are as follows: Amortized cost Gross unrealized holding gains Gross unrealized holding losses Fair value Debt issued by the U.S. government and agencies: Due in one year or less $ 25 — — 25 Debt issued by government sponsored enterprises: Due after one year through five years 310,172 287 (2,672 ) 307,787 Due after five years through ten years 25,746 — (28 ) 25,718 Equity securities 2,591 682 (116 ) 3,157 Municipal securities: Due in one year or less 810 15 — 825 Due after one year through five years 7,878 132 — 8,010 Due after five years through ten years 6,965 115 — 7,080 Due after ten years 51,839 2,391 — 54,230 Corporate debt issues: Due after ten years 18,267 2,579 (419 ) 20,427 Residential mortgage-backed securities: Fixed rate pass-through 72,852 3,149 (124 ) 75,877 Variable rate pass-through 66,140 3,466 (8 ) 69,598 Fixed rate non-agency CMOs 3,162 246 — 3,408 Fixed rate agency CMOs 226,413 685 (5,331 ) 221,767 Variable rate agency CMOs 113,842 657 (37 ) 114,462 Total residential mortgage-backed securities 482,409 8,203 (5,500 ) 485,112 Total marketable securities available-for-sale $ 906,702 14,404 (8,735 ) 912,371
Schedule of the portfolio of investment securities held-to-maturity	Marketable securities held to maturity at December 31, 2014 are as follows: Amortized cost Gross unrealized holding gains Gross unrealized holding losses Fair value Municipal securities: Due after five years through ten years $ 10,207 141 — 10,348 Due after ten years 56,545 1,314 — 57,859 Residential mortgage-backed securities: Fixed rate pass-through 8,236 477 — 8,713 Variable rate pass-through 4,273 122 — 4,395 Fixed rate agency CMOs 23,382 531 — 23,913 Variable rate agency CMOs 1,052 12 — 1,064 Total residential mortgage-backed securities 36,943 1,142 — 38,085 Total marketable securities held-to-maturity $ 103,695 2,597 — 106,292 Marketable securities held to maturity at December 31, 2015 are as follows: Amortized cost Gross unrealized holding gains Gross unrealized holding losses Fair value Municipal securities: Due after five years through ten years $ 274 1 — 275 Due after ten years 6,336 239 — 6,575 Residential mortgage-backed securities: Fixed rate pass-through 6,458 351 — 6,809 Variable rate pass-through 3,618 41 — 3,659 Fixed rate agency CMOs 14,033 219 — 14,252 Variable rate agency CMOs 970 12 — 982 Total residential mortgage-backed securities 25,079 623 — 25,702 Total marketable securities held-to-maturity $ 31,689 863 — 32,552
Information regarding the issuers and the carrying values of the entity's mortgage-backed securities	The following table presents information regarding the issuers and the carrying values of our mortgage-backed securities at December 31, 2015 and 2014 : December 31, 2015 2014 Residential mortgage backed securities: FNMA $ 234,204 230,051 GNMA 48,283 54,422 FHLMC 209,788 223,479 SBA 8,166 10,052 Other (including non-agency) 3,355 4,051 Total residential mortgage-backed securities $ 503,796 522,055
Schedule of the fair value and gross unrealized losses on investment securities, aggregated by investment category and length of time individual securities have been in a continuous unrealized loss position	The following table shows the fair value and gross unrealized losses on investment securities, aggregated by investment category and length of time that the individual securities have been in a continuous unrealized loss position at December 31, 2015 : Less than 12 months 12 months or more Total Unrealized Unrealized Unrealized Fair value loss Fair value loss Fair value loss U.S. government and agencies $ 143,751 (723 ) 92,961 (786 ) 236,712 (1,509 ) Corporate debt issues — — 2,021 (405 ) 2,021 (405 ) Equity securities 544 (6 ) — — 544 (6 ) Municipal securities 7,505 (4 ) — 7,505 (4 ) Residential mortgage-backed securities - agency 122,109 (598 ) 149,889 (3,762 ) 271,998 (4,360 ) Total temporarily impaired securities $ 273,909 (1,331 ) 244,871 (4,953 ) 518,780 (6,284 ) The following table shows the fair value and gross unrealized losses on investment securities, aggregated by investment category and length of time that the individual securities have been in a continuous unrealized loss position at December 31, 2014 : Less than 12 months 12 months or more Total Unrealized Unrealized Unrealized Fair value loss Fair value loss Fair value loss U.S. government and agencies $ 28,878 (67 ) 244,828 (2,633 ) 273,706 (2,700 ) Corporate debt issues — — 2,003 (419 ) 2,003 (419 ) Equity securities 506 (116 ) — — 506 (116 ) Residential mortgage-backed securities - agency 20,832 (79 ) 195,505 (5,421 ) 216,337 (5,500 ) Total temporarily impaired securities $ 50,216 (262 ) 442,336 (8,473 ) 492,552 (8,735 )
Schedule of categories of investment securities on which other-than-temporary impairment charges have been recorded in earnings	The following table sets forth the categories of investment securities as of December 31, 2015 on which other-than-temporary impairment charges have been recorded in earnings: Total Accumulated Category Amortized cost Fair value Unrealized gain impairment charges Freddie Mac preferred shares $ 1 10 9 (119 ) Trust preferred investments 11,137 13,437 2,300 (7,942 ) Non-agency CMOs 2,258 2,484 226 (494 ) Total $ 13,396 15,931 2,535 (8,555 )
Schedule of the cumulative roll forward of credit related impairment losses recognized in earnings for debt securities held and not intended to be sold	The table below shows a cumulative roll forward of credit related impairment losses recognized in earnings for debt securities held and not intended to be sold: December 31, 2015 2014 Beginning balance as of January 1, (1) $ 8,894 10,342 Credit losses on debt securities for which other-than-temporary impairment was not previously recognized — — Reduction for losses realized during the year (98 ) (1,448 ) Reduction for securities called realized during the year (360 ) — Additional credit losses on debt securities for which other-than-temporary impairment was previously recognized — — Ending balance as of December 31, $ 8,436 8,894 (1) The beginning balance represents credit losses included in other-than-temporary impairment charges recognized on debt securities in prior periods.

Loans Receivable and Allowanc39

Loans Receivable and Allowance for Loan Losses (Tables)	12 Months Ended
	Dec. 31, 2015
Receivables [Abstract]
Summary of loans receivable	Loans receivable at December 31, 2015 and 2014 are summarized in the table below: December 31, 2015 December 31, Originated Acquired Total 2014 Personal Banking: Residential mortgage loans $ 2,695,561 45,716 2,741,277 2,526,240 Home equity loans 1,055,907 131,199 1,187,106 1,066,131 Other consumer loans 307,961 202,656 510,617 242,744 Total Personal Banking 4,059,429 379,571 4,439,000 3,835,115 Business Banking: Commercial real estate loans 2,094,710 429,564 2,524,274 1,874,944 Commercial loans 372,540 65,175 437,715 419,525 Total Business Banking 2,467,250 494,739 2,961,989 2,294,469 Total loans receivable, gross 6,526,679 874,310 7,400,989 6,129,584 Deferred loan costs 14,806 5,259 20,065 6,095 Allowance for loan losses (60,970 ) (1,702 ) (62,672 ) (67,518 ) Undisbursed loan proceeds: Residential mortgage loans (10,778 ) — (10,778 ) (10,879 ) Commercial real estate loans (159,553 ) (13,287 ) (172,840 ) (73,760 ) Commercial loans (11,132 ) (4,183 ) (15,315 ) (61,149 ) Total loans receivable, net $ 6,299,052 860,397 7,159,449 5,922,373
Schedule of information related to the outstanding principal balance and related carrying value of acquired loans	The following table provides information related to the outstanding principal balance and related carrying value of acquired loans for the dates indicated: December 31, 2015 Acquired loans evaluated individually for future credit losses: Outstanding principal balance $ 21,069 Carrying value 16,867 Acquired loans evaluated collectively for future credit losses: Outstanding principal balance 848,194 Carrying value 839,973 Total acquired loans: Outstanding principal balance 869,263 Carrying value 856,840
Schedule of the changes in the accretable discount	The following table provides information related to the changes in the accretable discount, which includes income recognized from contractual cash flows for the dates indicated: Total Balance at December 31, 2014 $ — LNB Bancorp, Inc. acquisition 1,672 Accretion (377 ) Net reclassification from nonaccretable yield 724 Balance at December 31, 2015 $ 2,019
Schedule of the changes in the allowance for losses on loans receivable	The following table provides information related to changes in the allowance for losses on loans receivable for the year ended December 31, 2013 : Balance Provision Charge-offs Recoveries Balance Personal Banking: Residential mortgage loans $ 7,875 1,954 (2,501 ) 420 8,002 Home equity loans 7,245 932 (2,239 ) 258 8,294 Other consumer loans 5,487 5,304 (6,055 ) 1,082 5,156 Total Personal Banking 20,607 8,190 (10,795 ) 1,760 21,452 Business Banking: Commercial real estate loans 35,199 8,347 (10,042 ) 2,305 34,589 Commercial loans 10,880 1,346 (5,007 ) 1,389 13,152 Total Business Banking 46,079 9,693 (15,049 ) 3,694 47,741 Unallocated 4,662 636 — — 4,026 Total $ 71,348 18,519 (25,844 ) 5,454 73,219 The following table provides information related to changes in the allowance for losses on loans receivable for the year ended December 31, 2015 : Balance Provision Charge-offs Recoveries Balance Originated loans: Personal Banking: Residential mortgage loans $ 4,692 (96 ) (1,057 ) 264 5,581 Home equity loans 3,941 693 (1,716 ) 414 4,550 Other consumer loans 7,488 7,985 (8,073 ) 1,458 6,118 Total Personal Banking 16,121 8,582 (10,846 ) 2,136 16,249 Business Banking: Commercial real estate loans 32,348 540 (5,741 ) 4,160 33,389 Commercial loans 12,501 2,768 (7,814 ) 4,032 13,515 Total Business Banking 44,849 3,308 (13,555 ) 8,192 46,904 Unallocated (1) — (4,365 ) — — 4,365 Total originated loans 60,970 7,525 (24,401 ) 10,328 67,518 Acquired loans: Personal Banking: Residential mortgage loans 18 47 (69 ) 40 — Home equity loans 101 247 (708 ) 562 — Other consumer loans 110 188 (201 ) 123 — Total Personal Banking 229 482 (978 ) 725 — Business Banking: Commercial real estate loans 1,439 1,545 (585 ) 479 — Commercial loans 34 160 (369 ) 243 — Total Business Banking 1,473 1,705 (954 ) 722 — Total acquired loans 1,702 2,187 (1,932 ) 1,447 — Total $ 62,672 9,712 (26,333 ) 11,775 67,518 The following table provides information related to changes in the allowance for losses on loans receivable for the year ended December 31, 2014: Balance Provision Charge-offs Recoveries Balance Personal Banking: Residential mortgage loans $ 5,581 (556 ) (2,181 ) 443 7,875 Home equity loans 4,550 (1,106 ) (1,783 ) 194 7,245 Other consumer loans 6,118 5,864 (6,423 ) 1,190 5,487 Total Personal Banking 16,249 4,202 (10,387 ) 1,827 20,607 Business Banking: Commercial real estate loans 33,389 4,417 (8,422 ) 2,195 35,199 Commercial loans 13,515 11,992 (11,936 ) 2,579 10,880 Total Business Banking 46,904 16,409 (20,358 ) 4,774 46,079 Unallocated 4,365 (297 ) — — 4,662 Total $ 67,518 20,314 (30,745 ) 6,601 71,348
Schedule of loan portfolio by portfolio segment and by class of financing receivable	The following table provides information related to the loan portfolio by portfolio segment and by class of financing receivable as of December 31, 2015 : Recorded investment in loans receivable Allowance for loan losses Recorded investment in loans on nonaccrual (1) Recorded investment in loans 90 days or more past maturity and still accruing TDRs (1) Allowance for TDRs Additional commitments to customers with loans classified as TDRs Personal Banking: Residential mortgage loans $ 2,740,892 4,710 19,772 4 6,360 1,189 — Home equity loans 1,187,106 4,042 7,522 — 2,298 605 — Other consumer loans 520,289 7,598 3,452 976 — — — Total Personal Banking 4,448,287 16,350 30,746 980 8,658 1,794 — Business Banking: Commercial real estate loans 2,351,434 33,787 33,421 206 31,970 2,257 241 Commercial loans 422,400 12,535 7,495 148 10,487 631 79 Total Business Banking 2,773,834 46,322 40,916 354 42,457 2,888 320 Total $ 7,222,121 62,672 71,662 1,334 51,115 4,682 320 (1) Includes $21.1 million of nonaccrual TDRs. The following table provides information related to the loan portfolio by portfolio segment and by class of financing receivable as of December 31, 2014 : Recorded investment in loans receivable Allowance for loan losses Recorded investment in loans on nonaccrual (1) Recorded TDRs (1) Allowance for TDRs Additional commitments to customers with loans classified as TDRs Personal Banking: Residential mortgage loans $ 2,521,456 5,581 21,194 8 6,574 1,133 — Home equity loans 1,066,131 4,550 9,569 — 2,412 229 — Other consumer loans 242,744 6,118 2,820 206 — — — Total Personal Banking 3,830,331 16,249 33,583 214 8,986 1,362 — Business Banking: Commercial real estate loans 1,801,184 33,389 38,647 — 41,917 4,938 449 Commercial loans 358,376 13,515 7,578 21 10,885 1,095 814 Total Business Banking 2,159,560 46,904 46,225 21 52,802 6,033 1,263 Total $ 5,989,891 63,153 79,808 235 61,788 7,395 1,263 (1) Includes $24.5 million of nonaccrual TDRs.
Schedule of the composition of impaired loans by portfolio segment and by class of financing receivable	The following table provides information related to purchased credit impaired loans by portfolio segment and by class of financing receivable at and for the year ended December 31, 2015: Carrying value Outstanding principal balance Related impairment reserve Average recorded investment in impaired loans Interest income/ accretion recognized Personal Banking: Residental mortgage loans $ 1,981 2,910 14 2,083 41 Home equity loans 2,084 3,455 6 2,222 51 Other consumer loans 267 492 2 305 18 Total Personal Banking 4,332 6,857 22 4,610 110 Business Banking: Commercial real estate loans 12,288 13,946 353 12,867 249 Commercial loans 247 266 — 335 18 Total Business Banking 12,535 14,212 353 13,202 267 Total $ 16,867 21,069 375 17,812 377 The following table provides information related to the composition of impaired loans by portfolio segment and by class of financing receivable at and for the year ended December 31, 2015 : Nonaccrual loans 90 or more days delinquent Nonaccrual loans less than 90 days delinquent Loans less than 90 days delinquent reviewed for impairment TDRs less than 90 days delinquent not included elsewhere Total impaired loans Average recorded investment in impaired loans Interest income recognized on impaired loans Personal Banking: Residential mortgage loans $ 15,810 3,962 — 5,086 24,858 24,554 944 Home equity loans 5,650 1,872 — 1,847 9,369 9,644 497 Other consumer loans 2,900 552 — — 3,452 2,977 101 Total Personal Banking 24,360 6,386 — 6,933 37,679 37,175 1,542 Business Banking: Commercial real estate loans 16,449 16,972 16,121 16,467 66,009 77,166 3,226 Commercial loans 2,459 5,036 2,014 4,654 14,163 16,187 694 Total Business Banking 18,908 22,008 18,135 21,121 80,172 93,353 3,920 Total $ 43,268 28,394 18,135 28,054 117,851 130,528 5,462 The following table provides information related to the composition of impaired loans by portfolio segment and by class of financing receivable at and for the year ended December 31, 2014 : Nonaccrual loans 90 or more days delinquent Nonaccrual loans less than 90 days delinquent Loans less than 90 days delinquent reviewed for impairment TDRs less than 90 days delinquent not included elsewhere Total impaired loans Average recorded investment in impaired loans Interest income recognized on impaired loans Personal Banking: Residential mortgage loans $ 17,696 3,498 — 5,845 27,039 28,227 817 Home equity loans 6,606 2,963 — 1,706 11,275 11,753 485 Other consumer loans 2,450 370 — — 2,820 2,383 66 Total Personal Banking 26,752 6,831 — 7,551 41,134 42,363 1,368 Business Banking: Commercial real estate loans 11,099 27,548 26,400 12,128 74,337 90,187 3,589 Commercial loans 3,475 4,103 5,266 6,026 21,708 27,088 914 Total Business Banking 14,574 31,651 31,666 18,154 96,045 117,275 4,503 Total $ 41,326 38,482 31,666 25,705 137,179 159,638 5,871 The following table provides information related to the composition of impaired loans by portfolio segment and by class of financing receivable at and for the year ended December 31, 2013 : Nonaccrual loans 90 or more days delinquent Nonaccrual loans less than 90 days delinquent Loans less than 90 days delinquent reviewed for impairment TDRs less than 90 days delinquent not included elsewhere Total impaired loans Average recorded investment in impaired loans Interest income recognized on impaired loans Personal Banking: Residential mortgage loans $ 24,625 2,652 — 3,372 30,649 29,994 723 Home equity loans 8,344 1,519 — 1,810 11,673 10,828 383 Other consumer loans 2,057 200 — — 2,257 1,976 44 Total Personal Banking 35,026 4,371 — 5,182 44,579 42,798 1,150 Business Banking: Commercial real estate loans 18,433 23,370 39,199 13,060 94,062 90,912 3,678 Commercial loans 4,298 21,723 5,219 3,963 35,203 41,303 1,127 Total Business Banking 22,731 45,093 44,418 17,023 129,265 132,215 4,805 Total $ 57,757 49,464 44,418 22,205 173,844 175,013 5,955
Schedule of the evaluation of impaired loans by portfolio segment and by class of financing receivable	The following table provides information related to the evaluation of impaired loans by portfolio segment and by class of financing receivable as of and for the year ended December 31, 2015 : Loans collectively evaluated for impairment Loans individually evaluated for impairment Loans individually evaluated for impairment for which there is a related impairment reserve Related impairment reserve Loans individually evaluated for impairment for which there is no related reserve Personal Banking: Residential mortgage loans $ 2,733,741 7,151 7,151 1,189 — Home equity loans 1,184,808 2,298 2,298 605 — Other consumer loans 520,159 130 130 50 — Total Personal Banking 4,438,708 9,579 9,579 1,844 — Business Banking: Commercial real estate loans 2,297,599 53,835 35,937 2,675 17,898 Commercial loans 411,342 11,058 7,673 489 3,385 Total Business Banking 2,708,941 64,893 43,610 3,164 21,283 Total $ 7,147,649 74,472 53,189 5,008 21,283 The following table provides information related to the evaluation of impaired loans by portfolio segment and by class of financing receivable as of and for the year ended December 31, 2014 : Loans collectively evaluated for impairment Loans individually evaluated for impairment Loans individually evaluated for impairment for which there is a related impairment reserve Related impairment reserve Loans individually evaluated for impairment for which there is no related reserve Personal Banking: Residential mortgage loans $ 2,514,060 7,396 7,396 1,116 — Home equity loans 1,063,741 2,390 2,390 246 — Other consumer loans 242,678 66 66 1 — Total Personal Banking 3,820,479 9,852 9,852 1,363 — Business Banking: Commercial real estate loans 1,734,864 66,320 42,869 6,189 23,451 Commercial loans 343,416 14,960 10,938 1,378 4,022 Total Business Banking 2,078,280 81,280 53,807 7,567 27,473 Total $ 5,898,759 91,132 63,659 8,930 27,473
Schedule of roll forward of troubled debt restructurings	The following table provides a roll forward of troubled debt restructurings for the periods indicated: For the years ended December 31, 2015 2014 Number of contracts Amount Number of contracts Amount Beginning TDR balance: 248 $ 61,788 262 $ 79,166 New TDRs 26 8,537 46 9,460 Re-modified TDRs 3 6,386 11 3,672 Net paydowns (13,270 ) (15,825 ) Charge-offs: Residential mortgage loans — — — — Home equity loans 4 (159 ) 1 (130 ) Commercial real estate loans 4 (179 ) 10 (898 ) Commercial loans 2 (387 ) 10 (8,305 ) Paid-off loans: Residential mortgage loans 2 (109 ) — — Home equity loans 5 (194 ) 5 (103 ) Commercial real estate loans 15 (9,208 ) 10 (1,471 ) Commercial loans 14 (1,728 ) 24 (3,778 ) Transferred to real estate owned Commercial real estate loans 1 (362 ) — — Ending TDR balance: 227 $ 51,115 248 $ 61,788 Accruing TDRs $ 29,997 $ 37,329 Non-accrual TDRs 21,118 24,459
Schedule of troubled debt restructurings (including re-modified TDRs) by portfolio segment and by class of financing receivable	The following table provides information related to troubled debt restructurings (including re-modified TDRs) by portfolio segment and by class of financing receivable during the year ended December 31, 2015 : Number of contracts Recorded investment at the time of modification Current recorded investment Current allowance Troubled debt restructurings: Personal Banking: Residential mortgage loans 6 $ 364 357 21 Home equity loans 3 101 97 21 Other consumer loans — — — — Total Personal Banking 9 465 454 42 Business Banking: Commercial real estate loans 11 12,258 12,243 1,047 Commercial loans 9 2,200 2,184 156 Total Business Banking 20 14,458 14,427 1,203 Total 29 $ 14,923 14,881 1,245 At December 31, 2015, no TDRs that were modified in the previous twelve months had subsequently defaulted. The following table provides information related to troubled debt restructurings (including re-modified TDRs) by portfolio segment and by class of financing receivable during the year ended December 31, 2014 : Number of contracts Recorded investment at the time of modification Current recorded investment Current allowance Troubled debt restructurings: Personal Banking: Residential mortgage loans 17 $ 2,802 2,690 210 Home equity loans 6 570 507 1 Other consumer loans — — — — Total Personal Banking 23 3,372 3,197 211 Business Banking: Commercial real estate loans 11 2,010 1,793 202 Commercial loans 23 7,750 6,818 1,491 Total Business Banking 34 9,760 8,611 1,693 Total 57 $ 13,132 11,808 1,904 Number of contracts Recorded investment at the time of modification Current recorded investment Current allowance Troubled debt restructurings modified within the previous twelve months that have subsequently defaulted: Personal Banking: Residential mortgage loans 1 $ 78 77 — Home equity loans 1 360 331 1 Other consumer loans — — — — Total Personal Banking 2 438 408 1 Business Banking: Commercial real estate loans 1 12 5 1 Commercial loans 1 50 64 6 Total Business Banking 2 62 69 7 Total 4 $ 500 477 8 The following table provides information related to troubled debt restructurings (including re-modified TDRs) by portfolio segment and by class of financing receivable during the year ended December 31, 2013 : Number of contracts Recorded investment at the time of modification Current recorded investment Current allowance Troubled debt restructurings: Personal Banking: Residential mortgage loans 4 $ 374 319 50 Home equity loans 12 656 692 118 Other consumer loans — — — — Total Personal Banking 16 1,030 1,011 168 Business Banking: Commercial real estate loans 58 16,760 11,196 781 Commercial loans 47 13,321 12,754 162 Total Business Banking 105 30,081 23,950 943 Total 121 $ 31,111 24,961 1,111 Number of contracts Recorded investment at the time of modification Current recorded investment Current allowance Troubled debt restructurings modified within the previous twelve months that have subsequently defaulted: Personal Banking: Residential mortgage loans 1 $ 70 70 — Home equity loans — — — — Other consumer loans — — — — Total Personal Banking 1 70 70 — Business Banking: Commercial real estate loans 4 798 752 33 Commercial loans 1 23 8 1 Total Business Banking 5 821 760 34 Total 6 $ 891 830 34
Schedule of troubled debt restructurings (including re-modified TDRs) by type of modification by portfolio segment and by class of financing receivable	The following table provides information for troubled debt restructurings (including re-modified TDRs) by type of modification, by portfolio segment and class of financing receivable during the year ended December 31, 2015 : Number of Type of modification contracts Rate Payment Maturity date Other Total Personal Banking: Residential mortgage loans 6 $ 71 — 110 176 357 Home equity loans 3 96 — 1 — 97 Other consumer loans — — — — — — Total Personal Banking 9 167 — 111 176 454 Business Banking: Commercial real estate loans 11 174 — 11,961 108 12,243 Commercial loans 9 — — 1,264 920 2,184 Total Business Banking 20 174 — 13,225 1,028 14,427 Total 29 $ 341 — 13,336 1,204 14,881 The following table provides information for troubled debt restructurings (including re-modified TDRs) by type of modification, by portfolio segment and class of financing receivable during the year ended December 31, 2014 : Number of Type of modification contracts Rate Payment Maturity date Other Total Personal Banking: Residential mortgage loans 17 $ — 108 2,582 — 2,690 Home equity loans 6 — 138 369 — 507 Other consumer loans — — — — — — Total Personal Banking 23 — 246 2,951 — 3,197 Business Banking: Commercial real estate loans 11 — — 1,312 481 1,793 Commercial loans 23 498 1,638 4,093 589 6,818 Total Business Banking 34 498 1,638 5,405 1,070 8,611 Total 57 $ 498 1,884 8,356 1,070 11,808
Schedule of re-modified troubled debt restructurings by portfolio segment and by class of financing receivable	The following table provides information related to re-modified troubled debt restructurings by portfolio segment and by class of financing receivable for the year ended December 31, 2015 : Number of re- modified Type of re-modification TDRs Rate Payment Maturity date Other Total Personal Banking: Residential mortgage loans 1 $ — — — 45 45 Home equity loans 1 83 — — — 83 Other consumer loans — — — — — — Total Personal Banking 2 83 — — 45 128 Business Banking: Commercial real estate loans 1 — — 6,256 — 6,256 Commercial loans — — — — — — Total Business Banking 1 — — 6,256 — 6,256 Total 3 $ 83 — 6,256 45 6,384 The following table provides information related to re-modified troubled debt restructurings by portfolio segment and by class of financing receivable for the year ended December 31, 2014 : Number of re- modified Type of re-modification TDRs Rate Payment Maturity date Other Total Personal Banking: Residential mortgage loans 1 $ — — 76 — 76 Home equity loans — — — — — — Other consumer loans — — — — — — Total Personal Banking 1 — — 76 — 76 Business Banking: Commercial real estate loans 5 — — 119 115 234 Commercial loans 5 — — 3,230 55 3,285 Total Business Banking 10 — — 3,349 170 3,519 Total 11 $ — — 3,425 170 3,595
Schedule of loan delinquencies	The following table provides information related to loan delinquencies as of December 31, 2015 : 30-59 days delinquent 60-89 days delinquent 90 days or greater delinquent Total delinquency Current Total loans 90 days or greater delinquent and accruing (1) Originated loans Personal Banking: Residential mortgage loans $ 25,503 7,541 15,564 48,608 2,646,568 2,695,176 — Home equity loans 4,870 1,836 5,251 11,957 1,043,950 1,055,907 — Other consumer loans 6,092 2,340 2,857 11,289 301,085 312,374 — Total Personal Banking 36,465 11,717 23,672 71,854 3,991,603 4,063,457 — Business Banking: Commercial real estate loans 22,212 6,875 14,942 44,029 1,891,128 1,935,157 — Commercial loans 1,703 598 2,449 4,750 356,658 361,408 — Total Business Banking 23,915 7,473 17,391 48,779 2,247,786 2,296,565 — Total originated loans 60,380 19,190 41,063 120,633 6,239,389 6,360,022 — Acquired loans Personal Banking: Residential mortgage loans 440 249 786 1,475 44,241 45,716 540 Home equity loans 936 642 861 2,439 128,760 131,199 462 Other consumer loans 1,009 181 69 1,259 206,656 207,915 26 Total Personal Banking 2,385 1,072 1,716 5,173 379,657 384,830 1,028 Business Banking: Commercial real estate loans 2,665 1,353 4,089 8,107 408,170 416,277 2,582 Commercial loans 1,165 — 150 1,315 59,677 60,992 140 Total Business Banking 3,830 1,353 4,239 9,422 467,847 477,269 2,722 Total acquired loans 6,215 2,425 5,955 14,595 847,504 862,099 3,750 Total loans $ 66,595 21,615 47,018 135,228 7,086,893 7,222,121 3,750 (1) Represents acquired loans that were originally recorded at fair value upon acquisition. These loans are considered to be accruing because we can reasonably estimate future cash flows on and expect to fully collect the carrying value of these loans. Therefore, we are accreting the difference between the carrying value and their expected cash flows into interest income. The following table provides information related to loan delinquencies as of December 31, 2014 : 30-59 days delinquent 60-89 days delinquent 90 days or greater delinquent Total delinquency Current Total loans Personal Banking: Residential mortgage loans $ 27,443 6,970 17,696 52,109 2,469,347 2,521,456 Home equity loans 5,752 1,672 6,606 14,030 1,052,101 1,066,131 Other consumer loans 5,572 2,435 2,450 10,457 232,287 242,744 Total Personal Banking 38,767 11,077 26,752 76,596 3,753,735 3,830,331 Business Banking: Commercial real estate loans 4,956 2,038 11,099 18,093 1,783,091 1,801,184 Commercial loans 2,262 209 3,475 5,946 352,430 358,376 Total Business Banking 7,218 2,247 14,574 24,039 2,135,521 2,159,560 Total loans $ 45,985 13,324 41,326 100,635 5,889,256 5,989,891
Schedule of credit quality indicators	The following table sets forth information about credit quality indicators as of December 31, 2015 : Pass Special mention Substandard Doubtful Loss Total Originated loans Personal Banking: Residential mortgage loans $ 2,680,562 — 13,274 — 1,340 2,695,176 Home equity loans 1,048,397 — 7,510 — — 1,055,907 Other consumer loans 309,900 — 2,474 — — 312,374 Total Personal Banking 4,038,859 — 23,258 — 1,340 4,063,457 Business Banking: Commercial real estate loans 1,778,140 46,518 110,384 115 — 1,935,157 Commercial loans 299,455 23,023 37,820 1,110 — 361,408 Total Business Banking 2,077,595 69,541 148,204 1,225 — 2,296,565 Total originated loans 6,116,454 69,541 171,462 1,225 1,340 6,360,022 Acquired loans Personal Banking: Residential mortgage loans 44,930 — 786 — — 45,716 Home equity loans 130,338 — 861 — — 131,199 Other consumer loans 207,846 — 69 — — 207,915 Total Personal Banking 383,114 — 1,716 — — 384,830 Business Banking: Commercial real estate loans 392,811 6,872 16,594 — — 416,277 Commercial loans 59,948 707 337 — — 60,992 Total Business Banking 452,759 7,579 16,931 — — 477,269 Total acquired loans 835,873 7,579 18,647 — — 862,099 Total loans $ 6,952,327 77,120 190,109 1,225 1,340 7,222,121 The following table sets forth information about credit quality indicators as of December 31, 2014 : Pass Special mention Substandard Doubtful Loss Total Personal Banking: Residential mortgage loans $ 2,507,269 — 12,763 — 1,424 2,521,456 Home equity loans 1,059,525 — 6,606 — — 1,066,131 Other consumer loans 240,947 — 1,797 — — 242,744 Total Personal Banking 3,807,741 — 21,166 — 1,424 3,830,331 Business Banking: Commercial real estate loans 1,618,269 36,908 145,502 505 — 1,801,184 Commercial loans 286,234 23,690 46,280 2,172 — 358,376 Total Business Banking 1,904,503 60,598 191,782 2,677 — 2,159,560 Total loans $ 5,712,244 60,598 212,948 2,677 1,424 5,989,891
Schedule of financial instruments with off-balance-sheet risk	Financial instruments with off-balance-sheet risk as of December 31, 2015 and 2014 are presented in the following table: December 31, 2015 2014 Loan commitments $ 186,731 186,637 Undisbursed lines of credit 562,284 428,649 Standby letters of credit 32,719 23,564 Total $ 781,734 638,850

Accrued Interest Receivable (Ta

Accrued Interest Receivable (Tables)	12 Months Ended
	Dec. 31, 2015
Accrued Interest Receivable
Schedule of accrued interest receivable	Accrued interest receivable as of December 31, 2015 and 2014 is presented in the following table: December 31, 2015 2014 Investment securities $ 1,852 2,229 Mortgage-backed securities 960 875 Loans receivable 18,260 15,519 $ 21,072 18,623

Premises and Equipment (Tables)

Premises and Equipment (Tables)	12 Months Ended
	Dec. 31, 2015
Property, Plant and Equipment [Abstract]
Schedule of premises and equipment	Premises and equipment at December 31, 2015 and 2014 are summarized by major classification in the following table: December 31, 2015 2014 Land and land improvements $ 23,257 20,084 Office buildings and improvements 153,003 150,745 Furniture, fixtures and equipment 115,576 116,975 Leasehold improvements 19,239 12,312 Total, at cost 311,075 300,116 Less accumulated depreciation and amortization (156,724 ) (156,207 ) Premises and equipment, net $ 154,351 143,909
Schedule of minimum annual rentals	Minimum annual rentals by fiscal year are summarized in the following table: 2016 $ 4,553 2017 3,493 2018 2,572 2019 1,620 2020 1,329 Thereafter 3,388 Total $ 16,955

Goodwill and Other Intangible42

Goodwill and Other Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of intangible assets subject to amortization	The following table provides information for intangible assets subject to amortization for the years ended December 31, 2015 and 2014 : December 31, 2015 2014 Amortizable intangible assets: Core deposit intangibles — gross $ 30,578 30,578 Acquisitions 7,375 — Less: accumulated amortization (31,192 ) (30,578 ) Core deposit intangibles — net $ 6,761 — Customer and Contract intangible assets — gross 8,234 6,197 Acquisitions 262 2,037 Less: accumulated amortization (6,275 ) (5,201 ) Customer and Contract intangible assets — net $ 2,221 3,033
Schedule of the actual aggregate amortization expense as well as estimated aggregate amortization expense, based upon current levels of intangible assets	The following information shows the actual aggregate amortization expense for the years ended December 31, 2015 , 2014 and 2013 as well as the estimated aggregate amortization expense, based upon current levels of intangible assets, for each of the five succeeding fiscal years: For the year ended December 31, 2013 $ 1,210 For the year ended December 31, 2014 1,323 For the year ended December 31, 2015 1,688 For the year ending December 31, 2016 2,591 For the year ending December 31, 2017 2,090 For the year ending December 31, 2018 1,658 For the year ending December 31, 2019 1,226 For the year ending December 31, 2020 794
Schedule of the changes in carrying amount of goodwill	The following table provides information for the changes in the carrying amount of goodwill: Community Banks Consumer Finance Total Balance at December 31, 2013 $ 173,031 1,613 174,644 Goodwill acquired 679 — 679 Balance at December 31, 2014 173,710 1,613 175,323 Goodwill acquired 86,413 — 86,413 Balance at December 31, 2015 $ 260,123 1,613 261,736

Deposits (Tables)

Deposits (Tables)	12 Months Ended
	Dec. 31, 2015
Deposits [Abstract]
Schedule of deposit balances	Deposit balances at December 31, 2015 and 2014 are shown in the table below: December 31, 2015 2014 Savings deposits $ 1,386,017 1,209,287 Interest-bearing demand deposits 1,080,086 874,623 Noninterest-bearing demand deposits 1,177,256 891,248 Money market demand accounts 1,274,504 1,179,070 Time deposits 1,694,718 1,478,314 Total deposits $ 6,612,581 5,632,542
Summarizes the contractual maturity of the certificate accounts	The following table summarizes the contractual maturity of time deposits at December 31, 2015 and 2014 : December 31, 2015 2014 Due within 12 months $ 929,351 647,699 Due between 12 and 24 months 448,497 392,484 Due between 24 and 36 months 205,635 319,995 Due between 36 and 48 months 21,414 92,527 Due between 48 and 60 months 78,796 15,307 After 60 months 11,025 10,302 Total time deposits $ 1,694,718 1,478,314
Summarizes the interest expense incurred on the deposits	The following table summarizes the interest expense incurred on the respective deposits for the years ended December 31, 2015 , 2014 and 2013 : Years ended December 31, 2015 2014 2013 Savings deposits $ 3,387 3,286 3,595 Interest-bearing demand deposits 568 587 576 Money market demand accounts 3,222 3,174 3,042 Time deposits 16,878 18,275 22,066 Total interest expense $ 24,055 25,322 29,279

Borrowed Funds (Tables)

Borrowed Funds (Tables)	12 Months Ended
	Dec. 31, 2015
Debt Disclosure [Abstract]
Schedule of borrowed funds	Borrowed funds at December 31, 2015 and 2014 are presented in the following table: December 31, 2015 2014 Amount Average rate Amount Average rate Term notes payable to the FHLB of Pittsburgh: Due within one year $ 145,343 3.24 % 110,000 2.53 % Due between one and two years 125,000 3.68 % 145,395 3.24 % Due between two and three years 140,000 3.73 % 125,000 3.68 % Due between three and four years 125,000 4.32 % 125,000 4.03 % Due between four and five years 95,000 3.65 % 125,000 4.32 % Due between five and ten years 120,000 3.68 % 95,000 3.75 % 750,343 725,395 Revolving line of credit, FHLB of Pittsburgh 106,000 0.43 % — — Collateralized borrowings, due within one year 118,664 0.22 % 162,714 0.27 % Total borrowed funds $ 975,007 888,109

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Schedule of allocation of income tax	Total income tax was allocated for the years ended December 31, 2015 , 2014 and 2013 as follows: Years ended December 31, 2015 2014 2013 Income before income taxes $ 27,960 21,795 26,199 Shareholders’ equity for unrealized (loss)/ gain on securities available-for-sale (85 ) 4,286 (12,177 ) Shareholders’ equity for tax benefit for excess of fair value above cost of stock benefit plans (332 ) (945 ) (635 ) Shareholders’ equity for pension adjustment (848 ) (12,985 ) 9,904 Shareholders’ equity for swap fair value adjustment 699 618 1,714 Unallocated income tax $ 27,394 12,769 25,005
Schedule of income tax expense (benefit) applicable to income before taxes	Income tax expense applicable to income before taxes consists of: Years ended December 31, 2015 2014 2013 Current $ 21,670 13,200 24,937 Deferred 6,290 8,595 1,262 Total income tax expense $ 27,960 21,795 26,199
Schedule of reconciliation of the expected federal statutory rate to the effective rate	A reconciliation of the expected federal statutory income tax rate to the effective rate, expressed as a percentage of pretax income for the years ended December 31, 2015 , 2014 and 2013 , is as follows: Years ended December 31, 2015 2014 2013 Expected tax rate 35.0 % 35.0 % 35.0 % Tax-exempt interest income (3.0 )% (4.1 )% (4.3 )% State income tax, net of federal benefit 2.9 % 1.7 % 2.1 % Bank-owned life insurance (1.7 )% (1.8 )% (1.9 )% Dividends on stock plans (0.8 )% (4.0 )% (1.1 )% Low income housing and historic tax credits (1.4 )% (0.9 )% (1.6 )% Non-deductible acquisition expense 0.5 % — % — % Other 0.1 % 0.1 % 0.1 % Effective tax rate 31.6 % 26.0 % 28.3 %
Tax effects of temporary differences that give rise to significant portions of the deferred tax assets and deferred tax liabilities	The tax effects of temporary differences that give rise to significant portions of the deferred tax assets and deferred tax liabilities at December 31, 2015 and 2014 are presented below: December 31, 2015 2014 Deferred tax assets: Deferred fee income $ 189 193 Deferred compensation expense 3,717 3,688 Bad debts 19,478 19,851 Accrued postretirement benefit cost 644 724 Stock benefit plans 1,626 1,523 Writedown of investment securities 2,994 3,155 Accrued expenses 228 105 Pension and postretirement benefits 16,035 15,187 Unrealized loss on the fair value of derivatives 1,496 2,195 Purchase accounting 2,236 — Other 325 361 Total deferred tax assets 48,968 46,982 Deferred tax liabilities: Pension expense 7,557 4,487 Marketable securities available for sale 2,122 2,207 Purchase accounting — 1,842 Intangible assets 23,003 20,324 Mortgage servicing rights 120 313 Fixed assets 8,731 8,038 Other 460 475 Total deferred tax liabilities 41,993 37,686 Net deferred tax asset $ 6,975 9,296

Earnings Per Share (Tables)

Earnings Per Share (Tables)	12 Months Ended
	Dec. 31, 2015
Earnings Per Share [Abstract]
Schedule of computation of basic and diluted earnings per share	The computation of basic and diluted earnings per share for the years ended December 31, 2015 , 2014 and 2013 follows: Years ended December 31, 2015 2014 2013 Net income available to common shareholders $ 60,540 61,962 66,559 Weighted average common shares outstanding 94,314,420 91,535,298 90,626,324 Dilutive potential shares due to effect of stock options 515,369 739,699 844,489 Total weighted average common shares and dilutive potential shares 94,829,789 92,274,997 91,470,813 Basic earnings per share (1) $ 0.64 0.68 0.73 Diluted earnings per share (1) $ 0.64 0.67 0.73 (1) Not in thousands.

Employee Benefit Plans (Tables)

Employee Benefit Plans (Tables)	12 Months Ended
	Dec. 31, 2015
Stock options
Employee benefit plans
Schedule of activity under option plans	The following table summarizes the activity in our option plans during the years ended December 31, 2015 , 2014 and 2013 (amounts in this table are not in thousands): Years ended December 31, 2015 2014 2013 Number Weighted average exercise price Number Weighted average exercise price Number Weighted average exercise price Balance at beginning of year 6,402,407 $ 11.65 6,816,294 $ 11.46 7,044,753 $ 11.21 Granted (1) 665,370 12.37 592,550 13.15 590,300 12.44 Exercised (2) (474,253 ) 10.27 (745,419 ) 10.86 (727,415 ) 10.13 Forfeited (3) (287,028 ) 12.26 (261,018 ) 11.71 (91,344 ) 11.82 Balance at end of year 6,306,496 $ 11.81 6,402,407 $ 11.65 6,816,294 $ 11.46 Exercisable at end of year 3,431,113 $ 11.42 3,333,942 $ 11.20 2,916,621 $ 10.97 (1) Weighted average fair value of options at grant date: $1.14 , $1.45 and $1.03 , respectively. (2) The total intrinsic value of options exercised was $1.2 million , $2.3 million and $2.7 million , respectively. (3) Includes 7,007 options that expired without being exercised for the year ended December 31, 2015.
Schedule of number of options outstanding, number of options exercisable, and weighted average remaining life of all option grants	The following table summarizes the number of options outstanding, number of options exercisable, and weighted average remaining life of all option grants as of December 31, 2015 : Exercise Exercise Exercise Exercise Exercise Exercise Exercise Options outstanding: Number of options 315,487 331,882 50,110 270,543 422,500 232,858 465,493 Weighted average remaining contract life (years) 3.25 3.00 0.25 2.25 4.25 1.25 6.50 Options exercisable: Number of options 267,521 331,882 50,110 270,543 314,379 232,858 202,129 Weighted average remaining term - vested (years) 3.25 3.00 0.25 2.25 4.25 1.25 6.50 Exercise Exercise Exercise Exercise Exercise Exercise Exercise Total Options outstanding: Number of options 481,795 21,500 2,050,609 628,734 506,235 4,500 524,250 6,306,496 Weighted average remaining contract life (years) 5.25 5.50 5.50 9.50 7.50 1.50 8.50 5.72 Options exercisable: Number of options 305,141 8,644 1,095,267 66,551 172,272 4,500 109,316 3,431,113 Weighted average remaining term - vested (years) 5.25 5.50 5.50 9.50 7.50 1.50 8.50 4.23
Pension Plans
Employee benefit plans
Schedule of other changes in the defined benefit pension plans' plan assets and benefit obligations recognized in other comprehensive income	The following table sets forth other changes in the defined benefit pension plans’ plan assets and benefit obligations recognized in other comprehensive income: Years ended December 31, 2015 2014 2013 Net loss/ (gain) $ (420 ) 30,779 (27,568 ) Prior service cost/ (credit) — — (14 ) Amortization of prior service cost 2,323 2,322 2,321 Total recognized in other comprehensive income $ 1,903 33,101 (25,261 ) Total recognized in net periodic pension cost and other comprehensive income/ (loss) $ 4,753 32,506 (22,702 )
Schedule of defined benefit pension plans' funded status	The following table sets forth information for the defined benefit pension plans’ funded status at December 31, 2015 and 2014 : December 31, 2015 2014 Change in benefit obligation: Benefit obligation at beginning of year $ 159,587 121,767 Service cost 5,721 4,138 Interest cost 6,125 5,827 Acquisition 5,662 — Actuarial (gain)/ loss (1) (9,357 ) 31,722 Benefits paid (5,605 ) (3,867 ) Benefit obligation at end of year $ 162,133 159,587 Change in plan assets: Fair value of plan assets at beginning of year 140,183 130,491 Actual return on plan assets (2,264 ) 9,181 Employer contributions 6,460 4,378 Acquisition 4,881 — Benefits paid (5,605 ) (3,867 ) Fair value of plan assets at end of period $ 143,655 140,183 Funded status at end of year $ (18,478 ) (19,404 ) (1) The change in actuarial (gain)/ loss is due to a decrease in the discount rate as well as updates to the RP-2014 with MMP-2007 adjustments Mortality Table.
Schedule of assumptions used to develop the net periodic pension cost	The following table sets forth the assumptions used to develop the net periodic pension cost: Years ended December 31, 2015 2014 2013 Discount rate 3.89 % 4.86 % 4.06 % Expected long-term rate of return on assets 7.50 % 7.50 % 7.50 % Rate of increase in compensation levels 3.00 % 3.00 % 3.00 %
Schedule of assumptions used to determine benefit obligations	The following table sets forth the assumptions used to determine benefit obligations at the end of each period: Years ended December 31, 2015 2014 2013 Discount rate 4.25 % 3.89 % 4.86 % Expected long-term rate of return on assets 7.00 % 7.50 % 7.50 % Rate of increase in compensation levels 3.00 % 3.00 % 3.00 %
Schedule of certain information related to pension plans	The following table sets forth certain information related to our pension plans: December 31, 2015 2014 Projected benefit obligation $ 162,133 159,587 Accumulated benefit obligation 162,133 159,587 Fair value of plan assets 143,655 140,183
Schedule of weighted average asset allocation of defined benefit plans	The following table sets forth the weighted average asset allocation of defined benefit plans: Target December 31, Allocation 2015 2014 Debt securities 20 – 50% 20 % 20 % Equity securities 30 – 60% 69 % 71 % Other 5 – 50% 11 % 9 % Total 100 % 100 %
Schedule of allocation of plan assets	The following table sets forth the pension plan assets as of December 31, 2015 and 2014 : December 31, 2015 2014 Mutual funds — debt $ 28,316 27,635 Mutual funds — equity 98,517 99,009 Cash and cash equivalents 16,822 13,539
Postretirement Healthcare Plan
Employee benefit plans
Schedule of net periodic costs for the defined benefit pension plans and the post retirement healthcare plans	The following table sets forth the net periodic pension cost for the defined benefit pension plans for the years ended December 31, 2015 , 2014 and 2013 : Years ended December 31, 2015 2014 2013 Service cost $ 5,721 4,138 4,551 Interest cost 6,125 5,827 5,203 Expected return on plan assets (10,371 ) (9,663 ) (8,551 ) Net amortization and deferral 1,375 (897 ) 1,356 Net periodic pension (benefit)/ cost $ 2,850 (595 ) 2,559 Years ended December 31, 2015 2014 2013 Service cost $ — — — Interest cost 58 65 63 Amortization of net loss 60 48 53 Net period benefit cost $ 118 113 116
Schedule of other changes in the defined benefit pension plans' plan assets and benefit obligations recognized in other comprehensive income	The following table sets forth other changes in the postretirement healthcare plan’s plan assets and benefit obligations recognized in other comprehensive income: Years ended December 31, 2015 2014 2013 Net loss/ (gain) $ 273 195 (136 ) Total recognized in other comprehensive income $ 273 195 (136 ) Total recognized in net periodic benefit cost and other comprehensive income $ 391 308 (20 )
Schedule of defined benefit pension plans' funded status	December 31, 2015 2014 Change in benefit obligation: Benefit obligation at beginning of year $ 1,565 1,425 Service cost — — Interest cost 58 65 Actuarial loss 333 243 Benefits paid (219 ) (168 ) Benefit obligation at end of year $ 1,737 1,565 Change in plan assets: Fair value of plan assets at beginning of year — — Employer contributions 219 168 Benefits paid (219 ) (168 ) Fair value of plan assets at end of year $ — — Funded status at year end $ (1,737 ) (1,565 )
Schedule of assumptions used to develop the net periodic pension cost	The assumptions used to develop the preceding information for postretirement healthcare benefits are as follows: Years ended December 31, 2015 2014 2013 Discount rate 3.89 % 4.86 % 4.06 % Monthly cost of healthcare insurance per beneficiary (1) $ 470 384 351 Annual rate of increase in healthcare costs 4.00 % 4.00 % 4.00 % (1) Not in thousands
Schedule of accumulated benefit obligation in excess of plan assets	The following table sets forth information for plans with an accumulated benefit obligation in excess of plan assets: December 31, 2015 2014 Projected benefit obligation $ 1,737 1,565 Accumulated benefit obligation 1,737 1,565 Fair value of plan assets — —

Disclosures About Fair Value 48

Disclosures About Fair Value of Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2015
Fair Value Disclosures [Abstract]
Schedule of the carrying amount and estimated fair value of the entity's financial instruments included in the consolidated statement of financial condition	The following table sets forth the carrying amount and estimated fair value of our financial instruments included in the consolidated statement of financial condition at December 31, 2015 and 2014 : December 31, 2015 Carrying Estimated amount fair value Level 1 Level 2 Level 3 Financial assets: Cash and cash equivalents $ 167,408 167,408 167,408 — — Securities available-for-sale 874,405 874,405 1,894 863,556 8,955 Securities held-to-maturity 31,689 32,552 — 32,552 — Loans receivable, net 7,159,449 7,482,431 — — 7,482,431 Accrued interest receivable 21,072 21,072 21,072 — — FHLB Stock 40,903 40,903 — — — Total financial assets $ 8,294,926 8,618,771 190,374 896,108 7,491,386 Financial liabilities: Savings and checking accounts $ 4,917,863 4,917,863 4,917,863 — — Time deposits 1,694,718 1,710,388 — — 1,710,388 Borrowed funds 975,007 998,527 118,664 — 879,863 Junior subordinated debentures 111,213 115,268 — — 115,268 Cash flow hedges - swaps 4,276 4,276 — 4,276 — Accrued interest payable 1,993 1,993 1,993 — — Total financial liabilities $ 7,705,070 7,748,315 5,038,520 4,276 2,705,519 December 31, 2014 Carrying Estimated amount fair value Level 1 Level 2 Level 3 Financial assets: Cash and cash equivalents $ 240,706 240,706 240,706 — — Securities available-for-sale 912,371 912,371 3,157 898,617 10,597 Securities held-to-maturity 103,695 106,292 — 106,292 — Loans receivable, net 5,922,373 6,240,079 — — 6,240,079 Accrued interest receivable 18,623 18,623 18,623 — — FHLB Stock 33,293 33,293 — — — Total financial assets $ 7,231,061 7,551,364 262,486 1,004,909 6,250,676 Financial liabilities: Savings and checking accounts $ 4,154,228 4,154,228 4,154,228 — — Time deposits 1,478,314 1,498,539 — — 1,498,539 Borrowed funds 888,109 919,612 162,714 — 756,898 Junior subordinated debentures 103,094 109,435 — — 109,435 Cash flow hedges - swaps 6,273 6,273 — 6,273 — Accrued interest payable 936 936 936 — — Total financial liabilities $ 6,630,954 6,689,023 4,317,878 6,273 2,364,872
Schedule of assets and liabilities measured at fair value on a recurring basis	The following table represents assets and liabilities measured at fair value on a recurring basis as of December 31, 2015 : Level 1 Level 2 Level 3 Total at fair value Equity securities $ 1,894 — — 1,894 Debt securities: U.S. government and agencies — 11 — 11 Government sponsored enterprises — 294,440 — 294,440 States and political subdivisions — 82,868 — 82,868 Corporate — 7,520 8,955 16,475 Total debt securities — 384,839 8,955 393,794 Residential mortgage-backed securities: GNMA — 27,082 — 27,082 FNMA — 99,170 — 99,170 FHLMC — 50,369 — 50,369 Non-agency — 606 — 606 Collateralized mortgage obligations: GNMA — 10,669 — 10,669 FNMA — 122,528 — 122,528 FHLMC — 157,378 — 157,378 SBA — 8,166 — 8,166 Non-agency — 2,749 — 2,749 Total mortgage-backed securities — 478,717 — 478,717 Interest rate swaps — (4,276 ) — (4,276 ) Total assets and liabilities $ 1,894 859,280 8,955 870,129 The following table represents assets and liabilities measured at fair value on a recurring basis as of December 31, 2014 : Level 1 Level 2 Level 3 Total at fair value Equity securities $ 3,157 — — 3,157 Debt securities: U.S. government and agencies — 25 — 25 Government sponsored enterprises — 333,505 — 333,505 States and political subdivisions — 70,145 — 70,145 Corporate — 9,830 10,597 20,427 Total debt securities — 413,505 10,597 424,102 Residential mortgage-backed securities: GNMA — 29,216 — 29,216 FNMA — 73,497 — 73,497 FHLMC — 42,119 — 42,119 Non-agency — 643 — 643 Collateralized mortgage obligations: GNMA — 8,329 — 8,329 FNMA — 139,150 — 139,150 FHLMC — 178,698 — 178,698 SBA — 10,052 — 10,052 Non-agency — 3,408 — 3,408 Total mortgage-backed securities — 485,112 — 485,112 Interest rate swaps — (6,273 ) — (6,273 ) Total assets and liabilities $ 3,157 892,344 10,597 906,098
Schedule of reconciliation of debt securities measured at fair value on a recurring basis using significant unobservable inputs (Level 3)	The table below presents a reconciliation of all assets and liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3) for the year ended December 31, 2015 and 2014 : December 31, 2015 2014 Equity Debt Equity Debt securities securities securities securities Beginning balance January 1, $ — 10,597 — 12,251 Total net realized investment gains/ (losses) and net change in unrealized appreciation/ (depreciation): Included in net income as OTTI — — — — Included in other comprehensive income — (502 ) — (1,549 ) Purchases — — — — Sales/ calls — (1,140 ) — (105 ) Transfers into Level 3 — — — — Transfers out of Level 3 — — — — Ending balance December 31, $ — 8,955 — 10,597
Schedule of fair value measurement for nonrecurring assets	The following table represents the fair market measurement for only those nonrecurring assets that had a fair market value below the carrying amount as of December 31, 2015 : Level 1 Level 2 Level 3 Total assets at fair value Loans evaluated for impairment $ — — 48,181 48,181 Real estate owned — — 8,725 8,725 Total assets $ — — 56,906 56,906 The following table represents the fair market measurement for only those nonrecurring assets that had a fair market value below the carrying amount as of December 31, 2014 : Level 1 Level 2 Level 3 Total assets at fair value Loans evaluated for impairment $ — — 54,729 54,729 Real estate owned — — 16,759 16,759 Total assets $ — — 71,488 71,488
Schedule of quantitative information about assets measured at fair value on a recurring and nonrecurring basis for Level 3 Fair Value Measurements	The following table presents additional quantitative information about assets measured at fair value on a recurring and nonrecurring basis and for which we have utilized Level 3 inputs to determine fair value at December 31, 2015 : Fair value Valuation techniques Significant unobservable inputs Range (weighted average) Debt securities $ 8,955 Discounted cash Discount margin 0.35% to 2.10% (0.69)% flow Default rates 1.00% Prepayment speeds 1.00% annually Loans measured for impairment 48,181 Appraisal Estimated costs to sell 10% value (1) Discounted cash Discount rate 3.75% to 6.50% (5.13%) flow Real estate owned 8,725 Appraisal Estimated costs to sell 10% value (1) (1) Fair value is generally determined through independent appraisals of the underlying collateral, which may include Level 3 inputs that are not identifiable, or by using the discounted cash flow method if the loan is not collateral dependent.

Regulatory Capital Requiremen49

Regulatory Capital Requirements (Tables)	12 Months Ended
	Dec. 31, 2015
Regulatory Capital Requirements [Abstract]
Schedule of actual, required, and well capitalized levels	The actual, required, and well capitalized levels as of December 31, 2015 and 2014 were as follows: At December 31, 2015 Minimum capital Well capitalized Actual requirements requirements Amount Ratio Amount Ratio Amount Ratio Total capital (to risk weighted assets) Northwest Bancshares, Inc. $ 1,102,468 16.63 % 530,257 8.00 % 662,821 10.00 % Northwest Bank 1,006,230 15.20 % 529,498 8.00 % 661,872 10.00 % Tier 1 capital (to risk weighted assets) Northwest Bancshares, Inc. 1,039,574 15.68 % 397,693 6.00 % 530,257 8.00 % Northwest Bank 943,554 14.26 % 397,123 6.00 % 529,498 8.00 % CET 1 capital (to risk weighted assets) Northwest Bancshares, Inc. 931,699 14.06 % 298,269 4.50 % 430,834 6.50 % Northwest Bank 943,554 14.26 % 297,843 4.50 % 430,217 6.50 % Tier 1 capital (leverage) (to total assets) Northwest Bancshares, Inc. 1,039,574 11.96 % 347,582 4.00 % 434,477 5.00 % Northwest Bank 943,554 10.87 % 347,063 4.00 % 433,829 5.00 % At December 31, 2014 Minimum capital Well capitalized Actual requirements (1) requirements (1) Amount Ratio Amount Ratio Amount Ratio Total capital (to risk weighted assts) Northwest Bancshares, Inc. $ 1,062,802 20.29 % — — % — — % Northwest Bank 945,652 18.09 % 418,104 8.00 % 522,629 10.00 % Tier 1 capital (to risk weighted assets) Northwest Bancshares, Inc. 997,049 19.04 % — — % — — % Northwest Bank 880,290 16.84 % 209,052 4.00 % 313,578 6.00 % Tier 1 capital (leverage) (to total assets) Northwest Bancshares, Inc. 997,049 12.80 % — — % — — % Northwest Bank 880,290 11.55 % 304,883 4.00 % 381,104 5.00 % (1) The Federal Reserve did not yet have formal capital requirements established for Savings and Loan holding companies.

Components of Accumulated Oth50

Components of Accumulated Other Comprehensive Income (Tables)	12 Months Ended
	Dec. 31, 2015
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Schedule of the components of accumulated other comprehensive income	The following table sets forth the components of accumulated other comprehensive income as of December 31, 2015 and 2014 : December 31, 2015 2014 Unrealized gain on marketable securities available-for-sale $ 3,325 3,461 Fair value of interest rate swaps (2,779 ) (4,078 ) Defined benefit pension plans (25,081 ) (23,753 ) Accumulated other comprehensive income $ (24,535 ) (24,370 )
Schedule of the changes in accumulated other comprehensive income by component	The following table shows the changes in accumulated other comprehensive income by component for the year ended December 31, 2015 : Unrealized gains and losses on securities available-for- sale Change in fair value of interest rate swaps Change in defined benefit pension plans Total Balance as of January 1, $ 3,461 (4,078 ) (23,753 ) (24,370 ) Other comprehensive income/ (loss) before reclassification adjustments 315 1,299 (2,203 ) (589 ) Amounts reclassified from accumulated other comprehensive income (1), (2) (451 ) — 875 424 Net other comprehensive income/ (loss) (136 ) 1,299 (1,328 ) (165 ) Balance as of December 31, $ 3,325 (2,779 ) (25,081 ) (24,535 ) (1) Consists of realized gains on securities (gain on sales of investments, net) of $740 , net of tax (income tax expense) of $(289) . (2) Consists of amortization of prior service cost (compensation and employee benefits) of $2,323 and amortization of net loss (compensation and employee benefits) of $(3,758) , net of tax (income tax expense) of $560 . See note 15. The following table shows the changes in accumulated other comprehensive income by component for the year ended December 31, 2014 : Unrealized gains and losses on securities available-for- sale Change in fair value of interest rate swaps Change in defined benefit pension plans Total Balance as of January 1, $ (3,233 ) (5,224 ) (3,443 ) (11,900 ) Other comprehensive income/ (loss) before reclassification adjustments 9,042 1,146 (19,792 ) (9,604 ) Amounts reclassified from accumulated other comprehensive income (1), (2) (2,348 ) — (518 ) (2,866 ) Net other comprehensive income/ (loss) 6,694 1,146 (20,310 ) (12,470 ) Balance as of December 31, $ 3,461 (4,078 ) (23,753 ) (24,370 ) (1) Consists of realized gains on securities (gain on sales of investments, net) of $3,849 and other-than-temporary-impairment losses (net impairment losses) of $0 , net of tax (income tax expense) of $(1,501) . (2) Consists of amortization of prior service cost (compensation and employee benefits) of $2,323 and amortization of net loss (compensation and employee benefits) of $(1,473) , net of tax (income tax expense) of $(332) . See note 15. The following table shows the changes in accumulated other comprehensive income by component for the year ended December 31, 2013 : Unrealized gains and losses on securities available-for- sale Change in fair value of interest rate swaps Change in defined benefit pension plans Total Balance as of January 1, $ 15,853 (8,405 ) (18,936 ) (11,488 ) Other comprehensive income/ (loss) before reclassification adjustments (16,544 ) 3,181 14,577 1,214 Amounts reclassified from accumulated other comprehensive income (1), (2) (2,542 ) — 916 (1,626 ) Net other comprehensive income/ (loss) (19,086 ) 3,181 15,493 (412 ) Balance as of December 31, $ (3,233 ) (5,224 ) (3,443 ) (11,900 ) (1) Consists of realized losses on securities (gain on sales of investments, net) of 4,881 and other-than-temporary-impairment losses (net impairment losses) of $(713) , net of tax (income tax expense) of $1,626 . (2) Consists of amortization of prior service cost (compensation and employee benefits) of $2,321 and amortization of net loss (compensation and employee benefits) of $(3,730) , net of tax (income tax expense) of $493 . See note 15.

Parent Company Only Financial51

Parent Company Only Financial Statements - Condensed (Tables)	12 Months Ended
	Dec. 31, 2015
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Schedule of statements of financial condition	December 31, 2015 2014 Assets Cash and cash equivalents $ 91,056 110,699 Marketable securities available-for-sale 1,884 3,144 Investment in bank subsidiary 1,182,308 1,054,204 Other assets 3,547 4,109 Total assets $ 1,278,795 1,172,156 Liabilities and Shareholders’ Equity Liabilities: Debentures payable $ 111,213 103,094 Other liabilities 4,419 6,415 Total liabilities 115,632 109,509 Shareholders’ equity 1,163,163 1,062,647 Total liabilities and shareholders’ equity $ 1,278,795 1,172,156
Schedule of statements of income	Years ended December 31, 2015 2014 2013 Income: Interest income $ 1,258 1,248 1,467 Other income 659 3,424 5,961 Dividends from bank subsidiary 135,000 66,183 — Undistributed earnings from equity investment in bank subsidiary (70,854 ) (3,261 ) 66,003 Total income 66,063 67,594 73,431 Expense: Compensation and benefits 1,061 962 1,024 Other expense 1,356 572 234 Interest expense 4,926 4,691 5,444 Total expense 7,343 6,225 6,702 Income before income taxes 58,720 61,369 66,729 Federal and state income taxes (1,820 ) (593 ) 170 Net income $ 60,540 61,962 66,559
Schedule of statements of cash flows	Years ended December 31, 2015 2014 2013 Operating activities: Net income $ 60,540 61,962 66,559 Adjustments to reconcile net income to net cash provided by operating activities: Undistributed earnings of subsidiary 70,854 3,261 (66,183 ) Noncash stock benefit plan compensation expense 5,654 5,714 5,083 Gain on sale of marketable securities (54 ) (2,768 ) (5,139 ) Net change in other assets and liabilities (5,824 ) (2,352 ) (4,147 ) Net cash provided by/ (used in) operating activities 131,170 65,817 (3,827 ) Investing activities: Net sale of marketable securities 1,192 2,658 7,200 Acquisition, net of cash received (89,398 ) — — Net cash provided by/ (used in) investing activities (88,206 ) 2,658 7,200 Financing activities: Cash dividends paid (52,825 ) (149,932 ) (45,871 ) Share repurchases (7,847 ) (5,273 ) (4,459 ) Repayment of loan to ESOP 1,549 1,190 1,152 Redemption of junior subordinated debt (8,119 ) — — Excess tax benefit from stock-based compensation 332 945 635 Proceeds from options exercised 4,303 6,519 6,618 Net cash used in financing activities (62,607 ) (146,551 ) (41,925 ) Net decrease in cash and cash equivalents $ (19,643 ) (78,076 ) (38,552 ) Cash and cash equivalents at beginning of year 110,699 188,775 227,327 Net decrease in cash and cash equivalents (19,643 ) (78,076 ) (38,552 ) Cash and cash equivalents at end of year $ 91,056 110,699 188,775

Business Segments (Tables)

Business Segments (Tables)	12 Months Ended
	Dec. 31, 2015
Segment Reporting [Abstract]
Schedule of financial information for reportable segments	The following tables provide financial information for these segments. The All Other column represents the parent company, other nonbank subsidiaries, and elimination entries necessary to reconcile to the consolidated amounts presented in the financial statements. At or for the year ended Community Banking Consumer Finance All Other (1) Consolidated External interest income $ 300,746 17,978 856 319,580 Intersegment interest income 2,393 — (2,393 ) — Interest expense 51,895 2,393 2,039 56,327 Provision for loan losses 7,429 2,283 — 9,712 Noninterest income 67,167 1,555 114 68,836 Noninterest expense 219,793 12,120 1,964 233,877 Income tax expense/ (benefit) 28,642 1,138 (1,820 ) 27,960 Net income $ 62,547 1,599 (3,606 ) 60,540 Total assets $ 8,827,574 110,670 13,655 8,951,899 At or for the year ended Community Banking Consumer Finance All Other (1) Consolidated External interest income $ 285,635 18,789 1,003 305,427 Intersegment interest income 2,406 — (2,406 ) — Interest expense 52,291 2,406 1,890 56,587 Provision for loan losses 17,500 2,814 — 20,314 Noninterest income 66,431 1,517 2,818 70,766 Noninterest expense 202,489 11,968 1,078 215,535 Income tax expense 21,097 1,291 (593 ) 21,795 Net income $ 61,095 1,827 (960 ) 61,962 Total assets $ 7,650,665 107,216 17,152 7,775,033 At or for the year ended Community Banking Consumer Finance All Other (1) Consolidated External interest income $ 291,253 20,648 1,196 313,097 Intersegment interest income 2,691 — (2,691 ) — Interest expense 56,282 2,691 2,189 61,162 Provision for loan losses 15,206 3,313 — 18,519 Noninterest income 59,616 1,647 5,213 66,476 Noninterest expense 194,028 12,303 803 207,134 Income tax expense/ (benefit) 24,330 1,699 170 26,199 Net income $ 63,714 2,289 556 66,559 Total assets $ 7,745,433 109,249 25,177 7,879,859 (1) Eliminations consist of intercompany interest income and interest expense.

Guaranteed Preferred Benefici53

Guaranteed Preferred Beneficial Interests in Company’s Junior Subordinated Deferrable Interest Debentures (Trust-Preferred Securities) and Interest Rate Swap Agreements (Tables)	12 Months Ended
	Dec. 31, 2015
Guaranteed Preferred Beneficial Interests in Company's Junior Subordinated Deferrable Interest Debentures (Trust-Preferred Securities) and Interest Rate Swap Agreements
Schedule of liability derivatives included in other liabilities	December 31, Liability Derivatives (Included in Other Liabilities) 2015 2014 Cash flow hedges — swaps: Fair value $ 4,276 6,273 Notional amount 50,000 75,000 Collateral posted 4,705 6,805
Summary of guaranteed capital debt securities and junior subordinated deferrable interest debentures held by the trusts	The following table sets forth a summary of guaranteed capital debt securities and junior subordinated deferrable interest debentures held by the trusts as of December 31, 2015 and 2014 : Capital Debt December 31, Securities 2015 2014 Northwest Bancorp Capital Trust III $ 50,000 51,547 51,547 Northwest Bancorp Statutory Trust IV 50,000 51,547 51,547 LNB Trust II 7,875 8,119 — Total $ 107,875 111,213 103,094

Selected Quarterly Financial 54

Selected Quarterly Financial Data - Unaudited (Tables)	12 Months Ended
	Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Schedule of selected quarterly financial data	Three months ended March 31 June 30 September 30 December 31 (In thousands, except per share data) 2015: Interest income $ 76,880 75,970 81,091 85,639 Interest expense 13,899 13,792 14,150 14,486 Net interest income 62,981 62,178 66,941 71,153 Provision for loan losses 900 1,050 3,167 4,595 Noninterest income 14,625 16,525 18,140 19,546 Noninterest expenses 53,711 55,135 63,804 61,227 Income before income taxes 22,995 22,518 18,110 24,877 Income tax expense 6,825 7,213 5,238 8,684 Net income $ 16,170 15,305 12,872 16,193 Basic earnings per share $ 0.18 0.17 0.14 0.16 Diluted earnings per share $ 0.18 0.17 0.13 0.16 Three months ended March 31 June 30 September 30 December 31 (In thousands, except per share data) 2014: Interest income $ 75,326 76,987 76,528 76,586 Interest expense 14,204 14,214 14,187 13,982 Net interest income 61,122 62,773 62,341 62,604 Provision for loan losses 7,485 8,285 3,466 1,078 Noninterest income 19,381 16,427 17,737 17,221 Noninterest expenses 53,163 53,806 53,354 55,212 Income before income taxes 19,855 17,109 23,258 23,535 Income tax expense 5,244 4,435 5,926 6,190 Net income $ 14,611 12,674 17,332 17,345 Basic earnings per share $ 0.16 0.14 0.19 0.19 Diluted earnings per share $ 0.16 0.14 0.19 0.19 Three months ended March 31 June 30 September 30 December 31 (In thousands, except per share data) 2013: Interest income $ 79,475 78,723 77,850 77,049 Interest expense 15,645 15,436 15,276 14,805 Net interest income 63,830 63,287 62,574 62,244 Provision for loan losses 7,158 5,405 4,992 964 Noninterest income 16,341 13,379 15,989 20,767 Noninterest expenses 51,471 52,806 50,277 52,580 Income before income taxes 21,542 18,455 23,294 29,467 Income tax expense 6,357 5,020 5,727 9,095 Net income $ 15,185 13,435 17,567 20,372 Basic earnings per share $ 0.17 0.15 0.19 0.22 Diluted earnings per share $ 0.17 0.15 0.19 0.22

Summary of Significant Accoun55

Summary of Significant Accounting Policies - Loans Receivable and Allowance for Loan Losses and Other Narrative Information (Details)	12 Months Ended
	Dec. 31, 2015USD ($)officebank	Dec. 31, 2014USD ($)
Nature of Operations
Number of banking locations | bank	181
Number of consumer finance offices | office	51
Cash and Cash Equivalents
Maximum term of original maturity to classify instruments as cash and cash equivalents	3 months
Investment Securities
Securities classified as trading	$ 0	$ 0
Loans Receivable
Number of days in delinquency for accrued interest on loans to be considered for reversal, minimum	90 days
Number of days delinquent for loans to be placed on non-accrual status, minimum	90 days
Period of time to return TDRs included in impaired loans to performing status through the fulfilling of contractual terms	6 months
Allowance for Loan Losses and Provision for Loan Losses
Number of days for loans not deemed to be impaired	30 days
Business Banking
Allowance for Loan Losses and Provision for Loan Losses
Financing Receivable, Individually Evaluated For Impairment, Threshold Amount For Analysis	$ 1,000,000
Actual losses incurred through average number of rolling years	3 years
Personal Banking
Allowance for Loan Losses and Provision for Loan Losses
Actual losses incurred through average number of rolling years	3 years
Number of days delinquent for allowance for loans	90 days
Number of days delinquent for loans to be charged off or charged down unless that borrower has filed for bankruptcy	180 days

Summary of Significant Accoun56

Summary of Significant Accounting Policies - Premises and Equipment and Goodwill (Details)	12 Months Ended
	Dec. 31, 2015valuation_method
Goodwill
Number of valuation methodologies for impairment of goodwill	4
Core Deposit Intangibles
Useful life of core deposit intangibles	7 years
Minimum
Premises and Equipment
Estimated lives	3 years
Maximum
Premises and Equipment
Estimated lives	39 years

Summary of Significant Accoun57

Summary of Significant Accounting Policies - Stock Related Compensation and Segments (Details) $ in Millions	May. 20, 2015shares	May. 19, 2015shares	May. 21, 2014shares	May. 15, 2013shares	Dec. 31, 2015USD ($)segmentshares	Dec. 31, 2014USD ($)shares	Dec. 31, 2013USD ($)shares
Segment Reporting
Number of reportable segments | segment					2
Employees | Employee Stock Ownership Plan
Stock Related Compensation
Number of shares awarded					126,280
Stock options
Stock Related Compensation
Number of shares awarded					665,370	592,550	590,300
Vesting period		10 years			10 years
Stock-based aggregate disclosure
Compensation expense for unvested common share awards which is yet to be recognized | $					$ 4.3
Weighted average period over which stock option expense will be recognized					4 years 2 months 22 days
Weighted average assumptions
Expected volatility, minimum (as a percent)					17.00%
Expected volatility, maximum (as a percent)					33.00%
Risk-free interest rates, minimum (as a percent)					1.70%
Risk-free interest rates, maximum (as a percent)					6.50%
Stock options | Minimum
Weighted average assumptions
Dividend yields (as a percent)					1.60%
Expected lives					7 years
Stock options | Maximum
Weighted average assumptions
Dividend yields (as a percent)					5.10%
Expected lives					9 years
Stock options | Employees
Stock Related Compensation
Number of shares awarded		600,570	534,950	511,100	600,570
Stock options | Director
Stock Related Compensation
Number of shares awarded		64,800	57,600	79,200	64,800
Restricted common shares
Stock Related Compensation
Vesting period					10 years
Stock-based aggregate disclosure
Stock-based employee compensation expense | $					$ 3	$ 3	$ 2.4
Effect of compensation expense on net income included in income before income taxes | $					$ 1.8	$ 1.8	$ 1.6
Restricted common shares | Employees
Stock Related Compensation
Number of shares awarded	282,050		251,030	240,700	282,050
Restricted common shares | Director
Stock Related Compensation
Number of shares awarded	24,300		21,600	29,700	24,300

Acquisition - Narrative (Detail

Acquisition - Narrative (Details) - LNB $ / shares in Units, $ in Thousands	Aug. 14, 2015USD ($)branch$ / sharesshares	Dec. 31, 2015USD ($)
Business Acquisition [Line Items]
Total consideration paid	$ 180,958
Number of branch locations acquired | branch	21
Conversion, shares of Company's common stock, LNB share	1.461
Cash paid (in dollars per share) | $ / shares	$ 18.70
Shares issued in connection with acquisition (in shares) | shares	7,056,074
Northwest Bancshares, Inc. common stock issued	$ 90,608
Closing price of Company's stock (in dollars per share) | $ / shares	$ 12.84
Cash paid to LNB Bancorp, Inc. stockholders	$ 90,350
Estimated useful life	7 years
Direct costs		$ 9,800

Acquisition - Consideration Pai

Acquisition - Consideration Paid, Assets Acquired and Liabilities Assumed Recorded at Fair Value on Acquisition Date (Details) - USD ($) $ in Thousands	Aug. 14, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Recognized amounts of identifiable assets acquired and (liabilities assumed), at fair value
Goodwill		$ 261,736	$ 175,323	$ 174,644
LNB
Consideration paid:
Northwest Bancshares, Inc. common stock issued	$ 90,608
Cash paid to LNB Bancorp, Inc. stockholders	90,350
Total consideration paid	180,958
Recognized amounts of identifiable assets acquired and (liabilities assumed), at fair value
Cash and cash equivalents	29,680
Investment securities available for sale	184,169
Loans	928,101
Federal Home Loan Bank stock	3,840
Premises and equipment	12,374
Core deposit intangible	7,375
Other assets	45,698
Deposits	(1,033,992)
Borrowings	(63,169)
Other liabilities	(19,356)
Total indentifiable net assets	94,720
Goodwill	$ 86,238
Adjustments to Deposits, trust account deposits maintained by LNB		$ 17,400

Acquisition - Purchased Credit

Acquisition - Purchased Credit Impaired LNB Loan Portfolio (Details) - LNB $ in Thousands	Aug. 14, 2015USD ($)
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Acquired During Period [Abstract]
Contractually required principal and interest at acquisition	$ 41,175
Contractual cash flows not expected to be collected (nonaccretable discount)	(19,900)
Expected cash flows at acquisition	21,275
Interest component of expected cash flows (accretable discount)	(1,672)
Fair value of purchased credit impaired loans	$ 19,603

Marketable Securities - Availab

Marketable Securities - Available For Sale (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Amortized cost
Marketable securities available-for-sale, amortized cost	$ 868,956	$ 906,702
Gross unrealized holding gains
Marketable securities available-for-sale, gross unrealized holding gains	11,733	14,404
Gross unrealized holding losses
Marketable securities available-for-sale, gross unrealized holding losses	(6,284)	(8,735)
Fair value
Marketable securities available-for-sale, total fair value	874,405	912,371
U.S. government and agencies
Amortized cost
Due in one year or less	11	25
Gross unrealized holding gains
Due in one year or less	0	0
Gross unrealized holding losses
Due in one year or less	0	0
Fair value
Due in one year or less	11	25
Government sponsored enterprises
Amortized cost
Due in one year or less	15,500
Due after one year through five years	257,463	310,172
Due after five years through ten years	12,721	25,746
Due after ten years	9,815
Gross unrealized holding gains
Due in one year or less	3
Due after one year through five years	298	287
Due after five years through ten years	14	0
Due after ten years	135
Gross unrealized holding losses
Due in one year or less	(48)
Due after one year through five years	(1,395)	(2,672)
Due after five years through ten years	(23)	(28)
Due after ten years	(43)
Fair value
Due in one year or less	15,455
Due after one year through five years	256,366	307,787
Due after five years through ten years	12,712	25,718
Due after ten years	9,907
Equity securities
Amortized cost
Marketable securities available-for-sale, amortized cost	1,400	2,591
Gross unrealized holding gains
Marketable securities available-for-sale, gross unrealized holding gains	500	682
Gross unrealized holding losses
Marketable securities available-for-sale, gross unrealized holding losses	(6)	(116)
Fair value
Marketable securities available-for-sale, total fair value	1,894	3,157
Municipal securities
Amortized cost
Due in one year or less	1,684	810
Due after one year through five years	14,327	7,878
Due after five years through ten years	12,400	6,965
Due after ten years	52,286	51,839
Gross unrealized holding gains
Due in one year or less	8	15
Due after one year through five years	117	132
Due after five years through ten years	323	115
Due after ten years	1,727	2,391
Gross unrealized holding losses
Due in one year or less	0	0
Due after one year through five years	(4)	0
Due after five years through ten years	0	0
Due after ten years	0	0
Fair value
Due in one year or less	1,692	825
Due after one year through five years	14,440	8,010
Due after five years through ten years	12,723	7,080
Due after ten years	54,013	54,230
Corporate debt issues
Amortized cost
Due after ten years	14,463	18,267
Gross unrealized holding gains
Due after ten years	2,417	2,579
Gross unrealized holding losses
Due after ten years	(405)	(419)
Fair value
Due after ten years	16,475	20,427
Residential mortgage-backed securities
Amortized cost
Marketable securities available-for-sale, amortized cost	476,886	482,409
Gross unrealized holding gains
Marketable securities available-for-sale, gross unrealized holding gains	6,191	8,203
Gross unrealized holding losses
Marketable securities available-for-sale, gross unrealized holding losses	(4,360)	(5,500)
Fair value
Marketable securities available-for-sale, total fair value	478,717	485,112
Fixed rate | Pass-through
Amortized cost
Marketable securities available-for-sale, amortized cost	118,266	72,852
Gross unrealized holding gains
Marketable securities available-for-sale, gross unrealized holding gains	2,480	3,149
Gross unrealized holding losses
Marketable securities available-for-sale, gross unrealized holding losses	(420)	(124)
Fair value
Marketable securities available-for-sale, total fair value	120,326	75,877
Fixed rate | Non-agency CMOs
Amortized cost
Marketable securities available-for-sale, amortized cost	2,519	3,162
Gross unrealized holding gains
Marketable securities available-for-sale, gross unrealized holding gains	230	246
Gross unrealized holding losses
Marketable securities available-for-sale, gross unrealized holding losses	0	0
Fair value
Marketable securities available-for-sale, total fair value	2,749	3,408
Fixed rate | Agency CMOs
Amortized cost
Marketable securities available-for-sale, amortized cost	215,719	226,413
Gross unrealized holding gains
Marketable securities available-for-sale, gross unrealized holding gains	389	685
Gross unrealized holding losses
Marketable securities available-for-sale, gross unrealized holding losses	(3,881)	(5,331)
Fair value
Marketable securities available-for-sale, total fair value	212,227	221,767
Variable rate | Pass-through
Amortized cost
Marketable securities available-for-sale, amortized cost	54,292	66,140
Gross unrealized holding gains
Marketable securities available-for-sale, gross unrealized holding gains	2,616	3,466
Gross unrealized holding losses
Marketable securities available-for-sale, gross unrealized holding losses	(7)	(8)
Fair value
Marketable securities available-for-sale, total fair value	56,901	69,598
Variable rate | Agency CMOs
Amortized cost
Marketable securities available-for-sale, amortized cost	86,090	113,842
Gross unrealized holding gains
Marketable securities available-for-sale, gross unrealized holding gains	476	657
Gross unrealized holding losses
Marketable securities available-for-sale, gross unrealized holding losses	(52)	(37)
Fair value
Marketable securities available-for-sale, total fair value	$ 86,514	$ 114,462

Marketable Securities - Held To

Marketable Securities - Held To Maturity (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Amortized cost
Held-to-maturity securities, amortized cost	$ 31,689	$ 103,695
Gross unrealized holding gains
Held-to-maturity securities, gross unrealized holding gains	863	2,597
Gross unrealized holding losses
Held-to-maturity securities, gross unrealized holding losses	0	0
Fair value
Held-to-maturity securities, fair value	32,552	106,292
Municipal securities
Amortized cost
Due after five years through ten years	274	10,207
Due after ten years	6,336	56,545
Gross unrealized holding gains
Due after five years through ten years	1	141
Due after ten years	239	1,314
Gross unrealized holding losses
Due after five years through ten years	0	0
Due after ten years	0	0
Fair value
Due after five years through ten years	275	10,348
Due after ten years	6,575	57,859
Residential mortgage-backed securities
Amortized cost
Held-to-maturity securities, amortized cost	25,079	36,943
Gross unrealized holding gains
Held-to-maturity securities, gross unrealized holding gains	623	1,142
Gross unrealized holding losses
Held-to-maturity securities, gross unrealized holding losses	0	0
Fair value
Held-to-maturity securities, fair value	25,702	38,085
Fixed rate | Pass-through
Amortized cost
Held-to-maturity securities, amortized cost	6,458	8,236
Gross unrealized holding gains
Held-to-maturity securities, gross unrealized holding gains	351	477
Gross unrealized holding losses
Held-to-maturity securities, gross unrealized holding losses	0	0
Fair value
Held-to-maturity securities, fair value	6,809	8,713
Fixed rate | Agency CMOs
Amortized cost
Held-to-maturity securities, amortized cost	14,033	23,382
Gross unrealized holding gains
Held-to-maturity securities, gross unrealized holding gains	219	531
Gross unrealized holding losses
Held-to-maturity securities, gross unrealized holding losses	0	0
Fair value
Held-to-maturity securities, fair value	14,252	23,913
Variable rate | Pass-through
Amortized cost
Held-to-maturity securities, amortized cost	3,618	4,273
Gross unrealized holding gains
Held-to-maturity securities, gross unrealized holding gains	41	122
Gross unrealized holding losses
Held-to-maturity securities, gross unrealized holding losses	0	0
Fair value
Held-to-maturity securities, fair value	3,659	4,395
Variable rate | Agency CMOs
Amortized cost
Held-to-maturity securities, amortized cost	970	1,052
Gross unrealized holding gains
Held-to-maturity securities, gross unrealized holding gains	12	12
Gross unrealized holding losses
Held-to-maturity securities, gross unrealized holding losses	0	0
Fair value
Held-to-maturity securities, fair value	$ 982	$ 1,064

Marketable Securities - Issuers

Marketable Securities - Issuers and the Carrying Values of Mortgage-Backed Securities (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Marketable securities
Carrying value of marketable securities pledged	$ 331,800,000
Marketable securities classified as available-for-sale sold	1,246,000	$ 7,910,000	$ 16,003,000
Gross realized gains	121,000	4,400,000	5,800,000
Gross realized losses	67,000	0	0
Non-cash credit related other-than-temporary impairment	0	0	$ 713,000
Residential mortgage-backed securities
Marketable securities
Total residential mortgage-backed securities	503,796,000	522,055,000
Residential mortgage-backed securities | FNMA
Marketable securities
Total residential mortgage-backed securities	234,204,000	230,051,000
Residential mortgage-backed securities | GNMA
Marketable securities
Total residential mortgage-backed securities	48,283,000	54,422,000
Residential mortgage-backed securities | FHLMC
Marketable securities
Total residential mortgage-backed securities	209,788,000	223,479,000
Residential mortgage-backed securities | SBA
Marketable securities
Total residential mortgage-backed securities	8,166,000	10,052,000
Residential mortgage-backed securities | Other (including non-agency)
Marketable securities
Total residential mortgage-backed securities	$ 3,355,000	$ 4,051,000

Marketable Securities - Fair Va

Marketable Securities - Fair Value and Gross Unrealized Losses on Investment Securities (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2015USD ($)investment	Dec. 31, 2014USD ($)
Marketable securities
Less than 12 months - Fair value	$ 273,909	$ 50,216
Less than 12 months - Unrealized loss	(1,331)	(262)
12 months or more - Fair value	244,871	442,336
12 months or more - Unrealized loss	(4,953)	(8,473)
Total - Fair value	518,780	492,552
Total - Unrealized loss	$ (6,284)	(8,735)
Number of investments that are temporarily impaired | investment	148
Aggregate carrying amount of cost-method investment	$ 907,000
U.S. government and agencies
Marketable securities
Less than 12 months - Fair value	143,751	28,878
Less than 12 months - Unrealized loss	(723)	(67)
12 months or more - Fair value	92,961	244,828
12 months or more - Unrealized loss	(786)	(2,633)
Total - Fair value	236,712	273,706
Total - Unrealized loss	(1,509)	(2,700)
Corporate debt issues
Marketable securities
Less than 12 months - Fair value	0	0
Less than 12 months - Unrealized loss	0	0
12 months or more - Fair value	2,021	2,003
12 months or more - Unrealized loss	(405)	(419)
Total - Fair value	2,021	2,003
Total - Unrealized loss	(405)	(419)
Equity securities
Marketable securities
Less than 12 months - Fair value	544	506
Less than 12 months - Unrealized loss	(6)	(116)
12 months or more - Fair value	0	0
12 months or more - Unrealized loss	0	0
Total - Fair value	544	506
Total - Unrealized loss	(6)	(116)
Municipal securities
Marketable securities
Less than 12 months - Fair value	7,505
Less than 12 months - Unrealized loss	(4)
12 months or more - Fair value	0
Total - Fair value	7,505
Total - Unrealized loss	(4)
Residential mortgage-backed securities - agency | Agency CMOs
Marketable securities
Less than 12 months - Fair value	122,109	20,832
Less than 12 months - Unrealized loss	(598)	(79)
12 months or more - Fair value	149,889	195,505
12 months or more - Unrealized loss	(3,762)	(5,421)
Total - Fair value	271,998	216,337
Total - Unrealized loss	$ (4,360)	$ (5,500)

Marketable Securities - Categor

Marketable Securities - Categories of Investment Securities (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2015USD ($)
Marketable securities
Total - Amortized cost	$ 13,396
Total - Fair value	15,931
Total - Unrealized gain	2,535
Accumulated impairment charges	(8,555)
Freddie Mac preferred shares
Marketable securities
Total - Amortized cost	1
Total - Fair value	10
Total - Unrealized gain	9
Accumulated impairment charges	(119)
Trust preferred investments
Marketable securities
Total - Amortized cost	11,137
Total - Fair value	13,437
Total - Unrealized gain	2,300
Accumulated impairment charges	(7,942)
Non-agency CMOs
Marketable securities
Total - Amortized cost	2,258
Total - Fair value	2,484
Total - Unrealized gain	226
Accumulated impairment charges	$ (494)

Marketable Securities - Cumulat

Marketable Securities - Cumulative Roll Forward of Credit Related Impairment Losses Recognized in Earnings for Debt Securities Held and Not Intended to be Sold (Details 6) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Cumulative roll forward of credit related impairment losses recognized in earnings for debt securities held and not intended to be sold:
Beginning balance	$ 8,894	$ 10,342
Credit losses on debt securities for which other-than-temporary impairment was not previously recognized	0	0
Reduction for losses realized during the year	(98)	(1,448)
Reduction for securities called realized during the year	(360)	0
Additional credit losses on debt securities for which other-than-temporary impairment was previously recognized	0	0
Ending balance	$ 8,436	$ 8,894

Loans Receivable and Allowanc67

Loans Receivable and Allowance for Loan Losses - Summary of Originated and Acquired Loans (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans receivable, gross	$ 7,400,989	$ 6,129,584
Deferred loan costs	20,065	6,095
Allowance for loan losses	(62,672)	(67,518)	$ (71,348)	$ (73,219)
Loans Receivable, Net	7,159,449	5,922,373
Residential mortgage loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Undisbursed loan proceeds	(10,778)	(10,879)
Commercial real estate loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Undisbursed loan proceeds	(172,840)	(73,760)
Commercial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Undisbursed loan proceeds	(15,315)	(61,149)
Personal Banking
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans receivable, gross	4,439,000	3,835,115
Allowance for loan losses		(16,249)	(20,607)	(21,452)
Personal Banking | Residential mortgage loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans receivable, gross	2,741,277	2,526,240
Allowance for loan losses		(5,581)	(7,875)	(8,002)
Personal Banking | Home equity loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans receivable, gross	1,187,106	1,066,131
Allowance for loan losses		(4,550)	(7,245)	(8,294)
Personal Banking | Other consumer loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans receivable, gross	510,617	242,744
Allowance for loan losses		(6,118)	(5,487)	(5,156)
Business Banking
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans receivable, gross	2,961,989	2,294,469
Allowance for loan losses		(46,904)	(46,079)	(47,741)
Business Banking | Commercial real estate loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans receivable, gross	2,524,274	1,874,944
Allowance for loan losses		(33,389)	(35,199)	(34,589)
Business Banking | Commercial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans receivable, gross	437,715	419,525
Allowance for loan losses		(13,515)	$ (10,880)	$ (13,152)
Originated
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans receivable, gross	6,526,679
Deferred loan costs	14,806
Allowance for loan losses	(60,970)	(67,518)
Loans Receivable, Net	6,299,052
Originated | Residential mortgage loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Undisbursed loan proceeds	(10,778)
Originated | Commercial real estate loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Undisbursed loan proceeds	(159,553)
Originated | Commercial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Undisbursed loan proceeds	(11,132)
Originated | Personal Banking
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans receivable, gross	4,059,429
Allowance for loan losses	(16,121)	(16,249)
Originated | Personal Banking | Residential mortgage loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans receivable, gross	2,695,561
Allowance for loan losses	(4,692)	(5,581)
Originated | Personal Banking | Home equity loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans receivable, gross	1,055,907
Allowance for loan losses	(3,941)	(4,550)
Originated | Personal Banking | Other consumer loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans receivable, gross	307,961
Allowance for loan losses	(7,488)	(6,118)
Originated | Business Banking
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans receivable, gross	2,467,250
Allowance for loan losses	(44,849)	(46,904)
Originated | Business Banking | Commercial real estate loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans receivable, gross	2,094,710
Allowance for loan losses	(32,348)	(33,389)
Originated | Business Banking | Commercial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans receivable, gross	372,540
Allowance for loan losses	(12,501)	(13,515)
Acquired
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans receivable, gross	874,310
Deferred loan costs	5,259
Allowance for loan losses	(1,702)	0
Loans Receivable, Net	860,397
Acquired | Residential mortgage loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Undisbursed loan proceeds	0
Acquired | Commercial real estate loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Undisbursed loan proceeds	(13,287)
Acquired | Commercial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Undisbursed loan proceeds	(4,183)
Acquired | Personal Banking
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans receivable, gross	379,571
Allowance for loan losses	(229)	0
Acquired | Personal Banking | Residential mortgage loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans receivable, gross	45,716
Allowance for loan losses	(18)	0
Acquired | Personal Banking | Home equity loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans receivable, gross	131,199
Allowance for loan losses	(101)	0
Acquired | Personal Banking | Other consumer loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans receivable, gross	202,656
Allowance for loan losses	(110)	0
Acquired | Business Banking
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans receivable, gross	494,739
Allowance for loan losses	(1,473)	0
Acquired | Business Banking | Commercial real estate loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans receivable, gross	429,564
Allowance for loan losses	(1,439)	0
Acquired | Business Banking | Commercial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans receivable, gross	65,175
Allowance for loan losses	$ (34)	$ 0

Loans Receivable and Allowanc68

Loans Receivable and Allowance for Loan Losses - Narrative (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Receivables [Abstract]
Serviced loans for others	$ 776	$ 734.9	$ 851.4
Percentage of loan portfolio secured by properties located in Pennsylvania	65.00%	76.00%
Adjustable rate loans	$ 2,417	$ 1,876
Fixed rate loans	$ 4,984	$ 4,254

Loans Receivable and Allowanc69

Loans Receivable and Allowance for Loan Losses - Outstanding Principal Balance and Related Carrying Value of Acquired Loans (Details) $ in Thousands	Dec. 31, 2015USD ($)
Acquired
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding principal balance	$ 869,263
Carrying value	856,840
Acquired loans evaluated individually for future credit losses
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding principal balance	21,069
Carrying value	16,867
Acquired loans evaluated collectively for future credit losses
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding principal balance	848,194
Carrying value	$ 839,973

Loans Receivable and Allowanc70

Loans Receivable and Allowance for Loan Losses - Changes in the Accretable Discount (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2015USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	$ 0
Accretion	(377)
Net reclassification from nonaccretable yield	724
Ending balance	2,019
LNB | Acquired
Accounts, Notes, Loans and Financing Receivable [Line Items]
LNB Bancorp, Inc. acquisition	$ 1,672

Loans Receivable and Allowanc71

Loans Receivable and Allowance for Loan Losses - Composition of Acquired Impaired Loans by Portfolio Segment and by Class of Financing Receivable (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Composition of impaired loans by portfolio segment and by class of financing receivable
Carrying value	$ 117,851	$ 137,179	$ 173,844
Average recorded investment in impaired loans	130,528	159,638	175,013
Interest income/ accretion recognized	5,462	5,871	5,955
Acquired loans evaluated individually for future credit losses
Composition of impaired loans by portfolio segment and by class of financing receivable
Carrying value	16,867
Outstanding principal balance	21,069
Related impairment reserve	375
Average recorded investment in impaired loans	17,812
Interest income/ accretion recognized	377
Personal Banking
Composition of impaired loans by portfolio segment and by class of financing receivable
Carrying value	37,679	41,134	44,579
Average recorded investment in impaired loans	37,175	42,363	42,798
Interest income/ accretion recognized	1,542	1,368	1,150
Personal Banking | Acquired loans evaluated individually for future credit losses
Composition of impaired loans by portfolio segment and by class of financing receivable
Carrying value	4,332
Outstanding principal balance	6,857
Related impairment reserve	22
Average recorded investment in impaired loans	4,610
Interest income/ accretion recognized	110
Personal Banking | Residential mortgage loans
Composition of impaired loans by portfolio segment and by class of financing receivable
Carrying value	24,858	27,039	30,649
Average recorded investment in impaired loans	24,554	28,227	29,994
Interest income/ accretion recognized	944	817	723
Personal Banking | Residential mortgage loans | Acquired loans evaluated individually for future credit losses
Composition of impaired loans by portfolio segment and by class of financing receivable
Carrying value	1,981
Outstanding principal balance	2,910
Related impairment reserve	14
Average recorded investment in impaired loans	2,083
Interest income/ accretion recognized	41
Personal Banking | Home equity loans
Composition of impaired loans by portfolio segment and by class of financing receivable
Carrying value	9,369	11,275	11,673
Average recorded investment in impaired loans	9,644	11,753	10,828
Interest income/ accretion recognized	497	485	383
Personal Banking | Home equity loans | Acquired loans evaluated individually for future credit losses
Composition of impaired loans by portfolio segment and by class of financing receivable
Carrying value	2,084
Outstanding principal balance	3,455
Related impairment reserve	6
Average recorded investment in impaired loans	2,222
Interest income/ accretion recognized	51
Personal Banking | Other consumer loans
Composition of impaired loans by portfolio segment and by class of financing receivable
Carrying value	3,452	2,820	2,257
Average recorded investment in impaired loans	2,977	2,383	1,976
Interest income/ accretion recognized	101	66	44
Personal Banking | Other consumer loans | Acquired loans evaluated individually for future credit losses
Composition of impaired loans by portfolio segment and by class of financing receivable
Carrying value	267
Outstanding principal balance	492
Related impairment reserve	2
Average recorded investment in impaired loans	305
Interest income/ accretion recognized	18
Business Banking
Composition of impaired loans by portfolio segment and by class of financing receivable
Carrying value	80,172	96,045	129,265
Average recorded investment in impaired loans	93,353	117,275	132,215
Interest income/ accretion recognized	3,920	4,503	4,805
Business Banking | Acquired loans evaluated individually for future credit losses
Composition of impaired loans by portfolio segment and by class of financing receivable
Carrying value	12,535
Outstanding principal balance	14,212
Related impairment reserve	353
Average recorded investment in impaired loans	13,202
Interest income/ accretion recognized	267
Business Banking | Commercial real estate loans
Composition of impaired loans by portfolio segment and by class of financing receivable
Carrying value	66,009	74,337	94,062
Average recorded investment in impaired loans	77,166	90,187	90,912
Interest income/ accretion recognized	3,226	3,589	3,678
Business Banking | Commercial real estate loans | Acquired loans evaluated individually for future credit losses
Composition of impaired loans by portfolio segment and by class of financing receivable
Carrying value	12,288
Outstanding principal balance	13,946
Related impairment reserve	353
Average recorded investment in impaired loans	12,867
Interest income/ accretion recognized	249
Business Banking | Commercial loans
Composition of impaired loans by portfolio segment and by class of financing receivable
Carrying value	14,163	21,708	35,203
Average recorded investment in impaired loans	16,187	27,088	41,303
Interest income/ accretion recognized	694	$ 914	$ 1,127
Business Banking | Commercial loans | Acquired loans evaluated individually for future credit losses
Composition of impaired loans by portfolio segment and by class of financing receivable
Carrying value	247
Outstanding principal balance	266
Related impairment reserve	0
Average recorded investment in impaired loans	335
Interest income/ accretion recognized	$ 18

Loans Receivable and Allowanc72

Loans Receivable and Allowance for Loan Losses - Changes in the Allowance for Losses on Loans Receivable (Details) - USD ($) $ in Thousands	3 Months Ended												12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Changes in allowance for losses on allocated loans receivable
Balance at the beginning of the period				$ 67,518				$ 71,348				$ 73,219	$ 67,518	$ 71,348	$ 73,219
Provision	$ 4,595	$ 3,167	$ 1,050	900	$ 1,078	$ 3,466	$ 8,285	7,485	$ 964	$ 4,992	$ 5,405	7,158	9,712	20,314	18,519
Charge-offs													(26,333)	(30,745)	(25,844)
Recoveries													11,775	6,601	5,454
Balance at the end of the period	62,672				67,518				71,348				62,672	67,518	71,348
Personal Banking
Changes in allowance for losses on allocated loans receivable
Balance at the beginning of the period				16,249				20,607				21,452	16,249	20,607	21,452
Provision														4,202	8,190
Charge-offs														(10,387)	(10,795)
Recoveries														1,827	1,760
Balance at the end of the period					16,249				20,607					16,249	20,607
Personal Banking | Residential mortgage loans
Changes in allowance for losses on allocated loans receivable
Balance at the beginning of the period				5,581				7,875				8,002	5,581	7,875	8,002
Provision														(556)	1,954
Charge-offs														(2,181)	(2,501)
Recoveries														443	420
Balance at the end of the period					5,581				7,875					5,581	7,875
Personal Banking | Home equity loans
Changes in allowance for losses on allocated loans receivable
Balance at the beginning of the period				4,550				7,245				8,294	4,550	7,245	8,294
Provision														(1,106)	932
Charge-offs														(1,783)	(2,239)
Recoveries														194	258
Balance at the end of the period					4,550				7,245					4,550	7,245
Personal Banking | Other consumer loans
Changes in allowance for losses on allocated loans receivable
Balance at the beginning of the period				6,118				5,487				5,156	6,118	5,487	5,156
Provision														5,864	5,304
Charge-offs														(6,423)	(6,055)
Recoveries														1,190	1,082
Balance at the end of the period					6,118				5,487					6,118	5,487
Business Banking
Changes in allowance for losses on allocated loans receivable
Balance at the beginning of the period				46,904				46,079				47,741	46,904	46,079	47,741
Provision														16,409	9,693
Charge-offs														(20,358)	(15,049)
Recoveries														4,774	3,694
Balance at the end of the period					46,904				46,079					46,904	46,079
Business Banking | Commercial real estate loans
Changes in allowance for losses on allocated loans receivable
Balance at the beginning of the period				33,389				35,199				34,589	33,389	35,199	34,589
Provision														4,417	8,347
Charge-offs														(8,422)	(10,042)
Recoveries														2,195	2,305
Balance at the end of the period					33,389				35,199					33,389	35,199
Business Banking | Commercial loans
Changes in allowance for losses on allocated loans receivable
Balance at the beginning of the period				13,515				10,880				13,152	13,515	10,880	13,152
Provision														11,992	1,346
Charge-offs														(11,936)	(5,007)
Recoveries														2,579	1,389
Balance at the end of the period					13,515				10,880					13,515	10,880
Unallocated
Changes in allowance for losses on allocated loans receivable
Balance at the beginning of the period				4,365				$ 4,662				$ 4,026	4,365	4,662	4,026
Provision														(297)	636
Charge-offs														0	0
Recoveries														0	0
Balance at the end of the period					4,365				$ 4,662					4,365	$ 4,662
Originated
Changes in allowance for losses on allocated loans receivable
Balance at the beginning of the period				67,518									67,518
Provision													7,525
Charge-offs													(24,401)
Recoveries													10,328
Balance at the end of the period	60,970				67,518								60,970	67,518
Originated | Personal Banking
Changes in allowance for losses on allocated loans receivable
Balance at the beginning of the period				16,249									16,249
Provision													8,582
Charge-offs													(10,846)
Recoveries													2,136
Balance at the end of the period	16,121				16,249								16,121	16,249
Originated | Personal Banking | Residential mortgage loans
Changes in allowance for losses on allocated loans receivable
Balance at the beginning of the period				5,581									5,581
Provision													(96)
Charge-offs													(1,057)
Recoveries													264
Balance at the end of the period	4,692				5,581								4,692	5,581
Originated | Personal Banking | Home equity loans
Changes in allowance for losses on allocated loans receivable
Balance at the beginning of the period				4,550									4,550
Provision													693
Charge-offs													(1,716)
Recoveries													414
Balance at the end of the period	3,941				4,550								3,941	4,550
Originated | Personal Banking | Other consumer loans
Changes in allowance for losses on allocated loans receivable
Balance at the beginning of the period				6,118									6,118
Provision													7,985
Charge-offs													(8,073)
Recoveries													1,458
Balance at the end of the period	7,488				6,118								7,488	6,118
Originated | Business Banking
Changes in allowance for losses on allocated loans receivable
Balance at the beginning of the period				46,904									46,904
Provision													3,308
Charge-offs													(13,555)
Recoveries													8,192
Balance at the end of the period	44,849				46,904								44,849	46,904
Originated | Business Banking | Commercial real estate loans
Changes in allowance for losses on allocated loans receivable
Balance at the beginning of the period				33,389									33,389
Provision													540
Charge-offs													(5,741)
Recoveries													4,160
Balance at the end of the period	32,348				33,389								32,348	33,389
Originated | Business Banking | Commercial loans
Changes in allowance for losses on allocated loans receivable
Balance at the beginning of the period				13,515									13,515
Provision													2,768
Charge-offs													(7,814)
Recoveries													4,032
Balance at the end of the period	12,501				13,515								12,501	13,515
Originated | Unallocated
Changes in allowance for losses on allocated loans receivable
Balance at the beginning of the period				4,365									4,365
Provision													(4,365)
Charge-offs													0
Recoveries													0
Balance at the end of the period	0				4,365								0	4,365
Acquired
Changes in allowance for losses on allocated loans receivable
Balance at the beginning of the period				0									0
Provision													2,187
Charge-offs													(1,932)
Recoveries													1,447
Balance at the end of the period	1,702				0								1,702	0
Acquired | Personal Banking
Changes in allowance for losses on allocated loans receivable
Balance at the beginning of the period				0									0
Provision													482
Charge-offs													(978)
Recoveries													725
Balance at the end of the period	229				0								229	0
Acquired | Personal Banking | Residential mortgage loans
Changes in allowance for losses on allocated loans receivable
Balance at the beginning of the period				0									0
Provision													47
Charge-offs													(69)
Recoveries													40
Balance at the end of the period	18				0								18	0
Acquired | Personal Banking | Home equity loans
Changes in allowance for losses on allocated loans receivable
Balance at the beginning of the period				0									0
Provision													247
Charge-offs													(708)
Recoveries													562
Balance at the end of the period	101				0								101	0
Acquired | Personal Banking | Other consumer loans
Changes in allowance for losses on allocated loans receivable
Balance at the beginning of the period				0									0
Provision													188
Charge-offs													(201)
Recoveries													123
Balance at the end of the period	110				0								110	0
Acquired | Business Banking
Changes in allowance for losses on allocated loans receivable
Balance at the beginning of the period				0									0
Provision													1,705
Charge-offs													(954)
Recoveries													722
Balance at the end of the period	1,473				0								1,473	0
Acquired | Business Banking | Commercial real estate loans
Changes in allowance for losses on allocated loans receivable
Balance at the beginning of the period				0									0
Provision													1,545
Charge-offs													(585)
Recoveries													479
Balance at the end of the period	1,439				0								1,439	0
Acquired | Business Banking | Commercial loans
Changes in allowance for losses on allocated loans receivable
Balance at the beginning of the period				$ 0									0
Provision													160
Charge-offs													(369)
Recoveries													243
Balance at the end of the period	$ 34				$ 0								$ 34	$ 0

Loans Receivable and Allowanc73

Loans Receivable and Allowance for Loan Losses - Loan Portfolio by Portfolio Segment and by Class of Financing Receivable (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded investment in loans receivable	$ 7,222,121	$ 5,989,891
Allowance for loan losses	62,672	63,153
Recorded investment in loans on nonaccrual	71,662	79,808
Recorded investment in loans 90 days or more past maturity and still accruing	1,334	235
TDRs	51,115	61,788	$ 79,166
Allowance for TDRs	4,682	7,395
Additional commitments to customers with loans classified as TDRs	320	1,263
Nonaccrual TDRs	21,118	24,459
Personal Banking
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded investment in loans receivable	4,448,287	3,830,331
Allowance for loan losses	16,350	16,249
Recorded investment in loans on nonaccrual	30,746	33,583
Recorded investment in loans 90 days or more past maturity and still accruing	980	214
TDRs	8,658	8,986
Allowance for TDRs	1,794	1,362
Additional commitments to customers with loans classified as TDRs	0	0
Personal Banking | Residential mortgage loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded investment in loans receivable	2,740,892	2,521,456
Allowance for loan losses	4,710	5,581
Recorded investment in loans on nonaccrual	19,772	21,194
Recorded investment in loans 90 days or more past maturity and still accruing	4	8
TDRs	6,360	6,574
Allowance for TDRs	1,189	1,133
Additional commitments to customers with loans classified as TDRs	0	0
Personal Banking | Home equity loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded investment in loans receivable	1,187,106	1,066,131
Allowance for loan losses	4,042	4,550
Recorded investment in loans on nonaccrual	7,522	9,569
Recorded investment in loans 90 days or more past maturity and still accruing	0	0
TDRs	2,298	2,412
Allowance for TDRs	605	229
Additional commitments to customers with loans classified as TDRs	0	0
Personal Banking | Other consumer loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded investment in loans receivable	520,289	242,744
Allowance for loan losses	7,598	6,118
Recorded investment in loans on nonaccrual	3,452	2,820
Recorded investment in loans 90 days or more past maturity and still accruing	976	206
TDRs	0	0
Allowance for TDRs	0	0
Additional commitments to customers with loans classified as TDRs	0	0
Business Banking
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded investment in loans receivable	2,773,834	2,159,560
Allowance for loan losses	46,322	46,904
Recorded investment in loans on nonaccrual	40,916	46,225
Recorded investment in loans 90 days or more past maturity and still accruing	354	21
TDRs	42,457	52,802
Allowance for TDRs	2,888	6,033
Additional commitments to customers with loans classified as TDRs	320	1,263
Business Banking | Commercial real estate loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded investment in loans receivable	2,351,434	1,801,184
Allowance for loan losses	33,787	33,389
Recorded investment in loans on nonaccrual	33,421	38,647
Recorded investment in loans 90 days or more past maturity and still accruing	206	0
TDRs	31,970	41,917
Allowance for TDRs	2,257	4,938
Additional commitments to customers with loans classified as TDRs	241	449
Business Banking | Commercial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded investment in loans receivable	422,400	358,376
Allowance for loan losses	12,535	13,515
Recorded investment in loans on nonaccrual	7,495	7,578
Recorded investment in loans 90 days or more past maturity and still accruing	148	21
TDRs	10,487	10,885
Allowance for TDRs	631	1,095
Additional commitments to customers with loans classified as TDRs	$ 79	$ 814

Loans Receivable and Allowanc74

Loans Receivable and Allowance for Loan Losses - Composition of Impaired Loans by Portfolio Segment and Class of Financing Receivable (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Composition of impaired loans by portfolio segment and by class of financing receivable
Nonaccrual loans	$ 71,662	$ 79,808
Total impaired loans	117,851	137,179	$ 173,844
Average recorded investment in impaired loans	130,528	159,638	175,013
Interest income/ accretion recognized	5,462	5,871	5,955
Personal Banking
Composition of impaired loans by portfolio segment and by class of financing receivable
Nonaccrual loans	30,746	33,583
Total impaired loans	37,679	41,134	44,579
Average recorded investment in impaired loans	37,175	42,363	42,798
Interest income/ accretion recognized	1,542	1,368	1,150
Business Banking
Composition of impaired loans by portfolio segment and by class of financing receivable
Nonaccrual loans	40,916	46,225
Total impaired loans	80,172	96,045	129,265
Average recorded investment in impaired loans	93,353	117,275	132,215
Interest income/ accretion recognized	3,920	4,503	4,805
Residential mortgage loans | Personal Banking
Composition of impaired loans by portfolio segment and by class of financing receivable
Nonaccrual loans	19,772	21,194
Total impaired loans	24,858	27,039	30,649
Average recorded investment in impaired loans	24,554	28,227	29,994
Interest income/ accretion recognized	944	817	723
Home equity loans | Personal Banking
Composition of impaired loans by portfolio segment and by class of financing receivable
Nonaccrual loans	7,522	9,569
Total impaired loans	9,369	11,275	11,673
Average recorded investment in impaired loans	9,644	11,753	10,828
Interest income/ accretion recognized	497	485	383
Other consumer loans | Personal Banking
Composition of impaired loans by portfolio segment and by class of financing receivable
Nonaccrual loans	3,452	2,820
Total impaired loans	3,452	2,820	2,257
Average recorded investment in impaired loans	2,977	2,383	1,976
Interest income/ accretion recognized	101	66	44
Commercial real estate loans | Business Banking
Composition of impaired loans by portfolio segment and by class of financing receivable
Nonaccrual loans	33,421	38,647
Total impaired loans	66,009	74,337	94,062
Average recorded investment in impaired loans	77,166	90,187	90,912
Interest income/ accretion recognized	3,226	3,589	3,678
Commercial loans | Business Banking
Composition of impaired loans by portfolio segment and by class of financing receivable
Nonaccrual loans	7,495	7,578
Total impaired loans	14,163	21,708	35,203
Average recorded investment in impaired loans	16,187	27,088	41,303
Interest income/ accretion recognized	694	914	1,127
90 days or greater delinquent
Composition of impaired loans by portfolio segment and by class of financing receivable
Nonaccrual loans	43,268	41,326	57,757
90 days or greater delinquent | Personal Banking
Composition of impaired loans by portfolio segment and by class of financing receivable
Nonaccrual loans	24,360	26,752	35,026
90 days or greater delinquent | Business Banking
Composition of impaired loans by portfolio segment and by class of financing receivable
Nonaccrual loans	18,908	14,574	22,731
90 days or greater delinquent | Residential mortgage loans | Personal Banking
Composition of impaired loans by portfolio segment and by class of financing receivable
Nonaccrual loans	15,810	17,696	24,625
90 days or greater delinquent | Home equity loans | Personal Banking
Composition of impaired loans by portfolio segment and by class of financing receivable
Nonaccrual loans	5,650	6,606	8,344
90 days or greater delinquent | Other consumer loans | Personal Banking
Composition of impaired loans by portfolio segment and by class of financing receivable
Nonaccrual loans	2,900	2,450	2,057
90 days or greater delinquent | Commercial real estate loans | Business Banking
Composition of impaired loans by portfolio segment and by class of financing receivable
Nonaccrual loans	16,449	11,099	18,433
90 days or greater delinquent | Commercial loans | Business Banking
Composition of impaired loans by portfolio segment and by class of financing receivable
Nonaccrual loans	2,459	3,475	4,298
Less than 90 days delinquent
Composition of impaired loans by portfolio segment and by class of financing receivable
Nonaccrual loans	28,394	38,482	49,464
Loans less than 90 days delinquent reviewed for impairment	18,135	31,666	44,418
TDRs less than 90 days delinquent not included elsewhere	28,054	25,705	22,205
Less than 90 days delinquent | Personal Banking
Composition of impaired loans by portfolio segment and by class of financing receivable
Nonaccrual loans	6,386	6,831	4,371
Loans less than 90 days delinquent reviewed for impairment	0	0	0
TDRs less than 90 days delinquent not included elsewhere	6,933	7,551	5,182
Less than 90 days delinquent | Business Banking
Composition of impaired loans by portfolio segment and by class of financing receivable
Nonaccrual loans	22,008	31,651	45,093
Loans less than 90 days delinquent reviewed for impairment	18,135	31,666	44,418
TDRs less than 90 days delinquent not included elsewhere	21,121	18,154	17,023
Less than 90 days delinquent | Residential mortgage loans | Personal Banking
Composition of impaired loans by portfolio segment and by class of financing receivable
Nonaccrual loans	3,962	3,498	2,652
Loans less than 90 days delinquent reviewed for impairment	0	0	0
TDRs less than 90 days delinquent not included elsewhere	5,086	5,845	3,372
Less than 90 days delinquent | Home equity loans | Personal Banking
Composition of impaired loans by portfolio segment and by class of financing receivable
Nonaccrual loans	1,872	2,963	1,519
Loans less than 90 days delinquent reviewed for impairment	0	0	0
TDRs less than 90 days delinquent not included elsewhere	1,847	1,706	1,810
Less than 90 days delinquent | Other consumer loans | Personal Banking
Composition of impaired loans by portfolio segment and by class of financing receivable
Nonaccrual loans	552	370	200
Loans less than 90 days delinquent reviewed for impairment	0	0	0
TDRs less than 90 days delinquent not included elsewhere	0	0	0
Less than 90 days delinquent | Commercial real estate loans | Business Banking
Composition of impaired loans by portfolio segment and by class of financing receivable
Nonaccrual loans	16,972	27,548	23,370
Loans less than 90 days delinquent reviewed for impairment	16,121	26,400	39,199
TDRs less than 90 days delinquent not included elsewhere	16,467	12,128	13,060
Less than 90 days delinquent | Commercial loans | Business Banking
Composition of impaired loans by portfolio segment and by class of financing receivable
Nonaccrual loans	5,036	4,103	21,723
Loans less than 90 days delinquent reviewed for impairment	2,014	5,266	5,219
TDRs less than 90 days delinquent not included elsewhere	$ 4,654	$ 6,026	$ 3,963

Loans Receivable and Allowanc75

Loans Receivable and Allowance for Loan Losses - Evaluation of Impaired Loans by Portfolio Segment and by Class of Financing Receivable (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Evaluation of impaired loans by portfolio segment and by class of financing receivable
Loans collectively evaluated for impairment	$ 7,147,649	$ 5,898,759
Loans individually evaluated for impairment	74,472	91,132
Loans individually evaluated for impairment for which there is a related impairment reserve	53,189	63,659
Related impairment reserve	5,008	8,930
Loans individually evaluated for impairment for which there is no related reserve	21,283	27,473
Personal Banking
Evaluation of impaired loans by portfolio segment and by class of financing receivable
Loans collectively evaluated for impairment	4,438,708	3,820,479
Loans individually evaluated for impairment	9,579	9,852
Loans individually evaluated for impairment for which there is a related impairment reserve	9,579	9,852
Related impairment reserve	1,844	1,363
Loans individually evaluated for impairment for which there is no related reserve	0	0
Personal Banking | Residential mortgage loans
Evaluation of impaired loans by portfolio segment and by class of financing receivable
Loans collectively evaluated for impairment	2,733,741	2,514,060
Loans individually evaluated for impairment	7,151	7,396
Loans individually evaluated for impairment for which there is a related impairment reserve	7,151	7,396
Related impairment reserve	1,189	1,116
Loans individually evaluated for impairment for which there is no related reserve	0	0
Personal Banking | Home equity loans
Evaluation of impaired loans by portfolio segment and by class of financing receivable
Loans collectively evaluated for impairment	1,184,808	1,063,741
Loans individually evaluated for impairment	2,298	2,390
Loans individually evaluated for impairment for which there is a related impairment reserve	2,298	2,390
Related impairment reserve	605	246
Loans individually evaluated for impairment for which there is no related reserve	0	0
Personal Banking | Other consumer loans
Evaluation of impaired loans by portfolio segment and by class of financing receivable
Loans collectively evaluated for impairment	520,159	242,678
Loans individually evaluated for impairment	130	66
Loans individually evaluated for impairment for which there is a related impairment reserve	130	66
Related impairment reserve	50	1
Loans individually evaluated for impairment for which there is no related reserve	0	0
Business Banking
Evaluation of impaired loans by portfolio segment and by class of financing receivable
Loans collectively evaluated for impairment	2,708,941	2,078,280
Loans individually evaluated for impairment	64,893	81,280
Loans individually evaluated for impairment for which there is a related impairment reserve	43,610	53,807
Related impairment reserve	3,164	7,567
Loans individually evaluated for impairment for which there is no related reserve	21,283	27,473
Business Banking | Commercial real estate loans
Evaluation of impaired loans by portfolio segment and by class of financing receivable
Loans collectively evaluated for impairment	2,297,599	1,734,864
Loans individually evaluated for impairment	53,835	66,320
Loans individually evaluated for impairment for which there is a related impairment reserve	35,937	42,869
Related impairment reserve	2,675	6,189
Loans individually evaluated for impairment for which there is no related reserve	17,898	23,451
Business Banking | Commercial loans
Evaluation of impaired loans by portfolio segment and by class of financing receivable
Loans collectively evaluated for impairment	411,342	343,416
Loans individually evaluated for impairment	11,058	14,960
Loans individually evaluated for impairment for which there is a related impairment reserve	7,673	10,938
Related impairment reserve	489	1,378
Loans individually evaluated for impairment for which there is no related reserve	$ 3,385	$ 4,022

Loans Receivable and Allowanc76

Loans Receivable and Allowance for Loan Losses - Roll Forward of Troubled Debt Restructurings (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2015USD ($)contract	Dec. 31, 2014USD ($)contract
Number of contract
Beginning balance | contract	248	262
Number of contracts new TDRs | contract	26	46
Number of re-modified TDRs | contract	3	11
Ending balance | contract	227	248
Roll forward of troubled debt restructurings
Beginning TDR balance:	$ 61,788	$ 79,166
New TDRs	8,537	9,460
Re-modified TDRs	6,386	3,672
Net paydowns	(13,270)	(15,825)
Ending TDR balance:	51,115	61,788
Accruing TDRs	29,997	37,329
Non-accrual TDRs	$ 21,118	$ 24,459
Residential mortgage loans
Number of contract
Number of contracts charged off | contract	0	0
Number of contracts paid off | contract	2	0
Roll forward of troubled debt restructurings
Amount of contracts charged off	$ 0	$ 0
Amount of contracts paid off	$ (109)	$ 0
Home equity loans
Number of contract
Number of contracts charged off | contract	4	1
Number of contracts paid off | contract	5	5
Roll forward of troubled debt restructurings
Amount of contracts charged off	$ (159)	$ (130)
Amount of contracts paid off	$ (194)	$ (103)
Commercial real estate loans
Number of contract
Number of contracts charged off | contract	4	10
Number of contracts paid off | contract	15	10
Roll forward of troubled debt restructurings
Amount of contracts charged off	$ (179)	$ (898)
Amount of contracts paid off	$ (9,208)	$ (1,471)
Commercial loans
Number of contract
Number of contracts charged off | contract	2	10
Number of contracts paid off | contract	14	24
Number of contracts transferred to real estate owned | contract	1	0
Roll forward of troubled debt restructurings
Amount of contracts charged off	$ (387)	$ (8,305)
Amount of contracts paid off	(1,728)	(3,778)
Transferred to real estate owned	$ (362)	$ 0

Loans Receivable and Allowanc77

Loans Receivable and Allowance for Loan Losses - Troubled Debt Restructuring (Including Re-Modified TDRs) by Portfolio Segment and by Class of Financing Receivable (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2015USD ($)contract	Dec. 31, 2014USD ($)contract	Dec. 31, 2013USD ($)contract
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	29	57	121
Recorded investment at the time of modification	$ 14,923	$ 13,132	$ 31,111
Current recorded investment	14,881	11,808	24,961
Current allowance	$ 1,245	$ 1,904	$ 1,111
Troubled debt restructurings that subsequently defaulted:
Number of contracts | contract		4	6
Recorded investment at the time of modification		$ 500	$ 891
Current recorded investment		477	830
Current allowance		$ 8	$ 34
Personal Banking
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	9	23	16
Recorded investment at the time of modification	$ 465	$ 3,372	$ 1,030
Current recorded investment	454	3,197	1,011
Current allowance	$ 42	$ 211	$ 168
Troubled debt restructurings that subsequently defaulted:
Number of contracts | contract		2	1
Recorded investment at the time of modification		$ 438	$ 70
Current recorded investment		408	70
Current allowance		$ 1	$ 0
Personal Banking | Residential mortgage loans
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	6	17	4
Recorded investment at the time of modification	$ 364	$ 2,802	$ 374
Current recorded investment	357	2,690	319
Current allowance	$ 21	$ 210	$ 50
Troubled debt restructurings that subsequently defaulted:
Number of contracts | contract		1	1
Recorded investment at the time of modification		$ 78	$ 70
Current recorded investment		77	70
Current allowance		$ 0	$ 0
Personal Banking | Home equity loans
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	3	6	12
Recorded investment at the time of modification	$ 101	$ 570	$ 656
Current recorded investment	97	507	692
Current allowance	$ 21	$ 1	$ 118
Troubled debt restructurings that subsequently defaulted:
Number of contracts | contract		1	0
Recorded investment at the time of modification		$ 360	$ 0
Current recorded investment		331	0
Current allowance		$ 1	$ 0
Personal Banking | Other consumer loans
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	0	0	0
Recorded investment at the time of modification	$ 0	$ 0	$ 0
Current recorded investment	0	0	0
Current allowance	$ 0	$ 0	$ 0
Troubled debt restructurings that subsequently defaulted:
Number of contracts | contract		0	0
Recorded investment at the time of modification		$ 0	$ 0
Current recorded investment		0	0
Current allowance		$ 0	$ 0
Business Banking
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	20	34	105
Recorded investment at the time of modification	$ 14,458	$ 9,760	$ 30,081
Current recorded investment	14,427	8,611	23,950
Current allowance	$ 1,203	$ 1,693	$ 943
Troubled debt restructurings that subsequently defaulted:
Number of contracts | contract		2	5
Recorded investment at the time of modification		$ 62	$ 821
Current recorded investment		69	760
Current allowance		$ 7	$ 34
Business Banking | Commercial real estate loans
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	11	11	58
Recorded investment at the time of modification	$ 12,258	$ 2,010	$ 16,760
Current recorded investment	12,243	1,793	11,196
Current allowance	$ 1,047	$ 202	$ 781
Troubled debt restructurings that subsequently defaulted:
Number of contracts | contract		1	4
Recorded investment at the time of modification		$ 12	$ 798
Current recorded investment		5	752
Current allowance		$ 1	$ 33
Business Banking | Commercial loans
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	9	23	47
Recorded investment at the time of modification	$ 2,200	$ 7,750	$ 13,321
Current recorded investment	2,184	6,818	12,754
Current allowance	$ 156	$ 1,491	$ 162
Troubled debt restructurings that subsequently defaulted:
Number of contracts | contract		1	1
Recorded investment at the time of modification		$ 50	$ 23
Current recorded investment		64	8
Current allowance		$ 6	$ 1

Loans Receivable and Allowanc78

Loans Receivable and Allowance for Loan Losses - Troubled Debt Restructurings by Type of Modification (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2015USD ($)contract	Dec. 31, 2014USD ($)contract	Dec. 31, 2013USD ($)contract
Troubled debt restructurings
Number of contracts | contract	29	57	121
Total	$ 14,881	$ 11,808	$ 24,961
Number of re-modified TDRs | contract	3	11
Total	$ 6,384	$ 3,595
Rate
Troubled debt restructurings
Total	341	498
Total	83	0
Payment
Troubled debt restructurings
Total	0	1,884
Total	0	0
Maturity date
Troubled debt restructurings
Total	13,336	8,356
Total	6,256	3,425
Other
Troubled debt restructurings
Total	1,204	1,070
Total	$ 45	$ 170
Personal Banking
Troubled debt restructurings
Number of contracts | contract	9	23	16
Total	$ 454	$ 3,197	$ 1,011
Number of re-modified TDRs | contract	2	1
Total	$ 128	$ 76
Personal Banking | Rate
Troubled debt restructurings
Total	167	0
Total	83	0
Personal Banking | Payment
Troubled debt restructurings
Total	0	246
Total	0	0
Personal Banking | Maturity date
Troubled debt restructurings
Total	111	2,951
Total	0	76
Personal Banking | Other
Troubled debt restructurings
Total	176	0
Total	$ 45	$ 0
Personal Banking | Residential mortgage loans
Troubled debt restructurings
Number of contracts | contract	6	17	4
Total	$ 357	$ 2,690	$ 319
Number of re-modified TDRs | contract	1	1
Total	$ 45	$ 76
Personal Banking | Residential mortgage loans | Rate
Troubled debt restructurings
Total	71	0
Total	0	0
Personal Banking | Residential mortgage loans | Payment
Troubled debt restructurings
Total	0	108
Total	0	0
Personal Banking | Residential mortgage loans | Maturity date
Troubled debt restructurings
Total	110	2,582
Total	0	76
Personal Banking | Residential mortgage loans | Other
Troubled debt restructurings
Total	176	0
Total	$ 45	$ 0
Personal Banking | Home equity loans
Troubled debt restructurings
Number of contracts | contract	3	6	12
Total	$ 97	$ 507	$ 692
Number of re-modified TDRs | contract	1	0
Total	$ 83	$ 0
Personal Banking | Home equity loans | Rate
Troubled debt restructurings
Total	96	0
Total	83	0
Personal Banking | Home equity loans | Payment
Troubled debt restructurings
Total	0	138
Total	0	0
Personal Banking | Home equity loans | Maturity date
Troubled debt restructurings
Total	1	369
Total	0	0
Personal Banking | Home equity loans | Other
Troubled debt restructurings
Total	0	0
Total	$ 0	$ 0
Personal Banking | Other consumer loans
Troubled debt restructurings
Number of contracts | contract	0	0	0
Total	$ 0	$ 0	$ 0
Number of re-modified TDRs | contract	0	0
Total	$ 0	$ 0
Personal Banking | Other consumer loans | Rate
Troubled debt restructurings
Total	0	0
Total	0	0
Personal Banking | Other consumer loans | Payment
Troubled debt restructurings
Total	0	0
Total	0	0
Personal Banking | Other consumer loans | Maturity date
Troubled debt restructurings
Total	0	0
Total	0	0
Personal Banking | Other consumer loans | Other
Troubled debt restructurings
Total	0	0
Total	$ 0	$ 0
Business Banking
Troubled debt restructurings
Number of contracts | contract	20	34	105
Total	$ 14,427	$ 8,611	$ 23,950
Number of re-modified TDRs | contract	1	10
Total	$ 6,256	$ 3,519
Business Banking | Rate
Troubled debt restructurings
Total	174	498
Total	0	0
Business Banking | Payment
Troubled debt restructurings
Total	0	1,638
Total	0	0
Business Banking | Maturity date
Troubled debt restructurings
Total	13,225	5,405
Total	6,256	3,349
Business Banking | Other
Troubled debt restructurings
Total	1,028	1,070
Total	$ 0	$ 170
Business Banking | Commercial real estate loans
Troubled debt restructurings
Number of contracts | contract	11	11	58
Total	$ 12,243	$ 1,793	$ 11,196
Number of re-modified TDRs | contract	1	5
Total	$ 6,256	$ 234
Business Banking | Commercial real estate loans | Rate
Troubled debt restructurings
Total	174	0
Total	0	0
Business Banking | Commercial real estate loans | Payment
Troubled debt restructurings
Total	0	0
Total	0	0
Business Banking | Commercial real estate loans | Maturity date
Troubled debt restructurings
Total	11,961	1,312
Total	6,256	119
Business Banking | Commercial real estate loans | Other
Troubled debt restructurings
Total	108	481
Total	$ 0	$ 115
Business Banking | Commercial loans
Troubled debt restructurings
Number of contracts | contract	9	23	47
Total	$ 2,184	$ 6,818	$ 12,754
Number of re-modified TDRs | contract	0	5
Total	$ 0	$ 3,285
Business Banking | Commercial loans | Rate
Troubled debt restructurings
Total	0	498
Total	0	0
Business Banking | Commercial loans | Payment
Troubled debt restructurings
Total	0	1,638
Total	0	0
Business Banking | Commercial loans | Maturity date
Troubled debt restructurings
Total	1,264	4,093
Total	0	3,230
Business Banking | Commercial loans | Other
Troubled debt restructurings
Total	920	589
Total	$ 0	$ 55

Loans Receivable and Allowanc79

Loans Receivable and Allowance for Loan Losses - Loan Delinquencies (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Loan payment delinquencies
Total delinquency	$ 135,228
Current	7,086,893
Total loans	7,222,121	$ 5,989,891
90 days or greater delinquent and accruing	3,750
Personal Banking
Loan payment delinquencies
Total loans	4,448,287	3,830,331
Personal Banking | Residential mortgage loans
Loan payment delinquencies
Total loans	2,740,892	2,521,456
Personal Banking | Home equity loans
Loan payment delinquencies
Total loans	1,187,106	1,066,131
Personal Banking | Other consumer loans
Loan payment delinquencies
Total loans	520,289	242,744
Business Banking
Loan payment delinquencies
Total loans	2,773,834	2,159,560
Business Banking | Commercial real estate loans
Loan payment delinquencies
Total loans	2,351,434	1,801,184
Business Banking | Commercial loans
Loan payment delinquencies
Total loans	422,400	358,376
Originated
Loan payment delinquencies
Total delinquency	120,633	100,635
Current	6,239,389	5,889,256
Total loans	6,360,022	5,989,891
90 days or greater delinquent and accruing	0
Originated | Personal Banking
Loan payment delinquencies
Total delinquency	71,854	76,596
Current	3,991,603	3,753,735
Total loans	4,063,457	3,830,331
90 days or greater delinquent and accruing	0
Originated | Personal Banking | Residential mortgage loans
Loan payment delinquencies
Total delinquency	48,608	52,109
Current	2,646,568	2,469,347
Total loans	2,695,176	2,521,456
90 days or greater delinquent and accruing	0
Originated | Personal Banking | Home equity loans
Loan payment delinquencies
Total delinquency	11,957	14,030
Current	1,043,950	1,052,101
Total loans	1,055,907	1,066,131
90 days or greater delinquent and accruing	0
Originated | Personal Banking | Other consumer loans
Loan payment delinquencies
Total delinquency	11,289	10,457
Current	301,085	232,287
Total loans	312,374	242,744
90 days or greater delinquent and accruing	0
Originated | Business Banking
Loan payment delinquencies
Total delinquency	48,779	24,039
Current	2,247,786	2,135,521
Total loans	2,296,565	2,159,560
90 days or greater delinquent and accruing	0
Originated | Business Banking | Commercial real estate loans
Loan payment delinquencies
Total delinquency	44,029	18,093
Current	1,891,128	1,783,091
Total loans	1,935,157	1,801,184
90 days or greater delinquent and accruing	0
Originated | Business Banking | Commercial loans
Loan payment delinquencies
Total delinquency	4,750	5,946
Current	356,658	352,430
Total loans	361,408	358,376
90 days or greater delinquent and accruing	0
Acquired
Loan payment delinquencies
Total delinquency	14,595
Current	847,504
Total loans	862,099
90 days or greater delinquent and accruing	3,750
Acquired | Personal Banking
Loan payment delinquencies
Total delinquency	5,173
Current	379,657
Total loans	384,830
90 days or greater delinquent and accruing	1,028
Acquired | Personal Banking | Residential mortgage loans
Loan payment delinquencies
Total delinquency	1,475
Current	44,241
Total loans	45,716
90 days or greater delinquent and accruing	540
Acquired | Personal Banking | Home equity loans
Loan payment delinquencies
Total delinquency	2,439
Current	128,760
Total loans	131,199
90 days or greater delinquent and accruing	462
Acquired | Personal Banking | Other consumer loans
Loan payment delinquencies
Total delinquency	1,259
Current	206,656
Total loans	207,915
90 days or greater delinquent and accruing	26
Acquired | Business Banking
Loan payment delinquencies
Total delinquency	9,422
Current	467,847
Total loans	477,269
90 days or greater delinquent and accruing	2,722
Acquired | Business Banking | Commercial real estate loans
Loan payment delinquencies
Total delinquency	8,107
Current	408,170
Total loans	416,277
90 days or greater delinquent and accruing	2,582
Acquired | Business Banking | Commercial loans
Loan payment delinquencies
Total delinquency	1,315
Current	59,677
Total loans	60,992
90 days or greater delinquent and accruing	140
30-59 days delinquent
Loan payment delinquencies
Total delinquency	66,595
30-59 days delinquent | Originated
Loan payment delinquencies
Total delinquency	60,380	45,985
30-59 days delinquent | Originated | Personal Banking
Loan payment delinquencies
Total delinquency	36,465	38,767
30-59 days delinquent | Originated | Personal Banking | Residential mortgage loans
Loan payment delinquencies
Total delinquency	25,503	27,443
30-59 days delinquent | Originated | Personal Banking | Home equity loans
Loan payment delinquencies
Total delinquency	4,870	5,752
30-59 days delinquent | Originated | Personal Banking | Other consumer loans
Loan payment delinquencies
Total delinquency	6,092	5,572
30-59 days delinquent | Originated | Business Banking
Loan payment delinquencies
Total delinquency	23,915	7,218
30-59 days delinquent | Originated | Business Banking | Commercial real estate loans
Loan payment delinquencies
Total delinquency	22,212	4,956
30-59 days delinquent | Originated | Business Banking | Commercial loans
Loan payment delinquencies
Total delinquency	1,703	2,262
30-59 days delinquent | Acquired
Loan payment delinquencies
Total delinquency	6,215
30-59 days delinquent | Acquired | Personal Banking
Loan payment delinquencies
Total delinquency	2,385
30-59 days delinquent | Acquired | Personal Banking | Residential mortgage loans
Loan payment delinquencies
Total delinquency	440
30-59 days delinquent | Acquired | Personal Banking | Home equity loans
Loan payment delinquencies
Total delinquency	936
30-59 days delinquent | Acquired | Personal Banking | Other consumer loans
Loan payment delinquencies
Total delinquency	1,009
30-59 days delinquent | Acquired | Business Banking
Loan payment delinquencies
Total delinquency	3,830
30-59 days delinquent | Acquired | Business Banking | Commercial real estate loans
Loan payment delinquencies
Total delinquency	2,665
30-59 days delinquent | Acquired | Business Banking | Commercial loans
Loan payment delinquencies
Total delinquency	1,165
60-89 days delinquent
Loan payment delinquencies
Total delinquency	21,615
60-89 days delinquent | Originated
Loan payment delinquencies
Total delinquency	19,190	13,324
60-89 days delinquent | Originated | Personal Banking
Loan payment delinquencies
Total delinquency	11,717	11,077
60-89 days delinquent | Originated | Personal Banking | Residential mortgage loans
Loan payment delinquencies
Total delinquency	7,541	6,970
60-89 days delinquent | Originated | Personal Banking | Home equity loans
Loan payment delinquencies
Total delinquency	1,836	1,672
60-89 days delinquent | Originated | Personal Banking | Other consumer loans
Loan payment delinquencies
Total delinquency	2,340	2,435
60-89 days delinquent | Originated | Business Banking
Loan payment delinquencies
Total delinquency	7,473	2,247
60-89 days delinquent | Originated | Business Banking | Commercial real estate loans
Loan payment delinquencies
Total delinquency	6,875	2,038
60-89 days delinquent | Originated | Business Banking | Commercial loans
Loan payment delinquencies
Total delinquency	598	209
60-89 days delinquent | Acquired
Loan payment delinquencies
Total delinquency	2,425
60-89 days delinquent | Acquired | Personal Banking
Loan payment delinquencies
Total delinquency	1,072
60-89 days delinquent | Acquired | Personal Banking | Residential mortgage loans
Loan payment delinquencies
Total delinquency	249
60-89 days delinquent | Acquired | Personal Banking | Home equity loans
Loan payment delinquencies
Total delinquency	642
60-89 days delinquent | Acquired | Personal Banking | Other consumer loans
Loan payment delinquencies
Total delinquency	181
60-89 days delinquent | Acquired | Business Banking
Loan payment delinquencies
Total delinquency	1,353
60-89 days delinquent | Acquired | Business Banking | Commercial real estate loans
Loan payment delinquencies
Total delinquency	1,353
60-89 days delinquent | Acquired | Business Banking | Commercial loans
Loan payment delinquencies
Total delinquency	0
90 days or greater delinquent
Loan payment delinquencies
Total delinquency	47,018
90 days or greater delinquent | Originated
Loan payment delinquencies
Total delinquency	41,063	41,326
90 days or greater delinquent | Originated | Personal Banking
Loan payment delinquencies
Total delinquency	23,672	26,752
90 days or greater delinquent | Originated | Personal Banking | Residential mortgage loans
Loan payment delinquencies
Total delinquency	15,564	17,696
90 days or greater delinquent | Originated | Personal Banking | Home equity loans
Loan payment delinquencies
Total delinquency	5,251	6,606
90 days or greater delinquent | Originated | Personal Banking | Other consumer loans
Loan payment delinquencies
Total delinquency	2,857	2,450
90 days or greater delinquent | Originated | Business Banking
Loan payment delinquencies
Total delinquency	17,391	14,574
90 days or greater delinquent | Originated | Business Banking | Commercial real estate loans
Loan payment delinquencies
Total delinquency	14,942	11,099
90 days or greater delinquent | Originated | Business Banking | Commercial loans
Loan payment delinquencies
Total delinquency	2,449	$ 3,475
90 days or greater delinquent | Acquired
Loan payment delinquencies
Total delinquency	5,955
90 days or greater delinquent | Acquired | Personal Banking
Loan payment delinquencies
Total delinquency	1,716
90 days or greater delinquent | Acquired | Personal Banking | Residential mortgage loans
Loan payment delinquencies
Total delinquency	786
90 days or greater delinquent | Acquired | Personal Banking | Home equity loans
Loan payment delinquencies
Total delinquency	861
90 days or greater delinquent | Acquired | Personal Banking | Other consumer loans
Loan payment delinquencies
Total delinquency	69
90 days or greater delinquent | Acquired | Business Banking
Loan payment delinquencies
Total delinquency	4,239
90 days or greater delinquent | Acquired | Business Banking | Commercial real estate loans
Loan payment delinquencies
Total delinquency	4,089
90 days or greater delinquent | Acquired | Business Banking | Commercial loans
Loan payment delinquencies
Total delinquency	$ 150

Loans Receivable and Allowanc80

Loans Receivable and Allowance for Loan Losses - Credit Quality Indicators (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Credit quality indicators
Total loans	$ 7,222,121	$ 5,989,891
Pass
Credit quality indicators
Total loans	6,952,327
Special mention
Credit quality indicators
Total loans	77,120
Substandard
Credit quality indicators
Total loans	190,109
Doubtful
Credit quality indicators
Total loans	1,225
Loss
Credit quality indicators
Total loans	1,340
Special mention or substandard | Minimum
Credit quality indicators
Total loans	1,000
Personal Banking
Credit quality indicators
Total loans	4,448,287	3,830,331
Personal Banking | Residential mortgage loans
Credit quality indicators
Total loans	2,740,892	2,521,456
Personal Banking | Home equity loans
Credit quality indicators
Total loans	1,187,106	1,066,131
Personal Banking | Other consumer loans
Credit quality indicators
Total loans	520,289	242,744
Business Banking
Credit quality indicators
Total loans	2,773,834	2,159,560
Business Banking | Commercial real estate loans
Credit quality indicators
Total loans	2,351,434	1,801,184
Business Banking | Commercial loans
Credit quality indicators
Total loans	422,400	358,376
Originated
Credit quality indicators
Total loans	6,360,022	5,989,891
Originated | Pass
Credit quality indicators
Total loans	6,116,454	5,712,244
Originated | Special mention
Credit quality indicators
Total loans	69,541	60,598
Originated | Substandard
Credit quality indicators
Total loans	171,462	212,948
Originated | Doubtful
Credit quality indicators
Total loans	1,225	2,677
Originated | Loss
Credit quality indicators
Total loans	1,340	1,424
Originated | Personal Banking
Credit quality indicators
Total loans	4,063,457	3,830,331
Originated | Personal Banking | Pass
Credit quality indicators
Total loans	4,038,859	3,807,741
Originated | Personal Banking | Special mention
Credit quality indicators
Total loans	0	0
Originated | Personal Banking | Substandard
Credit quality indicators
Total loans	23,258	21,166
Originated | Personal Banking | Doubtful
Credit quality indicators
Total loans	0	0
Originated | Personal Banking | Loss
Credit quality indicators
Total loans	1,340	1,424
Originated | Personal Banking | Residential mortgage loans
Credit quality indicators
Total loans	2,695,176	2,521,456
Originated | Personal Banking | Residential mortgage loans | Pass
Credit quality indicators
Total loans	2,680,562	2,507,269
Originated | Personal Banking | Residential mortgage loans | Special mention
Credit quality indicators
Total loans	0	0
Originated | Personal Banking | Residential mortgage loans | Substandard
Credit quality indicators
Total loans	13,274	12,763
Originated | Personal Banking | Residential mortgage loans | Doubtful
Credit quality indicators
Total loans	0	0
Originated | Personal Banking | Residential mortgage loans | Loss
Credit quality indicators
Total loans	1,340	1,424
Originated | Personal Banking | Home equity loans
Credit quality indicators
Total loans	1,055,907	1,066,131
Originated | Personal Banking | Home equity loans | Pass
Credit quality indicators
Total loans	1,048,397	1,059,525
Originated | Personal Banking | Home equity loans | Special mention
Credit quality indicators
Total loans	0	0
Originated | Personal Banking | Home equity loans | Substandard
Credit quality indicators
Total loans	7,510	6,606
Originated | Personal Banking | Home equity loans | Doubtful
Credit quality indicators
Total loans	0	0
Originated | Personal Banking | Home equity loans | Loss
Credit quality indicators
Total loans	0	0
Originated | Personal Banking | Other consumer loans
Credit quality indicators
Total loans	312,374	242,744
Originated | Personal Banking | Other consumer loans | Pass
Credit quality indicators
Total loans	309,900	240,947
Originated | Personal Banking | Other consumer loans | Special mention
Credit quality indicators
Total loans	0	0
Originated | Personal Banking | Other consumer loans | Substandard
Credit quality indicators
Total loans	2,474	1,797
Originated | Personal Banking | Other consumer loans | Doubtful
Credit quality indicators
Total loans	0	0
Originated | Personal Banking | Other consumer loans | Loss
Credit quality indicators
Total loans	0	0
Originated | Business Banking
Credit quality indicators
Total loans	2,296,565	2,159,560
Originated | Business Banking | Pass
Credit quality indicators
Total loans	2,077,595	1,904,503
Originated | Business Banking | Special mention
Credit quality indicators
Total loans	69,541	60,598
Originated | Business Banking | Substandard
Credit quality indicators
Total loans	148,204	191,782
Originated | Business Banking | Doubtful
Credit quality indicators
Total loans	1,225	2,677
Originated | Business Banking | Loss
Credit quality indicators
Total loans	0	0
Originated | Business Banking | Commercial real estate loans
Credit quality indicators
Total loans	1,935,157	1,801,184
Originated | Business Banking | Commercial real estate loans | Pass
Credit quality indicators
Total loans	1,778,140	1,618,269
Originated | Business Banking | Commercial real estate loans | Special mention
Credit quality indicators
Total loans	46,518	36,908
Originated | Business Banking | Commercial real estate loans | Substandard
Credit quality indicators
Total loans	110,384	145,502
Originated | Business Banking | Commercial real estate loans | Doubtful
Credit quality indicators
Total loans	115	505
Originated | Business Banking | Commercial real estate loans | Loss
Credit quality indicators
Total loans	0	0
Originated | Business Banking | Commercial loans
Credit quality indicators
Total loans	361,408	358,376
Originated | Business Banking | Commercial loans | Pass
Credit quality indicators
Total loans	299,455	286,234
Originated | Business Banking | Commercial loans | Special mention
Credit quality indicators
Total loans	23,023	23,690
Originated | Business Banking | Commercial loans | Substandard
Credit quality indicators
Total loans	37,820	46,280
Originated | Business Banking | Commercial loans | Doubtful
Credit quality indicators
Total loans	1,110	2,172
Originated | Business Banking | Commercial loans | Loss
Credit quality indicators
Total loans	0	$ 0
Acquired
Credit quality indicators
Total loans	862,099
Acquired | Pass
Credit quality indicators
Total loans	835,873
Acquired | Special mention
Credit quality indicators
Total loans	7,579
Acquired | Substandard
Credit quality indicators
Total loans	18,647
Acquired | Doubtful
Credit quality indicators
Total loans	0
Acquired | Loss
Credit quality indicators
Total loans	0
Acquired | Personal Banking
Credit quality indicators
Total loans	384,830
Acquired | Personal Banking | Pass
Credit quality indicators
Total loans	383,114
Acquired | Personal Banking | Special mention
Credit quality indicators
Total loans	0
Acquired | Personal Banking | Substandard
Credit quality indicators
Total loans	1,716
Acquired | Personal Banking | Doubtful
Credit quality indicators
Total loans	0
Acquired | Personal Banking | Loss
Credit quality indicators
Total loans	0
Acquired | Personal Banking | Residential mortgage loans
Credit quality indicators
Total loans	45,716
Acquired | Personal Banking | Residential mortgage loans | Pass
Credit quality indicators
Total loans	44,930
Acquired | Personal Banking | Residential mortgage loans | Special mention
Credit quality indicators
Total loans	0
Acquired | Personal Banking | Residential mortgage loans | Substandard
Credit quality indicators
Total loans	786
Acquired | Personal Banking | Residential mortgage loans | Doubtful
Credit quality indicators
Total loans	0
Acquired | Personal Banking | Residential mortgage loans | Loss
Credit quality indicators
Total loans	0
Acquired | Personal Banking | Home equity loans
Credit quality indicators
Total loans	131,199
Acquired | Personal Banking | Home equity loans | Pass
Credit quality indicators
Total loans	130,338
Acquired | Personal Banking | Home equity loans | Special mention
Credit quality indicators
Total loans	0
Acquired | Personal Banking | Home equity loans | Substandard
Credit quality indicators
Total loans	861
Acquired | Personal Banking | Home equity loans | Doubtful
Credit quality indicators
Total loans	0
Acquired | Personal Banking | Home equity loans | Loss
Credit quality indicators
Total loans	0
Acquired | Personal Banking | Other consumer loans
Credit quality indicators
Total loans	207,915
Acquired | Personal Banking | Other consumer loans | Pass
Credit quality indicators
Total loans	207,846
Acquired | Personal Banking | Other consumer loans | Special mention
Credit quality indicators
Total loans	0
Acquired | Personal Banking | Other consumer loans | Substandard
Credit quality indicators
Total loans	69
Acquired | Personal Banking | Other consumer loans | Doubtful
Credit quality indicators
Total loans	0
Acquired | Personal Banking | Other consumer loans | Loss
Credit quality indicators
Total loans	0
Acquired | Business Banking
Credit quality indicators
Total loans	477,269
Acquired | Business Banking | Pass
Credit quality indicators
Total loans	452,759
Acquired | Business Banking | Special mention
Credit quality indicators
Total loans	7,579
Acquired | Business Banking | Substandard
Credit quality indicators
Total loans	16,931
Acquired | Business Banking | Doubtful
Credit quality indicators
Total loans	0
Acquired | Business Banking | Loss
Credit quality indicators
Total loans	0
Acquired | Business Banking | Commercial real estate loans
Credit quality indicators
Total loans	416,277
Acquired | Business Banking | Commercial real estate loans | Pass
Credit quality indicators
Total loans	392,811
Acquired | Business Banking | Commercial real estate loans | Special mention
Credit quality indicators
Total loans	6,872
Acquired | Business Banking | Commercial real estate loans | Substandard
Credit quality indicators
Total loans	16,594
Acquired | Business Banking | Commercial real estate loans | Doubtful
Credit quality indicators
Total loans	0
Acquired | Business Banking | Commercial real estate loans | Loss
Credit quality indicators
Total loans	0
Acquired | Business Banking | Commercial loans
Credit quality indicators
Total loans	60,992
Acquired | Business Banking | Commercial loans | Pass
Credit quality indicators
Total loans	59,948
Acquired | Business Banking | Commercial loans | Special mention
Credit quality indicators
Total loans	707
Acquired | Business Banking | Commercial loans | Substandard
Credit quality indicators
Total loans	337
Acquired | Business Banking | Commercial loans | Doubtful
Credit quality indicators
Total loans	0
Acquired | Business Banking | Commercial loans | Loss
Credit quality indicators
Total loans	$ 0

Loans Receivable and Allowanc81

Loans Receivable and Allowance for Loan Losses - Off-Balance Sheet Financial Instruments (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Financial instruments with off-balance-sheet risk
Financial instruments with off-balance-sheet risk	$ 781,734,000	$ 638,850,000
Recourse provisions for recovery of amounts from third parties	0	0
Loan commitments
Financial instruments with off-balance-sheet risk
Financial instruments with off-balance-sheet risk	186,731,000	186,637,000
Outstanding loan commitments for fixed rate loans	81,800,000
Outstanding loan commitments for adjustable rate loans	104,900,000
Undisbursed lines of credit
Financial instruments with off-balance-sheet risk
Financial instruments with off-balance-sheet risk	562,284,000	428,649,000
Standby letters of credit
Financial instruments with off-balance-sheet risk
Financial instruments with off-balance-sheet risk	32,719,000	23,564,000
Maximum potential amount of future payments	32,700,000
Maximum potential amount of future payments fully collateralized	24,000,000
Liability recognized for the obligations	$ 1,300,000	$ 1,100,000

Accrued Interest Receivable (De

Accrued Interest Receivable (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Accrued Interest Receivable
Investment securities	$ 1,852	$ 2,229
Mortgage-backed securities	960	875
Loans receivable	18,260	15,519
Accrued interest receivable	$ 21,072	$ 18,623

Federal Home Loan Bank Stock (D

Federal Home Loan Bank Stock (Details) - Federal Home Loan Bank of Pittsburgh $ in Millions	12 Months Ended
	Dec. 31, 2015USD ($)capital_stock	Dec. 31, 2014USD ($)
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Number of subclasses of capital stock required to invest in for membership | capital_stock	2
Dividend received on capital stock | $	$ 2.8	$ 1.8
Subclass B-1
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Investment in capital stock of FHLB, at cost, as a percent of member asset value, as defined by FHLB	0.10%
Subclass B-1 | Minimum
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Investment in capital stock of FHLB, at cost, as a percent of member asset value, as defined by FHLB	0.05%
Subclass B-1 | Maximum
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Investment in capital stock of FHLB, at cost, as a percent of member asset value, as defined by FHLB	1.00%
Subclass B-2
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Investment in capital stock of FHLB, at cost, as a percent of borrowings outstanding	4.00%
Investment in capital stock of FHLB, at cost, as a percent of acquired member assets	0.00%
Investment in capital stock of FHLB, at cost, as a percent of certain letters of credit	0.75%
Investment in capital stock of FHLB, at cost, as a percent of outstanding advance commitments settling more than 30 days after trade	4.00%
Subclass B-2 | Minimum
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Investment in capital stock of FHLB, at cost, as a percent of borrowings outstanding	2.00%
Investment in capital stock of FHLB, at cost, as a percent of acquired member assets	0.00%
Investment in capital stock of FHLB, at cost, as a percent of certain letters of credit	0.00%
Investment in capital stock of FHLB, at cost, as a percent of outstanding advance commitments settling more than 30 days after trade	0.00%
Subclass B-2 | Maximum
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Investment in capital stock of FHLB, at cost, as a percent of borrowings outstanding	6.00%
Investment in capital stock of FHLB, at cost, as a percent of acquired member assets	6.00%
Investment in capital stock of FHLB, at cost, as a percent of certain letters of credit	4.00%
Investment in capital stock of FHLB, at cost, as a percent of outstanding advance commitments settling more than 30 days after trade	6.00%

Premises and Equipment - By Maj

Premises and Equipment - By Major Classification (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Premises and Equipment
Total, at cost	$ 311,075	$ 300,116
Less accumulated depreciation and amortization	(156,724)	(156,207)
Premises and equipment, net	154,351	143,909
Depreciation and amortization expense	13,300	12,000	$ 11,900
Land and land improvements
Premises and Equipment
Total, at cost	23,257	20,084
Office buildings and improvements
Premises and Equipment
Total, at cost	153,003	150,745
Furniture, fixtures and equipment
Premises and Equipment
Total, at cost	115,576	116,975
Leasehold improvements
Premises and Equipment
Total, at cost	$ 19,239	$ 12,312

Premises and Equipment - Minimu

Premises and Equipment - Minimum Annual Rentals by Fiscal Year (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Minimum annual rentals
2,016	$ 4,553
2,017	3,493
2,018	2,572
2,019	1,620
2,020	1,329
Thereafter	3,388
Total	16,955
Rental expense	$ 4,600	$ 4,400	$ 4,200

Goodwill and Other Intangible86

Goodwill and Other Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Amortizable intangible assets:
Amortization expense	$ 1,688	$ 1,323	$ 1,210
Estimated amortization expense
For the year ending December 31, 2016	2,591
For the year ending December 31, 2017	2,090
For the year ending December 31, 2018	1,658
For the year ending December 31, 2019	1,226
For the year ending December 31, 2020	794
Core Deposits
Amortizable intangible assets:
Intangible asset - gross	30,578	30,578
Acquisitions	7,375	0
Less: accumulated amortization	(31,192)	(30,578)
Intangible asset - net	6,761	0
Customer and Contract
Amortizable intangible assets:
Intangible asset - gross	8,234	6,197
Acquisitions	262	2,037
Less: accumulated amortization	(6,275)	(5,201)
Intangible asset - net	$ 2,221	$ 3,033

Goodwill and Other Intangible87

Goodwill and Other Intangible Assets - Changes in the Carrying Amount of Goodwill (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Changes in the carrying amount of goodwill
Balance at the beginning of the period	$ 175,323	$ 174,644
Goodwill acquired	86,413	679
Balance at the end of the period	261,736	175,323
Community Banks
Changes in the carrying amount of goodwill
Balance at the beginning of the period	173,710	173,031
Goodwill acquired	86,413	679
Balance at the end of the period	260,123	173,710
Consumer Finance
Changes in the carrying amount of goodwill
Balance at the beginning of the period	1,613	1,613
Goodwill acquired	0	0
Balance at the end of the period	$ 1,613	$ 1,613

Deposits (Details)

Deposits (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Deposits [Abstract]
Savings deposits	$ 1,386,017,000	$ 1,209,287,000
Interest-bearing demand deposits	1,080,086,000	874,623,000
Noninterest-bearing demand deposits	1,177,256,000	891,248,000
Money market demand accounts	1,274,504,000	1,179,070,000
Time deposits	1,694,718,000	1,478,314,000
Total deposits	6,612,581,000	5,632,542,000
Aggregate amount of certificates of deposit with a minimum denomination of $100,000	518,700,000	351,900,000
Maximum amount of customer deposits that are federally insured	250,000
Deposits in accounts exceeding $250,000	1,327,000,000
Contractual maturity of the certificate accounts
Due within 12 months	929,351,000	647,699,000
Due between 12 and 24 months	448,497,000	392,484,000
Due between 24 and 36 months	205,635,000	319,995,000
Due between 36 and 48 months	21,414,000	92,527,000
Due between 48 and 60 months	78,796,000	15,307,000
After 60 months	11,025,000	10,302,000
Total time deposits	1,694,718,000	1,478,314,000
Interest expense incurred on deposits
Savings deposits	3,387,000	3,286,000	$ 3,595,000
Interest-bearing demand deposits	568,000	587,000	576,000
Money market demand accounts	3,222,000	3,174,000	3,042,000
Time deposits	16,878,000	18,275,000	22,066,000
Total interest expense	$ 24,055,000	$ 25,322,000	$ 29,279,000

Borrowed Funds (Details)

Borrowed Funds (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Debt Instrument [Line Items]
Total borrowed funds, Amount	$ 975,007,000	$ 888,109,000
Term notes payable to the FHLB of Pittsburgh:
Debt Instrument [Line Items]
Due within one year, Amount	145,343,000	110,000,000
Due between one and two years, Amount	125,000,000	145,395,000
Due between two and three years, Amount	140,000,000	125,000,000
Due between three and four years, Amount	125,000,000	125,000,000
Due between four and five years, Amount	95,000,000	125,000,000
Due between five and ten years, Amount	120,000,000	95,000,000
Total borrowed funds, Amount	$ 750,343,000	$ 725,395,000
Due within one year, Average rate	3.24%	2.53%
Due between one and two years, Average rate	3.68%	3.24%
Due between two and three years, Average rate	3.73%	3.68%
Due between three and four years, Average rate	4.32%	4.03%
Due between four and five years, Average rate	3.65%	4.32%
Due between five and ten years, Average rate	3.68%	3.75%
Revolving line of credit, FHLB of Pittsburgh
Debt Instrument [Line Items]
Revolving line of credit, FHLB of Pittsburgh, Amount	$ 106,000,000	$ 0
Revolving line of credit, FHLB of Pittsburgh, Average rate	0.43%	0.00%
Maximum commitment	$ 150,000,000
Collateralized borrowings, due within one year
Debt Instrument [Line Items]
Due within one year, Amount	$ 118,664,000	$ 162,714,000
Due within one year, Average rate	0.22%	0.27%
Average amount of agreements outstanding	$ 144,700,000	$ 155,700,000	$ 150,100,000
Maximum amount of outstanding security repurchase agreement	$ 166,400,000	$ 174,200,000	$ 171,800,000

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended												12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Allocation of total income tax
Income before income taxes	$ 8,684	$ 5,238	$ 7,213	$ 6,825	$ 6,190	$ 5,926	$ 4,435	$ 5,244	$ 9,095	$ 5,727	$ 5,020	$ 6,357	$ 27,960	$ 21,795	$ 26,199
Shareholders’ equity for unrealized (loss)/ gain on securities available-for-sale													(85)	4,286	(12,177)
Shareholders’ equity for tax benefit for excess of fair value above cost of stock benefit plans													(332)	(945)	(635)
Shareholders’ equity for pension adjustment													(848)	(12,985)	9,904
Shareholders’ equity for swap fair value adjustment													699	618	1,714
Unallocated income tax													27,394	12,769	25,005
Income tax expense applicable to income before taxes
Current													21,670	13,200	24,937
Deferred													6,290	8,595	1,262
Total provision for income taxes	8,684	$ 5,238	$ 7,213	$ 6,825	6,190	$ 5,926	$ 4,435	$ 5,244	$ 9,095	$ 5,727	$ 5,020	$ 6,357	$ 27,960	$ 21,795	$ 26,199
Reconciliation of the expected federal statutory income tax rate to the effective rate
Expected tax rate (as a percent)													35.00%	35.00%	35.00%
Tax-exempt interest income (as a percent)													(3.00%)	(4.10%)	(4.30%)
State income tax, net of federal benefit (as a percent)													2.90%	1.70%	2.10%
Bank-owned life insurance (as a percent)													(1.70%)	(1.80%)	(1.90%)
Dividends on stock plans (as a percent)													(0.80%)	(4.00%)	(1.10%)
Low income housing and historic tax credits (as a percent)													(1.40%)	(0.90%)	(1.60%)
Non-deductible acquisition expense (as a percent)													0.50%	0.00%	0.00%
Other (as a percent)													0.10%	0.10%	0.10%
Effective tax rate (as a percent)													31.60%	26.00%	28.30%
Deferred tax assets:
Deferred fee income	189				193								$ 189	$ 193
Deferred compensation expense	3,717				3,688								3,717	3,688
Bad debts	19,478				19,851								19,478	19,851
Accrued postretirement benefit cost	644				724								644	724
Stock benefit plans	1,626				1,523								1,626	1,523
Writedown of investment securities	2,994				3,155								2,994	3,155
Accrued expenses	228				105								228	105
Pension and postretirement benefits	16,035				15,187								16,035	15,187
Unrealized loss on the fair value of derivatives	1,496				2,195								1,496	2,195
Purchase accounting	2,236				0								2,236	0
Other	325				361								325	361
Total deferred tax assets	48,968				46,982								48,968	46,982
Deferred tax liabilities:
Pension expense	7,557				4,487								7,557	4,487
Marketable securities available for sale	2,122				2,207								2,122	2,207
Purchase accounting	0				1,842								0	1,842
Intangible assets	23,003				20,324								23,003	20,324
Mortgage servicing rights	120				313								120	313
Fixed assets	8,731				8,038								8,731	8,038
Other	460				475								460	475
Total deferred tax liabilities	41,993				37,686								41,993	37,686
Net deferred tax asset	$ 6,975				$ 9,296								$ 6,975	$ 9,296

Income Taxes - Narrative (Detai

Income Taxes - Narrative (Details) - USD ($)	Dec. 31, 2015	Aug. 14, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Valuation allowance for deferred tax assets	$ 0
Operating loss carryforwards
Deferred tax liabilities related to acquisition	41,993,000		$ 37,686,000
Unrecognized tax benefits liability	0
Accrued amount of payment of interest or penalties	0
Federal
Operating loss carryforwards
Net operating losses	9,400,000
Expected income tax refund	$ 3,200,000
LNB
Operating loss carryforwards
Deferred tax liabilities related to acquisition		$ 3,700,000

Shareholders' Equity (Details)

Shareholders' Equity (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Stockholders' Equity Note [Abstract]
Bad debt deductions for which no deferred income taxes have been provided	$ 39.1	$ 39.1

Earnings Per Share - Narrative

Earnings Per Share - Narrative (Details) - Stock options - $ / shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Antidilutive securities excluded from the calculation of earnings per share
Options excluded from the calculation of earnings per share (in shares)	524,250
Weighted average share price during the reporting period (in dollars per share)	$ 13.15
Average share price during the reporting period (in dollars per share)	$ 12.64	$ 13.34	$ 13.25

Earnings Per Share - Computatio

Earnings Per Share - Computation of Basic and Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended												12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Earnings Per Share [Abstract]
Net income available to common shareholders	$ 16,193	$ 12,872	$ 15,305	$ 16,170	$ 17,345	$ 17,332	$ 12,674	$ 14,611	$ 20,372	$ 17,567	$ 13,435	$ 15,185	$ 60,540	$ 61,962	$ 66,559
Weighted average common shares outstanding													94,314,420	91,535,298	90,626,324
Dilutive potential shares due to effect of stock options													515,369	739,699	844,489
Total weighted average common shares and dilutive potential shares													94,829,789	92,274,997	91,470,813
Basic earnings per share (in dollars per share)	$ 0.16	$ 0.14	$ 0.17	$ 0.18	$ 0.19	$ 0.19	$ 0.14	$ 0.16	$ 0.22	$ 0.19	$ 0.15	$ 0.17	$ 0.64	$ 0.68	$ 0.73
Diluted earnings per share (in dollars per share)	$ 0.16	$ 0.13	$ 0.17	$ 0.18	$ 0.19	$ 0.19	$ 0.14	$ 0.16	$ 0.22	$ 0.19	$ 0.15	$ 0.17	$ 0.64	$ 0.67	$ 0.73

Employee Benefit Plans - Pensio

Employee Benefit Plans - Pension Plans, Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Defined Contribution Plan Disclosure [Line Items]
Total expense for all retirement plans	$ 4.6	$ 1	$ 4.1
Postretirement Healthcare Plan
Defined Contribution Plan Disclosure [Line Items]
Employer matching contribution	50.00%
Employee matching contribution	6.00%

Employee Benefit Plans - Compon

Employee Benefit Plans - Components of Net Periodic Pension Cost and Other Amounts Recognized In OCI (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Components of net periodic pension cost
Service cost	$ 0	$ 0	$ 0
Pension Plans
Components of net periodic pension cost
Service cost	5,721	4,138	4,551
Interest cost	6,125	5,827	5,203
Expected return on plan assets	(10,371)	(9,663)	(8,551)
Net amortization and deferral	1,375	(897)	1,356
Net periodic pension (benefit)/ cost	2,850	(595)	2,559
Changes in the defined benefit pension plans’ plan assets and benefit obligations recognized in other comprehensive income
Net loss/ (gain)	(420)	30,779	(27,568)
Prior service cost/ (credit)	0	0	(14)
Amortization of prior service cost	2,323	2,322	2,321
Total recognized in other comprehensive income	1,903	33,101	(25,261)
Total recognized in net periodic pension cost and other comprehensive income/ (loss)	$ 4,753	32,506	(22,702)
Postretirement Healthcare Plan
Employee benefit plans
Defined Benefit Plan, Requisite Service Age, Minimum	55 years
Components of net periodic pension cost
Service cost	$ 0	0
Interest cost	58	65	63
Net amortization and deferral	60	48	53
Net periodic pension (benefit)/ cost	118	113	116
Changes in the defined benefit pension plans’ plan assets and benefit obligations recognized in other comprehensive income
Net loss/ (gain)	273	195	(136)
Total recognized in other comprehensive income	273	195	(136)
Total recognized in net periodic pension cost and other comprehensive income/ (loss)	391	$ 308	$ (20)
Estimated net loss for the postretirement healthcare benefit plan that will be amortized from accumulated other comprehensive income into net periodic benefit cost over the next year	$ 90

Employee Benefit Plans - Define

Employee Benefit Plans - Defined Benefit Pension Plans' Funded Status (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Change in benefit obligation:
Service cost	$ 0	$ 0	$ 0
Pension Plans
Estimated net loss and prior service cost that will be amortized from accumulated other comprehensive income into net periodic cost over the next year
Estimated net loss that will be amortized from accumulated other comprehensive income into net periodic cost over the next year	3,600,000
Prior service credit that will be amortized from accumulated other comprehensive income into net periodic cost over the next year	(2,300,000)
Change in benefit obligation:
Benefit obligation at beginning of year	159,587,000	121,767,000
Service cost	5,721,000	4,138,000	4,551,000
Interest cost	6,125,000	5,827,000	5,203,000
Acquisition	5,662,000	0
Actuarial (gain)/ loss	(9,357,000)	31,722,000
Benefits paid	(5,605,000)	(3,867,000)
Benefit obligation at end of year	162,133,000	159,587,000	121,767,000
Change in plan assets:
Fair value of plan assets at beginning of year	140,183,000	130,491,000
Actual return on plan assets	(2,264,000)	9,181,000
Employer contributions	6,460,000	4,378,000
Acquisition	4,881,000	0
Benefits paid	(5,605,000)	(3,867,000)
Fair value of plan assets at end of period	143,655,000	140,183,000	$ 130,491,000
Funded status at end of year	$ (18,478,000)	$ (19,404,000)
Assumptions used to develop the net periodic pension cost
Discount rate	3.89%	4.86%	4.06%
Expected long-term rate of return on assets	7.50%	7.50%	7.50%
Rate of increase in compensation levels	3.00%	3.00%	3.00%
Assumptions used to determine benefit obligations
Discount rate	4.25%	3.89%	4.86%
Expected long-term rate of return on assets	7.00%	7.50%	7.50%
Rate of increase in compensation levels	3.00%	3.00%	3.00%
Postretirement Healthcare Plan
Change in benefit obligation:
Benefit obligation at beginning of year	$ 1,565,000	$ 1,425,000
Service cost	0	0
Interest cost	58,000	65,000	$ 63,000
Actuarial (gain)/ loss	333,000	243,000
Benefits paid	(219,000)	(168,000)
Benefit obligation at end of year	1,737,000	1,565,000	1,425,000
Change in plan assets:
Fair value of plan assets at beginning of year	0	0
Employer contributions	219,000	168,000
Benefits paid	(219,000)	(168,000)
Fair value of plan assets at end of period	0	0	$ 0
Funded status at end of year	$ (1,737,000)	$ (1,565,000)
Assumptions used to develop the net periodic pension cost
Discount rate	3.89%	4.86%	4.06%
Monthly cost of healthcare insurance per beneficiary	$ 470	$ 384	$ 351
Annual rate of increase in healthcare costs	4.00%	4.00%	4.00%

Employee Benefit Plans - Fair V

Employee Benefit Plans - Fair Value of Plan Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Pension Plans
Employee benefit plans
Accumulated benefit obligation for funded defined benefit pension plan	$ 155,900	$ 153,900	$ 116,800
Accumulated benefit obligation for unfunded defined benefit pension plan	6,300	5,600	5,000
Accumulated benefit obligation in excess of plan assets
Projected benefit obligation	162,133	159,587	121,767
Accumulated benefit obligation	162,133	159,587
Fair value of plan assets	$ 143,655	$ 140,183	130,491
Target allocation of any one stock, maximum (as a percent)	10.00%
Maximum average maturity of bond portfolio	10 years
Target Allocation
Total (as a percent)	100.00%	100.00%
Pension Plans | Debt securities
Accumulated benefit obligation in excess of plan assets
Target Allocation of securities, minimum (as a percent)	20.00%
Target Allocation of securities, maximum (as a percent)	50.00%
Target Allocation
Target Allocation of securities, minimum (as a percent)	20.00%
Target Allocation of securities, maximum (as a percent)	50.00%
Total (as a percent)	20.00%	20.00%
Pension Plans | Equity securities
Accumulated benefit obligation in excess of plan assets
Target Allocation of securities, minimum (as a percent)	30.00%
Target Allocation of securities, maximum (as a percent)	60.00%
Target Allocation
Target Allocation of securities, minimum (as a percent)	30.00%
Target Allocation of securities, maximum (as a percent)	60.00%
Total (as a percent)	69.00%	71.00%
Pension Plans | Other
Accumulated benefit obligation in excess of plan assets
Target Allocation of securities, minimum (as a percent)	5.00%
Target Allocation of securities, maximum (as a percent)	50.00%
Target Allocation
Target Allocation of securities, minimum (as a percent)	5.00%
Target Allocation of securities, maximum (as a percent)	50.00%
Total (as a percent)	11.00%	9.00%
Pension Plans | Minimum
Accumulated benefit obligation in excess of plan assets
Anticipated contribution	$ 4,000
Pension Plans | Maximum
Accumulated benefit obligation in excess of plan assets
Anticipated contribution	8,000
Postretirement Healthcare Plan
Accumulated benefit obligation in excess of plan assets
Projected benefit obligation	1,737	$ 1,565	1,425
Accumulated benefit obligation	1,737	1,565
Fair value of plan assets	$ 0	$ 0	$ 0

Employee Benefit Plans - Pens99

Employee Benefit Plans - Pension Plan Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Pension Plans
Employee benefit plans
Fair value of plan assets	$ 143,655	$ 140,183	$ 130,491
Benefits expected to be paid in each year
2,016	4,500
2,017	4,700
2,018	5,000
2,019	5,500
2,020	5,800
2020 to 2024	34,900
Pension Plans | Level 1 | Mutual funds — debt
Employee benefit plans
Fair value of plan assets	28,316	27,635
Pension Plans | Level 1 | Mutual funds — equity
Employee benefit plans
Fair value of plan assets	98,517	99,009
Pension Plans | Level 1 | Cash and cash equivalents
Employee benefit plans
Fair value of plan assets	16,822	13,539
Postretirement Healthcare Plan
Employee benefit plans
Fair value of plan assets	$ 0	$ 0	$ 0
Effect of 1-percent increase in the assumed health care cost trend rates
Effect of 1-percent increase on health care cost percentage	5.00%
Effect of 1-percent increase in assumed health care cost trend rates on interest cost in current period	$ 10
Effect of 1-percent increase in assumed health care cost trend rates on postretirement benefit obligation	$ 74

Employee Benefit Plans - Employ

Employee Benefit Plans - Employee Stock Ownership Plan (Details) - Employee Stock Ownership Plan - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Employee stock ownership plan
Minimum employee age required to participate in the plan	21 years
Period of service to be completed to participate in the plan	12 months
Minimum number of working hours required for employees to participate in the plan	1000 hours
Outstanding balance of loan	$ 21,700
Compensation expense	$ 335	$ 3,000	$ 1,700
Number of shares to be released each December 31	126,280
Number of shares of common stock unallocated	1,767,930
Unallocated shares, fair value	$ 23,700

Employee Benefit Plans - Share-

Employee Benefit Plans - Share-Based Awards (Details) - USD ($) $ / shares in Units, $ in Millions	May. 20, 2015	May. 19, 2015	May. 21, 2014	May. 15, 2013	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Apr. 20, 2011
Restricted common shares
Recognition and Retention Plan and Stock Option Plans
Weighted average grant date fair value of shares issued (in dollars per share)	$ 12.31		$ 13.22	$ 12.55
Market value of shares issued	$ 3.8		$ 3.6	$ 3.4
Number of shares forfeited					77,718
Vesting period					10 years
Restricted common shares | 2011 Equity Incentive Plan
Recognition and Retention Plan and Stock Option Plans
Number of shares authorized								2,806,233
Number of shares forfeited					259,778
Restricted common shares | 2013 issuance
Recognition and Retention Plan and Stock Option Plans
Percentage of granted awards which will vest					30.00%
Restricted common shares | 2014 issuance
Recognition and Retention Plan and Stock Option Plans
Percentage of granted awards which will vest					20.00%
Restricted common shares | 2015 issuance
Recognition and Retention Plan and Stock Option Plans
Percentage of granted awards which will vest					10.00%
Stock options
Recognition and Retention Plan and Stock Option Plans
Vesting period		10 years			10 years
Exercise period		10 years
Number
Balance at beginning of year (in shares)					6,402,407	6,816,294	7,044,753
Granted (in shares)					665,370	592,550	590,300
Exercised (in shares)					(474,253)	(745,419)	(727,415)
Forfeited (in shares)					(287,028)	(261,018)	(91,344)
Balance at end of year (in shares)					6,306,496	6,402,407	6,816,294
Exercisable at end of year (in shares)					3,431,113	3,333,942	2,916,621
Weighted average exercise price
Balance at beginning of year (in dollars per share)					$ 11.65	$ 11.46	$ 11.21
Granted (in dollars per share)		$ 12.37	$ 13.15		12.37	13.15	12.44
Exercised (in dollars per share)					10.27	10.86	10.13
Forfeited (in dollars per share)					12.26	11.71	11.82
Balance at end of year (in dollars per share)					11.81	11.65	11.46
Exercisable at end of year (in dollars per share)					11.42	11.20	10.97
Additional disclosure
Weighted average fair value of options at grant date (in dollars per share)				$ 12.44	$ 1.14	$ 1.45	$ 1.03
Total intrinsic value of options exercised					$ 1.2	$ 2.3	$ 2.7
Options that expired without being exercised (in shares)					7,007
Aggregate intrinsic value of all options expected to vest					$ 6.8
Aggregate intrinsic value of all options fully vested					$ 3.2
Stock options | 2011 Equity Incentive Plan
Recognition and Retention Plan and Stock Option Plans
Number of shares authorized								7,015,583
Director | Restricted common shares
Recognition and Retention Plan and Stock Option Plans
Number of shares issued	24,300		21,600	29,700	24,300
Director | Stock options
Number
Granted (in shares)		64,800	57,600	79,200	64,800
Employees | Restricted common shares
Recognition and Retention Plan and Stock Option Plans
Number of shares issued	282,050		251,030	240,700	282,050
Employees | Stock options
Number
Granted (in shares)		600,570	534,950	511,100	600,570

Employee Benefit Plans - Number

Employee Benefit Plans - Number of Options Outstanding and Exercisable and Weighted Average Remaining Life of All Option Grants (Details)	12 Months Ended
	Dec. 31, 2015$ / sharesshares
Exercise price $7.48
Outstanding and exercisable options
Exercise price (in dollars per share) | $ / shares	$ 7.48
Options outstanding:
Number of options (in shares)	315,487
Weighted average remaining contract life (years)	3 years 3 months
Options exercisable:
Number of options (in shares)	267,521
Weighted average remaining term - vested (years)	3 years 3 months
Exercise price $9.79
Outstanding and exercisable options
Exercise price (in dollars per share) | $ / shares	$ 9.79
Options outstanding:
Number of options (in shares)	331,882
Weighted average remaining contract life (years)	3 years
Options exercisable:
Number of options (in shares)	331,882
Weighted average remaining term - vested (years)	3 years
Exercise price $9.86
Outstanding and exercisable options
Exercise price (in dollars per share) | $ / shares	$ 9.86
Options outstanding:
Number of options (in shares)	50,110
Weighted average remaining contract life (years)	3 months
Options exercisable:
Number of options (in shares)	50,110
Weighted average remaining term - vested (years)	3 months
Exercise price $11.12
Outstanding and exercisable options
Exercise price (in dollars per share) | $ / shares	$ 11.12
Options outstanding:
Number of options (in shares)	270,543
Weighted average remaining contract life (years)	2 years 3 months
Options exercisable:
Number of options (in shares)	270,543
Weighted average remaining term - vested (years)	2 years 3 months
Exercise price $11.49
Outstanding and exercisable options
Exercise price (in dollars per share) | $ / shares	$ 11.49
Options outstanding:
Number of options (in shares)	422,500
Weighted average remaining contract life (years)	4 years 3 months
Options exercisable:
Number of options (in shares)	314,379
Weighted average remaining term - vested (years)	4 years 3 months
Exercise price $11.51
Outstanding and exercisable options
Exercise price (in dollars per share) | $ / shares	$ 11.51
Options outstanding:
Number of options (in shares)	232,858
Weighted average remaining contract life (years)	1 year 3 months
Options exercisable:
Number of options (in shares)	232,858
Weighted average remaining term - vested (years)	1 year 3 months
Exercise price $11.70
Outstanding and exercisable options
Exercise price (in dollars per share) | $ / shares	$ 11.70
Options outstanding:
Number of options (in shares)	465,493
Weighted average remaining contract life (years)	6 years 6 months
Options exercisable:
Number of options (in shares)	202,129
Weighted average remaining term - vested (years)	6 years 6 months
Exercise price $12.12
Outstanding and exercisable options
Exercise price (in dollars per share) | $ / shares	$ 12.12
Options outstanding:
Number of options (in shares)	481,795
Weighted average remaining contract life (years)	5 years 3 months
Options exercisable:
Number of options (in shares)	305,141
Weighted average remaining term - vested (years)	5 years 3 months
Exercise price $12.17
Outstanding and exercisable options
Exercise price (in dollars per share) | $ / shares	$ 12.17
Options outstanding:
Number of options (in shares)	21,500
Weighted average remaining contract life (years)	5 years 6 months
Options exercisable:
Number of options (in shares)	8,644
Weighted average remaining term - vested (years)	5 years 6 months
Exercise price $12.32
Outstanding and exercisable options
Exercise price (in dollars per share) | $ / shares	$ 12.32
Options outstanding:
Number of options (in shares)	2,050,609
Weighted average remaining contract life (years)	5 years 6 months
Options exercisable:
Number of options (in shares)	1,095,267
Weighted average remaining term - vested (years)	5 years 6 months
Exercise Price $12.37
Outstanding and exercisable options
Exercise price (in dollars per share) | $ / shares	$ 12.37
Options outstanding:
Number of options (in shares)	628,734
Weighted average remaining contract life (years)	9 years 6 months
Options exercisable:
Number of options (in shares)	66,551
Weighted average remaining term - vested (years)	9 years 6 months
Exercise price $12.44
Outstanding and exercisable options
Exercise price (in dollars per share) | $ / shares	$ 12.44
Options outstanding:
Number of options (in shares)	506,235
Weighted average remaining contract life (years)	7 years 6 months
Options exercisable:
Number of options (in shares)	172,272
Weighted average remaining term - vested (years)	7 years 6 months
Exercise price $12.48
Outstanding and exercisable options
Exercise price (in dollars per share) | $ / shares	$ 12.48
Options outstanding:
Number of options (in shares)	4,500
Weighted average remaining contract life (years)	1 year 6 months
Options exercisable:
Number of options (in shares)	4,500
Weighted average remaining term - vested (years)	1 year 6 months
Exercise Price $13.15
Outstanding and exercisable options
Exercise price (in dollars per share) | $ / shares	$ 13.15
Options outstanding:
Number of options (in shares)	524,250
Weighted average remaining contract life (years)	8 years 6 months
Options exercisable:
Number of options (in shares)	109,316
Weighted average remaining term - vested (years)	8 years 6 months
Exercise price $11.81
Outstanding and exercisable options
Exercise price (in dollars per share) | $ / shares	$ 11.81
Options outstanding:
Number of options (in shares)	6,306,496
Weighted average remaining contract life (years)	5 years 8 months 19 days
Options exercisable:
Number of options (in shares)	3,431,113
Weighted average remaining term - vested (years)	4 years 2 months 23 days

Disclosures About Fair Value103

Disclosures About Fair Value of Financial Instruments - Carrying Amount and Estimated Fair Value of Financial Instruments (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Fair Value Disclosures [Abstract]
Significant unrealized appreciation or depreciation in financial instruments	$ 0	$ 0
Financial assets:
Securities available-for-sale	874,405,000	912,371,000
Securities held-to-maturity	32,552,000	106,292,000
Accrued interest receivable	21,072,000	18,623,000
Financial liabilities:
Borrowed funds	975,007,000	888,109,000
Junior subordinated debentures	111,213,000	103,094,000
Assets transferred between Level 1 and Level 2	0	0
Liabilities transferred between Level 1 and Level 2	0	0
Level 1
Financial assets:
Cash and cash equivalents	167,408,000	240,706,000
Securities available-for-sale	1,894,000	3,157,000
Securities held-to-maturity	0	0
Loans receivable, net	0	0
Accrued interest receivable	21,072,000	18,623,000
FHLB Stock	0	0
Total financial assets	190,374,000	262,486,000
Financial liabilities:
Savings and checking accounts	4,917,863,000	4,154,228,000
Time deposits	0	0
Borrowed funds	118,664,000	162,714,000
Junior subordinated debentures	0	0
Cash flow hedges - swaps	0	0
Accrued interest payable	1,993,000	936,000
Total financial liabilities	5,038,520,000	4,317,878,000
Level 2
Financial assets:
Cash and cash equivalents	0	0
Securities available-for-sale	863,556,000	898,617,000
Securities held-to-maturity	32,552,000	106,292,000
Loans receivable, net	0	0
Accrued interest receivable	0	0
FHLB Stock	0	0
Total financial assets	896,108,000	1,004,909,000
Financial liabilities:
Savings and checking accounts	0	0
Time deposits	0	0
Borrowed funds	0	0
Junior subordinated debentures	0	0
Cash flow hedges - swaps	4,276,000	6,273,000
Accrued interest payable	0	0
Total financial liabilities	4,276,000	6,273,000
Level 3
Financial assets:
Cash and cash equivalents	0	0
Securities available-for-sale	8,955,000	10,597,000
Securities held-to-maturity	0	0
Loans receivable, net	7,482,431,000	6,240,079,000
Accrued interest receivable	0	0
FHLB Stock	0	0
Total financial assets	7,491,386,000	6,250,676,000
Financial liabilities:
Savings and checking accounts	0	0
Time deposits	1,710,388,000	1,498,539,000
Borrowed funds	879,863,000	756,898,000
Junior subordinated debentures	115,268,000	109,435,000
Cash flow hedges - swaps	0	0
Accrued interest payable	0	0
Total financial liabilities	2,705,519,000	2,364,872,000
Carrying amount
Financial assets:
Cash and cash equivalents	167,408,000	240,706,000
Securities available-for-sale	874,405,000	912,371,000
Securities held-to-maturity	31,689,000	103,695,000
Loans receivable, net	7,159,449,000	5,922,373,000
Accrued interest receivable	21,072,000	18,623,000
FHLB Stock	40,903,000	33,293,000
Total financial assets	8,294,926,000	7,231,061,000
Financial liabilities:
Savings and checking accounts	4,917,863,000	4,154,228,000
Time deposits	1,694,718,000	1,478,314,000
Borrowed funds	975,007,000	888,109,000
Junior subordinated debentures	111,213,000	103,094,000
Cash flow hedges - swaps	4,276,000	6,273,000
Accrued interest payable	1,993,000	936,000
Total financial liabilities	7,705,070,000	6,630,954,000
Estimated fair value
Financial assets:
Cash and cash equivalents	167,408,000	240,706,000
Securities available-for-sale	874,405,000	912,371,000
Securities held-to-maturity	32,552,000	106,292,000
Loans receivable, net	7,482,431,000	6,240,079,000
Accrued interest receivable	21,072,000	18,623,000
FHLB Stock	40,903,000	33,293,000
Total financial assets	8,618,771,000	7,551,364,000
Financial liabilities:
Savings and checking accounts	4,917,863,000	4,154,228,000
Time deposits	1,710,388,000	1,498,539,000
Borrowed funds	998,527,000	919,612,000
Junior subordinated debentures	115,268,000	109,435,000
Cash flow hedges - swaps	4,276,000	6,273,000
Accrued interest payable	1,993,000	936,000
Total financial liabilities	$ 7,748,315,000	$ 6,689,023,000

Disclosures About Fair Value104

Disclosures About Fair Value of Financial Instruments - Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Assets and liabilities measured at fair value on a recurring basis
Securities available-for-sale	$ 874,405	$ 912,371
Level 1
Assets and liabilities measured at fair value on a recurring basis
Securities available-for-sale	1,894	3,157
Interest rate swaps	0	0
Total assets and liabilities	190,374	262,486
Level 2
Assets and liabilities measured at fair value on a recurring basis
Securities available-for-sale	863,556	898,617
Interest rate swaps	(4,276)	(6,273)
Total assets and liabilities	896,108	1,004,909
Level 3
Assets and liabilities measured at fair value on a recurring basis
Securities available-for-sale	8,955	10,597
Interest rate swaps	0	0
Total assets and liabilities	7,491,386	6,250,676
Measured on recurring basis
Assets and liabilities measured at fair value on a recurring basis
Total assets and liabilities	870,129	906,098
Measured on recurring basis | Equity securities
Assets and liabilities measured at fair value on a recurring basis
Securities available-for-sale	1,894	3,157
Measured on recurring basis | Debt securities
Assets and liabilities measured at fair value on a recurring basis
Securities available-for-sale	393,794	424,102
Measured on recurring basis | Debt securities | U.S. government and agencies
Assets and liabilities measured at fair value on a recurring basis
Securities available-for-sale	11	25
Measured on recurring basis | Debt securities | Government sponsored enterprises
Assets and liabilities measured at fair value on a recurring basis
Securities available-for-sale	294,440	333,505
Measured on recurring basis | Debt securities | States and political subdivisions
Assets and liabilities measured at fair value on a recurring basis
Securities available-for-sale	82,868	70,145
Measured on recurring basis | Debt securities | Corporate
Assets and liabilities measured at fair value on a recurring basis
Securities available-for-sale	16,475	20,427
Measured on recurring basis | Mortgage-backed securities
Assets and liabilities measured at fair value on a recurring basis
Mortgage-backed securities	478,717	485,112
Measured on recurring basis | Residential mortgage-backed securities | GNMA
Assets and liabilities measured at fair value on a recurring basis
Mortgage-backed securities	27,082	29,216
Measured on recurring basis | Residential mortgage-backed securities | FNMA
Assets and liabilities measured at fair value on a recurring basis
Mortgage-backed securities	99,170	73,497
Measured on recurring basis | Residential mortgage-backed securities | FHLMC
Assets and liabilities measured at fair value on a recurring basis
Mortgage-backed securities	50,369	42,119
Measured on recurring basis | Residential mortgage-backed securities | Non-agency
Assets and liabilities measured at fair value on a recurring basis
Mortgage-backed securities	606	643
Measured on recurring basis | Collateralized mortgage obligations | GNMA
Assets and liabilities measured at fair value on a recurring basis
Mortgage-backed securities	10,669	8,329
Measured on recurring basis | Collateralized mortgage obligations | FNMA
Assets and liabilities measured at fair value on a recurring basis
Mortgage-backed securities	122,528	139,150
Measured on recurring basis | Collateralized mortgage obligations | FHLMC
Assets and liabilities measured at fair value on a recurring basis
Mortgage-backed securities	157,378	178,698
Measured on recurring basis | Collateralized mortgage obligations | SBA
Assets and liabilities measured at fair value on a recurring basis
Mortgage-backed securities	8,166	10,052
Measured on recurring basis | Collateralized mortgage obligations | Non-agency
Assets and liabilities measured at fair value on a recurring basis
Mortgage-backed securities	2,749	3,408
Measured on recurring basis | Interest rate swaps
Assets and liabilities measured at fair value on a recurring basis
Interest rate swaps	(4,276)	(6,273)
Measured on recurring basis | Level 1
Assets and liabilities measured at fair value on a recurring basis
Total assets and liabilities	1,894	3,157
Measured on recurring basis | Level 1 | Equity securities
Assets and liabilities measured at fair value on a recurring basis
Securities available-for-sale	1,894	3,157
Measured on recurring basis | Level 1 | Debt securities
Assets and liabilities measured at fair value on a recurring basis
Securities available-for-sale	0	0
Measured on recurring basis | Level 1 | Debt securities | U.S. government and agencies
Assets and liabilities measured at fair value on a recurring basis
Securities available-for-sale	0	0
Measured on recurring basis | Level 1 | Debt securities | Government sponsored enterprises
Assets and liabilities measured at fair value on a recurring basis
Securities available-for-sale	0	0
Measured on recurring basis | Level 1 | Debt securities | States and political subdivisions
Assets and liabilities measured at fair value on a recurring basis
Securities available-for-sale	0	0
Measured on recurring basis | Level 1 | Debt securities | Corporate
Assets and liabilities measured at fair value on a recurring basis
Securities available-for-sale	0	0
Measured on recurring basis | Level 1 | Mortgage-backed securities
Assets and liabilities measured at fair value on a recurring basis
Mortgage-backed securities	0	0
Measured on recurring basis | Level 1 | Residential mortgage-backed securities | GNMA
Assets and liabilities measured at fair value on a recurring basis
Mortgage-backed securities	0	0
Measured on recurring basis | Level 1 | Residential mortgage-backed securities | FNMA
Assets and liabilities measured at fair value on a recurring basis
Mortgage-backed securities	0	0
Measured on recurring basis | Level 1 | Residential mortgage-backed securities | FHLMC
Assets and liabilities measured at fair value on a recurring basis
Mortgage-backed securities	0	0
Measured on recurring basis | Level 1 | Residential mortgage-backed securities | Non-agency
Assets and liabilities measured at fair value on a recurring basis
Mortgage-backed securities	0	0
Measured on recurring basis | Level 1 | Collateralized mortgage obligations | GNMA
Assets and liabilities measured at fair value on a recurring basis
Mortgage-backed securities	0	0
Measured on recurring basis | Level 1 | Collateralized mortgage obligations | FNMA
Assets and liabilities measured at fair value on a recurring basis
Mortgage-backed securities	0	0
Measured on recurring basis | Level 1 | Collateralized mortgage obligations | FHLMC
Assets and liabilities measured at fair value on a recurring basis
Mortgage-backed securities	0	0
Measured on recurring basis | Level 1 | Collateralized mortgage obligations | SBA
Assets and liabilities measured at fair value on a recurring basis
Mortgage-backed securities	0	0
Measured on recurring basis | Level 1 | Collateralized mortgage obligations | Non-agency
Assets and liabilities measured at fair value on a recurring basis
Mortgage-backed securities	0	0
Measured on recurring basis | Level 1 | Interest rate swaps
Assets and liabilities measured at fair value on a recurring basis
Interest rate swaps	0	0
Measured on recurring basis | Level 2
Assets and liabilities measured at fair value on a recurring basis
Total assets and liabilities	859,280	892,344
Measured on recurring basis | Level 2 | Equity securities
Assets and liabilities measured at fair value on a recurring basis
Securities available-for-sale	0	0
Measured on recurring basis | Level 2 | Debt securities
Assets and liabilities measured at fair value on a recurring basis
Securities available-for-sale	384,839	413,505
Measured on recurring basis | Level 2 | Debt securities | U.S. government and agencies
Assets and liabilities measured at fair value on a recurring basis
Securities available-for-sale	11	25
Measured on recurring basis | Level 2 | Debt securities | Government sponsored enterprises
Assets and liabilities measured at fair value on a recurring basis
Securities available-for-sale	294,440	333,505
Measured on recurring basis | Level 2 | Debt securities | States and political subdivisions
Assets and liabilities measured at fair value on a recurring basis
Securities available-for-sale	82,868	70,145
Measured on recurring basis | Level 2 | Debt securities | Corporate
Assets and liabilities measured at fair value on a recurring basis
Securities available-for-sale	7,520	9,830
Measured on recurring basis | Level 2 | Mortgage-backed securities
Assets and liabilities measured at fair value on a recurring basis
Mortgage-backed securities	478,717	485,112
Measured on recurring basis | Level 2 | Residential mortgage-backed securities | GNMA
Assets and liabilities measured at fair value on a recurring basis
Mortgage-backed securities	27,082	29,216
Measured on recurring basis | Level 2 | Residential mortgage-backed securities | FNMA
Assets and liabilities measured at fair value on a recurring basis
Mortgage-backed securities	99,170	73,497
Measured on recurring basis | Level 2 | Residential mortgage-backed securities | FHLMC
Assets and liabilities measured at fair value on a recurring basis
Mortgage-backed securities	50,369	42,119
Measured on recurring basis | Level 2 | Residential mortgage-backed securities | Non-agency
Assets and liabilities measured at fair value on a recurring basis
Mortgage-backed securities	606	643
Measured on recurring basis | Level 2 | Collateralized mortgage obligations | GNMA
Assets and liabilities measured at fair value on a recurring basis
Mortgage-backed securities	10,669	8,329
Measured on recurring basis | Level 2 | Collateralized mortgage obligations | FNMA
Assets and liabilities measured at fair value on a recurring basis
Mortgage-backed securities	122,528	139,150
Measured on recurring basis | Level 2 | Collateralized mortgage obligations | FHLMC
Assets and liabilities measured at fair value on a recurring basis
Mortgage-backed securities	157,378	178,698
Measured on recurring basis | Level 2 | Collateralized mortgage obligations | SBA
Assets and liabilities measured at fair value on a recurring basis
Mortgage-backed securities	8,166	10,052
Measured on recurring basis | Level 2 | Collateralized mortgage obligations | Non-agency
Assets and liabilities measured at fair value on a recurring basis
Mortgage-backed securities	2,749	3,408
Measured on recurring basis | Level 2 | Interest rate swaps
Assets and liabilities measured at fair value on a recurring basis
Interest rate swaps	(4,276)	(6,273)
Measured on recurring basis | Level 3
Assets and liabilities measured at fair value on a recurring basis
Total assets and liabilities	8,955	10,597
Measured on recurring basis | Level 3 | Equity securities
Assets and liabilities measured at fair value on a recurring basis
Securities available-for-sale	0	0
Measured on recurring basis | Level 3 | Debt securities
Assets and liabilities measured at fair value on a recurring basis
Securities available-for-sale	8,955	10,597
Measured on recurring basis | Level 3 | Debt securities | U.S. government and agencies
Assets and liabilities measured at fair value on a recurring basis
Securities available-for-sale	0	0
Measured on recurring basis | Level 3 | Debt securities | Government sponsored enterprises
Assets and liabilities measured at fair value on a recurring basis
Securities available-for-sale	0	0
Measured on recurring basis | Level 3 | Debt securities | States and political subdivisions
Assets and liabilities measured at fair value on a recurring basis
Securities available-for-sale	0	0
Measured on recurring basis | Level 3 | Debt securities | Corporate
Assets and liabilities measured at fair value on a recurring basis
Securities available-for-sale	8,955	10,597
Measured on recurring basis | Level 3 | Mortgage-backed securities
Assets and liabilities measured at fair value on a recurring basis
Mortgage-backed securities	0	0
Measured on recurring basis | Level 3 | Residential mortgage-backed securities | GNMA
Assets and liabilities measured at fair value on a recurring basis
Mortgage-backed securities	0	0
Measured on recurring basis | Level 3 | Residential mortgage-backed securities | FNMA
Assets and liabilities measured at fair value on a recurring basis
Mortgage-backed securities	0	0
Measured on recurring basis | Level 3 | Residential mortgage-backed securities | FHLMC
Assets and liabilities measured at fair value on a recurring basis
Mortgage-backed securities	0	0
Measured on recurring basis | Level 3 | Residential mortgage-backed securities | Non-agency
Assets and liabilities measured at fair value on a recurring basis
Mortgage-backed securities	0	0
Measured on recurring basis | Level 3 | Collateralized mortgage obligations | GNMA
Assets and liabilities measured at fair value on a recurring basis
Mortgage-backed securities	0	0
Measured on recurring basis | Level 3 | Collateralized mortgage obligations | FNMA
Assets and liabilities measured at fair value on a recurring basis
Mortgage-backed securities	0	0
Measured on recurring basis | Level 3 | Collateralized mortgage obligations | FHLMC
Assets and liabilities measured at fair value on a recurring basis
Mortgage-backed securities	0	0
Measured on recurring basis | Level 3 | Collateralized mortgage obligations | SBA
Assets and liabilities measured at fair value on a recurring basis
Mortgage-backed securities	0	0
Measured on recurring basis | Level 3 | Collateralized mortgage obligations | Non-agency
Assets and liabilities measured at fair value on a recurring basis
Mortgage-backed securities	0	0
Measured on recurring basis | Level 3 | Interest rate swaps
Assets and liabilities measured at fair value on a recurring basis
Interest rate swaps	$ 0	$ 0

Disclosures About Fair Value105

Disclosures About Fair Value of Financial Instruments - Reconciliation of all Assets and Liabilities Measured at Fair Value on a Recurring Basis Using Significant Unobservable Inputs (Level 3) (Details) - Level 3 - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Equity securities
Reconciliation of all assets and liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3)
Balance at the beginning of the period	$ 0	$ 0
Total net realized investment gains/ (losses) and net change in unrealized appreciation/ (depreciation):
Included in net income as OTTI	0	0
Included in other comprehensive income	0	0
Purchases	0	0
Sales/ calls	0	0
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Balance at the end of the period	0	0
Debt securities
Reconciliation of all assets and liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3)
Balance at the beginning of the period	10,597	12,251
Total net realized investment gains/ (losses) and net change in unrealized appreciation/ (depreciation):
Included in net income as OTTI	0	0
Included in other comprehensive income	(502)	(1,549)
Purchases	0	0
Sales/ calls	(1,140)	(105)
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Balance at the end of the period	$ 8,955	$ 10,597

Disclosures About Fair Value106

Disclosures About Fair Value of Financial Instruments - Nonrecurring Assets that had Fair Market Values Below the Carrying Amount (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Fair value measurement for nonrecurring assets that had a fair market value below the carrying amount
Total assets	$ 56,906	$ 71,488
Loans evaluated for impairment
Fair value measurement for nonrecurring assets that had a fair market value below the carrying amount
Total assets	48,181	54,729
Real estate owned
Fair value measurement for nonrecurring assets that had a fair market value below the carrying amount
Total assets	8,725	16,759
Level 1
Fair value measurement for nonrecurring assets that had a fair market value below the carrying amount
Total assets	0	0
Level 1 | Loans evaluated for impairment
Fair value measurement for nonrecurring assets that had a fair market value below the carrying amount
Total assets	0	0
Level 1 | Real estate owned
Fair value measurement for nonrecurring assets that had a fair market value below the carrying amount
Total assets	0	0
Level 2
Fair value measurement for nonrecurring assets that had a fair market value below the carrying amount
Total assets	0	0
Level 2 | Loans evaluated for impairment
Fair value measurement for nonrecurring assets that had a fair market value below the carrying amount
Total assets	0	0
Level 2 | Real estate owned
Fair value measurement for nonrecurring assets that had a fair market value below the carrying amount
Total assets	0	0
Level 3
Fair value measurement for nonrecurring assets that had a fair market value below the carrying amount
Total assets	56,906	71,488
Level 3 | Loans evaluated for impairment
Fair value measurement for nonrecurring assets that had a fair market value below the carrying amount
Total assets	48,181	54,729
Level 3 | Real estate owned
Fair value measurement for nonrecurring assets that had a fair market value below the carrying amount
Total assets	$ 8,725	$ 16,759

Disclosures About Fair Value107

Disclosures About Fair Value of Financial Instruments - Additional Quantitative Information, Assets Measured at Fair Value, Recurring and Nonrecurring Basis, Level 3 Input (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2015USD ($)
Debt securities
Quantitative information for Level 3 Fair Value Measurements Assets
Fair value	$ 8,955
Debt securities | Discounted cash flow
Quantitative information for Level 3 Fair Value Measurements Assets
Default rates	1.00%
Prepayment speeds	1.00%
Debt securities | Discounted cash flow | Minimum
Quantitative information for Level 3 Fair Value Measurements Assets
Discount margin	0.35%
Debt securities | Discounted cash flow | Maximum
Quantitative information for Level 3 Fair Value Measurements Assets
Discount margin	2.10%
Debt securities | Discounted cash flow | Weighted Average
Quantitative information for Level 3 Fair Value Measurements Assets
Discount margin	0.69%
Loans evaluated for impairment
Quantitative information for Level 3 Fair Value Measurements Assets
Fair value	$ 48,181
Estimated costs to sell	10.00%
Loans evaluated for impairment | Discounted cash flow | Minimum
Quantitative information for Level 3 Fair Value Measurements Assets
Discount rate	3.75%
Loans evaluated for impairment | Discounted cash flow | Maximum
Quantitative information for Level 3 Fair Value Measurements Assets
Discount rate	6.50%
Loans evaluated for impairment | Discounted cash flow | Weighted Average
Quantitative information for Level 3 Fair Value Measurements Assets
Discount rate	5.13%
Real estate owned
Quantitative information for Level 3 Fair Value Measurements Assets
Fair value	$ 8,725
Estimated costs to sell	10.00%

Regulatory Capital Requireme108

Regulatory Capital Requirements (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Northwest Bancshares, Inc.
Total capital (to risk weighted assets)
Actual Amount	$ 1,102,468	$ 1,062,802
Actual Ratio (as a percent)	16.63%	20.29%
Minimum Capital Requirements Amount	$ 530,257	$ 0
Minimum Capital Requirements Ratio (as a percent)	8.00%	0.00%
Well Capitalized Requirements Amount	$ 662,821	$ 0
Well Capitalized Requirements Ratio (as a percent)	10.00%	0.00%
Tier 1 capital (to risk weighted assets)
Actual Amount	$ 1,039,574	$ 997,049
Actual Ratio (as a percent)	15.68%	19.04%
Minimum Capital Requirements Amount	$ 397,693	$ 0
Minimum Capital Requirements Ratio (as a percent)	6.00%	0.00%
Well Capitalized Requirements Amount	$ 530,257	$ 0
Well Capitalized Requirements Ratio (as a percent)	8.00%	0.00%
CET 1 capital (to risk weighted assets)
Actual Amount	$ 931,699
Actual Ratio (as a percent)	14.06%
Minimum Capital Requirements Amount	$ 298,269
Minimum Capital Requirements Ratio (as a percent)	4.50%
Well Capitalized Requirements Amount	$ 430,834
Well Capitalized Requirements Ratio (as a percent)	6.50%
Tier 1 capital (leverage) (to total assets)
Actual Amount	$ 1,039,574	$ 997,049
Actual Ratio (as a percent)	11.96%	12.80%
Minimum Capital Requirements Amount	$ 347,582	$ 0
Minimum Capital Requirements Ratio (as a percent)	4.00%	0.00%
Well Capitalized Requirements Amount	$ 434,477	$ 0
Well Capitalized Requirements Ratio (as a percent)	5.00%	0.00%
Northwest Bank
Total capital (to risk weighted assets)
Actual Amount	$ 1,006,230	$ 945,652
Actual Ratio (as a percent)	15.20%	18.09%
Minimum Capital Requirements Amount	$ 529,498	$ 418,104
Minimum Capital Requirements Ratio (as a percent)	8.00%	8.00%
Well Capitalized Requirements Amount	$ 661,872	$ 522,629
Well Capitalized Requirements Ratio (as a percent)	10.00%	10.00%
Tier 1 capital (to risk weighted assets)
Actual Amount	$ 943,554	$ 880,290
Actual Ratio (as a percent)	14.26%	16.84%
Minimum Capital Requirements Amount	$ 397,123	$ 209,052
Minimum Capital Requirements Ratio (as a percent)	6.00%	4.00%
Well Capitalized Requirements Amount	$ 529,498	$ 313,578
Well Capitalized Requirements Ratio (as a percent)	8.00%	6.00%
CET 1 capital (to risk weighted assets)
Actual Amount	$ 943,554
Actual Ratio (as a percent)	14.26%
Minimum Capital Requirements Amount	$ 297,843
Minimum Capital Requirements Ratio (as a percent)	4.50%
Well Capitalized Requirements Amount	$ 430,217
Well Capitalized Requirements Ratio (as a percent)	6.50%
Tier 1 capital (leverage) (to total assets)
Actual Amount	$ 943,554	$ 880,290
Actual Ratio (as a percent)	10.87%	11.55%
Minimum Capital Requirements Amount	$ 347,063	$ 304,883
Minimum Capital Requirements Ratio (as a percent)	4.00%	4.00%
Well Capitalized Requirements Amount	$ 433,829	$ 381,104
Well Capitalized Requirements Ratio (as a percent)	5.00%	5.00%

Components of Accumulated Ot109

Components of Accumulated Other Comprehensive Income - (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Unrealized gain on marketable securities available-for-sale	$ 3,325	$ 3,461
Fair value of interest rate swaps	(2,779)	(4,078)
Defined benefit pension plans	(25,081)	(23,753)
Accumulated other comprehensive income	$ (24,535)	$ (24,370)	$ (11,900)	$ (11,488)

Components of Accumulated Ot110

Components of Accumulated Other Comprehensive Income - Changes in Accumulated Other Comprehensive Income by Component (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Changes in accumulated other comprehensive income by component
Balance at the beginning of the period	$ (24,370,000)	$ (11,900,000)	$ (11,488,000)
Other comprehensive income/ (loss) before reclassification adjustments	(589,000)	(9,604,000)	1,214,000
Amounts reclassified from accumulated other comprehensive income	424,000	(2,866,000)	(1,626,000)
Other comprehensive loss	(165,000)	(12,470,000)	(412,000)
Balance at the end of the period	(24,535,000)	(24,370,000)	(11,900,000)
Other than temporary impairment losses (net impairment losses)	0	0	(713,000)
Income tax expense (benefit) related to compensation and employee benefits	(905,000)	(905,000)	(812,000)
Unrealized gains and losses on securities available-for-sale
Changes in accumulated other comprehensive income by component
Balance at the beginning of the period	3,461,000	(3,233,000)	15,853,000
Other comprehensive income/ (loss) before reclassification adjustments	315,000	9,042,000	(16,544,000)
Amounts reclassified from accumulated other comprehensive income	(451,000)	(2,348,000)	(2,542,000)
Other comprehensive loss	(136,000)	6,694,000	(19,086,000)
Balance at the end of the period	3,325,000	3,461,000	(3,233,000)
Realized gains (losses) on securities, net of tax	740,000	3,849,000	(4,881,000)
Other than temporary impairment losses (net impairment losses)		0	(713,000)
Tax expense (benefit) on realized gains (losses) on securities	289,000	1,501,000	(1,626,000)
Change in fair value of interest rate swaps
Changes in accumulated other comprehensive income by component
Balance at the beginning of the period	(4,078,000)	(5,224,000)	(8,405,000)
Other comprehensive income/ (loss) before reclassification adjustments	1,299,000	1,146,000	3,181,000
Amounts reclassified from accumulated other comprehensive income	0	0	0
Other comprehensive loss	1,299,000	1,146,000	3,181,000
Balance at the end of the period	(2,779,000)	(4,078,000)	(5,224,000)
Change in defined benefit pension plans
Changes in accumulated other comprehensive income by component
Balance at the beginning of the period	(23,753,000)	(3,443,000)	(18,936,000)
Other comprehensive income/ (loss) before reclassification adjustments	(2,203,000)	(19,792,000)	14,577,000
Amounts reclassified from accumulated other comprehensive income	875,000	(518,000)	916,000
Other comprehensive loss	(1,328,000)	(20,310,000)	15,493,000
Balance at the end of the period	(25,081,000)	(23,753,000)	(3,443,000)
Amortization of prior service cost (compensation and employee benefits)	2,323,000	2,323,000	2,321,000
Amortization of net gain (loss) (compensation and employee benefits)	(3,758,000)	(1,473,000)	(3,730,000)
Income tax expense (benefit) related to compensation and employee benefits	$ 560,000	$ (332,000)	$ 493,000

Parent Company Only Financia111

Parent Company Only Financial Statements - Condensed - Statements of Financial Condition (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Assets
Cash and cash equivalents	$ 167,408	$ 240,706	$ 391,905	$ 451,704
Marketable securities available-for-sale (amortized cost of $868,956 and $906,702)	874,405	912,371
Other assets	54,670	60,586
Total assets	8,951,899	7,775,033	7,879,859
Liabilities:
Debentures payable	111,213	103,094
Other liabilities	54,207	57,198
Total liabilities	7,788,736	6,712,386
Shareholders’ equity	1,163,163	1,062,647	1,155,185	1,127,032
Total liabilities and shareholders’ equity	8,951,899	7,775,033
Parent Company
Assets
Cash and cash equivalents	91,056	110,699	$ 188,775	$ 227,327
Marketable securities available-for-sale (amortized cost of $868,956 and $906,702)	1,884	3,144
Investment in bank subsidiary	1,182,308	1,054,204
Other assets	3,547	4,109
Total assets	1,278,795	1,172,156
Liabilities:
Debentures payable	111,213	103,094
Other liabilities	4,419	6,415
Total liabilities	115,632	109,509
Shareholders’ equity	1,163,163	1,062,647
Total liabilities and shareholders’ equity	$ 1,278,795	$ 1,172,156

Parent Company Only Financia112

Parent Company Only Financial Statements - Condensed - Statements of Income (Details) - USD ($) $ in Thousands	3 Months Ended												12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income:
Interest income	$ 85,639	$ 81,091	$ 75,970	$ 76,880	$ 76,586	$ 76,528	$ 76,987	$ 75,326	$ 77,049	$ 77,850	$ 78,723	$ 79,475	$ 319,580	$ 305,427	$ 313,097
Expense:
Other expense													9,031	9,797	9,962
Interest expense	14,486	14,150	13,792	13,899	13,982	14,187	14,214	14,204	14,805	15,276	15,436	15,645	56,327	56,587	61,162
Income before income taxes	24,877	18,110	22,518	22,995	23,535	23,258	17,109	19,855	29,467	23,294	18,455	21,542	88,500	83,757	92,758
Federal and state income taxes	8,684	5,238	7,213	6,825	6,190	5,926	4,435	5,244	9,095	5,727	5,020	6,357	27,960	21,795	26,199
Net income	$ 16,193	$ 12,872	$ 15,305	$ 16,170	$ 17,345	$ 17,332	$ 12,674	$ 14,611	$ 20,372	$ 17,567	$ 13,435	$ 15,185	60,540	61,962	66,559
Parent Company
Income:
Interest income													1,258	1,248	1,467
Other income													659	3,424	5,961
Dividends from bank subsidiary													135,000	66,183	0
Undistributed earnings from equity investment in bank subsidiary													(70,854)	(3,261)	66,003
Total income													66,063	67,594	73,431
Expense:
Compensation and benefits													1,061	962	1,024
Other expense													1,356	572	234
Interest expense													4,926	4,691	5,444
Total expense													7,343	6,225	6,702
Income before income taxes													58,720	61,369	66,729
Federal and state income taxes													(1,820)	(593)	170
Net income													$ 60,540	$ 61,962	$ 66,559

Parent Company Only Financia113

Parent Company Only Financial Statements - Condensed - Statements of Cash Flows (Details) - USD ($) $ in Thousands	3 Months Ended												12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Operating activities:
Net Income	$ 16,193	$ 12,872	$ 15,305	$ 16,170	$ 17,345	$ 17,332	$ 12,674	$ 14,611	$ 20,372	$ 17,567	$ 13,435	$ 15,185	$ 60,540	$ 61,962	$ 66,559
Adjustments to reconcile net income to net cash provided by operating activities:
Noncash stock benefit plan compensation expense													5,570	5,711	5,083
Gain on sale of marketable securities													(1,037)	(4,930)	(6,118)
Net cash provided by operating activities													113,202	90,572	130,207
Investing activities:
Proceeds from sale of marketable securities available-for-sale													1,246	7,910	16,003
Acquisition, net of cash received													(61,108)	(2,792)	0
Net cash used in investing activities													(88,812)	(67,995)	(76,150)
Financing activities:
Cash dividends paid													(52,825)	(149,932)	(45,871)
Share repurchases													(7,847)	(5,273)	(4,459)
Redemption of junior subordinated debt													(8,119)	0	0
Excess tax benefit from stock-based compensation													332	945	635
Proceeds from options exercised													4,303	6,519	6,618
Net cash used in financing activities													(97,688)	(173,776)	(113,856)
Net decrease in cash and cash equivalents													(73,298)	(151,199)	(59,799)
Cash and cash equivalents at beginning of period				240,706				391,905				451,704	240,706	391,905	451,704
Cash and cash equivalents at end of period	167,408				240,706				391,905				167,408	240,706	391,905
Parent Company
Operating activities:
Net Income													60,540	61,962	66,559
Adjustments to reconcile net income to net cash provided by operating activities:
Undistributed earnings of subsidiary													70,854	3,261	(66,183)
Noncash stock benefit plan compensation expense													5,654	5,714	5,083
Gain on sale of marketable securities													(54)	(2,768)	(5,139)
Net change in other assets and liabilities													(5,824)	(2,352)	(4,147)
Net cash provided by operating activities													131,170	65,817	(3,827)
Investing activities:
Proceeds from sale of marketable securities available-for-sale													1,192	2,658	7,200
Acquisition, net of cash received													(89,398)	0	0
Net cash used in investing activities													(88,206)	2,658	7,200
Financing activities:
Cash dividends paid													(52,825)	(149,932)	(45,871)
Share repurchases													(7,847)	(5,273)	(4,459)
Repayment of loan to ESOP													1,549	1,190	1,152
Redemption of junior subordinated debt													(8,119)	0	0
Excess tax benefit from stock-based compensation													332	945	635
Proceeds from options exercised													4,303	6,519	6,618
Net cash used in financing activities													(62,607)	(146,551)	(41,925)
Net decrease in cash and cash equivalents													(19,643)	(78,076)	(38,552)
Cash and cash equivalents at beginning of period				$ 110,699				$ 188,775				$ 227,327	110,699	188,775	227,327
Cash and cash equivalents at end of period	$ 91,056				$ 110,699				$ 188,775				$ 91,056	$ 110,699	$ 188,775

Business Segments (Details)

Business Segments (Details) $ in Thousands	3 Months Ended												12 Months Ended
	Dec. 31, 2015USD ($)	Sep. 30, 2015USD ($)	Jun. 30, 2015USD ($)	Mar. 31, 2015USD ($)	Dec. 31, 2014USD ($)	Sep. 30, 2014USD ($)	Jun. 30, 2014USD ($)	Mar. 31, 2014USD ($)	Dec. 31, 2013USD ($)	Sep. 30, 2013USD ($)	Jun. 30, 2013USD ($)	Mar. 31, 2013USD ($)	Dec. 31, 2015USD ($)segment	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)
Segment Reporting [Abstract]
Number of reportable business segments | segment													2
Business Segments
Interest income	$ 85,639	$ 81,091	$ 75,970	$ 76,880	$ 76,586	$ 76,528	$ 76,987	$ 75,326	$ 77,049	$ 77,850	$ 78,723	$ 79,475	$ 319,580	$ 305,427	$ 313,097
Interest expense	14,486	14,150	13,792	13,899	13,982	14,187	14,214	14,204	14,805	15,276	15,436	15,645	56,327	56,587	61,162
Provision for loan losses	4,595	3,167	1,050	900	1,078	3,466	8,285	7,485	964	4,992	5,405	7,158	9,712	20,314	18,519
Noninterest income	19,546	18,140	16,525	14,625	17,221	17,737	16,427	19,381	20,767	15,989	13,379	16,341	68,836	70,766	66,476
Noninterest expense	61,227	63,804	55,135	53,711	55,212	53,354	53,806	53,163	52,580	50,277	52,806	51,471	233,877	215,535	207,134
Income tax expense/ (benefit)	8,684	5,238	7,213	6,825	6,190	5,926	4,435	5,244	9,095	5,727	5,020	6,357	27,960	21,795	26,199
Net income	16,193	$ 12,872	$ 15,305	$ 16,170	17,345	$ 17,332	$ 12,674	$ 14,611	20,372	$ 17,567	$ 13,435	$ 15,185	60,540	61,962	66,559
Total assets	8,951,899				7,775,033				7,879,859				8,951,899	7,775,033	7,879,859
Intersegment
Business Segments
Interest income													0	0	0
Community Banks
Business Segments
Interest income													300,746	285,635	291,253
Interest expense													51,895	52,291	56,282
Provision for loan losses													7,429	17,500	15,206
Noninterest income													67,167	66,431	59,616
Noninterest expense													219,793	202,489	194,028
Income tax expense/ (benefit)													28,642	21,097	24,330
Net income													62,547	61,095	63,714
Total assets	8,827,574				7,650,665				7,745,433				8,827,574	7,650,665	7,745,433
Community Banks | Intersegment
Business Segments
Interest income													2,393	2,406	2,691
Consumer Finance
Business Segments
Interest income													17,978	18,789	20,648
Interest expense													2,393	2,406	2,691
Provision for loan losses													2,283	2,814	3,313
Noninterest income													1,555	1,517	1,647
Noninterest expense													12,120	11,968	12,303
Income tax expense/ (benefit)													1,138	1,291	1,699
Net income													1,599	1,827	2,289
Total assets	110,670				107,216				109,249				110,670	107,216	109,249
Consumer Finance | Intersegment
Business Segments
Interest income													0	0	0
All Other
Business Segments
Interest income													856	1,003	1,196
Interest expense													2,039	1,890	2,189
Provision for loan losses													0	0	0
Noninterest income													114	2,818	5,213
Noninterest expense													1,964	1,078	803
Income tax expense/ (benefit)													(1,820)	(593)	170
Net income													(3,606)	(960)	556
Total assets	$ 13,655				$ 17,152				$ 25,177				13,655	17,152	25,177
All Other | Intersegment
Business Segments
Interest income													$ (2,393)	$ (2,406)	$ (2,691)

Guaranteed Preferred Benefic115

Guaranteed Preferred Beneficial Interests in Company’s Junior Subordinated Deferrable Interest Debentures (Trust-Preferred Securities) and Interest Rate Swap Agreements - Narrative (Details)	Dec. 15, 2005USD ($)$ / sharesshares	Dec. 05, 2005USD ($)$ / sharesshares	Sep. 30, 2008USD ($)	Dec. 31, 2015USD ($)trustderivative$ / sharesshares	Dec. 31, 2014USD ($)
Guaranteed Preferred Beneficial Interests in the Company's Junior Subordinated Deferrable Interest Debentures (Trust Preferred Securities) and Interest Rate Swaps
Number of statutory business trusts owned | trust				2
Junior subordinated deferrable interest debentures held by trusts that issued guaranteed capital debt securities				$ 111,213,000	$ 103,094,000
Hedge ineffectiveness for swaps				$ 0
Interest rate swaps
Guaranteed Preferred Beneficial Interests in the Company's Junior Subordinated Deferrable Interest Debentures (Trust Preferred Securities) and Interest Rate Swaps
Number of agreements | derivative				2
Collateral posted				$ 4,705,000	6,805,000
Fair value, liability				4,276,000	6,273,000
Northwest Bancorp Capital Trust III | Swap 2 | Interest rate swaps
Guaranteed Preferred Beneficial Interests in the Company's Junior Subordinated Deferrable Interest Debentures (Trust Preferred Securities) and Interest Rate Swaps
Fixed rate (as a percent)			4.61%
Northwest Bancorp Capital Trust III | Swap 2 | Interest rate swaps | Cash flow hedges
Guaranteed Preferred Beneficial Interests in the Company's Junior Subordinated Deferrable Interest Debentures (Trust Preferred Securities) and Interest Rate Swaps
Notional amount			$ 25,000,000
Northwest Bancorp Capital Trust III | Swap 4 | Interest rate swaps
Guaranteed Preferred Beneficial Interests in the Company's Junior Subordinated Deferrable Interest Debentures (Trust Preferred Securities) and Interest Rate Swaps
Original term of swaps			10 years
Northwest Bancorp Statutory Trust IV | Swap 4 | Interest rate swaps
Guaranteed Preferred Beneficial Interests in the Company's Junior Subordinated Deferrable Interest Debentures (Trust Preferred Securities) and Interest Rate Swaps
Original term of swaps			10 years
Trust preferred investments
Guaranteed Preferred Beneficial Interests in the Company's Junior Subordinated Deferrable Interest Debentures (Trust Preferred Securities) and Interest Rate Swaps
Total value of cumulative trust preferred securities issued				107,875,000
Junior subordinated deferrable interest debentures held by trusts that issued guaranteed capital debt securities				$ 111,213,000	103,094,000
Maximum period for which interest payment on the subordinated debentures can be deferred				5 years
Interest deferral				$ 0
Trust preferred investments | Northwest Bancorp Capital Trust III
Guaranteed Preferred Beneficial Interests in the Company's Junior Subordinated Deferrable Interest Debentures (Trust Preferred Securities) and Interest Rate Swaps
Cumulative trust preferred securities issued (in shares) | shares		50,000
Cumulative trust preferred securities issued, liquidation value per preferred security (in dollars per security) | $ / shares		$ 1,000
Total value of cumulative trust preferred securities issued		$ 50,000,000		50,000,000
Variable rate basis		three-month LIBOR
Spread on variable rate basis (as a percent)		1.38%
Junior subordinated deferrable interest debentures held by trusts that issued guaranteed capital debt securities				$ 51,547,000	51,547,000
Effective interest rate (as a percent)				1.98%
Trust preferred investments | Northwest Bancorp Statutory Trust IV
Guaranteed Preferred Beneficial Interests in the Company's Junior Subordinated Deferrable Interest Debentures (Trust Preferred Securities) and Interest Rate Swaps
Cumulative trust preferred securities issued (in shares) | shares	50,000
Cumulative trust preferred securities issued, liquidation value per preferred security (in dollars per security) | $ / shares	$ 1,000
Total value of cumulative trust preferred securities issued	$ 50,000,000			$ 50,000,000
Variable rate basis	three-month LIBOR
Spread on variable rate basis (as a percent)	1.38%
Junior subordinated deferrable interest debentures held by trusts that issued guaranteed capital debt securities				$ 51,547,000	51,547,000
Effective interest rate (as a percent)				1.89%
Trust preferred investments | Northwest Bancorp Statutory Trust IV | Swap 4
Guaranteed Preferred Beneficial Interests in the Company's Junior Subordinated Deferrable Interest Debentures (Trust Preferred Securities) and Interest Rate Swaps
Fixed rate (as a percent)			4.09%
Trust preferred investments | Northwest Bancorp Statutory Trust IV | Swap 4 | Cash flow hedges
Guaranteed Preferred Beneficial Interests in the Company's Junior Subordinated Deferrable Interest Debentures (Trust Preferred Securities) and Interest Rate Swaps
Notional amount			$ 25,000,000
Trust preferred investments | LNB Trust I and LNB Trust II
Guaranteed Preferred Beneficial Interests in the Company's Junior Subordinated Deferrable Interest Debentures (Trust Preferred Securities) and Interest Rate Swaps
Fixed interest rate of securities				6.64%
Trust preferred investments | LNB Trust II
Guaranteed Preferred Beneficial Interests in the Company's Junior Subordinated Deferrable Interest Debentures (Trust Preferred Securities) and Interest Rate Swaps
Total value of cumulative trust preferred securities issued				$ 7,875,000
Junior subordinated deferrable interest debentures held by trusts that issued guaranteed capital debt securities				$ 8,119,000	$ 0
LNB
Guaranteed Preferred Beneficial Interests in the Company's Junior Subordinated Deferrable Interest Debentures (Trust Preferred Securities) and Interest Rate Swaps
Number of statutory business trusts owned | trust				2
Cumulative Preferred Stock | Trust preferred investments | LNB Trust I and LNB Trust II
Guaranteed Preferred Beneficial Interests in the Company's Junior Subordinated Deferrable Interest Debentures (Trust Preferred Securities) and Interest Rate Swaps
Securities outstanding (in shares) | shares				7,875
Liquidation value per preferred security (in dollars per security) | $ / shares				$ 1,000
Securities outstanding, liquidation value				$ 7,875,000
LIBOR | Trust preferred investments | LNB Trust I and LNB Trust II
Guaranteed Preferred Beneficial Interests in the Company's Junior Subordinated Deferrable Interest Debentures (Trust Preferred Securities) and Interest Rate Swaps
Spread on variable rate basis (as a percent)				1.48%

Guaranteed Preferred Benefic116

Guaranteed Preferred Beneficial Interests in Company’s Junior Subordinated Deferrable Interest Debentures (Trust-Preferred Securities) and Interest Rate Swap Agreements - Liability Derivatives (Details) - Interest rate swaps - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Liability Derivatives, Included in Other Liabilities
Fair value	$ 4,276	$ 6,273
Notional amount	50,000	75,000
Collateral posted	$ 4,705	$ 6,805

Guaranteed Preferred Benefic117

Guaranteed Preferred Beneficial Interests in Company’s Junior Subordinated Deferrable Interest Debentures (Trust-Preferred Securities) and Interest Rate Swap Agreements (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014	Dec. 15, 2005	Dec. 05, 2005
Guaranteed Preferred Beneficial Interests in the Company's Junior Subordinated Deferrable Interest Debentures (Trust Preferred Securities) and Interest Rate Swaps
Junior subordinated deferrable interest debentures held by trusts that issued guaranteed capital debt securities	$ 111,213	$ 103,094
Trust preferred investments
Guaranteed Preferred Beneficial Interests in the Company's Junior Subordinated Deferrable Interest Debentures (Trust Preferred Securities) and Interest Rate Swaps
Total value of cumulative trust preferred securities issued	107,875
Junior subordinated deferrable interest debentures held by trusts that issued guaranteed capital debt securities	111,213	103,094
Trust preferred investments | Northwest Bancorp Capital Trust III
Guaranteed Preferred Beneficial Interests in the Company's Junior Subordinated Deferrable Interest Debentures (Trust Preferred Securities) and Interest Rate Swaps
Total value of cumulative trust preferred securities issued	50,000			$ 50,000
Junior subordinated deferrable interest debentures held by trusts that issued guaranteed capital debt securities	51,547	51,547
Trust preferred investments | Northwest Bancorp Statutory Trust IV
Guaranteed Preferred Beneficial Interests in the Company's Junior Subordinated Deferrable Interest Debentures (Trust Preferred Securities) and Interest Rate Swaps
Total value of cumulative trust preferred securities issued	50,000		$ 50,000
Junior subordinated deferrable interest debentures held by trusts that issued guaranteed capital debt securities	51,547	51,547
Trust preferred investments | LNB Trust II
Guaranteed Preferred Beneficial Interests in the Company's Junior Subordinated Deferrable Interest Debentures (Trust Preferred Securities) and Interest Rate Swaps
Total value of cumulative trust preferred securities issued	7,875
Junior subordinated deferrable interest debentures held by trusts that issued guaranteed capital debt securities	$ 8,119	$ 0

Selected Quarterly Financial118

Selected Quarterly Financial Data - Unaudited (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended												12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Quarterly Financial Information Disclosure [Abstract]
Interest income	$ 85,639	$ 81,091	$ 75,970	$ 76,880	$ 76,586	$ 76,528	$ 76,987	$ 75,326	$ 77,049	$ 77,850	$ 78,723	$ 79,475	$ 319,580	$ 305,427	$ 313,097
Interest expense	14,486	14,150	13,792	13,899	13,982	14,187	14,214	14,204	14,805	15,276	15,436	15,645	56,327	56,587	61,162
Net interest income	71,153	66,941	62,178	62,981	62,604	62,341	62,773	61,122	62,244	62,574	63,287	63,830	263,253	248,840	251,935
Provision for loan losses	4,595	3,167	1,050	900	1,078	3,466	8,285	7,485	964	4,992	5,405	7,158	9,712	20,314	18,519
Noninterest income	19,546	18,140	16,525	14,625	17,221	17,737	16,427	19,381	20,767	15,989	13,379	16,341	68,836	70,766	66,476
Noninterest expenses	61,227	63,804	55,135	53,711	55,212	53,354	53,806	53,163	52,580	50,277	52,806	51,471	233,877	215,535	207,134
Income before income taxes	24,877	18,110	22,518	22,995	23,535	23,258	17,109	19,855	29,467	23,294	18,455	21,542	88,500	83,757	92,758
Income tax expense/ (benefit)	8,684	5,238	7,213	6,825	6,190	5,926	4,435	5,244	9,095	5,727	5,020	6,357	27,960	21,795	26,199
Net income	$ 16,193	$ 12,872	$ 15,305	$ 16,170	$ 17,345	$ 17,332	$ 12,674	$ 14,611	$ 20,372	$ 17,567	$ 13,435	$ 15,185	$ 60,540	$ 61,962	$ 66,559
Basic earnings per share (in dollars per share)	$ 0.16	$ 0.14	$ 0.17	$ 0.18	$ 0.19	$ 0.19	$ 0.14	$ 0.16	$ 0.22	$ 0.19	$ 0.15	$ 0.17	$ 0.64	$ 0.68	$ 0.73
Diluted earnings per share (in dollars per share)	$ 0.16	$ 0.13	$ 0.17	$ 0.18	$ 0.19	$ 0.19	$ 0.14	$ 0.16	$ 0.22	$ 0.19	$ 0.15	$ 0.17	$ 0.64	$ 0.67	$ 0.73

Subsequent Events - Unaudited (

Subsequent Events - Unaudited (Details) - Subsequent Event $ in Millions	2 Months Ended
	Feb. 29, 2016USD ($)office
Facilities to be Consolidated to Nearby Locations
Subsequent Event [Line Items]
Number of offices | office	24
Facilities to be Converted Into Drive-Up Only Facilities
Subsequent Event [Line Items]
Number of offices | office	2
Facility Consolidation and Conversion
Subsequent Event [Line Items]
Expected expenses associated with consolidation and conversion of facilities	$ 5
Minimum | Operating Expense | Facility Consolidation and Conversion
Subsequent Event [Line Items]
Expected annual reduction to pretax operating expenses	5
Maximum | Operating Expense | Facility Consolidation and Conversion
Subsequent Event [Line Items]
Expected annual reduction to pretax operating expenses	$ 6