Heritage Financial (HFWA) 10-K 1 Mar 19 2018 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2018	Feb. 19, 2019	Jun. 30, 2018
Document and Entity Information [Abstract]
Entity Registrant Name	HERITAGE FINANCIAL CORP /WA/
Entity Central Index Key	1,046,025
Document Type	10-K
Document Period End Date	Dec. 31, 2018
Amendment Flag	false
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	FY
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		36,879,557
Entity Public Float			$ 1,164,701,672
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes

Consolidated Statements of Fina

Consolidated Statements of Financial Condition - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
ASSETS
Cash on hand and in banks	$ 92,704	$ 78,293
Interest earning deposits	69,206	24,722
Cash and cash equivalents	161,910	103,015
Investment securities available for sale, at fair value	976,095	810,530
Loans held for sale	1,555	2,288
Loans receivable, net	3,654,160	2,849,071
Allowance for loan losses	(35,042)	(32,086)
Total loans receivable, net	3,619,118	2,816,985
Other real estate owned	1,983	0
Premises and equipment, net	81,100	60,325
Federal Home Loan Bank stock, at cost	6,076	8,347
Bank owned life insurance	93,612	75,091
Accrued interest receivable	15,403	12,244
Prepaid expenses and other assets	98,522	99,328
Other intangible assets, net	20,614	6,088
Goodwill	240,939	119,029
Total assets	5,316,927	4,113,270
LIABILITIES AND STOCKHOLDERS' EQUITY
Deposits	4,432,402	3,393,060
Federal Home Loan Bank advances	0	92,500
Junior subordinated debentures	20,302	20,009
Securities sold under agreement to repurchase	31,487	31,821
Accrued expenses and other liabilities	72,013	67,575
Total liabilities	4,556,204	3,604,965
Stockholders’ equity:
Preferred stock, no par value, 2,500,000 shares authorized; no shares issued and outstanding at December 31, 2018 and 2017	0	0
Common stock, no par value, 50,000,000 shares authorized; 36,874,055 and 29,927,746 shares issued and outstanding at December 31, 2018 and 2017, respectively	591,806	360,590
Retained earnings	176,372	149,013
Accumulated other comprehensive loss, net	(7,455)	(1,298)
Total stockholders’ equity	760,723	508,305
Total liabilities and stockholders’ equity	$ 5,316,927	$ 4,113,270

Consolidated Statements of Fi_2

Consolidated Statements of Financial Condition (Parenthetical) - $ / shares	Dec. 31, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Preferred stock, no par value (in usd per share)
Preferred stock, shares authorized	2,500,000	2,500,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, no par value (in usd per share)
Common stock, shares authorized	50,000,000	50,000,000
Common stock, shares issued	36,874,055	29,927,746
Common stock, shares outstanding	36,874,055	29,927,746

Consolidated Statements of Inco

Consolidated Statements of Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
INTEREST INCOME:
Interest and fees on loans	$ 175,466	$ 129,213	$ 122,147
Taxable interest on investment securities	17,602	12,688	11,215
Nontaxable interest on investment securities	4,649	5,269	4,870
Interest on other interest earning assets	1,642	539	280
Total interest income	199,359	147,709	138,512
INTEREST EXPENSE:
Deposits	10,397	6,049	5,010
Junior subordinated debentures	1,263	1,014	880
Other borrowings	753	1,283	116
Total interest expense	12,413	8,346	6,006
Net interest income	186,946	139,363	132,506
Provision for loan losses	5,129	4,220	4,931
Net interest income after provision for loan losses	181,817	135,143	127,575
NONINTEREST INCOME:
Service charges and other fees	18,914	18,004	14,354
Gain on sale of investment securities, net	137	6	1,315
Gain on sale of loans, net	2,759	7,696	6,994
Interest rate swap fees	564	1,045	1,854
Other income	9,291	8,828	7,102
Total noninterest income	31,665	35,579	31,619
NONINTEREST EXPENSE:
Compensation and employee benefits	86,830	64,268	61,405
Occupancy and equipment	19,779	15,396	15,763
Data processing	9,888	8,176	7,312
Marketing	3,228	2,943	2,835
Professional services	9,670	4,777	3,606
State and local taxes	3,210	2,461	2,616
Federal deposit insurance premium	1,480	1,435	1,620
Other real estate owned, net	106	(70)	334
Amortization of intangible assets	3,819	1,286	1,415
Other expense	11,385	9,903	9,567
Total noninterest expense	149,395	110,575	106,473
Income before income taxes	64,087	60,147	52,721
Income tax expense	11,030	18,356	13,803
Net income	$ 53,057	$ 41,791	$ 38,918
Basic earnings per common share (in usd per share)	$ 1.49	$ 1.39	$ 1.30
Diluted earnings per common share (in usd per share)	1.49	1.39	1.30
Dividends declared per common share (in usd per share)	$ 0.72	$ 0.61	$ 0.72

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ 53,057	$ 41,791	$ 38,918
Change in fair value of investment securities available for sale, net of tax of $(1,591), $826 and $(2,316), respectively	(5,956)	1,530	(4,311)
Reclassification adjustment for net gain from sale of investment securities available for sale included in income, net of tax of $(29), $(2) and $(461), respectively	(108)	(4)	(854)
Other comprehensive (loss) income	(6,064)	1,526	(5,165)
Comprehensive income	$ 46,993	$ 43,317	$ 33,753

Consolidated Statements of Co_2

Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statement of Comprehensive Income [Abstract]
Change in fair value of securities available for sale, tax	$ (1,591)	$ 826	$ (2,316)
Reclassification adjustment of net gain from sale of investment securities available for sale included in income, tax	$ (29)	$ (2)	$ (461)

Consolidated Statement of Stock

Consolidated Statement of Stockholders' Equity - USD ($) $ in Thousands	Total	Common stock	Retained earnings	Accumulated other comprehensive income (loss), net
Balance at beginning of the year, shares at Dec. 31, 2015		29,975,000
Balance at the beginning of the year at Dec. 31, 2015	$ 469,970	$ 359,451	$ 107,960	$ 2,559
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Restricted stock awards granted, net of forfeitures, shares		110,000
Restricted stock awards granted, net of forfeitures	$ 0
Exercise of stock options, shares	37,713	38,000
Exercise of stock options	$ 560	$ 560
Stock-based compensation expense	1,840	1,840
Net excess tax benefits from vesting of restricted stock	103	$ 103
Common stock repurchased, shares		(168,000)
Common stock repurchased	(2,894)	$ (2,894)
Net income	38,918		38,918
Other comprehensive income (loss), net of tax	(5,165)			(5,165)
Common stock issued in business combinations	0
Cash dividends declared on common stock	(21,569)		(21,569)
Balance at end of the year, shares at Dec. 31, 2016		29,955,000
Balance at the end of the year at Dec. 31, 2016	481,763	$ 359,060	125,309	(2,606)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
ASU Implementation				0
Restricted stock awards forfeited, shares		(10,000)
Restricted stock awards forfeited	$ 0
Exercise of stock options, shares	12,662	13,000
Exercise of stock options	$ 164	$ 164
Stock-based compensation expense	2,103	$ 2,103
Common stock repurchased, shares		(30,000)
Common stock repurchased	(737)	$ (737)
Net income	41,791		41,791
Other comprehensive income (loss), net of tax	1,526			1,526
Common stock issued in business combinations	0
Cash dividends declared on common stock	(18,305)		(18,305)
Balance at end of the year, shares at Dec. 31, 2017		29,928,000
Balance at the end of the year at Dec. 31, 2017	508,305	$ 360,590	149,013	(1,298)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
ASU Implementation				(218)
Restricted stock units vested, net of restricted stock awards forfeited, shares		29,000
Restricted stock units vested, net of restricted stock awards forfeited	$ 0
Exercise of stock options, shares	9,842	10,000
Exercise of stock options	$ 133	$ 133
Stock-based compensation expense	2,744	$ 2,744
Common stock repurchased, shares		(53,000)
Common stock repurchased	(1,704)	$ (1,704)
Net income	53,057		53,057
Other comprehensive income (loss), net of tax	(6,064)			(6,064)
Common stock issued in business combinations, shares		6,960,000
Common stock issued in business combinations	230,043	$ 230,043
Cash dividends declared on common stock	(25,791)		(25,791)
Balance at end of the year, shares at Dec. 31, 2018		36,874,000
Balance at the end of the year at Dec. 31, 2018	$ 760,723	$ 591,806	$ 176,372	(7,455)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
ASU Implementation				$ (93)

Consolidated Statement of Sto_2

Consolidated Statement of Stockholders' Equity (Parenthetical) - $ / shares	Oct. 24, 2018	Jul. 24, 2018	Apr. 25, 2018	Jan. 24, 2018	Oct. 25, 2017	Jul. 25, 2017	Apr. 25, 2017	Jan. 25, 2017	Oct. 26, 2016	Jul. 20, 2016	Apr. 20, 2016	Jan. 27, 2016	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statement of Stockholders' Equity [Abstract]
Dividends declared per common share (in usd per share)	$ 0.17	$ 0.15	$ 0.15	$ 0.15	$ 0.13	$ 0.13	$ 0.13	$ 0.12	$ 0.12	$ 0.12	$ 0.12	$ 0.11	$ 0.27	$ 0.15	$ 0.15	$ 0.15	$ 0.23	$ 0.13	$ 0.13	$ 0.12	$ 0.72	$ 0.61	$ 0.72

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash flows from operating activities:
Net income	$ 53,057	$ 41,791	$ 38,918
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation of premises and equipment, amortization of securities available for sale, and amortization of discount of junior subordinated debentures	9,808	10,704	12,709
Changes in net deferred loan costs, net of amortization	(150)	(1,007)	(1,422)
Provision for loan losses	5,129	4,220	4,931
Net change in accrued interest receivable, prepaid expenses and other assets, accrued expenses and other liabilities	10,195	11,634	2,147
Stock-based compensation expense	2,744	2,103	1,840
Net excess tax benefit from exercise of stock-based compensation	0	0	(123)
Amortization of intangible assets	3,819	1,286	1,415
Origination of loans held for sale	(76,101)	(108,696)	(145,107)
Proceeds from sale of loans	79,237	121,482	148,121
Earnings on bank owned life insurance	(1,753)	(1,424)	(1,460)
Valuation adjustment on other real estate owned	49	0	383
Gain on sale of loans, net	(2,759)	(7,696)	(6,994)
Gain on sale of investment securities, net	(137)	(6)	(1,315)
Gain on sale of assets held for sale	(798)	(747)	0
Loss on sale of other real estate owned	0	(144)	(173)
Impairment of assets held for sale	75	0	0
Loss on sale or write-off of furniture, equipment and leasehold improvements	32	13	110
Net cash provided by operating activities	82,447	73,513	53,980
Cash flows from investing activities:
Loans originated, net of principal payments	(98,563)	(235,154)	(263,387)
Maturities of other interest earning deposits	0	0	6,709
Maturities, calls and payments of investment securities available for sale	92,563	98,894	129,408
Purchase of investment securities available for sale	(342,141)	(149,914)	(267,657)
Purchase of premises and equipment	(23,265)	(3,063)	(6,722)
Proceeds from sales of other loans	9,993	28,874	21,077
Proceeds from sales of other real estate owned	198	930	2,486
Proceeds from sales of investment securities available for sale	156,014	31,028	140,373
Proceeds from sales of assets held for sale	1,908	1,849	0
Proceeds from redemption of Federal Home Loan Bank stock	26,538	30,018	23,732
Purchases of Federal Home Loan Bank stock	(22,524)	(30,801)	(27,148)
Proceeds from sales of premises and equipment	28	0	659
Purchase of bank owned life insurance	(54)	(4,394)	(8,000)
Proceeds from BOLI death benefit	0	1,101	0
Capital contributions to low-income housing tax credit partnerships and new market tax credit partnerships, net	(8,303)	(10,762)	(4,456)
Net cash received from acquisitions	105,974	0	0
Net cash used in investing activities	(101,634)	(241,394)	(252,926)
Cash flows from financing activities:
Net increase in deposits	214,740	163,412	121,361
Federal Home Loan Bank advances	554,950	763,350	660,900
Repayments of Federal Home Loan Bank advances	(663,450)	(750,450)	(581,300)
Common stock cash dividends paid	(25,791)	(18,305)	(21,569)
Net (decrease)/increase in securities sold under agreement to repurchase	(796)	9,717	(1,110)
Proceeds from exercise of stock options	133	164	540
Net excess tax benefit from exercise of stock-based compensation	0	0	123
Repurchase of common stock	(1,704)	(737)	(2,894)
Net cash provided by financing activities	78,082	167,151	176,051
Net increase (decrease) in cash and cash equivalents	58,895	(730)	(22,895)
Cash and cash equivalents at beginning of year	103,015	103,745	126,640
Cash and cash equivalents at end of year	161,910	103,015	103,745
Supplemental disclosures of cash flow information:
Cash paid for interest	12,385	8,399	5,998
Cash paid for income taxes	5,634	2,045	11,500
Supplemental non-cash disclosures of cash flow information:
Transfers of loans receivable to other real estate owned	434	32	1,431
Transfers of properties held for sale recorded in premises and equipment, net to prepaid expenses and other assets	1,836	2,687	0
Transfer of BOLI to prepaid expenses and other assets	421	0	0
Investment in low income housing tax credit partnership and related funding commitment	0	33,171	19,663
Business Combinations:
Common stock issued in business combinations	230,043	0	0
Assets acquired (liabilities assumed) in acquisitions:
Investment securities available for sale	84,846	0	0
Loans receivable	718,620	0	0
Other real estate owned	1,796	0	0
Premises and equipment	3,785	0	0
Federal Home Loan Bank stock	1,743	0	0
Accrued interest receivable	2,454	0	0
Bank owned life insurance	17,116	0	0
Prepaid expenses and other assets	2,957	0	0
Other intangible assets	18,345	0	0
Goodwill	121,910	0	0
Deposits	(824,602)	0	0
Federal Home Loan Bank advances	(16,000)	0	0
Securities sold under agreement to repurchase	(462)	0	0
Accrued expenses and other liabilities	$ (8,439)	$ 0	$ 0

Description of Business, Basis

Description of Business, Basis of Presentation and Significant Accounting Policies and Recently Issued Accounting Pronouncements	12 Months Ended
	Dec. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of Business, Basis of Presentation and Significant Accounting Policies and Recently Issued Accounting Pronouncements	Description of Business, Basis of Presentation, Significant Accounting Policies and Recently Issued Accounting Pronouncements (a) Description of Business Heritage Financial Corporation ("Heritage" or the “Company”) is a bank holding company that was incorporated in the State of Washington in August 1997. The Company is primarily engaged in the business of planning, directing and coordinating the business activities of its wholly-owned subsidiary, Heritage Bank (the “Bank”). The Bank is a Washington-chartered commercial bank and its deposits are insured by the FDIC. The Bank is headquartered in Olympia, Washington and conducts business from its 64 branch offices located throughout Washington State and the greater Portland, Oregon area. The Bank’s business consists primarily of commercial lending and deposit relationships with small businesses and their owners in its market areas and attracting deposits from the general public. The Bank also makes real estate construction and land development loans, consumer loans and originates first mortgage loans on residential properties primarily located in its market areas. Effective January 16, 2018, the Company completed the acquisition of Puget Sound Bancorp, Inc. (“Puget Sound”), the holding company for Puget Sound Bank, both of Bellevue, Washington (“Puget Sound Merger”) and on July 2, 2018, the Company completed the acquisition of Premier Commercial Bancorp ("Premier Commercial"), the holding company for Premier Community Bank, both of Hillsboro, Oregon ("Premier Merger"). See Note (2) Business Combinations for additional information on the Puget Sound Merger and the Premier Merger (collectively the "Premier and Puget Mergers"). (b) Basis of Presentation The accounting and reporting policies of the Company and its subsidiaries conform to U.S. Generally Accepted Accounting Principles (“GAAP”). In preparing the Consolidated Financial Statements, management makes estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of income and expenses during the reporting periods. Actual results could differ from these estimates. The accompanying Consolidated Financial Statements include the accounts of the Company and its wholly owned subsidiary, the Bank. All significant intercompany balances and transactions among the Company and the Bank have been eliminated in consolidation. Certain prior year amounts in the Consolidated Statements of Income have been reclassified to conform to the current year’s presentation. Reclassifications had no effect on the prior years' net income or stockholders’ equity. (c) Significant Accounting Policies Cash and Cash Equivalents Cash and cash equivalents include cash on hand and due from banks and interest-bearing balances due from the Federal Reserve Bank. Cash equivalents have a maturity of 90 days or less at the time of purchase. Investment Securities The Company identifies investments as held to maturity or available for sale at the time of acquisition. Securities are classified as held to maturity when the Company has the ability and positive intent to hold them to maturity. Securities classified as available for sale are available for future liquidity requirements and may be sold prior to maturity. As of December 31, 2018 and December 31, 2017 the Bank does not hold any securities classified as held to maturity. See Note (3) Investment Securities for additional information. Securities available for sale are carried at fair value. Interest income includes amortization of purchase premiums or accretion of purchase discounts using the interest method. Unrealized gains and losses on securities available for sale are generally excluded from earnings and are reported in other comprehensive income (loss), net of related income taxes. Realized gains and losses on sale of investment securities are computed on the specific identification method. Transfers of securities between the available for sale and held to maturity categories are accounted for at fair value. Management evaluates securities for other-than-temporary impairment on at least a quarterly basis, and more frequently when economic or market conditions warrant such an evaluation. Although these evaluations involve significant judgment, an unrealized loss in the fair value of a debt security is generally deemed to be temporary when a) the fair value of the security is below the carrying value primarily due to changes in interest rates; b) there has not been significant deterioration in the financial condition of the issuer; and, c) it is not more likely than not that the Company will be required to, nor does it have the intent to, sell the security before the anticipated recovery of its remaining carrying value. If any of these criteria is not met, the impairment is split into two components as follows: 1) other-than-temporary impairment related to credit loss, which must be recognized in the income statement and 2) other-than-temporary impairment related to other factors, which is recognized in other comprehensive income (loss). The credit loss is defined as the difference between the present value of the cash flows expected to be collected and the amortized cost basis. For debt securities with other-than-temporary impairment, the previous amortized cost basis less the other-than-temporary impairment recognized in earnings shall be the new amortized cost basis of the security. In subsequent periods, the Company accretes into interest income the difference between the new amortized cost basis and cash flows expected to be collected prospectively over the life of the debt security . Continued deterioration of market conditions could result in additional impairment losses recognized within the investment portfolio. Other factors that may be considered in determining whether a decline in the value of a debt security is “other-than-temporary” include ratings by recognized rating agencies; actions of commercial banks or other lenders relative to the continued extension of credit facilities to the issuer of the security; the financial condition, capital strength and near-term prospects of the issuer and recommendations of investment advisors or market analysts. Loans Held for Sale Mortgage loans held for sale are carried at the lower of amortized cost or fair value. Any loan that management does not have the intent and ability to hold for the foreseeable future or until maturity or payoff is classified as held for sale at the time of origination, purchase or securitization, or when such decision is made. Unrealized losses on such loans are recorded as a valuation allowance and included in income. Loans Receivable and Loan Commitments Loans receivable include loans originated by the Bank as well as loans acquired in business combinations. Loans acquired in a business combination are designated as “purchased” loans. These loans are recorded at their fair value at acquisition date, factoring in credit losses expected to be incurred over the life of the loan. Accordingly, an allowance for loan losses is not carried over or recorded as of the acquisition date. Loans purchased with evidence of credit deterioration since origination for which it is probable that all contractually required payments will not be collected are accounted for under FASB ASC 310-30, Loans and Debt Securities Acquired with Deteriorated Credit Quality . These loans are identified as purchased credit impaired ("PCI") loans. In situations where such loans have similar risk characteristics, loans may be aggregated into pools to estimate cash flows. A pool is accounted for as a single asset with a single interest rate, cumulative loss rate and cash flow expectation. Expected cash flows at the acquisition date in excess of the fair value of loan or pool are considered to be accretable yield, which is recognized as interest income over the life of the loan or pool using a level yield method if the timing and amount of the future cash flows of the loan or pool is reasonably estimable. The cash flows expected over the life of the PCI loan or pool are estimated quarterly using an external cash flow model that projects cash flows and calculates the carrying values of the loans or pools, book yields, effective interest income and impairment, if any, based on loan or pool level events. Assumptions as to default rates, loss severity and prepayment speeds are utilized to calculate the expected cash flows. To the extent actual or projected cash flows are less than previously estimated, additional provisions for loan losses on the purchased loan portfolios will be recognized immediately into earnings. To the extent actual or projected cash flows are more than previously estimated, the increase in cash flows is recognized immediately as a recapture of provision for loan losses up to the amount of any provision previously recognized for that loan or pool, if any, then prospectively recognized in interest income as a yield adjustment. Any disposals of a loan in a pool, including sale of a loan, payment in full or foreclosure results in the removal of the loan from the loan pool at the carrying amount. Loans accounted for under FASB ASC 310-30 are generally considered accruing and performing loans as the loans accrete interest income over the estimated life of the loan when cash flows are reasonably estimable. Accordingly, PCI loans that are contractually past due are still considered to be accruing and performing loans. If the timing and amount of cash flows is not reasonably estimable, the loans may be classified as nonaccrual loans and interest income may be recognized on a cash basis or all cash payments may be accounted for a as a reduction of the principal amount outstanding. Loans purchased that are not accounted for under FASB ASC 310-30 are accounted for under FASB ASC 310-20, Receivables—Nonrefundable fees and Other Costs . These loans are identified as non-PCI loans, and are initially recorded at their fair value, which is estimated using an external cash flow model and assumptions similar to the FASB ASC 310-30 loans. The difference between the estimated fair value and the unpaid principal balance at acquisition date is recognized as interest income over the life of the loan using an effective interest method for non-revolving credits or a straight-line method, which approximates the effective interest method, for revolving credits. Any unrecognized discount for a loan that is subsequently repaid in full will be recognized immediately into income. Loans are generally recorded at the unpaid principal balance, net of premiums, unearned discounts and net deferred loan origination fees and costs. The premiums and unearned discounts may include values determined in purchase accounting. Interest on loans is calculated using the simple interest method based on the daily balance of the principal amount outstanding and is credited to income as earned. Loans are considered past due or delinquent when principal or interest payments are past due 30 days or more. The Company's policies for determining past due or delinquency status, placing loans on nonaccrual status, recording payments received on nonaccrual loans, resuming accrual of interest, and charging off uncollectible loans generally do not differ by loan segments or classes. Any differences are denoted in the applicable sections below. Delinquent Loans : Commercial loans are serviced by the relationship manger assigned to the account. System generated delinquency reports are provided to all relationship managers monthly, and relationship managers take follow up action as needed, including contacting the borrower and transferring seriously delinquent loans to the Bank’s Special Assets Department for collection. Consumer loans are monitored by the Bank’s Consumer Collections Department, with initial delinquency notices sent after 15 days, with follow up notices at 30 and 45 days. The Consumer Collections Department attempts to make direct contact with the borrower to establish a plan to bring the loan current. Consumer loans that become 90 days delinquent are charged off. Nonaccrual and Charged-off Loans : Loans on which the accrual of interest has been discontinued are designated as nonaccrual loans. Delinquent loans may remain on accrual status between 30 days and 89 days past due. The accrual of interest is generally discontinued at the time the loan is 90 days delinquent unless the credit is well secured and in the process of collection. Loans are placed on nonaccrual at an earlier date if collection of the contractual principal or interest is doubtful. All interest accrued but not collected on loans deemed nonaccrual during the period is reversed against interest income in that period. The interest payments received on nonaccrual loans are generally accounted for on the cost-recovery method whereby the interest payment is applied to the principal balances. Loans may be returned to accrual status when improvements in credit quality eliminate the doubt as to the full collectability of both interest and principal and a period of sustained performance has occurred. Substantially all loans that are nonaccrual are also considered impaired. Income recognition on impaired loans conforms to that used on nonaccrual loans. Loans are generally charged-off if collection of the contractual principal or interest as scheduled in the loan agreement is doubtful. Credit card loans and other consumer loans are typically charged-off no later than 180 days past due. Impaired Loans : The Bank routinely tests its classified loans for potential impairment. Classified loans that may be impaired are identified using the Bank's normal loan review procedures, which include post-approval reviews, quarterly reviews by credit administration of criticized loan reports, scheduled internal reviews, underwriting during extensions and renewals, and the analysis of information routinely received on a borrower’s financial performance. A loan is considered impaired when, based on current information and events, it is probable the Bank will be unable to collect the scheduled payments of principal or interest when due according to the original contractual terms of the loan agreement. Factors considered by management in determining impairment include payment status, collateral value, and the probability of collecting scheduled principal and interest payments when due. Loans that experience insignificant payment delays and payment shortfalls generally are not classified as impaired. Management determines the significance of payment delays and payment shortfalls on a case-by-case basis, taking into consideration all of the circumstances surrounding the loan and the borrowers, including length of the delay, the reasons for the delay, the borrower’s prior payment record, and the amounts of the shortfall in relation to the principal and interest owed. Impairment is measured on a loan-by-loan basis by either the present value of expected future cash flows discounted at the loan’s effective interest rate, or as a practical expedient the loan’s observable market price or the fair value of the collateral (less cost to sell) if the loan is collateral dependent. Income recognition on impaired loans conforms to that used on nonaccrual loans. Subsequent to an initial measure of impairment and based on new information received, if there is a significant change in the amount or timing of a loan’s expected future cash flows or a change in the value of collateral or market price of a loan, the impairment is recalculated. However, the net carrying value of a loan never exceeds the recorded investment in the loan. Troubled Debt Restructures : A troubled debt restructured loan (“TDR”) is a restructuring in which the Bank, for economic or legal reasons related to a borrower’s financial difficulties, grants a concession to a borrower that it would not otherwise consider. These concessions may include changes of the interest rate, forbearance of the outstanding principal or accrued interest, extension of the maturity date, delay in the timing of the regular payment, or any other actions intended to minimize potential losses. The Bank does not forgive principal for a majority of its TDRs, but in those situations where principal is forgiven, the entire amount of such principal forgiveness is immediately charged off to the extent not done so prior to the modification. The Bank also considers insignificant delays in payments when determining if a loan should be classified as a TDR. The Company has implemented more stringent definitions of concessions and impairment measures for PCI loans which are not in pools as these loans have known credit deteriorations and are generally accreting income at a lower discounted rate as compared to the contractual note rate based on the guidance of FASB ASC 310-30. Modifications of PCI loans which are not in pools are considered TDRs if they result in a decrease in expected cash flows when compared to the pre-modification expected cash flows, without any other changes to the agreement to consider. A loan that has been placed on nonaccrual status that is subsequently restructured will usually remain on nonaccrual status until the borrower is able to demonstrate repayment performance in compliance with the restructured terms for a sustained period, typically for six months. A restructured loan may return to accrual status sooner based on other significant events or mitigating circumstances. A loan that has not been placed on nonaccrual status may be restructured and such loan may remain on accrual status after such restructuring. In these circumstances, the borrower has made payments before the restructuring and is expected to continue to perform after the restructuring. Generally, this type of restructuring involves a reduction in the loan interest rate and/or a change to interest-only payments for a period of time. The restructured loan is considered impaired despite the accrual status and a specific valuation allowance, if any, is calculated in the manner previously described. A TDR is considered defaulted if, during the 12-month period after the restructure, the loan has not performed in accordance to the restructured terms. Defaults include loans whose payments are 90 days or more past due and loans whose revised maturity date passed and no further modifications will be granted for that borrower. A loan may subsequently be excluded from the TDR disclosures if: (i) the restructured interest rate was greater than or equal to the interest rate of a new loan with comparable risk at the time of the restructure, and (ii) the loan is no longer impaired based on the terms of the restructured agreement. The Bank's policy is that the borrower must demonstrate a sustained period, typically six consecutive months, of payments in accordance with the modified loan before it can be reviewed for removal from the TDR disclosure under the second criteria. However, the loan must be reported as a TDR in at least one annual report on Form 10-K. Once a loan has been classified as a TDR, it will continue to be disclosed as an impaired loan until paid off or charged-off, even if the loan subsequently is no longer disclosed as a TDR. Unfunded Loan Commitments : Unfunded loan commitments are generally related to the unused portion of the total commitment of a loan or providing credit facilities to clients of the Bank and are not actively traded financial instruments. These unfunded commitments are disclosed as financial instruments with off-balance sheet risk in Note (14) Commitments and Contingencies and Note (18) Fair Value Measurements in the Notes to Consolidated Financial Statements. Loan Fees and Costs Loan origination fees and certain direct origination costs are deferred and amortized as an adjustment of the yields of the loans over their contractual lives, adjusted for prepayment of the loans, using the effective interest method or the straight-line method, which approximates the effective interest method. In the event loans are sold, the unamortized net deferred loan origination fees or costs are recognized as a component of the gain or loss on the sale of loans. Allowance for Loan Losses Allowance for Loan Losses : The allowance for loan losses is a reserve established through a provision for loan losses charged to expense, which represents management’s best estimate of probable losses that have been incurred within the existing portfolio of loans. Loan losses are charged against the allowance when management believes the uncollectibility of a loan balance is confirmed. Subsequent recoveries, if any, are credited to the allowance. The allowance for loan losses on loans designated as non-PCI loans is similar to the methodology described below except that for non-PCI loans, the remaining unaccreted discounts resulting from the fair value adjustments recorded at the time the loans were purchased are additionally factored into the allowance methodology. The allowance for loan losses on PCI loans is described in the “Allowance for Loan Losses on Purchased Credit Impaired Loans” section below. The allowance, in the judgment of management, is necessary to reserve for estimated loan losses from risks inherent in the loan portfolio. The Company’s allowance for loan losses methodology includes allowance allocations calculated in accordance with FASB ASC 310, Receivables and allowance allocations calculated in accordance with FASB ASC 450, Contingencies . Accordingly, the methodology is based on historical loss experience by type of credit, specific homogeneous risk pools and specific loss allocations, with adjustments for current events and conditions. The Company’s process for determining the appropriate level of the allowance for loan losses is designed to account for credit deterioration as it occurs. The provision for loan losses reflects loan quality trends, including the levels of and trends related to nonaccrual loans, past due loans, classified loans and net charge-offs or recoveries, among other factors. The provision for loan losses also reflects all actions taken on all loans for a particular period. Therefore, the amount of the provision reflects not only the necessary increases in the allowance for loan losses related to newly identified criticized loans, but it also reflects actions taken related to other loans including, among other things, any necessary increases or decreases in specific valuation allowances for impaired loans or loan pools. The level of the allowance reflects management’s continuing evaluation of known and inherent risks in the loan portfolio. Portions of the allowance may be allocated for specific credits; however, the entire allowance is available for any credit that, in management’s judgment, could be charged off. Loans which management determines are impaired are individually evaluated for impairment, and specific valuation allowances are recorded, if any, on these loans based on the methodology previously described. Loans that are determined not to meet management's definition of impaired are collectively evaluated for impairment based on (i) historical loss factors determined in accordance with FASB ASC 450 based on historical loan loss experience for similar loans with similar characteristics and trends; and (ii) environmental loss factors that reflect the impact of current conditions, as determined in accordance with FASB ASC 450 based on general economic conditions and other qualitative risk factors both internal and external to the Company. The historical loss factors and environmental loss factors are combined and multiplied against the unguaranteed outstanding principal balances of loans in pools of similar loans with similar characteristics. The Company evaluates specific loans for credit quality indicators and performs regular analysis and evaluation of problem loans. Loans are classified based on an internal credit risk grading process that evaluates, among other things: (i) the obligor’s ability to repay; (ii) the underlying collateral, if any; and (iii) the economic environment and industry in which the borrower operates. This analysis is performed at the loan officer level for all loans. When a loan is performing, but has an assigned risk grade other than pass, the loan officer analyzes the loan to determine an appropriate monitoring and collection strategy. When a loan is nonperforming or has been classified as a nonaccrual loan, a member from the special assets department will analyze the loan to determine if it is impaired. If the loan is considered impaired, the special assets department will evaluate the need for a specific valuation allowance on the loan. Specific valuation allowances are determined by analyzing the borrower’s ability to repay amounts owed, collateral deficiencies and economic conditions affecting the borrower’s industry, among other things. Historical loss factors are calculated based on the historical loss experience and recovery experience of specific classes of loans. The Company calculates historical loss ratios for the classes of loans based on the proportion of actual charge-offs and recoveries experienced to the total loans in the pool for a rolling twelve-quarter average. Environmental loss factors are based on general economic conditions and other qualitative risk factors both internal and external to the Company. In general, such valuation allowances are determined by evaluating, among other things: (i) levels of and trends in delinquencies, classified and impaired loans; (ii) levels of and trends in charge-offs and recoveries; (iii) trends in volume and terms of loans (iv) effects of changes in risk selection and underwriting standards, and other changes in lending policies, procedures, and practices; (v) experience, ability, and depth of lending management and other relevant staff; (vi) national and local economic trends and conditions; (vii) other external factors such as competition, legal, and regulatory; (viii) effects of changes in credit concentrations, and (ix) other factors. Management evaluates the degree of risk that each one of these components has on the quality of the loan portfolio on a quarterly basis. Each component is determined to be on a scale of risk. The results are then utilized in a matrix to determine an appropriate environmental loss factor for each class of loan. The allowance for loan losses evaluation is inherently subjective, as it requires estimates that are susceptible to significant revision as more information becomes available. While management utilizes its best judgment and information available to recognize losses on loans, future additions to the allowance may be necessary based on declines in local and national economic conditions. In addition, various regulatory agencies, as an integral part of their examination process, periodically review the Bank’s allowance for loan losses. Such agencies may require the Bank to make adjustments to the allowance based on their judgments about information available to them at the time of their examinations. The Company believes the allowance for loan losses is appropriate given all of the above considerations. Allowance for Loan Losses on Purchased Credit Impaired Loans: The PCI loans acquired in the Company's mergers and acquisitions are subject to the Company’s internal and external credit review. Under the accounting guidance of FASB ASC 310-30, the allowance for loan losses on PCI loans is measured at each financial reporting period, or measurement date, based on expected cash flows. If and when credit deterioration, or decreases in expected cash flows previously estimated, occurs subsequent to the acquisition date, a provision for loan losses will be charged to earnings as of the measurement date. Allowance for Losses on Unfunded Commitments: The Bank is also party to financial instruments with off-balance sheet risk in the normal course of business to meet the financing needs of its customers. These financial instruments include commitments to extend credit and standby letters of credit. Those instruments involve, to varying degrees, elements of credit risk in excess of the disbursed amounts recognized in the Consolidated Statements of Financial Condition. The Company has a policy in which it evaluates the risk on a quarterly basis, and provides for an allowance for credit losses, as necessary. The methodology is similar to the allowance for loan losses, and includes an estimate of the probability of drawdown of the loan commitment. Based on its analysis, the Company has recorded an allowance for off-balance sheet financial instruments of $306,000 and $170,000 as of December 31, 2018 and 2017 , respectively. This allowance is reported within accrued expenses and other liabilities on the Company's Consolidated Statements of Financial Condition. Mortgage Banking Operations The Bank sells one-to-four family residential loans on a servicing-released basis. The Bank recognizes a gain or loss to the extent that the sale proceeds of the loan sold differs from the net book value at the time of sale. Income from one-to-four family residential loans brokered to other lenders is recognized into income on date of loan closing. Commitments to sell one-to-four family residential loans are made primarily during the period between the taking of the loan application and the closing of the loan. The timing of making these sale commitments is dependent upon the timing of the borrower’s election to lock-in the mortgage interest rate and fees prior to loan closing. Most of these sale commitments are made on a best-efforts basis whereby the Bank is only obligated to sell the loan if the loan is approved and closed by the Bank. Commitments to fund one-to-four family residential loans (interest rate locks) to be sold into the secondary market and forward commitments for the future delivery of these loans are accounted for as free standing derivatives. Fair values of these mortgage derivatives are estimated based on changes in mortgage interest rates between the date the interest on the loan was locked and the balance sheet date. The Company enters into forward commitments for the future delivery of one-to-four family residential loans when interest rate locks are entered into, in order to hedge the interest rate risk resulting from its commitments to fund the loans. Changes in the fair values of these derivatives are included in other income. The fair value of these derivative instruments was no t significant at December 31, 2018 and 2017 . Other Real Estate Owned Other real estate acquired by the Company in partial or full satisfaction of a loan obligation is classified as held for sale. When acquired, the property is recorded at the estimated fair value (less the costs to sell) at the date of acquisition, not to exceed net realizable value, and any resulting write-down is charged to the allowance for loan losses. Physical possession of residential real estate property collateralizing a consumer mortgage loan occurs when legal title is obtained upon completion of foreclosure or when the borrower conveys all interest in the properly to satisfy the loan through completion of a deed in lieu of foreclosure or through a similar legal agreement. After acquisition, all costs incurred in maintaining the property are expensed except for costs relating to the development and improvement of the property which are capitalized to the extent of the property’s net realizable value. If the estimated realizable value of the other real estate owned property declines after the acquisition date, the valuation adjustment is charged to other real estate owned expense, net on the Consolidated Statements of Income. Premises and Equipment Premises and equipment, including leasehold improvements, are stated at cost less accumulated depreciation. Depreciation is computed using the straight-line method over the estimated useful lives of the assets or the lease period, whichever is shorter. The estimated useful lives used to compute depreciation and amortization for buildings and building improvements is 15 to 39 years; and for furniture, fixtures and equipment is three to seven years. The Company reviews buildings, leasehold improvements and equipment for impairment whenever events or changes in the circumstances indicate that the undiscounted cash flows for the property are less than its carrying value. If identified, an impairment loss is recognized through a charge to earnings based on the fair value

Business Combinations

Business Combinations	12 Months Ended
	Dec. 31, 2018
Business Combinations [Abstract]
Business Combinations	Business Combinations During the year ended December 31, 2018 , the Company completed the acquisitions of Puget Sound Bancorp and Premier Commercial Bancorp. There were no acquisitions completed during the year ended December 31, 2017 . Puget Sound Merger: On July 26, 2017, the Company, along with the Bank, and Puget Sound Bancorp, Inc. and its wholly owned subsidiary bank, Puget Sound Bank, jointly announced the signing of a definitive agreement. The Puget Sound Merger was effective on January 16, 2018. As of the acquisition date, Puget Sound merged into Heritage and Puget Sound Bank merged into Heritage Bank. Pursuant to the terms of the Puget Sound Merger, all outstanding Puget Sound restricted stock awards became immediately vested on the acquisition date of the Puget Sound Merger. Puget Sound shareholders received 1.1688 shares of Heritage common stock per share of Puget Sound stock. Heritage issued an aggregate of 4,112,258 shares of its common stock based on the January 12, 2018 closing price of Heritage Common stock of $31.80 for total fair value of common shares issued of $130.8 million and paid cash of $3,000 for fractional shares in the transaction for total consideration paid of $130.8 million . Total consideration includes $851,000 representing 26,741 shares which were forfeited by the Puget Sound shareholders to pay applicable taxes. The Company incurred acquisition-related costs of approximately $5.4 million and $810,000 for the year ended December 31, 2018 and 2017, respectively, for the Puget Sound Merger. Premier Merger: On March 24, 2018, the Company, along with the Bank, and Premier Commercial Bancorp and its wholly owned subsidiary bank, Premier Community Bank, jointly announced the signing of a definitive agreement. The Premier Merger was effective on July 2, 2018. As of the acquisition date, Premier merged into Heritage and Premier Commercial Bank merged into Heritage Bank. Pursuant to the terms of the Premier Merger, Premier Commercial shareholders received 0.4863 shares of Heritage common stock in exchange for each share of Premier Commercial common stock based on the closing date price per share of Heritage common stock on June 29, 2018 of $34.85 . Heritage issued an aggregate of 2,848,579 shares of its common stock and paid cash of $2,000 for fractional shares in the transaction for total consideration paid of $99.3 million . The Company incurred acquisition-related costs of approximately $4.9 million for the year ended December 31, 2018 for the Premier Merger. Business Combination Accounting: The Premier Merger and Puget Sound Merger resulted in $53.4 million and $68.5 million , respectively, of goodwill. This goodwill is not deductible for tax purposes. The primary reason for the Premier and Puget Mergers was to create depth in the Company's geographic footprint consistent with its ongoing growth strategy, focused heavily on metro markets, and to achieve operational scale and realize efficiencies of a larger combined organization. The mergers constitute business acquisitions as defined by FASB ASC 805, Business Combinations. FASB ASC 805 establishes principles and requirements for how the acquirer of a business recognizes and measures in its financial statements the identifiable assets acquired and the liabilities assumed. Heritage was considered the acquirer in these transactions. Accordingly, the preliminary estimates of fair values of Premier Commercial and Puget Sound assets, including the identifiable intangible assets, and the assumed liabilities, were measured and recorded as of the respective acquisition dates. Fair values on the acquisition dates are preliminary and represent management’s best estimates based on available information and facts and circumstances in existence on the acquisition date. Fair values are subject to refinement for up to one year after the closing date of the acquisitions as additional information regarding the closing date fair values becomes available. The Company finalized the purchase price allocation for both mergers as of December 31, 2018 and recorded an adjustment to the Premier Commercial fair values of total loans receivable, prepaid expenses and other assets and accrued expenses and other liabilities during the quarter end December 31, 2018 with a net impact to goodwill acquired of $102,000 . The fair value estimates of the assets acquired and liabilities assumed in the Premier and Puget Mergers were as follows: Premier Merger Puget Sound Merger (In thousands) Assets Cash and cash equivalents $ 22,534 $ 25,889 Interest earning deposits 3,309 54,247 Investment securities available for sale 4,493 80,353 Loans receivable (1) 330,158 388,462 Other real estate owned 1,796 — Premises and equipment, net 3,053 732 Federal Home Loan Bank stock, at cost 1,120 623 Bank owned life insurance 10,852 6,264 Accrued interest receivable 1,006 1,448 Prepaid expenses and other assets 1,603 1,354 Other intangible assets 7,075 11,270 Total assets acquired $ 386,999 $ 570,642 Liabilities Deposits $ 318,717 $ 505,885 Federal Home Loan Bank advances 16,000 — Securities sold under agreement to repurchase 462 — Accrued expenses and other liabilities 5,935 2,504 Total liabilities acquired $ 341,114 $ 508,389 Fair value of net assets acquired $ 45,885 $ 62,253 (1) The outstanding loan balance acquired in the Premier Merger and Puget Sound Merger was $335.4 million and $392.7 million , respectively, at the acquisition date. A summary of the net assets purchased and the estimated fair value adjustments and resulting goodwill recognized from the Premier and Puget Sound Mergers are presented in the following tables. Goodwill represents the excess of the consideration transferred over the estimated fair value of the net assets acquired and liabilities assumed. Premier Merger Puget Sound Merger (In thousands) Consideration transferred $ 99,275 $ 130,773 Cost basis of net assets on merger date $ 40,629 $ 54,405 Fair value adjustments: Investment securities (135 ) (348 ) Total loans receivable, net (111 ) 1,400 Other real estate owned (1,017 ) — Premises and equipment 1,312 (121 ) Other intangible assets 7,075 9,207 Prepaid expenses and other assets (1,912 ) (2,282 ) Deposits (310 ) (62 ) Accrued expenses and other liabilities 354 54 Fair value of net assets on merger date $ 45,885 $ 62,253 Goodwill recognized from the mergers $ 53,390 $ 68,520 The operating results of the Company for the year ended December 31, 2018 include the operating results produced by the net assets acquired in the Premier and Puget Mergers since the July 2, 2018 and January 16, 2018 merger dates. The Company has considered the requirement of FASB ASC 805 related to the contribution of the Premier and Puget Mergers to the Company’s results of operations. The table below presents only the significant results for the acquired businesses since the July 2, 2018 and January 16, 2018 merger dates: Premier Merger (1) Puget Sound Merger (1) Total Year ended December 31, 2018 (In thousands) Interest income: Interest and fees on loans (2) $ 10,462 $ 21,898 $ 32,360 Interest income: Interest and fees on investments (3) 76 59 135 Interest income: Other interest earning assets 174 113 287 Interest expense (445 ) (682 ) (1,127 ) Provision for loan losses for loans (700 ) (850 ) (1,550 ) Noninterest income 125 472 597 Noninterest expense (4) (7,558 ) (11,230 ) (18,788 ) Net effect, pre-tax $ 2,134 $ 9,780 $ 11,914 (1) The Premier Merger was completed on July 2, 2018. The Puget Sound Merger was completed on January 16, 2018. (2) Includes the accretion of the discount on the purchased loans of $4.1 million during the year ended December 31, 2018 . (3) All securities acquired in the Puget Sound Merger were sold with trade date of January 16, 2018 and settlement dates on or before February 14, 2018. (4) Excludes certain compensation and employee benefits for management as it is impracticable to determine due to the integration of the operations for this merger. Also includes certain acquisition-related costs incurred by the Company. The following table presents certain pro forma information, for illustrative purposes only, for the years ended December 31, 2018 and 2017 as if the Premier and Puget Mergers had occurred on January 1, 2017. The estimated pro forma information combines the historical results of Premier Commercial and Puget Sound with the Company's consolidated historical results and includes certain adjustments reflecting the estimated impact of certain fair value adjustments for the respective periods. The pro forma information is not indicative of what would have occurred had the Premier and Puget Mergers occurred on January 1, 2017. In particular, the pro forma information does not consider any changes to the provision for loan losses resulting from recorded loans at fair value. Additionally, Heritage expects to achieve further operating savings and other business synergies, including interest income growth, as a result of the Premier and Puget Mergers which are not reflected in the pro forma amounts in the following table. As a result, actual amounts will differ from the pro forma information presented. Pro Forma for the Year Ended December 31, 2018 2017 (Dollars in thousands, except per share amounts) Net interest income $ 194,989 $ 174,190 Net income 69,515 41,551 Basic earnings per common share $ 1.88 $ 1.12 Dilutive Earnings per common share $ 1.87 $ 1.12 The Company believes that the historical Premier Commercial and Puget Sound operating results, individually or collectively, are not considered of enough significance to be meaningful to the Company’s results of operations.

Investment Securities

Investment Securities	12 Months Ended
	Dec. 31, 2018
Investments, Debt and Equity Securities [Abstract]
Investment Securities	Investment Securities The Company’s investment policy is designed primarily to provide and maintain liquidity, generate a favorable return on assets without incurring undue interest rate and credit risk, and complement the Bank’s lending activities. As a result of the adoption of FASB ASU 2016-01 on January 1, 2018, equity investments (except for investments accounted for under the equity method of accounting) are now measured at fair value, with changes in fair value recognized in earnings. These investments were previously measured at fair value, with changes in fair value recognized in accumulated other comprehensive income (loss). Accordingly, these securities are no longer classified as investment securities available for sale and their presentation is not comparable to the presentation as of December 31, 2017. See Note (1) Description of Business, Basis of Presentation, Significant Accounting Policies and Recently Issued Accounting Pronouncements, as well as the Equity Securities section discussed below. Available for sale investment securities (a) Securities by Type and Maturity The amortized cost, gross unrealized gains, gross unrealized losses and fair values of investment securities available for sale at the dates indicated were as follows: Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value (In thousands) December 31, 2018 U.S. Treasury and U.S. Government-sponsored agencies $ 101,595 $ 155 $ (147 ) $ 101,603 Municipal securities 158,461 1,209 (806 ) 158,864 Mortgage-backed securities and collateralized mortgage obligations (1) : Residential 337,295 426 (6,119 ) 331,602 Commercial 338,250 1,035 (5,524 ) 333,761 Corporate obligations 25,662 36 (135 ) 25,563 Other asset-backed securities 24,278 424 — 24,702 Total $ 985,541 $ 3,285 $ (12,731 ) $ 976,095 December 31, 2017 U.S. Treasury and U.S. Government-sponsored agencies $ 13,460 $ 6 $ (24 ) $ 13,442 Municipal securities 247,358 3,720 (1,063 ) 250,015 Mortgage-backed securities and collateralized mortgage obligations (1) : Residential 282,724 422 (2,935 ) 280,211 Commercial 219,696 444 (3,061 ) 217,079 Collateralized loan obligations 4,561 19 — 4,580 Corporate obligations 16,594 220 (44 ) 16,770 Other securities (2) 27,781 652 — 28,433 Total $ 812,174 $ 5,483 $ (7,127 ) $ 810,530 (1) Issued and guaranteed by U.S. Government-sponsored agencies. (2) Primarily asset-backed securities. There were no securities classified as trading or held to maturity at December 31, 2018 or December 31, 2017 . The amortized cost and fair value of investment securities available for sale at December 31, 2018 , by contractual maturity, are set forth below. Actual maturities may differ from contractual maturities because certain borrowers have the right to call or prepay obligations with or without call or prepayment penalties. Amortized Cost Fair Value (In thousands) Due in one year or less $ 38,547 $ 38,478 Due after one year through five years 193,191 192,556 Due after five years through ten years 272,408 268,779 Due after ten years 481,395 476,282 Total $ 985,541 $ 976,095 (b) Unrealized Losses and Other-Than-Temporary Impairments The following table shows the gross unrealized losses and fair value of the Company's investment securities available for sale that are not deemed to be other-than-temporarily impaired, aggregated by investment category and length of time that the individual securities have been in continuous unrealized loss positions as of December 31, 2018 and December 31, 2017 : Less than 12 Months 12 Months or Longer Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses (In thousands) December 31, 2018 U.S. Treasury and U.S. Government-sponsored agencies $ 46,992 $ (58 ) $ 7,350 $ (89 ) $ 54,342 $ (147 ) Municipal securities 31,157 (159 ) 38,792 (647 ) 69,949 (806 ) Mortgage-backed securities and collateralized mortgage obligations (1) : Residential 66,620 (247 ) 193,726 (5,872 ) 260,346 (6,119 ) Commercial 43,531 (272 ) 190,585 (5,252 ) 234,116 (5,524 ) Corporate obligations 13,736 (87 ) 1,951 (48 ) 15,687 (135 ) Total $ 202,036 $ (823 ) $ 432,404 $ (11,908 ) $ 634,440 $ (12,731 ) December 31, 2017 U.S. Treasury and U.S. Government-sponsored agencies $ 11,436 $ (24 ) $ — $ — $ 11,436 $ (24 ) Municipal securities 39,298 (384 ) 26,509 (679 ) 65,807 (1,063 ) Mortgage-backed securities and collateralized mortgage obligations (1) : Residential 175,847 (1,296 ) 66,380 (1,639 ) 242,227 (2,935 ) Commercial 75,121 (700 ) 90,822 (2,361 ) 165,943 (3,061 ) Corporate obligations 3,472 (44 ) — — 3,472 (44 ) Total $ 305,174 $ (2,448 ) $ 183,711 $ (4,679 ) $ 488,885 $ (7,127 ) (1) Issued and guaranteed by U.S. Government-sponsored agencies. The Company has evaluated these investment securities available for sale as of December 31, 2018 and December 31, 2017 and has determined that the decline in their value is not other-than-temporary. The unrealized losses are primarily due to increases in market interest rates. The fair value of these securities is expected to recover as the securities approach their maturity date. None of the underlying issuers of the municipal securities and corporate obligations had credit ratings that were below investment grade levels at December 31, 2018 or December 31, 2017 . The Company has the ability and intent to hold the investments until recovery of the securities' amortized cost which may be the maturity date of the securities. For the years ended December 31, 2018 , 2017 and 2016 there were no other-than-temporary charges recorded to net income. (c) Realized Gains and Losses The following table presents the gross realized gains and losses on the sale of securities available for sale for the years ended December 31, 2018 , 2017 and 2016 : Year ended December 31, 2018 2017 2016 (In thousands) Gross realized gains $ 273 $ 193 $ 1,518 Gross realized losses (136 ) (187 ) (203 ) Net realized gains $ 137 $ 6 $ 1,315 (d) Pledged Securities The following table summarizes the amortized cost and fair value of investment securities available for sale that are pledged as collateral for the following obligations at December 31, 2018 and December 31, 2017 : December 31, 2018 December 31, 2017 Amortized Cost Fair Value Amortized Cost Fair Value (In thousands) Washington and Oregon state to secure public deposits $ 199,026 $ 196,786 $ 206,377 $ 206,425 Repurchase agreements 48,173 47,407 48,750 48,237 Other securities pledged 20,778 20,482 12,484 12,498 Total $ 267,977 $ 264,675 $ 267,611 $ 267,160 (e) Equity Securities The Company holds an equity security with a readily determinable fair value of $114,000 and $146,000 as of December 31, 2018 and December 31, 2017 , respectively. As a result of the adoption of FASB ASU 2016-01, this security is no longer classified as an investment security available for sale and has been reclassified to prepaid expenses and other assets on the Company's Consolidated Statements of Financial Condition as of December 31, 2018 . As such, its presentation is not comparable to the presentation as of December 31, 2017 . The Company recorded the tax-effected unrealized gain on the equity security through an adjustment to accumulated other comprehensive income (loss), net and retained earnings in the Consolidated Statement of Stockholders' Equity during the year ended December 31, 2018 .

Loans Receivable

Loans Receivable	12 Months Ended
	Dec. 31, 2018
Loans and Leases Receivable Disclosure [Abstract]
Loan Receivable	Loans Receivable The Company originates loans in the ordinary course of business and has also acquired loans through mergers and acquisitions. Disclosures related to the Company's recorded investment in loans receivable generally exclude accrued interest receivable and net deferred fees or costs as they were deemed insignificant. (a) Loan Origination/Risk Management The Company categorizes loans in one of the four segments of the total loan portfolio: commercial business, one-to-four family residential, real estate construction and land development and consumer. Within these segments are classes of loans for which management monitors and assesses credit risk in the loan portfolios. The Company has certain lending policies and procedures in place that are designed to maximize loan income within an acceptable level of risk. Management reviews and approves these policies and procedures on a regular basis. A reporting system supplements the review process by providing management with frequent reports related to loan production, loan quality, concentrations of credit, loan delinquencies and nonperforming and criticized loans. The Company also conducts internal loan reviews and validates the credit risk assessment on a periodic basis and presents the results of these reviews to management. The loan review process complements and reinforces the risk identification and assessment decisions made by loan officers and credit personnel, as well as the Company’s policies and procedures. A discussion of the risk characteristics of each loan portfolio segment is as follows: Commercial Business : There are three significant classes of loans in the commercial business portfolio segment: commercial and industrial, owner-occupied commercial real estate and non-owner occupied commercial real estate. The owner and non-owner occupied commercial real estate classes are both considered commercial real estate loans. As the commercial and industrial loans carry different risk characteristics than the commercial real estate loans, they are discussed separately below. Commercial and industrial. Commercial and industrial loans are primarily made based on the identified cash flows of the borrower and secondarily on the underlying collateral provided by the borrower. The cash flows of borrowers, however, may not be as expected and the collateral securing these loans may fluctuate in value. Most commercial and industrial loans are secured by the assets being financed or other business assets such as accounts receivable or inventory and may include a personal guarantee; however, some short-term loans may be made on an unsecured basis. In the case of loans secured by accounts receivable, the availability of funds for the repayment of these loans may be substantially dependent on the ability of the borrower to collect amounts due from its customers. Commercial and industrial loans carry more risk than other loans because the borrowers’ cash flow is less predictable, and in the event of a default, the amount of loss is potentially greater and more difficult to quantify because the value of the collateral securing these loans may fluctuate, may be uncollectible, or may be obsolete or of limited use, among other things. Commercial real estate. The Company originates commercial real estate loans primarily within its primary market areas. These loans are subject to underwriting standards and processes similar to commercial and industrial loans in that these loans are viewed primarily as cash flow loans and secondarily as loans secured by real estate properties. Commercial real estate lending typically involves higher loan principal amounts and payments on loans, and repayment is dependent on successful operation and management of the properties. The value of the real estate securing these loans can be adversely affected by conditions in the real estate market or the economy. There is little difference in risk between owner-occupied commercial real estate loans and non-owner occupied commercial real estate loans. One-to-Four Family Residential : The majority of the Company’s one-to-four family residential loans are secured by single-family residences located in its primary market areas. The Company’s underwriting standards require that single-family portfolio loans generally are owner-occupied and do not exceed 80% of the lower of appraised value at origination or cost of the underlying collateral. Terms of maturity typically range from 15 to 30 years. The Company sells most of its single-family loans in the secondary market and retains a smaller portion in its loan portfolio. Real Estate Construction and Land Development : The Company originates construction loans for one-to-four family residential and for five or more family residential and commercial properties. The one-to-four family residential construction loans generally include construction of custom homes whereby the home buyer is the borrower. The Company also provides financing to builders for the construction of pre-sold homes and, in selected cases, to builders for the construction of speculative residential property. Substantially all construction loans are short-term in nature and priced with variable rates of interest. Construction lending can involve a higher level of risk than other types of lending because funds are advanced partially based upon the value of the project, which is uncertain prior to the project’s completion. Because of the uncertainties inherent in estimating construction costs as well as the market value of a completed project and the effects of governmental regulation of real property, the Company’s estimates with regard to the total funds required to complete a project and the related loan-to-value ratio may vary from actual results. As a result, construction loans often involve the disbursement of substantial funds with repayment dependent, in part, on the success of the ultimate project and the ability of the borrower to sell or lease the property or refinance the indebtedness. If the Company’s estimate of the value of a project at completion proves to be overstated, it may have inadequate security for repayment of the loan and may incur a loss if the borrower does not repay the loan. Sources of repayment for these types of loans may be pre-committed permanent loans from approved long-term lenders, sales of developed property or an interim loan commitment from the Company until permanent financing is obtained. These loans are closely monitored by on-site inspections and are considered to have higher risks than other real estate loans due to their ultimate repayment being dependent upon successful completion of the construction project, interest rate changes, government regulation of real property, general economic conditions and the availability of long-term financing. Consumer : The Company originates consumer loans and lines of credit that are both secured and unsecured. The underwriting process for these loans ensures a qualifying primary and secondary source of repayment. Underwriting standards for home equity loans are significantly influenced by statutory requirements, which include, but are not limited to, a maximum loan-to-value percentage of 80% , collection remedies, the number of such loans a borrower can have at one time and documentation requirements. To monitor and manage consumer loan risk, policies and procedures are developed and modified, as needed. The majority of consumer loans are for relatively small amounts disbursed among many individual borrowers which reduces the credit risk for this type of loan. To further reduce the risk, trend reports are reviewed by management on a regular basis. The Company also originates indirect consumer loans. These loans are for new and used automobile and recreational vehicles that are originated indirectly by selected dealers located in the Company's market areas. The Company has limited its purchase of indirect loans primarily to dealerships that are established and well-known in their market areas and to applicants that are not classified as sub-prime. Loans receivable at December 31, 2018 and December 31, 2017 consisted of the following portfolio segments and classes: December 31, 2018 December 31, 2017 (In thousands) Commercial business: Commercial and industrial $ 853,606 $ 645,396 Owner-occupied commercial real estate 779,814 622,150 Non-owner occupied commercial real estate 1,304,463 986,594 Total commercial business 2,937,883 2,254,140 One-to-four family residential 101,763 86,997 Real estate construction and land development: One-to-four family residential 102,730 51,985 Five or more family residential and commercial properties 112,730 97,499 Total real estate construction and land development 215,460 149,484 Consumer 395,545 355,091 Gross loans receivable 3,650,651 2,845,712 Net deferred loan costs 3,509 3,359 Loans receivable, net 3,654,160 2,849,071 Allowance for loan losses (35,042 ) (32,086 ) Total loans receivable, net $ 3,619,118 $ 2,816,985 (b) Concentrations of Credit Most of the Company’s lending activity occurs within its primary market areas which are concentrated along the I-5 corridor from Whatcom County to Clark County in Washington State and Multnomah County and Washington County in Oregon, as well as other contiguous markets. The majority of the Company’s loan portfolio consists of (in order of balances at December 31, 2018 ) non-owner occupied commercial real estate, commercial and industrial and owner-occupied commercial real estate. As of December 31, 2018 and December 31, 2017 , there were no concentrations of loans related to any single industry in excess of 10% of the Company’s total loans. (c) Credit Quality Indicators As part of the on-going monitoring of the credit quality of the Company’s loan portfolio, management tracks certain credit quality indicators including trends related to (i) the risk grade of the loans, (ii) the level of classified loans, (iii) net charge-offs, (iv) nonperforming loans and (v) the general economic conditions of the United States of America, and specifically the states of Washington and Oregon. The Company utilizes a risk grading matrix to assign a risk grade to each of its loans. Loans are graded on a scale of 1 to 10. A description of the general characteristics of the risk grades is as follows: • Grades 1 to 5: These grades are considered “pass grade” and include loans with negligible to above average but acceptable risk. These borrowers generally have strong to acceptable capital levels and consistent earnings and debt service capacity. Loans with the higher grades within the “pass” category may include borrowers who are experiencing unusual operating difficulties, but have acceptable payment performance to date. Increased monitoring of financial information and/or collateral may be appropriate. Loans with this grade show no immediate loss exposure. • Grade 6: This grade includes "Watch" loans and is considered a “pass grade”. The grade is intended to be utilized on a temporary basis for pass grade borrowers where a potentially significant risk-modifying action is anticipated in the near term. • Grade 7: This grade includes “Other Assets Especially Mentioned” (“OAEM”) loans in accordance with regulatory guidelines, and is intended to highlight loans with elevated risks. Loans with this grade show signs of deteriorating profits and capital, and the borrower might not be strong enough to sustain a major setback. The borrower is typically higher than normally leveraged, and outside support might be modest and likely illiquid. The loan is at risk of further decline unless active measures are taken to correct the situation. • Grade 8: This grade includes “Substandard” loans in accordance with regulatory guidelines, which the Company has determined have a high credit risk. These loans also have well-defined weaknesses which make payment default or principal exposure likely, but not yet certain. The borrower may have shown serious negative trends in financial ratios and performance. Such loans may be dependent upon collateral liquidation, a secondary source of repayment or an event outside of the normal course of business. Loans with this grade can be placed on accrual or nonaccrual status based on the Company’s accrual policy. • Grade 9: This grade includes “Doubtful” loans in accordance with regulatory guidelines, and the Company has determined these loans to have excessive credit risk. Such loans are placed on nonaccrual status and may be dependent upon collateral having a value that is difficult to determine or upon some near-term event which lacks certainty. Additionally, these loans generally have a specific valuation allowance or have been partially charged-off for the amount considered uncollectible. • Grade 10: This grade includes “Loss” loans in accordance with regulatory guidelines, and the Company has determined these loans have the highest risk of loss. Such loans are charged-off or charged-down when payment is acknowledged to be uncertain or when the timing or value of payments cannot be determined. “Loss” is not intended to imply that the loan or some portion of it will never be paid, nor does it in any way imply that there has been a forgiveness of debt. Numerical loan grades for loans are established at the origination of the loan. Loan grades are reviewed on a quarterly basis, or more frequently if necessary, by the credit department. For consumer loans, the Bank follows the FDIC’s Uniform Retail Credit Classification and Account Management Policy for subsequent classification in the event of payment delinquencies or default. Typically, an individual loan grade will not be changed from the prior period unless there is a specific indication of credit deterioration or improvement. Credit deterioration is evidenced by delinquency, direct communications with the borrower, or other borrower information that becomes known to management. Credit improvements are evidenced by known facts regarding the borrower or the collateral property. The loan grades relate to the likelihood of losses in that the higher the grade, the greater the loss potential. Loans with a pass grade may have some estimated inherent losses, but to a lesser extent than the other loan grades. The OAEM loan grade is transitory in that the Company is waiting on additional information to determine the likelihood and extent of the potential loss. The likelihood of loss for OAEM graded loans, however, is greater than Watch graded loans because there has been measurable credit deterioration. Loans with a Substandard grade are generally loans for which the Company has individually analyzed for potential impairment. For Doubtful and Loss graded loans, the Company is almost certain of the losses, and the outstanding principal balances are generally charged-off to the realizable value. The following tables present the balance of the loans receivable by credit quality indicator as of December 31, 2018 and December 31, 2017 . December 31, 2018 Pass OAEM Substandard Doubtful/Loss Total (In thousands) Commercial business: Commercial and industrial $ 788,395 $ 16,168 $ 49,043 $ — $ 853,606 Owner-occupied commercial real estate 741,227 27,724 10,863 — 779,814 Non-owner occupied commercial real estate 1,283,077 9,438 11,948 — 1,304,463 Total commercial business 2,812,699 53,330 71,854 — 2,937,883 One-to-four family residential 100,401 — 1,362 — 101,763 Real estate construction and land development: One-to-four family residential 101,519 258 953 — 102,730 Five or more family residential and commercial properties 112,678 52 — — 112,730 Total real estate construction and land development 214,197 310 953 — 215,460 Consumer 390,808 — 4,213 524 395,545 Gross loans receivable $ 3,518,105 $ 53,640 $ 78,382 $ 524 $ 3,650,651 December 31, 2017 Pass OAEM Substandard Doubtful/Loss Total (In thousands) Commercial business: Commercial and industrial $ 597,697 $ 19,536 $ 28,163 $ — $ 645,396 Owner-occupied commercial real estate 595,455 12,668 14,027 — 622,150 Non-owner occupied commercial real estate 955,450 10,494 20,650 — 986,594 Total commercial business 2,148,602 42,698 62,840 — 2,254,140 One-to-four family residential 85,762 — 1,235 — 86,997 Real estate construction and land development: One-to-four family residential 49,925 537 1,523 — 51,985 Five or more family residential and commercial properties 96,404 707 388 — 97,499 Total real estate construction and land development 146,329 1,244 1,911 — 149,484 Consumer 349,590 — 4,976 525 355,091 Gross loans receivable $ 2,730,283 $ 43,942 $ 70,962 $ 525 $ 2,845,712 Potential problem loans are loans classified as OAEM or worse that are currently accruing interest and are not considered impaired, but which management is closely monitoring because the financial information of the borrower causes concern as to their ability to meet their loan repayment terms. Potential problem loans may include PCI loans as these loans continue to accrete loan discounts established at acquisition based on the guidance of FASB ASC 310-30. Potential problem loans as of December 31, 2018 and December 31, 2017 were $101.3 million and $83.5 million , respectively. (d) Nonaccrual Loans Nonaccrual loans, segregated by segments and classes of loans, were as follows as of December 31, 2018 and December 31, 2017 : December 31, 2018 December 31, 2017 (In thousands) Commercial business: Commercial and industrial $ 6,639 $ 3,110 Owner-occupied commercial real estate 4,212 4,090 Non-owner occupied commercial real estate 1,713 1,898 Total commercial business 12,564 9,098 One-to-four family residential 71 81 Real estate construction and land development: One-to-four family residential 899 1,247 Total real estate construction and land development 899 1,247 Consumer 169 277 Nonaccrual loans $ 13,703 $ 10,703 PCI loans are not included in the nonaccrual loan table above because these loans are accounted for under FASB ASC 310-30, which provides that accretable yield is calculated based on a loan's expected cash flow even if the loan is not performing under its contractual terms. (e) Past due loans The Company performs an aging analysis of past due loans using policies consistent with regulatory reporting requirements with categories of 30-89 days past due and 90 or more days past due. The balances of past due loans, segregated by segments and classes of loans, as of December 31, 2018 and December 31, 2017 were as follows: December 31, 2018 30-89 Days 90 Days or Greater Total Past Due Current Total (In thousands) Commercial business: Commercial and industrial $ 2,988 $ 2,281 $ 5,269 $ 848,337 $ 853,606 Owner-occupied commercial real estate 563 600 1,163 778,651 779,814 Non-owner occupied commercial real estate 5,347 1,461 6,808 1,297,655 1,304,463 Total commercial business 8,898 4,342 13,240 2,924,643 2,937,883 One-to-four family residential 227 — 227 101,536 101,763 Real estate construction and land development: One-to-four family residential 665 234 899 101,831 102,730 Five or more family residential and commercial properties — — — 112,730 112,730 Total real estate construction and land development 665 234 899 214,561 215,460 Consumer 2,568 — 2,568 392,977 395,545 Gross loans receivable $ 12,358 $ 4,576 $ 16,934 $ 3,633,717 $ 3,650,651 December 31, 2017 30-89 Days 90 Days or Greater Total Past Due Current Total (In thousands) Commercial business: Commercial and industrial $ 2,993 $ 1,172 $ 4,165 $ 641,231 $ 645,396 Owner-occupied commercial real estate 1,277 1,225 2,502 619,648 622,150 Non-owner occupied commercial real estate 870 3,314 4,184 982,410 986,594 Total commercial business 5,140 5,711 10,851 2,243,289 2,254,140 One-to-four family residential 513 — 513 86,484 86,997 Real estate construction and land development: One-to-four family residential 84 1,331 1,415 50,570 51,985 Five or more family residential and commercial properties 40 — 40 97,459 97,499 Total real estate construction and land development 124 1,331 1,455 148,029 149,484 Consumer 1,939 687 2,626 352,465 355,091 Gross loans receivable $ 7,716 $ 7,729 $ 15,445 $ 2,830,267 $ 2,845,712 There were no loans 90 days or more past due that were still accruing interest as of December 31, 2018 or December 31, 2017 , excluding PCI loans. (f) Impaired loans Impaired loans include nonaccrual loans and performing TDR loans. The balances of impaired loans as of December 31, 2018 and December 31, 2017 are set forth in the following tables: December 31, 2018 Recorded Investment With No Specific Valuation Allowance Recorded Investment With Specific Valuation Allowance Total Recorded Investment Unpaid Contractual Principal Balance Related Specific Valuation Allowance (In thousands) Commercial business: Commercial and industrial $ 2,523 $ 20,119 $ 22,642 $ 24,176 $ 2,607 Owner-occupied commercial real estate 816 5,000 5,816 6,150 1,142 Non-owner occupied commercial real estate 3,352 2,924 6,276 6,414 206 Total commercial business 6,691 28,043 34,734 36,740 3,955 One-to-four family residential — 279 279 293 76 Real estate construction and land development: One-to-four family residential 899 — 899 1,662 — Total real estate construction and land development 899 — 899 1,662 — Consumer — 527 527 538 139 Total $ 7,590 $ 28,849 $ 36,439 $ 39,233 $ 4,170 December 31, 2017 Recorded Investment With No Specific Valuation Allowance Recorded Investment With Specific Valuation Allowance Total Recorded Investment Unpaid Contractual Principal Balance Related Specific Valuation Allowance (In thousands) Commercial business: Commercial and industrial $ 2,127 $ 9,872 $ 11,999 $ 12,489 $ 1,326 Owner-occupied commercial real estate 2,452 4,356 6,808 7,054 621 Non-owner occupied commercial real estate 4,722 11,297 16,019 16,172 1,222 Total commercial business 9,301 25,525 34,826 35,715 3,169 One-to-four family residential — 299 299 308 93 Real estate construction and land development: One-to-four family residential 938 309 1,247 2,200 2 Five or more family residential and commercial properties — 645 645 645 37 Total real estate construction and land development 938 954 1,892 2,845 39 Consumer 160 282 442 466 54 Total $ 10,399 $ 27,060 $ 37,459 $ 39,334 $ 3,355 The average recorded investment of impaired loans for the year ended December 31, 2018 , 2017 and 2016 are set forth in the following table: Year Ended December 31, 2018 2017 2016 (In thousands) Commercial business: Commercial and industrial $ 16,773 $ 11,310 $ 10,207 Owner-occupied commercial real estate 11,312 5,401 4,540 Non-owner occupied commercial real estate 9,465 12,162 11,709 Total commercial business 37,550 28,873 26,456 One-to-four family residential 290 309 279 Real estate construction and land development: One-to-four family residential 1,091 2,315 3,305 Five or more family residential and commercial properties 129 903 1,656 Total real estate construction and land development 1,220 3,218 4,961 Consumer 428 351 645 Total $ 39,488 $ 32,751 $ 32,341 For the years ended December 31, 2018 , 2017 and 2016 , no interest income was recognized subsequent to a loan’s classification as nonaccrual. For the years ended December 31, 2018 , 2017 and 2016 , the Bank recorded $1.4 million , $1.2 million and $651,000 , respectively, of interest income related to performing TDR loans. (g) Troubled Debt Restructured Loans The majority of the Bank’s TDR loans are a result of granting extensions of maturity on troubled credits which have already been adversely classified. The Bank grants such extensions to reassess the borrower’s financial status and to develop a plan for repayment. The second most prevalent concessions are certain modifications with extensions that also include interest rate reductions. Certain TDR loans were additionally re-amortized over a longer period of time. These modifications would all be considered a concession for a borrower that could not obtain similar financing terms from another source other than from the Bank. The financial effects of each modification will vary based on the specific restructure. For the majority of the Bank’s TDR loans, the loans were interest-only with a balloon payment at maturity. If the interest rate is not adjusted and the modified terms are consistent with other similar credits being offered, the Bank may not experience any loss associated with the restructure. If, however, the restructure involves forbearance agreements or interest rate modifications, the Bank may not collect all the principal and interest based on the original contractual terms. The Bank estimates the necessary allowance for loan losses on TDR loans using the same guidance as used for other impaired loans. The recorded investment balance and related allowance for loan losses of performing and nonaccrual TDR loans as of December 31, 2018 and December 31, 2017 were as follows: December 31, 2018 December 31, 2017 Performing TDRs Nonaccrual TDRs Performing Nonaccrual (In thousands) TDR loans $ 22,736 $ 6,943 $ 26,757 $ 5,193 Allowance for loan losses on TDR loans 2,257 658 2,635 379 The unfunded commitment to borrowers related to TDR loans was $943,000 and $1.2 million at December 31, 2018 and December 31, 2017 , respectively. Loans that were modified as TDR loans during the years ended December 31, 2018 , 2017 and 2016 are set forth in the following table: Year Ended December 31, 2018 2017 2016 Number of Contracts (1) Recorded Investment (1) (2) Number of Contracts (1) Recorded Investment (1) (2) Number of Contracts (1) Recorded Investment (1) (2) (Dollars in thousands) Commercial business: Commercial and industrial 31 $ 16,129 19 $ 7,212 19 $ 7,398 Owner-occupied commercial real estate 4 2,521 3 1,366 2 569 Non-owner occupied commercial real estate 3 2,944 4 9,574 2 2,121 Total commercial business 38 21,594 26 18,152 23 10,088 Real estate construction and land development: One-to-four family residential 2 665 2 938 5 2,206 Five or more family residential and commercial properties — — — — 1 1,078 Total real estate construction and land development 2 665 2 938 6 3,284 Consumer 13 236 8 110 6 66 Total TDR loans 53 $ 22,495 36 $ 19,200 35 $ 13,438 (1) Number of contracts and outstanding principal balance represent loans which have balances as of period end as certain loans may have been paid-down or charged-off during the years ended December 31, 2018 , 2017 and 2016 . (2) Includes subsequent payments after modifications and reflects the balance as of period end. As the Bank did not forgive any principal or interest balance as part of the loan modification, the Bank’s recorded investment in each loan at the date of modification (pre-modification) did not change as a result of the modification (post-modification), except when the modification was the initial advance on a one-to-four family residential real estate construction and land development loan under a master guidance line. There were no advances on these types of loans during the years ended December 31, 2018 , 2017 and 2016 . The related specific valuation allowance at December 31, 2018 for loans that were modified as TDR loans during the year ended December 31, 2018 was $2.3 million . The related specific valuation allowance at December 31, 2017 for loans that were modified as TDR loans during the year ended December 31, 2017 was $1.8 million . Certain loans included in the tables above may have been previously reported as TDR loans. The Bank typically grants shorter extension periods to continually monitor these TDR loans despite the fact that the extended date might not be the date the Bank expects sufficient cash flow from these borrowers. The Bank does not consider these modifications a subsequent default of a TDR as new loan terms, specifically new maturity dates, were granted. The potential losses related to these loans would have been considered in the period the loan was first reported as a TDR loan and are adjusted, as necessary, in the current period based on more recent information. Loans that were modified during the previous twelve months that subsequently defaulted during the years ended December 31, 2018 , 2017 and 2016 are included in the following table: Year Ended December 31, 2018 2017 2016 Number of Contracts Recorded Investment (1) Number of Recorded Investment (1) Number of Recorded Investment (1) (Dollars in thousands) Commercial business: Commercial and industrial 5 $ 1,890 1 $ 283 — $ — Owner-occupied commercial real estate 1 65 1 80 1 488 Total commercial business 6 1,955 2 363 1 488 Real estate construction and land development: One-to-four family residential 2 665 2 938 2 1,143 Total real estate construction and land development 2 665 2 938 2 1,143 Consumer — — 1 7 — — Total 8 $ 2,620 5 $ 1,308 3 $ 1,631 (1) Number of contracts and outstanding principal balance represent loans which have balances as of period end as certain loans may have been paid-down or charged-off during the years ended December 31, 2018 , 2017 and 2016 . During the year ended December 31, 2018 , one commercial and industrial loan totaling $882,000 defaulted due to being greater than 90 days past due the modified terms during the year ended December 31, 2018. The remaining seven loans defaulted because they were past their modified maturity dates, and the borrowers have not subsequently repaid the credits. The Bank has chosen not to extend the maturities on these loans.The Bank had a specific valuation allowance of $260,000 at December 31, 2018 related to the credits which defaulted during the year ended December 31, 2018 . During the year ended December 31, 2017 , one consumer loan defaulted due to being greater than 90 days past due the modified terms, but the loan became current as of December 31, 2017 . The remaining four loans defaulted as they were past their modified maturity dates, and the borrowers had not repaid the credits. The Bank has chosen not to extend the maturities on these loans. During the year ended December 31, 2016 , all three loans defaulted because they were past their modified maturity dates, and the borrowers had not repaid the credits. At December 31, 2016 , the Bank was in the process of granting addition extensions on these loans. The Bank had a specific valuation allowance of $1,000 and $111,000 at December 31, 2017 and 2016 , respectively, related to the credits which defaulted during the related year ends. (h) Purchased Credit Impaired Loans The Company acquired certain loans and designated them as PCI loans, which are accounted for under FASB ASC 310-30. No loans acquired in the Premier and Puget Mergers were considered PCI. The following table reflects the outstanding principal balance and recorded investment of the PCI loans at December 31, 2018 and December 31, 2017 : December 31, 2018 December 31, 2017 Outstanding Principal Recorded Investment Outstanding Principal Recorded Investment (In thousands) Commercial business: Commercial and industrial $ 6,319 $ 3,433 $ 8,818 $ 2,912 Owner-occupied commercial real estate 7,830 7,215 12,230 11,515 Non-owner occupied commercial real estate 8,685 7,059 14,295 13,342 Total commercial business 22,834 17,707 35,343 27,769 One-to-four family residential 3,169 3,315 4,120 5,255 Real estate construction and land development: One-to-four family residential 67 380 841 89 Five or more family residential and commercial properties 188 43 2,361 2,035 Total real estate construction and land development 255 423 3,202 2,124 Consumer 2,203 3,462 3,974 5,455 Gross PCI loans $ 28,461 $ 24,907 $ 46,639 $ 40,603 On the acquisition dates, the amount by which the undiscounted expected cash flows of the PCI loans exceeded the estimated fair value of the loan is the “accretable yield.” The accretable yield is then measured at each financial reporting date and represents the difference between the remaining undiscounted expected cash flows and the current carrying value of the PCI loans. The following table summarizes the accretable yield on the PCI loans for the years ended December 31, 2018 , 2017 and 2016 . Year Ended December 31, 2018 2017 2016 (In thousands) Balance at the beginning of the year $ 11,224 $ 13,860 $ 17,592 Accretion (2,674 ) (3,471 ) (4,962 ) Disposal and other (2,871 ) (2,758 ) (3,329 ) Reclassification from (to) nonaccreatable difference 3,814 3,593 4,559 Balance at the end of the year $ 9,493 $ 11,224 $ 13,860 (i) Related Party Loans In the ordinary course of business, the Company has granted loans to certain directors, executive officers and their affiliates (collectively referred to as “related parties”). Activity in related party loans for the years ended December 31, 2018 , 2017 and 2016 was as follows: Year Ended December 31, 2018 2017 2016 (in thousands) Balance outstanding

Allowance for Loan Losses

Allowance for Loan Losses	12 Months Ended
	Dec. 31, 2018
Receivables [Abstract]
Allowance for Loan Losses	Allowance for Loan Losses The allowance for loan losses is maintained at a level deemed appropriate by management to provide for probable incurred credit losses in the loan portfolio. A summary of the changes in the allowance for loan losses during the years ended December 31, 2018 , 2017 and 2016 is as follows: Year Ended December 31, 2018 2017 2016 (In thousands) Balance at the beginning of the year $ 32,086 $ 31,083 $ 29,746 Charge-offs (3,605 ) (4,838 ) (6,085 ) Recoveries of loans previously charged-off 1,432 1,621 2,491 Provision for loan losses 5,129 4,220 4,931 Balance at the end of the year $ 35,042 $ 32,086 $ 31,083 The following table details the activity in the allowance for loan losses disaggregated by segment and class for the year ended December 31, 2018 : Balance at Beginning of Year Charge-offs Recoveries Provision for Loan Losses Balance at End of Year (In thousands) Commercial business: Commercial and industrial $ 9,910 $ (1,250 ) $ 901 $ 1,782 $ 11,343 Owner-occupied commercial real estate 3,992 (1 ) 7 900 4,898 Non-owner occupied commercial real estate 8,097 (149 ) — (478 ) 7,470 Total commercial business 21,999 (1,400 ) 908 2,204 23,711 One-to-four family residential 1,056 (45 ) — 192 1,203 Real estate construction and land development: One-to-four family residential 862 — 11 367 1,240 Five or more family residential and commercial properties 1,190 — — (236 ) 954 Total real estate construction and land development 2,052 — 11 131 2,194 Consumer 6,081 (2,160 ) 513 2,147 6,581 Unallocated 898 — — 455 1,353 Total $ 32,086 $ (3,605 ) $ 1,432 $ 5,129 $ 35,042 The following table details the allowance for loan losses disaggregated on the basis of the Company's impairment method as of December 31, 2018 : Loans Individually Evaluated for Impairment Loans Collectively Evaluated for Impairment PCI Loans Total Allowance for Loan Losses (In thousands) Commercial business: Commercial and industrial $ 2,607 $ 7,913 $ 823 $ 11,343 Owner-occupied commercial real estate 1,142 3,063 693 4,898 Non-owner occupied commercial real estate 206 6,630 634 7,470 Total commercial business 3,955 17,606 2,150 23,711 One-to-four family residential 76 1,015 112 1,203 Real estate construction and land development: One-to-four family residential — 1,040 200 1,240 Five or more family residential and commercial properties — 875 79 954 Total real estate construction and land development — 1,915 279 2,194 Consumer 139 5,965 477 6,581 Unallocated — 1,353 — 1,353 Total $ 4,170 $ 27,854 $ 3,018 $ 35,042 The following table details the recorded investment balance of the loan receivables disaggregated on the basis of the Company’s impairment method as of December 31, 2018 : Loans Individually Evaluated for Impairment Loans Collectively Evaluated for Impairment PCI Loans Total Gross Loans Receivable (In thousands) Commercial business: Commercial and industrial $ 22,642 $ 827,531 $ 3,433 $ 853,606 Owner-occupied commercial real estate 5,816 766,783 7,215 779,814 Non-owner occupied commercial real estate 6,276 1,291,128 7,059 1,304,463 Total commercial business 34,734 2,885,442 17,707 2,937,883 One-to-four family residential 279 98,169 3,315 101,763 Real estate construction and land development: One-to-four family residential 899 101,451 380 102,730 Five or more family residential and commercial properties — 112,687 43 112,730 Total real estate construction and land development 899 214,138 423 215,460 Consumer 527 391,556 3,462 395,545 Total $ 36,439 $ 3,589,305 $ 24,907 $ 3,650,651 The following table details the activity in the allowance for loan losses disaggregated by segment and class for the year ended December 31, 2017 : Balance at Beginning of Year Charge-offs Recoveries Provision for Loan Losses Balance at End of Year (In thousands) Commercial business: Commercial and industrial $ 10,968 $ (859 ) $ 792 $ (991 ) $ 9,910 Owner-occupied commercial real estate 3,661 (1,579 ) 155 1,755 3,992 Non-owner occupied commercial real estate 7,753 — — 344 8,097 Total commercial business 22,382 (2,438 ) 947 1,108 21,999 One-to-four family residential 1,015 (30 ) 2 69 1,056 Real estate construction and land development: One-to-four family residential 797 (556 ) 202 419 862 Five or more family residential and commercial properties 1,359 — — (169 ) 1,190 Total real estate construction and land development 2,156 (556 ) 202 250 2,052 Consumer 5,024 (1,814 ) 470 2,401 6,081 Unallocated 506 — — 392 898 Total $ 31,083 $ (4,838 ) $ 1,621 $ 4,220 $ 32,086 The following table details the allowance for loan losses disaggregated on the basis of the Company's impairment method as of December 31, 2017 : Loans Individually Evaluated for Impairment Loans Collectively Evaluated for Impairment PCI Loans Total Allowance for Loan Losses (In thousands) Commercial business: Commercial and industrial $ 1,326 $ 7,558 $ 1,026 $ 9,910 Owner-occupied commercial real estate 621 2,557 814 3,992 Non-owner occupied commercial real estate 1,222 5,919 956 8,097 Total commercial business 3,169 16,034 2,796 21,999 One-to-four family residential 93 798 165 1,056 Real estate construction and land development: One-to-four family residential 2 635 225 862 Five or more family residential and commercial properties 37 1,064 89 1,190 Total real estate construction and land development 39 1,699 314 2,052 Consumer 54 5,303 724 6,081 Unallocated — 898 — 898 Total $ 3,355 $ 24,732 $ 3,999 $ 32,086 The following table details the recorded investment balance of the loan receivables disaggregated on the basis of the Company’s impairment method as of December 31, 2017 : Loans Individually Evaluated for Impairment Loans Collectively Evaluated for Impairment PCI Loans Total Gross Loans Receivable (In thousands) Commercial business: Commercial and industrial $ 11,999 $ 630,485 $ 2,912 $ 645,396 Owner-occupied commercial real estate 6,808 603,827 11,515 622,150 Non-owner occupied commercial real estate 16,019 957,233 13,342 986,594 Total commercial business 34,826 2,191,545 27,769 2,254,140 One-to-four family residential 299 81,443 5,255 86,997 Real estate construction and land development: One-to-four family residential 1,247 50,649 89 51,985 Five or more family residential and commercial properties 645 94,819 2,035 97,499 Total real estate construction and land development 1,892 145,468 2,124 149,484 Consumer 442 349,194 5,455 355,091 Total $ 37,459 $ 2,767,650 $ 40,603 $ 2,845,712 The following table details the activity in the allowance for loan losses disaggregated by segment and class for the year ended December 31, 2016 : Balance at Beginning of Year Charge-offs Recoveries Provision for Loan Losses Balance at End of Year (In thousands) Commercial business: Commercial and industrial $ 9,972 $ (3,265 ) $ 1,844 $ 2,417 $ 10,968 Owner-occupied commercial real estate 4,370 (538 ) — (171 ) 3,661 Non-owner occupied commercial real estate 7,722 (350 ) — 381 7,753 Total commercial business 22,064 (4,153 ) 1,844 2,627 22,382 One-to-four family residential 1,157 — 2 (144 ) 1,015 Real estate construction and land development: One-to-four family residential 1,058 (100 ) 83 (244 ) 797 Five or more family residential and commercial properties 813 (54 ) — 600 1,359 Total real estate construction and land development 1,871 (154 ) 83 356 2,156 Consumer 4,309 (1,778 ) 562 1,931 5,024 Unallocated 345 — — 161 506 Total $ 29,746 $ (6,085 ) $ 2,491 $ 4,931 $ 31,083

Other Real Estate Owned

Other Real Estate Owned	12 Months Ended
	Dec. 31, 2018
Banking and Thrift [Abstract]
Other Real Estate Owned	Other Real Estate Owned Changes in other real estate owned during the years ended December 31, 2018 , 2017 and 2016 were as follows: Year Ended December 31, 2018 2017 2016 (In thousands Balance at the beginning of the year $ — $ 754 $ 2,019 Additions 434 32 1,431 Additions from acquisitions 1,796 — — Proceeds from dispositions (198 ) (930 ) (2,486 ) Gain on sale, net — 144 173 Valuation adjustment (49 ) — (383 ) Balance at the end of the year $ 1,983 $ — $ 754 At December 31, 2018 , the carrying amount of other real estate owned that was the result of foreclosure and obtaining physical possession of residential real estate properties was $434,000 . At December 31, 2018 , there were no consumer mortgage loans secured by residential real estate properties (which would be included in the one-to-four family residential loans in Note (4) Loans Receivable ) for which formal foreclosure proceedings were in process.

Premises and Equipment

Premises and Equipment	12 Months Ended
	Dec. 31, 2018
Property, Plant and Equipment [Abstract]
Premises and Equipment	Premises and Equipment A summary of premises and equipment is as follows: December 31, 2018 December 31, 2017 (In thousands) Land $ 22,954 $ 21,483 Buildings and building improvements 69,315 50,984 Furniture, fixtures and equipment 25,354 20,894 Total premises and equipment 117,623 93,361 Less: Accumulated depreciation 36,523 33,036 Premises and equipment, net $ 81,100 $ 60,325 Total depreciation expense on premises and equipment was $4.4 million , $3.9 million and $3.9 million for the years ended December 31, 2018 , 2017 and 2016 , respectively.

Goodwill and Other Intangible A

Goodwill and Other Intangible Assets	12 Months Ended
	Dec. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Other Intangible Assets	Goodwill and Other Intangible Assets (a) Goodwill The Company’s goodwill represents the excess of the purchase price over the fair value of net assets acquired in the recent Premier Merger on July 2, 2018 and Puget Sound Merger on January 16, 2018 and the historical acquisitions of Washington Banking Company on May 1, 2014; Valley Community Bancshares on July 15, 2013; Western Washington Bancorp in 2006 and North Pacific Bank in 1998. The following table presents the change in goodwill for the periods indicated: Year Ended December 31, 2018 2017 2016 (In thousands) Balance at the beginning of the period $ 119,029 $ 119,029 $ 119,029 Additions as a result of acquisitions (1) 121,910 — — Balance at the end of the period $ 240,939 $ 119,029 $ 119,029 (1) See Note (2) Business Combinations At December 31, 2018 , the Company’s step-one analysis concluded that the reporting unit’s fair value of the reporting unit exceeded the carrying value, such that the Company's goodwill was not considered impaired. Similarly, no goodwill impairment charges were required, or recorded, for the years ended December 31, 2017 and 2016 . Even though there was no goodwill impairment at December 31, 2018 , changes in the economic environment, operations of the reporting unit or other adverse events could result in future impairment charges which could have a material impact on the Company’s operating results. (b) Other Intangible Assets The other intangible assets represent the core deposit intangible ("CDI") acquired in business combinations. The useful life of the CDI was estimated to be ten years related to the acquisitions of Premier Commercial Bancorp, Puget Sound Bancorp, Washington Banking Company, and Valley Community Bancshares and estimated to be five years related to the acquisition of Northwest Commercial Bank. The following table presents the change in other intangible assets for the periods indicated: Year Ended December 31, 2018 2017 2016 (In thousands) Balance at the beginning of the year $ 6,088 $ 7,374 $ 8,789 Additions as a result of acquisitions (1) 18,345 — — Amortization (3,819 ) (1,286 ) (1,415 ) Balance at the end of the year $ 20,614 $ 6,088 $ 7,374 (1) See Note (2) Business Combinations The estimated aggregate amortization expense related to these intangible assets for future years is as follows: Year Ending December 31, (In thousands) 2019 $ 4,001 2020 3,525 2021 3,111 2022 2,750 2023 2,435 Thereafter 4,792 $ 20,614

Deposits

Deposits	12 Months Ended
	Dec. 31, 2018
Deposits [Abstract]
Deposits	Deposits Deposits consisted of the following: December 31, 2018 December 31, 2017 Amount Percent Amount Percent (Dollars in thousands) Noninterest demand deposits $ 1,362,268 30.7 % $ 944,791 27.8 % Interest bearing demand deposits 1,317,513 29.7 1,051,752 31.1 Money market accounts 765,316 17.3 499,618 14.7 Savings accounts 520,413 11.8 498,501 14.7 Total non-maturity deposits 3,965,510 89.5 2,994,662 88.3 Certificate of deposit accounts 466,892 10.5 398,398 11.7 Total deposits $ 4,432,402 100.0 % $ 3,393,060 100.0 % Accrued interest payable on deposits was $144,000 and $124,000 as of December 31, 2018 and 2017 , respectively and is included in accrued expenses and other liabilities in the Consolidated Statements of Financial Condition. Interest expense, by category, was as follows: Year Ended December 31, 2018 2017 2016 (In thousands) Interest bearing demand deposits $ 2,728 $ 1,812 $ 1,569 Money market accounts 1,654 682 749 Savings accounts 2,056 1,311 756 Certificate of deposit accounts 3,959 2,244 1,936 $ 10,397 $ 6,049 $ 5,010 Scheduled maturities of certificates of deposit for future years are as follows: Year Ending December 31, (In thousands) 2019 $ 313,830 2020 93,675 2021 14,608 2022 24,914 2023 19,847 Thereafter 18 $ 466,892 Certificates of deposit issued in denominations equal to or in excess of $250,000 totaled $146.2 million and $113.7 million as of December 31, 2018 and 2017 , respectively.

Junior Subordinated Debentures

Junior Subordinated Debentures	12 Months Ended
	Dec. 31, 2018
Debt Disclosure [Abstract]
Junior Subordinated Debentures	Junior Subordinated Debentures As part of the acquisition of Washington Banking Company on May 1, 2014, the Company assumed trust preferred securities and junior subordinated debentures with a total fair value of $18.9 million at the merger date. Washington Banking Master Trust, a Delaware statutory business trust, was a wholly-owned subsidiary of the Washington Banking Company created for the exclusive purposes of issuing and selling capital securities and utilizing sale proceeds to acquire junior subordinated debentures issued by the Washington Banking Company. During 2007, the Trust issued $25.0 million of trust preferred securities with a 30 -year maturity, callable after the fifth year. The trust preferred securities have a quarterly adjustable rate based upon the three-month London Interbank Offered Rate (“LIBOR”) plus 1.56% . On the merger date, the Company acquired the Trust, which retained the Washington Banking Master Trust name, and assumed the performance and observance of the covenants under the indenture related to the trust preferred securities. The adjustable rate of the trust preferred securities at December 31, 2018 was 4.37% . The weighted average rate of the junior subordinated debentures was as follows for the indicated periods: Year Ended December 31, 2018 2017 2016 Weighted average rate (1) 6.27 % 5.11 % 4.50 % (1) The weighted average rate includes the accretion of the discount established at the merger date which is amortized over the life of the trust preferred securities. The junior subordinated debentures are the sole assets of the Trust and payments under the junior subordinated debentures are the sole revenues of the Trust. At December 31, 2018 and December 31, 2017 , the balance of the junior subordinated debentures, net of unaccreted discount, was $20.3 million and $20.0 million , respectively. All of the common securities of the Trust are owned by the Company. Heritage has fully and unconditionally guaranteed the capital securities along with all obligations of the Trust under the trust agreements. For financial reporting purposes, the Company's investment in the Master Trust is accounted for under the equity method and is included in prepaid expenses and other assets on the Company's Consolidated Statements of Financial Condition. The junior subordinated debentures issued and guaranteed by the Company and held by the Master Trust are reflected as liabilities on the Company's Consolidated Statements of Financial Condition.

Repurchase Agreements

Repurchase Agreements	12 Months Ended
	Dec. 31, 2018
Disclosure of Repurchase Agreements [Abstract]
Repurchase Agreements	Repurchase Agreements The Company utilizes repurchase agreements with one -day maturities as a supplement to funding sources. Repurchase agreements are secured by pledged investment securities available for sale. Under the repurchase agreements, the Company is required to maintain an aggregate market value of securities pledged greater than the balance of the repurchase agreements. The Company is required to pledge additional securities to cover any declines below the balance of the repurchase agreements. For additional information on the total value of investment securities pledged for repurchase agreements see Note (3) Investment Securities . The following table presents the Company's repurchase agreement obligations by class of collateral pledged: December 31, 2018 December 31, 2017 (In thousands) U.S. Treasury and U.S. Government-sponsored agencies $ 4,878 $ — Mortgage-backed securities and collateralized mortgage obligations (1) : Residential 9,335 11,239 Commercial 17,274 20,582 Total repurchase agreements $ 31,487 $ 31,821 (1) Issued and guaranteed by U.S. Government-sponsored agencies.

Other Borrowings

Other Borrowings	12 Months Ended
	Dec. 31, 2018
Debt Disclosure [Abstract]
Other Borrowings	Other Borrowings (a) FHLB The Federal Home Loan Bank ("FHLB") of Des Moines functions as a member-owned cooperative providing credit for member financial institutions. Advances are made pursuant to several different programs. Each credit program has its own interest rate and range of maturities. Limitations on the amount of advances are based on a percentage of the Bank's assets or on the FHLB’s assessment of the institution’s creditworthiness. At December 31, 2018 , the Bank maintained a credit facility with the FHLB of Des Moines with available borrowing capacity of $921.7 million . The Bank had no FHLB advances outstanding at December 31, 2018 . At December 31, 2017 there were short-term FHLB advances outstanding of $92.5 million with maturity dates within 30 days. The following table sets forth the details of FHLB advances during and as of the years ended December 31, 2018 and 2017 : December 31, 2018 December 31, 2017 (In thousands) FHLB Advances: Average balance during the year $ 33,913 $ 105,646 Maximum month-end balance during the year $ 154,500 $ 137,450 Weighted average rate during the year 1.98 % 1.16 % Weighted average rate at the end of year n/a 1.56 % Advances from the FHLB are collateralized by a blanket pledge on FHLB stock owned by the Bank, deposits at the FHLB, certain one-to-four single family residential loans or other assets, investment securities which are obligations of or guaranteed by the United States or other assets. In accordance with the pledge agreement, the Company must maintain unencumbered collateral in an amount equal to varying percentages ranging from 100% to 160% of outstanding advances depending on the type of collateral. (b) Federal Funds Purchased The Bank maintains advance lines with Wells Fargo Bank, US Bank, The Independent Bankers Bank and Pacific Coast Bankers’ Bank to purchase federal funds of up to $90.0 million as of December 31, 2018 . The lines generally mature annually or are reviewed annually. As of December 31, 2018 and 2017 , there were no federal funds purchased. (c) Credit Facilities The Bank maintains a credit facility with the Federal Reserve Bank of San Francisco with available borrowing capacity of $37.4 million as of December 31, 2018 . There were no borrowings outstanding as of December 31, 2018 or 2017 . Any advances on the credit facility would have to be first secured by the Bank's investment securities or loans receivable.

Employee Benefit Plans

Employee Benefit Plans	12 Months Ended
	Dec. 31, 2018
Retirement Benefits [Abstract]
Employee Benefit Plans	Employee Benefit Plans (a) 401(k) Plan The Company provides its eligible employees with a 401(k) plan called "Heritage Financial Corporation 401(k) Profit Sharing Plan and Trust" (the “Plan”). The Company funds certain Plan costs as incurred. The Plan includes the Company’s salary savings 401(k) plan for its employees. All employees hired may participate in the Plan the first of the month following thirty days of service. Participants may contribute a portion of their salary, which is matched by the Company at 50% , not to be greater than 3% of eligible compensation, up to certain Internal Revenue Service limits. A Roth feature was added to the plan in 2016. All participants are 100% vested in all accounts at all times. Employer matching contributions for the years ended December 31, 2018 , 2017 and 2016 were $1.4 million , $1.1 million and $1.0 million , respectively. The profit sharing portion of the Plan is a defined contribution retirement plan. All profit sharing and discretionary contributions are completely discretionary. Participants are eligible for profit sharing contributions upon credit of 1,000 hours of service during the plan year, the attainment of 18 years of age, and employment on the last day of the year. Employees are vested in profit sharing contributions in the same manner as employer matching contributions discussed above. For the years ended December 31, 2018 , 2017 and 2016 , the Company made no employer profit sharing contributions. (b) Employment Agreements The Company has entered into contracts with certain senior officers that provide benefits under certain conditions following termination without cause, and/or following a change in control of the Company. (c) Deferred Compensation Plan During 2012, the Company adopted a Deferred Compensation Plan, which provides its directors and select executive officers with the opportunity to defer current compensation. Under the Plan, participants are permitted to elect to defer compensation and the Company has the discretion to make additional contributions to the Plan on behalf of any participant based on a number of factors. Compensation expense under the Deferred Compensation Plan totaled $810,000 , $652,000 and $540,000 for the years ended December 31, 2018 , 2017 and 2016 , respectively. The Company’s contributions totaled $583,000 , $453,000 and $521,000 for the years ended December 31, 2018 , 2017 and 2016 , respectively. As of December 31, 2018 and 2017 , the carrying value of the obligation related to the deferred compensation plans was $3.7 million and $2.8 million , respectively. (d) Split-Dollar Life Insurance Benefit Plan In conjunction with the Washington Banking Merger, the Company assumed the split-dollar life insurance benefit plan previously maintained by Washington Banking. Life insurance policies are maintained for current or former officers of the Bank or former Washington Banking officers that are subject to split-dollar life insurance agreements, which continue after the participant's employment and retirement. All participants are fully vested in their split-dollar life insurance benefits. The accrued benefit liability for the split-dollar life insurance agreements represents the present value of the future death benefits payable to the participants' beneficiaries. The split-dollar life insurance projected benefit obligation is included in accrued expenses and other liabilities on the Company's Consolidated Statements of Financial Condition. As of December 31, 2018 and 2017 , the carrying value of the obligation was $268,000 and $250,000 , respectively. (e) Salary Continuation Plan In conjunction with the Premier Merger, the Company assumed an unfunded deferred compensation plan for select former Premier Commercial executive officers, some of which are current Heritage officers. Under the Salary Continuation Plan, the Company will pay each participant, or their beneficiary, specified benefits over specified periods beginning with the individual's termination of service due to retirement subject to early termination provisions. A liability is accrued for the obligation under this plan. As of December 31, 2018 , the carrying value of the obligation was $4.6 million . The expense incurred for the Salary Continuation Plan was $184,000 during the year ended December 31, 2018. There was no expense incurred for the Salary Continuation Plan during the years ended December 31, 2017 and 2016.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies (a) Lease Commitments The Bank leases certain premises and equipment under operating leases. Rental expense of leased premises and equipment was $6.1 million , $3.8 million and $4.4 million for the years ended December 31, 2018 , 2017 and 2016 , respectively, which is included in occupancy and equipment expense on the Company's Consolidated Statements of Income. The estimated future minimum annual rental commitments under noncancelable leases having an original or remaining term of more than one year are as follows: Year Ending December 31, (In thousands) 2019 $ 4,766 2020 4,251 2021 2,477 2022 1,704 2023 1,568 Thereafter 1,788 $ 16,554 The leases contain various provisions for increases in rental rates, based either on changes in the published Consumer Price Index or a predetermined escalation schedule. Substantially all of the leases provide the Company with the option to extend the lease term one or more times following expiration of the initial term. (b) Commitments to Extend Credit In the ordinary course of business, the Company may enter into various types of transactions that include commitments to extend credit that are not included in the Consolidated Financial Statements. The Company applies the same credit standards to these commitments as it uses in all its lending activities and has included these commitments in its lending risk evaluations. The majority of the commitments presented below are variable rate. The Company’s exposure to credit and market risk under commitments to extend credit is represented by the amount of these commitments. The following table presents outstanding commitments to extend credit, including letters of credit, at the dates indicated: December 31, 2018 December 31, 2017 (In thousands) Commercial business: Commercial and industrial $ 568,215 $ 363,272 Owner-occupied commercial real estate 13,065 6,815 Non-owner occupied commercial real estate 13,621 13,543 Total commercial business 594,901 383,630 One-to-four family residential — — Real estate construction and land development: One-to-four family residential 59,772 38,160 Five or more family residential and commercial properties 95,535 86,787 Total real estate construction and land development 155,307 124,947 Consumer 239,822 204,625 Total outstanding commitments $ 990,030 $ 713,202 (c) Variable Interests The Company has two equity investments in Low-Income Housing Tax Credit partnerships ("LIHTCs") which are indirect federal subsidies that finance low-income housing projects. The Company reported the investments in the unconsolidated LIHTCs as prepaid expenses and other assets on the Company’s Statements of Financial Condition with carrying values of $50.9 million and $54.0 million as of December 31, 2018 and 2017 , respectively. As a limited liability investor in these partnerships, the Company receives tax benefits in the form of tax deductions from partnership operating losses and federal income tax credits. The federal income tax credits are earned over a 10-year period as a result of the investment properties meeting certain criteria and are subject to recapture for noncompliance with such criteria over a 15-year period. The Company accounts for the LIHTCs under the proportional amortization method and amortizes the initial cost of the investment in proportion to the tax credits and other tax benefits received and recognizes the net investment performance on the Company's Consolidated Statements of Income as a component of income tax expense. During the years ended December 31, 2018 , 2017 , and 2016 the Company recognized tax benefits of $2.4 million , $2.9 million and $640,000 , respectively. See Note (21) Income Taxes for further information on tax benefits. The maximum exposure to loss in the LIHTCs is the amount of equity invested and credit extended by the Company. Loans to these entities are underwritten in substantially the same manner as are other loans and are generally secured. The Company has evaluated the variable interests held by the Company in each LIHTC investment and determined that the Company does not have controlling financial interests in such investments, and is not the primary beneficiary. Total unfunded contingent commitments related to the Company’s LIHTC investments totaled $31.5 million and $39.8 million at December 31, 2018 and 2017 , respectively, and is reported as accrued expenses and other liabilities on the Company's Statements of Financial Condition. The Company expects to fund LIHTC commitments of $26.4 million during the year ended December 31, 2019 and $523,000 during the year ended December 31, 2020, with the remaining commitments of $4.5 million paid by December 31, 2034. There were no impairment losses on the Company’s LIHTC investments during the years ended December 31, 2018 , 2017 or 2016 . The Company also made a total of $25.0 million of Qualified Equity Investments ("QEIs") into three Certified Development Entities (“CDEs”) in May 2014 and is eligible to receive New Markets Tax Credits (“NMTC”) on the QEIs. The NMTC program provides federal tax incentives to investors to make investments in distressed communities and promotes economic improvements through the development of successful businesses in these communities. The NMTC is available to investors over a seven-year period and is subject to recapture if certain events occur during such period. Gross tax credits related to the Company's CDEs totaling $9.8 million are available through 2020 . The Company is required to fund 85 percent of a tranche to claim the entire tax credit, and it had until May 15, 2015 to complete the funding. The tranche was funded in 2015 before the deadline. The Company accounts for its NMTC on the equity method and reported the investment balance as prepaid expenses and other assets on the Company’s Statements of Financial Condition with carrying value of $25.7 million and $25.8 million at December 31, 2018 and December 31, 2017 , respectively. The Company recorded investment income of $708,000 , $735,000 and $740,000 during the years ended December 31, 2018 , 2017 and 2016 , respectively, in other income on the Company's Statements of Income.

Derivative Financial Instrument

Derivative Financial Instruments	12 Months Ended
	Dec. 31, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Financial Instruments	Derivative Financial Instruments The Company has entered into certain interest rate swap contracts that are not designated as hedging instruments. The purpose of these derivative contracts is primarily to provide commercial business loan customers the ability to convert their loans from variable to fixed interest rates. Upon the origination of a derivative contract with a customer, the Company simultaneously enters into an offsetting derivative contract with a third party in order to offset its exposure on the variable and fixed rate components of the customer agreement. The Company recognizes immediate income based upon the difference in the bid/ask spread of the underlying transactions with its customers and the third party, which is recorded in interest rate swap fees on the Consolidated Statements of Income. Because the Company acts only as an intermediary for its customer, subsequent changes in the fair value of the underlying derivative contracts offset each other and do not significantly impact the Company’s results of operations. The notional amounts and estimated fair values of interest rate derivative contracts outstanding at December 31, 2018 and December 31, 2017 are presented in the following table: December 31, 2018 December 31, 2017 Notional Amounts Estimated Fair Value Notional Amounts Estimated Fair Value (In thousands) Non-hedging interest rate derivatives Interest rate swaps with customer (1) $ 171,798 $ (1,643 ) $ 146,537 $ (882 ) Interest rate swap with third party (1) 171,798 1,643 146,537 882 (1) The estimated fair value of the derivative included in prepaid and other assets on the Consolidated Statements of Financial Condition was $5.1 million and $3.4 million as of December 31, 2018 and 2017 , respectively. The estimated fair value of the derivative included in accrued expenses and other liabilities on the Consolidated Statements of Financial Condition was $5.1 million and $3.4 million as of December 31, 2018 and 2017 , respectively.

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2018
Stockholders' Equity Note [Abstract]
Stockholders' Equity	Stockholders’ Equity (a) Earnings Per Common Share The following table illustrates the reconciliation of weighted average shares used for earnings per common share computations for the years ended December 31, 2018 , 2017 and 2016 : Year Ended December 31, 2018 2017 2016 (In thousands) Net income: Net income $ 53,057 $ 41,791 $ 38,918 Dividends and undistributed earnings allocated to participating securities (321 ) (293 ) (358 ) Net income allocated to common shareholders $ 52,736 $ 41,498 $ 38,560 Basic: Weighted average common shares outstanding 35,281,408 29,937,400 29,963,365 Restricted stock awards (87,405 ) (179,581 ) (285,063 ) Total basic weighted average common shares outstanding 35,194,003 29,757,819 29,678,302 Diluted: Basic weighted average common shares outstanding 35,194,003 29,757,819 29,678,302 Effect of potentially dilutive common shares (1) 177,587 91,512 13,851 Total diluted weighted average common shares outstanding 35,371,590 29,849,331 29,692,153 (1) Represents the effect of the assumed exercise of stock options and vesting of restricted stock awards and units. Potential dilutive shares are excluded from the computation of earnings per share if their effect is anti-dilutive. For the years ended December 31, 2018 and December 31, 2017 , there were no anti-dilutive shares outstanding related to options to acquire common stock. For the year ended December 31, 2016 , anti-dilutive shares outstanding related to options to acquire common stock totaled 436 . Anti-dilution occurs when the exercise price of a stock option or the unrecognized compensation cost per share of a restricted stock award exceeds the market price of the Company’s stock. (b) Dividends The timing and amount of cash dividends paid on the Company's common stock depends on the Company’s earnings, capital requirements, financial condition and other relevant factors. Dividends on common stock from the Company depend substantially upon receipt of dividends from the Bank, which is the Company’s predominant source of income. The following table summarizes the dividend activity for the years ended December 31, 2018 , 2017 and 2016 : Declared Cash Dividend per Share Record Date Paid Date January 27, 2016 $0.11 February 10, 2016 February 24, 2016 April 20, 2016 $0.12 May 5, 2016 May 19, 2016 July 20, 2016 $0.12 August 4, 2016 August 18, 2016 October 26, 2016 $0.12 November 8, 2016 November 22, 2016 October 26, 2016 $0.25 November 8, 2016 November 22, 2016 * January 25, 2017 $0.12 February 9, 2017 February 23, 2017 April 25, 2017 $0.13 May 10, 2017 May 24, 2017 July 25, 2017 $0.13 August 10, 2017 August 24, 2017 October 25, 2017 $0.13 November 8, 2017 November 22, 2017 October 25, 2017 $0.10 November 8, 2017 November 22, 2017 * January 24, 2018 $0.15 February 7, 2018 February 21, 2018 April 25, 2018 $0.15 May 10, 2018 May 24, 2018 July 24, 2018 $0.15 August 9, 2018 August 23, 2018 October 24, 2018 $0.17 November 7, 2018 November 21, 2018 October 24, 2018 $0.10 November 7, 2018 November 21, 2018 * * Denotes a special dividend. The FDIC and the Washington State Department of Financial Institutions, Division of Banks have the authority under their supervisory powers to prohibit the payment of dividends by the Bank to the Company. Additionally, current guidance from the Board of Governors of the Federal Reserve System ("Federal Reserve") provides, among other things, that dividends per share on the Company’s common stock generally should not exceed earnings per share, measured over the previous four fiscal quarters. Current regulations allow the Company and the Bank to pay dividends on their common stock if the Company’s or the Bank’s regulatory capital would not be reduced below the statutory capital requirements set by the Federal Reserve and the FDIC. (c) Stock Repurchase Program The Company has had various stock repurchase programs since March 1999. On October 23, 2014, the Company's Board of Directors authorized the repurchase of up to 5% of the Company's outstanding common shares, or approximately 1,513,000 shares, under the eleventh stock repurchase plan. The number, timing and price of shares repurchased will depend on business and market conditions, and other factors, including opportunities to deploy the Company's capital. Since the inception of the eleventh plan, the Company has repurchased 579,996 shares at an average share prices of $16.67 . No shares were repurchased under this plan during the years ended December 31, 2018 and 2017 . During the year ended December 31, 2016 , 138,000 shares were repurchased with an average share price of $17.16 . In addition to the stock repurchases under a plan, the Company repurchases shares to pay withholding taxes on the vesting of restricted stock awards and units. The following table provides total repurchased shares for the periods indicated: Year Ended December 31, 2018 2017 2016 Repurchased shares to pay withholding taxes (1) 53,256 29,429 29,512 Stock repurchase to pay withholding taxes average share price $ 31.99 $ 25.01 $ 17.82 (1) During the year ended December 31, 2018 , the Company repurchased 26,741 shares related to the withholding taxes due on the accelerated vesting of the restricted stock units of Puget Sound which were converted to Heritage common stock shares with a share price of $31.80 under the terms of the Puget Sound Merger. See Note (2) Business Combinations . There were no shares repurchased as a result of the accelerated vesting of the restricted stock awards related to the Premier Merger. (d) Issuance of Common Stock In conjunction with the Premier Merger effective on July 2, 2018 and the Puget Sound Merger effective on January 16, 2018, Heritage issued 2,848,579 and 4,112,258 shares, respectively, of the Company's common stock at the merger date share price of $34.85 and $31.80 , respectively, for a fair value of $99.3 million and $130.8 million , respectively. In addition, common stock was issued during the years ended December 31, 2018, 2017 and 2016 related to the exercise of stock options and issuance of restricted stock awards as further described in Note (19) Stock-Based Compensation .

Accumulated Other Comprehensive

Accumulated Other Comprehensive Loss	12 Months Ended
	Dec. 31, 2018
Equity [Abstract]
Accumulated Other Comprehensive Loss	Accumulated Other Comprehensive Loss The changes in accumulated other comprehensive (loss) income (“AOCI”), all of which are due to changes in the fair value of available for sale securities and are net of tax, during the years ended December 31, 2018 , 2017 and 2016 are as follows: December 31, 2018 December 31, 2017 December 31, 2016 (In thousands) Balance of AOCI at the beginning of the year $ (1,298 ) $ (2,606 ) $ 2,559 Other comprehensive (loss) income before reclassification (5,956 ) 1,530 (4,311 ) Amounts reclassified from AOCI for gain on sale of investment securities included in net income (108 ) (4 ) (854 ) Net current period other comprehensive (loss) income (6,064 ) 1,526 (5,165 ) ASU 2016-01 and 2018-02 Implementations (93 ) (218 ) — Balance of AOCI at the end of the year $ (7,455 ) $ (1,298 ) $ (2,606 )

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements Fair value is the exchange price that would be received for an asset or paid to transfer a liability (exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. There are three levels of inputs that may be used to measure fair values: Level 1 : Valuations for assets and liabilities traded in active exchange markets, or interest in open-end mutual funds that allow the Company to sell its ownership interest back to the fund at net asset value on a daily basis. Valuations are obtained from readily available pricing sources for market transactions involving identical assets, liabilities, or funds. Level 2 : Valuations for assets and liabilities traded in less active dealer or broker markets, such as quoted prices for similar assets or liabilities, quoted prices in markets that are not active, or valuations using methodologies with observable inputs. Level 3 : Valuations for assets and liabilities that are derived from other valuation methodologies, such as option pricing models, discounted cash flow models and similar techniques using unobservable inputs, and not based on market exchange, dealer, or broker traded transactions. Level 3 valuations incorporate certain assumptions and projections in determining the fair value assigned to such assets or liabilities. (a) Recurring and Nonrecurring Basis The Company used the following methods and significant assumptions to measure the fair value of certain assets on a recurring and nonrecurring basis: Investment Securities Available for Sale : The fair values of all investment securities are based upon the assumptions that market participants would use in pricing the security. If available, fair values of investment securities are determined by quoted market prices (Level 1). For investment securities where quoted market prices are not available, fair values are calculated based on market prices on similar securities (Level 2). For investment securities where quoted prices or market prices of similar securities are not available, fair values are calculated by using observable and unobservable inputs such as discounted cash flows or other market indicators (Level 3). Security valuations are obtained from third party pricing services for comparable assets or liabilities. Impaired Loans : At the time a loan is considered impaired, its impairment is measured based on either the present value of expected future cash flows discounted at the loan’s effective interest rate, the observable market price, or the fair market value of the collateral (less costs to sell) if the loan is collateral-dependent. Impaired loans for which impairment is measured using the discounted cash flow approach are not considered to be measured at fair value because the loan’s effective interest rate is generally not a fair value input, and for the purposes of fair value disclosures, the fair value of these loans are measured commensurate with non-impaired loans. If the Company utilizes the fair market value of the collateral method, the fair value used to measure impairment is commonly based on recent real estate appraisals. These appraisals may utilize a single valuation approach or a combination of approaches including comparable sales and the income approach. Adjustments are routinely made in the appraisal process by independent appraisers to adjust for differences between the comparable sales and income data available. Such adjustments are usually significant and typically result in a Level 3 classification of the inputs for determining fair value. Non-real estate collateral may be valued using an appraisal, net book value based on the borrower’s financial statements, or aging reports, adjusted or discounted based on management’s historical knowledge, changes in market conditions from the time of the valuation and management’s expertise and knowledge of the client and client’s business (Level 3). Impaired loans are evaluated on a quarterly basis and impairment is adjusted accordingly. Other Real Estate Owned : Assets acquired through or instead of loan foreclosure are initially recorded at fair value less costs to sell when acquired, establishing a new cost basis. These assets are subsequently accounted for at lower of cost or fair value less costs to sell. Fair value is commonly based on recent real estate appraisals. These appraisals may utilize a single valuation approach or a combination of approaches including comparable sales and the income approach. Adjustments are routinely made in the appraisal process by independent appraisers to adjust for differences between the comparable sales and income data available. Such adjustments are usually significant and typically result in Level 3 classification of the inputs for determining fair value. Appraisals for both collateral-dependent impaired loans and other real estate owned are performed by certified general appraisers for commercial properties or certified residential appraisers for residential properties whose qualifications and licenses have been reviewed and verified by the Company. Once received, the Company reviews the assumptions and approaches utilized in the appraisal as well as the resulting fair value in comparison with independent data sources such as recent market data or industry-wide statistics. On a quarterly basis, the Company compares the actual selling price of collateral that has been liquidated to the most recent appraised value to determine what additional adjustment should be made to the appraisal value to arrive at fair value. Derivative Financial Instruments: The Company obtains broker or dealer quotes to value its interest rate derivative contracts, which use valuation models using observable market data as of the measurement date (Level 2). Recurring Basis The following tables summarize the balances of assets and liabilities measured at fair value on a recurring basis as of December 31, 2018 and December 31, 2017 : December 31, 2018 Total Level 1 Level 2 Level 3 (In thousands) Assets Investment securities available for sale: U.S. Treasury and U.S. Government-sponsored agencies $ 101,603 $ 15,936 $ 85,667 $ — Municipal securities 158,864 — 158,864 — Mortgage backed securities and collateralized mortgage obligations: Residential 331,602 — 331,602 — Commercial 333,761 — 333,761 — Corporate obligations 25,563 — 25,563 — Other asset-backed securities 24,702 24,702 — Total investment securities available for sale 976,095 15,936 960,159 — Derivative assets - interest rate swaps 5,095 — 5,095 — Liabilities Derivative liabilities - interest rate swaps $ 5,095 $ — $ 5,095 $ — December 31, 2017 Total Level 1 Level 2 Level 3 (In thousands) Assets Investment securities available for sale: U.S. Treasury and U.S. Government-sponsored agencies $ 13,442 $ — $ 13,442 $ — Municipal securities 250,015 — 250,015 — Mortgage backed securities and collateralized mortgage obligations: Residential 280,211 — 280,211 — Commercial 217,079 — 217,079 — Collateralized loan obligations 4,580 — 4,580 — Corporate obligations 16,770 — 16,770 — Other securities 28,433 146 28,287 — Total investment securities available for sale 810,530 146 810,384 — Derivative assets - interest rate swaps 3,418 — 3,418 — Liabilities Derivative liabilities - interest rate swaps $ 3,418 $ — $ 3,418 $ — There were no transfers between Level 1 and Level 2 during the years ended December 31, 2018 and 2017 . Nonrecurring Basis The Company may be required to measure certain financial assets and liabilities at fair value on a nonrecurring basis. These adjustments to fair value usually result from application of lower-of-cost-or-market accounting or write-downs of individual assets. The tables below represent assets measured at fair value on a nonrecurring basis at December 31, 2018 and December 31, 2017 and the net losses recorded in earnings during years ended December 31, 2018 and 2017 : Basis (1) Fair Value at December 31, 2018 Total Level 1 Level 2 Level 3 Net Losses Recorded in Earnings During the Year Ended December 31, 2018 (In thousands) Impaired loans: Commercial business: Commercial and industrial $ 117 $ 107 $ — $ — $ 107 $ 10 Non-owner occupied commercial real estate 1,378 1,102 — — 1,102 150 Total commercial business 1,495 1,209 — — 1,209 160 Consumer 9 7 — — 7 8 Total assets measured at fair value on a nonrecurring basis $ 1,504 $ 1,216 $ — $ — $ 1,216 $ 168 (1) Basis represents the unpaid principal balance of impaired loans. Basis (1) Fair Value at December 31, 2017 Total Level 1 Level 2 Level 3 Net Losses (Gains) Recorded in Earnings During the Year Ended December 31, 2017 (In thousands) Impaired loans: Real estate construction and land development: One-to-four family residential $ 976 $ 307 $ — $ — $ 307 $ (558 ) Total assets measured at fair value on a nonrecurring basis $ 976 $ 307 $ — $ — $ 307 $ (558 ) (1) Basis represents the unpaid principal balance of impaired loans. The following table presents quantitative information about Level 3 fair value measurements for financial instruments measured at fair value on a non-recurring basis at December 31, 2018 and December 31, 2017 : December 31, 2018 Fair Value Valuation Technique(s) Unobservable Input(s) Range of Inputs; Weighted Average (Dollars in thousands) Impaired loans $ 1,216 Market approach Adjustment for differences between the comparable sales 10.4% - (37.3%); (10.9%) December 31, 2017 Fair Value Valuation Technique(s) Unobservable Input(s) Range of Inputs; Weighted Average (Dollars in thousands) Impaired loans $ 307 Market approach Adjustment for differences between the comparable sales (91.5%) - (14.4%); (44.0%) (b) Fair Value of Financial Instruments Because broadly traded markets do not exist for most of the Company’s financial instruments, the fair value calculations attempt to incorporate the effect of current market conditions at a specific time. These determinations are subjective in nature, involve uncertainties and matters of significant judgment and do not include tax ramifications; therefore, the results cannot be determined with precision, substantiated by comparison to independent markets and may not be realized in an actual sale or immediate settlement of the instruments. There may be inherent weaknesses in any calculation technique, and changes in the underlying assumptions used, including discount rates and estimates of future cash flows, could significantly affect the results. For all of these reasons, the aggregation of the fair value calculations presented herein do not represent, and should not be construed to represent, the underlying value of the Company. The tables below present the carrying value amount of the Company’s financial instruments and their corresponding estimated fair values at the dates indicated: December 31, 2018 Carrying Value Fair Value Fair Value Measurements Using: Level 1 Level 2 Level 3 (In thousands) Financial Assets: Cash and cash equivalents $ 161,910 $ 161,910 $ 161,910 $ — $ — Investment securities available for sale 976,095 976,095 15,936 960,159 — Federal Home Loan Bank stock 6,076 N/A N/A N/A N/A Loans held for sale 1,555 1,605 — 1,605 — Total loans receivable, net 3,619,118 3,614,348 — — 3,614,348 Accrued interest receivable 15,403 15,403 68 4,091 11,244 Derivative assets - interest rate swaps 5,095 5,095 — 5,095 — Equity security 114 114 114 — — Financial Liabilities: Noninterest deposits, interest bearing demand deposits, money market accounts and savings accounts $ 3,965,510 $ 3,965,510 $ 3,965,510 $ — $ — Certificate of deposit accounts 466,892 470,222 — 470,222 — Securities sold under agreement to repurchase 31,487 31,487 31,487 — — Junior subordinated debentures 20,302 20,500 — — 20,500 Accrued interest payable 191 191 63 81 47 Derivative liabilities - interest rate swaps 5,095 5,095 — 5,095 — December 31, 2017 Carrying Value Fair Value Fair Value Measurements Using: Level 1 Level 2 Level 3 (In thousands) Financial Assets: Cash and cash equivalents $ 103,015 $ 103,015 $ 103,015 $ — $ — Investment securities available for sale 810,530 810,530 146 810,384 — Federal Home Loan Bank stock 8,347 N/A N/A N/A N/A Loans held for sale 2,288 2,364 — 2,364 — Total loans receivable, net 2,816,985 2,810,401 — — 2,810,401 Accrued interest receivable 12,244 12,244 23 3,772 8,449 Derivative assets - interest rate swaps 3,418 3,418 — 3,418 — Financial Liabilities: Noninterest deposits, interest bearing demand deposits, money market accounts and savings accounts $ 2,994,662 $ 2,994,662 $ 2,994,662 $ — $ — Certificate of deposit accounts 398,398 397,039 — 397,039 — Federal Home Loan Bank advances 92,500 92,500 — 92,500 — Securities sold under agreement to repurchase 31,821 31,821 31,821 — — Junior subordinated debentures 20,009 18,500 — — 18,500 Accrued interest payable 162 162 45 79 38 Derivative liabilities - interest rate swaps 3,418 3,418 — 3,418 —

Stock-Based Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation	Stock-Based Compensation On July 24, 2014, the Company's shareholders approved the Heritage Financial Corporation 2014 Omnibus Equity Plan ("Equity Plan") that provides for the issuance of 1,500,000 shares of the Company's common stock in the form of stock options, stock appreciation rights, stock awards (which includes restricted stock units, restricted stock awards, performance units, performance shares or bonus shares) and cash incentive awards. The Company issues new shares of common stock to satisfy share option exercises and restricted stock awards. As of December 31, 2018 , shares remain available for future issuance under the Equity Plan totaled 955,282 . (a) Stock Option Awards Stock options generally vest ratably over three years and expire five years after they become exercisable or vest ratably over four years and expire ten years from date of grant. For the years ended December 31, 2018 , 2017 and 2016 , the Company did not recognize any compensation expense or related tax benefit related to stock options as all of the compensation expense related to the outstanding stock options had been previously recognized. The intrinsic value from options exercised during the years ended December 31, 2018 , 2017 and 2016 was $202,000 , $161,000 and $177,000 , respectively. The cash proceeds from options exercised during the years ended December 31, 2018 , 2017 and 2016 were $132,000 , $164,000 and $540,000 , respectively. The following table summarizes the stock option activity for the years ended December 31, 2018 , 2017 and 2016 : Shares Weighted-Average Exercise Price Weighted-Average Remaining Contractual Term (In years) Aggregate Intrinsic Value (In thousands) Outstanding at December 31, 2015 79,408 $ 14.19 Exercised (37,713 ) 14.31 Forfeited or expired (4,200 ) 16.80 Outstanding at December 31, 2016 37,495 13.77 Exercised (12,662 ) 12.97 Forfeited or expired (1,602 ) 13.76 Outstanding at December 31, 2017 23,231 14.21 Exercised (9,842 ) 13.45 Forfeited or expired (831 ) 14.77 Outstanding, vested and expected to vest and exercisable at December 31, 2018 12,558 $ 14.77 1.39 $ 188 (b) Restricted Stock Awards Restricted stock awards granted generally have a four -year cliff vesting or four -year ratable vesting schedule. For the years ended December 31, 2018 , 2017 and 2016 the Company recognized compensation expense related to restricted stock awards of $907,000 , $1.4 million and $1.8 million , respectively, and a related tax benefit of $191,000 , $488,000 and $644,000 , respectively. As of December 31, 2018 , the total unrecognized compensation expense related to non-vested restricted stock awards was $556,000 and the related weighted average period over which the compensation expense is expected to be recognized is approximately 0.88 years. The vesting date fair value of the restricted stock awards that vested during the years ended December 31, 2018 , 2017 and 2016 was $2.2 million , $2.9 million and $2.0 million , respectively. The following table summarizes the restricted stock award activity for the years ended December 31, 2018 , 2017 and 2016 : Shares Weighted-Average Grant Date Fair Value Nonvested at December 31, 2015 264,521 $ 15.92 Granted 121,039 17.60 Vested (112,516 ) 15.62 Forfeited (11,748 ) 16.62 Nonvested at December 31, 2016 261,296 16.80 Vested (113,479 ) 16.55 Forfeited (10,418 ) 16.80 Nonvested at December 31, 2017 137,399 17.00 Vested (67,877 ) 16.74 Forfeited (3,489 ) 16.92 Nonvested at December 31, 2018 66,033 $ 17.28 (c) Restricted Stock Units During 2017, the Company began issuing stock-settled restricted stock unit awards ("RSU") and performance-based stock-settled restricted stock unit awards ("PRSU"), collectively called "units". RSUs granted vest ratably over three years . PRSUs granted generally have a three -year cliff vesting schedule. Additionally, PRSU grants may be subject to performance-based vesting as well as other approved vesting conditions. The number of shares of actually delivered pursuant to the PRSUs depends on the performance of the Company's Total Shareholder Return and Return on Average Assets over the performance period in relation to the performance of the common stock of a predetermined peer group. The conditions of the grants allow for an actual payout ranging between no payout and 150% of target. The payout level is calculated based on actual performance achieved during the performance period compared to a defined peer group. The fair value of such PRSUs was determined using a Monte Carlo simulation and will be recognized over the subsequent three years . The Monte-Carlo simulation model uses the same input assumptions as the Black-Scholes model; however, it also further incorporates into the fair value determination the possibility that the market condition may not be satisfied. Compensation costs related to these awards are recognized regardless of whether the market condition is satisfied, provided that the requisite service has been provided. Expected volatilities in the model were estimated using a historical period consistent with the performance period of approximately three years . The risk-free interest rate was based on the United States Treasury rate for a term commensurate with the expected life of the grant. The Company used the following assumptions to estimate the fair value of PRSUs granted during February 2018 and 2017: 2018 2017 Shares issued 5,550 6,089 Expected Term in Years 2.84 2.85 Weighted-Average Risk Free Interest Rate 2.39 % 1.40 % Expected Dividend Yield — % — % Weighted-Average Fair Value 27.69 24.39 Correlation coefficient ABA NASDAQ Community Bank Index ABA NASDAQ Community Bank Index Range of peer company volatilities 18.99% - 51.42% 17.8% - 63.1% Range of peer company correlation coefficients 28.16% - 94.29% 8.24% - 89.79% Heritage volatility 22.30 % 21.80 % Heritage correlation coefficient 76.44 % 75.93 % For the year ended December 31, 2018 and 2017 , the Company recognized compensation expense related to the units of $1.8 million and $712,000 , respectively, and a related tax benefit of $387,000 and $249,000 , respectively. As of December 31, 2018 , the total unrecognized compensation expense related to non-vested units was $3.5 million and the related weighted-average period over which the compensation expense is expected to be recognized is approximately 2.17 years. The vesting date fair value of the units that vested during the year ended December 31, 2018 was $1.0 million . There were no PRSUs that vested during the years end December 31, 2018 and 2017 . The following table summarizes the unit activity for the year ended December 31, 2018 and 2017 : Units Weighted-Average Grant Date Fair Value Nonvested at December 31, 2016 — $ — Granted 92,356 25.31 Forfeited (1,812 ) 25.35 Nonvested at December 31, 2017 90,544 25.31 Granted 125,633 30.62 Vested (32,375 ) 25.44 Forfeited (4,617 ) 27.82 Nonvested at December 31, 2018 179,185 $ 28.94

Cash Requirement

Cash Requirement	12 Months Ended
	Dec. 31, 2018
Banking and Thrift [Abstract]
Cash Requirement	Cash Requirement The Company is required to maintain an average reserve balance with the Federal Reserve Bank or maintain such reserve balance in the form of cash. The required reserve balance at December 31, 2018 and December 31, 2017 was $9.2 million and $60,000 , respectively, and was met by holding cash and maintaining an average balance with the Federal Reserve Bank.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes Income tax expense is substantially due to Federal income taxes as the provision for the state of Oregon income taxes is insignificant. Income tax expense for the years ended December 31, 2018 , 2017 and 2016 consisted of the following: Year Ended December 31, 2018 2017 2016 (In thousands) Current tax expense $ 9,658 $ 12,171 $ 6,885 Deferred tax expense 1,372 6,185 6,918 Income tax expense $ 11,030 $ 18,356 $ 13,803 A reconciliation of the Company's effective income tax rate with the Federal statutory income tax rate of 35% for the years 2017 and 2016 and 21% for the year 2018 is as follows: Year Ended December 31, 2018 2017 2016 (In thousands) Income tax expense at Federal statutory rate $ 13,502 $ 21,051 $ 18,452 Tax-exempt instruments (1,879 ) (3,212 ) (3,198 ) Non-deductible acquisition costs 336 210 — Federal tax credits and other benefits (1) (515 ) (1,510 ) (931 ) Effects of BOLI (330 ) (531 ) (511 ) Revaluation of net deferred tax assets 2,568 — Other, net (84 ) (220 ) (9 ) Income tax expense $ 11,030 $ 18,356 $ 13,803 (1) Federal tax credits are provided for under the NMTC program and LIHTC programs as described in Note (14) Commitments and Contingencies . Tax benefits related to these credits were recognized for financial reporting purposes in the same period that the credits were recognized in the Company's income tax returns. Other benefits include the proportional amortization of the LIHTC of $3.1 million , $2.2 million and $523,000 , for the years ended December 31, 2018 , 2017 and 2016 , respectively. On December 22, 2017, the U.S. Government enacted comprehensive tax legislation commonly referred to as the Tax Cuts and Jobs Act (the "Tax Act"). The Tax Act amended the Internal Revenue Code to reduce tax rates and modify policies, credits, and deductions for individuals and businesses. For businesses, the Tax Act reduced the corporate federal tax rate from a maximum of 35% to a flat 21% rate. The corporate tax rate reduction was effective January 1, 2018. The Tax Act required a revaluation the Company’s deferred tax assets and liabilities to account for the future impact of lower corporate tax rates and other provisions of the legislation. As a result of the Company's revaluation, the net deferred tax asset was reduced through an increase to the provision for income tax during the year ended December 31, 2017. The following table presents major components of the deferred income tax asset (liability) resulting from differences between financial reporting and tax basis: December 31, 2018 December 31, 2017 (In thousands) Deferred tax assets: Allowance for loan losses $ 6,941 $ 6,699 Accrued compensation 3,379 1,779 Stock compensation 769 660 Net unrealized losses charged to other comprehensive income on securities 2,070 347 Market discount on purchased loans 1,054 539 Foregone interest on nonaccrual loans 811 471 Net operating loss carryforward acquired from NCB 336 270 Other Real Estate Owned 754 — Other deferred tax assets 364 763 Total deferred tax assets 16,478 11,528 Deferred tax liabilities: Deferred loan fees, net (3,333 ) (2,518 ) Premises and equipment (1,819 ) (1,091 ) FHLB stock (569 ) (557 ) Goodwill and other intangible assets (3,526 ) (304 ) Federal tax credits (1,457 ) (1,107 ) Junior subordinated debentures (1,176 ) (1,215 ) Other deferred tax liabilities (540 ) (847 ) Total deferred tax liabilities (12,420 ) (7,639 ) Deferred tax asset, net $ 4,058 $ 3,889 In assessing the realizability of deferred tax assets, management considers whether it is more likely than not that some portion or all of the deferred tax assets will not be realized. A valuation allowance is required to be recognized for the portion of the deferred tax asset that will not be realized. The ultimate realization of deferred tax assets is dependent upon the generation of future taxable income during the periods in which those temporary differences become deductible. As of December 31, 2018 , based upon the level of historical taxable income and projections for future taxable income over the periods in which the deferred tax assets are deductible, management expects to realize the benefits of these deductible differences. The Company had a net operating loss carryforward of $1.6 million and $1.3 million at December 31, 2018 and 2017 , respectively, that will begin to expire in 2024 . The Company is limited to the amount of the net operating loss carryforward that it can deduct each year. A tax planning strategy has been developed that management believes will enable the Company to deduct all of the net operating loss carryforwards prior to the expiration date. Based on these estimates, management has no t recorded a valuation allowance as of December 31, 2018 and 2017 . As of December 31, 2018 and 2017 , the Company had an insignificant amount of unrecognized tax benefits, none of which would materially affect its effective tax rate if recognized. The Company does not anticipate that the amount of unrecognized tax benefits will significantly increase or decrease in the next 12 months. The amount of interest and penalties accrued as of December 31, 2018 and 2017 and for the years ended December 31, 2018 , 2017 and 2016 were immaterial. The Company has qualified under provisions of the Internal Revenue Code to compute income taxes after deductions of additions to the bad debt reserves when it was registered as a Savings Bank. At December 31, 2018 , the Company had a taxable temporary difference of approximately $2.8 million that arose before 1988 (base-year amount). In accordance with FASB ASC 740, a deferred tax liability of an estimated $980,000 has not been recognized for the temporary difference. Management does not expect this temporary difference to reverse in the foreseeable future. The Company and its subsidiary file a United States consolidated federal income tax return and an Oregon State income tax return, and the tax years subject to examination by the Internal Revenue Service are the years ended December 31, 2018 , 2017 , 2016 and 2015 .

Regulatory Capital Requirements

Regulatory Capital Requirements	12 Months Ended
	Dec. 31, 2018
Regulatory Capital Requirements [Abstract]
Regulatory Capital Requirements	Regulatory Capital Requirements The Company is a bank holding company under the supervision of the Federal Reserve Bank. Bank holding companies are subject to capital adequacy requirements of the Federal Reserve under the Bank Holding Company Act of 1956, as amended, and the regulations of the Federal Reserve. Heritage Bank is a federally insured institution and thereby is subject to the capital requirements established by the FDIC. The Federal Reserve capital requirements generally parallel the FDIC requirements. Failure to meet minimum capital requirements can initiate certain mandatory, and possibly additional discretionary, actions by regulators that, if undertaken, could have a direct material effect on the Company’s consolidated financial statements and operations. Management believes as of December 31, 2018 , the Company and the Bank meet all capital adequacy requirements to which they are subject. As of December 31, 2018 and December 31, 2017 , the most recent regulatory notifications categorized the Bank as well capitalized under the regulatory framework for prompt corrective action. There are no conditions or events since that notification that management believes have changed the Bank's categories. Minimum Well- Actual $ % $ % $ % (Dollars in thousands) As of December 31, 2018: The Company consolidated Common equity Tier 1 capital to risk-weighted assets $ 197,189 4.5 % N/A N/A $ 510,618 11.7 % Tier 1 leverage capital to average assets 201,920 4.0 N/A N/A 530,920 10.5 Tier 1 capital to risk-weighted assets 262,918 6.0 N/A N/A 530,920 12.1 Total capital to risk-weighted assets 350,558 8.0 N/A N/A 566,268 12.9 Heritage Bank Common equity Tier 1 capital to risk-weighted assets 197,004 4.5 284,561 6.5 513,993 11.7 Tier 1 leverage capital to average assets 203,339 4.0 254,174 5.0 513,993 10.1 Tier 1 capital to risk-weighted assets 262,671 6.0 350,229 8.0 513,993 11.7 Total capital to risk-weighted assets 350,229 8.0 437,786 10.0 549,341 12.5 As of December 31, 2017: The Company consolidated Common equity Tier 1 capital to risk-weighted assets $ 154,522 4.5 % N/A N/A $ 386,689 11.3 % Tier 1 leverage capital to average assets 159,494 4.0 N/A N/A 406,687 10.2 Tier 1 capital to risk-weighted assets 206,029 6.0 N/A N/A 406,687 11.8 Total capital to risk-weighted assets 274,706 8.0 N/A N/A 439,044 12.8 Heritage Bank Common equity Tier 1 capital to risk-weighted assets 154,400 4.5 223,023 6.5 391,092 11.4 Tier 1 leverage capital to average assets 159,300 4.0 199,125 5.0 391,092 9.8 Tier 1 capital to risk-weighted assets 205,867 6.0 274,490 8.0 391,092 11.4 Total capital to risk-weighted assets 274,490 8.0 343,112 10.0 423,348 12.3 The Company is subject to capital adequacy requirements of the Basel Committee on Banking Supervision, commonly called Basel III. Under the capital requirements both the Company and the Bank are required to have a common equity Tier 1 capital ratio of 4.5%. In addition, both the Company and the Bank are required to have a Tier 1 leverage ratio of 4.0%, a Tier 1 risk-based ratio of 6.0% and a total risk-based ratio of 8.0%. Both the Company and the Bank are required to establish a “conservation buffer”, consisting of common equity Tier 1 capital of more than 2.5% above the minimum risk-based capital ratios. The capital conservation buffer is designed to ensure that banks build up capital buffers outside periods of stress which can be drawn down as losses are incurred. An institution that does not meet the conservation buffer will be subject to restrictions on certain activities including payment of dividends, stock repurchases and discretionary bonuses to executive officers. The capital conservation buffer requirement began to be phased-in on January 1, 2016 when more than 0.625% of risk-weighted assets was required, and increases by 0.625% on each subsequent January 1, until it is fully phased-in on January 1, 2019. Certain calculations under the rules will also have phase-in periods. At December 31, 2018 , the capital conservation buffer was 4.92% and 4.55% for the Company and the Bank, respectively.

Heritage Financial Corporation

Heritage Financial Corporation (Parent Company Only)	12 Months Ended
	Dec. 31, 2018
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Heritage Financial Corporation (Parent Company Only)	Heritage Financial Corporation (Parent Company Only) Following is the condensed financial statements of the Parent Company. HERITAGE FINANCIAL CORPORATION (PARENT COMPANY ONLY) Condensed Statements of Financial Condition December 31, 2018 December 31, 2017 (In thousands) ASSETS Cash and interest earning deposits $ 14,602 $ 11,904 Investment in subsidiary bank 764,097 512,655 Other assets 2,520 4,696 Total assets $ 781,219 $ 529,255 LIABILITIES AND STOCKHOLDERS’ EQUITY Junior subordinated debentures $ 20,302 $ 20,009 Other liabilities 194 941 Total stockholders’ equity 760,723 508,305 Total liabilities and stockholders’ equity $ 781,219 $ 529,255 HERITAGE FINANCIAL CORPORATION (PARENT COMPANY ONLY) Condensed Statements of Income Year Ended December 31, 2018 2017 2016 (In thousands) INTEREST INCOME: Interest and dividends on interest earning deposits and other assets $ 7 $ 44 $ 34 Total interest income 7 44 34 INTEREST EXPENSE: Junior subordinated debentures 1,263 1,014 880 Total interest expense 1,263 1,014 880 Net interest expense (1,256 ) (970 ) (846 ) NONINTEREST INCOME: Dividends from subsidiary bank 30,000 23,000 30,000 Equity in undistributed income of subsidiary bank 29,258 21,755 11,848 Other income 22 — — Total noninterest income 59,280 44,755 41,848 NONONTEREST EXPENSE: Professional services 3,063 768 385 Other expense 3,833 3,726 3,437 Total noninterest expense 6,896 4,494 3,822 Income before income taxes 51,128 39,291 37,180 Income tax benefit (1,929 ) (2,500 ) (1,738 ) Net income $ 53,057 $ 41,791 $ 38,918 HERITAGE FINANCIAL CORPORATION (PARENT COMPANY ONLY) Condensed Statements of Cash Flows Year Ended December 31, 2018 2017 2016 (In thousands) Cash flows from operating activities: Net income $ 53,057 $ 41,791 $ 38,918 Adjustments to reconcile net income to net cash provided by operating activities: Equity in undistributed income of subsidiary bank (29,258 ) (21,755 ) (11,848 ) Net excess tax benefit from exercise of stock options and vesting of restricted stock — — (123 ) Stock-based compensation expense 2,744 2,103 1,840 Net change in other assets and liabilities 1,735 (1,925 ) (1,141 ) Net cash provided by operating activities 28,278 20,214 27,646 Cash flows from investing activities: Net cash received from acquisitions 1,782 — — Net cash provided by investing activities 1,782 — — Cash flows from financing activities: Common stock cash dividends paid (25,791 ) (18,305 ) (21,569 ) Proceeds from exercise of stock options 133 164 540 Net excess tax benefit from exercise of stock options and vesting of restricted stock — — 123 Repurchase of common stock (1,704 ) (737 ) (2,894 ) Net cash used in financing activities (27,362 ) (18,878 ) (23,800 ) Net increase in cash and cash equivalents 2,698 1,336 3,846 Cash and cash equivalents at the beginning of year 11,904 10,568 6,722 Cash and cash equivalents at the end of year $ 14,602 $ 11,904 $ 10,568 Supplemental non-cash disclosures of cash flow information: Common stock issued for business combinations $ 230,043 $ — $ — Capital contribution of net assets acquired in business combinations to Bank 228,261 — —

Selected Quarterly Financial Da

Selected Quarterly Financial Data	12 Months Ended
	Dec. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
Selected Quarterly Financial Data (Unaudited)	Selected Quarterly Financial Data (Unaudited) Results of operations on a quarterly basis were as follows: Year Ended December 31, 2018 First Quarter Second Quarter Third Quarter Fourth Quarter (Dollars in thousands, except per share amounts) Interest income $ 43,247 $ 46,671 $ 54,576 $ 54,865 Interest expense 2,410 2,928 3,480 3,595 Net interest income 40,837 43,743 51,096 51,270 Provision for loan losses 1,152 1,750 1,065 1,162 Net interest income after provision for loan losses 39,685 41,993 50,031 50,108 Noninterest income 7,548 7,573 8,080 8,464 Noninterest expense 36,747 35,706 39,597 37,345 Income before provision for income taxes 10,486 13,860 18,514 21,227 Income tax expense 1,399 2,003 3,010 4,618 Net income $ 9,087 $ 11,857 $ 15,504 $ 16,609 Basic earnings per common share $ 0.27 $ 0.35 $ 0.42 $ 0.45 Diluted earnings per common share 0.27 0.35 0.42 0.45 Cash dividends declared on common stock 0.15 0.15 0.15 0.27 Year Ended December 31, 2017 First Quarter Second Quarter Third Quarter Fourth Quarter (Dollars in thousands, except per share amounts) Interest income $ 34,849 $ 36,041 $ 37,275 $ 39,544 Interest expense 1,717 1,907 2,333 2,389 Net interest income 33,132 34,134 34,942 37,155 Provision for loan losses 867 1,131 884 1,338 Net interest income after provision for loan losses 32,265 33,003 34,058 35,817 Noninterest income 7,363 10,709 8,443 9,064 Noninterest expense 27,223 27,809 27,955 27,588 Income before provision for income taxes 12,405 15,903 14,546 17,293 Income tax expense 3,089 4,075 3,922 7,270 Net income $ 9,316 $ 11,828 $ 10,624 $ 10,023 Basic earnings per common share $ 0.31 $ 0.40 $ 0.35 $ 0.33 Diluted earnings per common share 0.31 0.40 0.35 0.33 Cash dividends declared on common stock 0.12 0.13 0.13 0.23

Description of Business, Basi_2

Description of Business, Basis of Presentation and Significant Accounting Policies and Recently Issued Accounting Pronouncements (Policies)	12 Months Ended
	Dec. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of Business	Description of Business Heritage Financial Corporation ("Heritage" or the “Company”) is a bank holding company that was incorporated in the State of Washington in August 1997. The Company is primarily engaged in the business of planning, directing and coordinating the business activities of its wholly-owned subsidiary, Heritage Bank (the “Bank”). The Bank is a Washington-chartered commercial bank and its deposits are insured by the FDIC. The Bank is headquartered in Olympia, Washington and conducts business from its 64 branch offices located throughout Washington State and the greater Portland, Oregon area. The Bank’s business consists primarily of commercial lending and deposit relationships with small businesses and their owners in its market areas and attracting deposits from the general public. The Bank also makes real estate construction and land development loans, consumer loans and originates first mortgage loans on residential properties primarily located in its market areas.
Basis of Presentation	Basis of Presentation The accounting and reporting policies of the Company and its subsidiaries conform to U.S. Generally Accepted Accounting Principles (“GAAP”). In preparing the Consolidated Financial Statements, management makes estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of income and expenses during the reporting periods. Actual results could differ from these estimates. The accompanying Consolidated Financial Statements include the accounts of the Company and its wholly owned subsidiary, the Bank. All significant intercompany balances and transactions among the Company and the Bank have been eliminated in consolidation.
Reclassifications	Certain prior year amounts in the Consolidated Statements of Income have been reclassified to conform to the current year’s presentation. Reclassifications had no effect on the prior years' net income or stockholders’ equity.
Cash and Cash Equivalents	Cash and Cash Equivalents Cash and cash equivalents include cash on hand and due from banks and interest-bearing balances due from the Federal Reserve Bank. Cash equivalents have a maturity of 90 days or less at the time of purchase.
Investment Securities	Investment Securities The Company identifies investments as held to maturity or available for sale at the time of acquisition. Securities are classified as held to maturity when the Company has the ability and positive intent to hold them to maturity. Securities classified as available for sale are available for future liquidity requirements and may be sold prior to maturity. As of December 31, 2018 and December 31, 2017 the Bank does not hold any securities classified as held to maturity. See Note (3) Investment Securities for additional information. Securities available for sale are carried at fair value. Interest income includes amortization of purchase premiums or accretion of purchase discounts using the interest method. Unrealized gains and losses on securities available for sale are generally excluded from earnings and are reported in other comprehensive income (loss), net of related income taxes. Realized gains and losses on sale of investment securities are computed on the specific identification method. Transfers of securities between the available for sale and held to maturity categories are accounted for at fair value. Management evaluates securities for other-than-temporary impairment on at least a quarterly basis, and more frequently when economic or market conditions warrant such an evaluation. Although these evaluations involve significant judgment, an unrealized loss in the fair value of a debt security is generally deemed to be temporary when a) the fair value of the security is below the carrying value primarily due to changes in interest rates; b) there has not been significant deterioration in the financial condition of the issuer; and, c) it is not more likely than not that the Company will be required to, nor does it have the intent to, sell the security before the anticipated recovery of its remaining carrying value. If any of these criteria is not met, the impairment is split into two components as follows: 1) other-than-temporary impairment related to credit loss, which must be recognized in the income statement and 2) other-than-temporary impairment related to other factors, which is recognized in other comprehensive income (loss). The credit loss is defined as the difference between the present value of the cash flows expected to be collected and the amortized cost basis. For debt securities with other-than-temporary impairment, the previous amortized cost basis less the other-than-temporary impairment recognized in earnings shall be the new amortized cost basis of the security. In subsequent periods, the Company accretes into interest income the difference between the new amortized cost basis and cash flows expected to be collected prospectively over the life of the debt security . Continued deterioration of market conditions could result in additional impairment losses recognized within the investment portfolio. Other factors that may be considered in determining whether a decline in the value of a debt security is “other-than-temporary” include ratings by recognized rating agencies; actions of commercial banks or other lenders relative to the continued extension of credit facilities to the issuer of the security; the financial condition, capital strength and near-term prospects of the issuer and recommendations of investment advisors or market analysts.
Loans Held for Sale	Loans Held for Sale Mortgage loans held for sale are carried at the lower of amortized cost or fair value. Any loan that management does not have the intent and ability to hold for the foreseeable future or until maturity or payoff is classified as held for sale at the time of origination, purchase or securitization, or when such decision is made. Unrealized losses on such loans are recorded as a valuation allowance and included in income.
Loans Receivable and Loan Commitments	Loans Receivable and Loan Commitments Loans receivable include loans originated by the Bank as well as loans acquired in business combinations. Loans acquired in a business combination are designated as “purchased” loans. These loans are recorded at their fair value at acquisition date, factoring in credit losses expected to be incurred over the life of the loan. Accordingly, an allowance for loan losses is not carried over or recorded as of the acquisition date. Loans purchased with evidence of credit deterioration since origination for which it is probable that all contractually required payments will not be collected are accounted for under FASB ASC 310-30, Loans and Debt Securities Acquired with Deteriorated Credit Quality . These loans are identified as purchased credit impaired ("PCI") loans. In situations where such loans have similar risk characteristics, loans may be aggregated into pools to estimate cash flows. A pool is accounted for as a single asset with a single interest rate, cumulative loss rate and cash flow expectation. Expected cash flows at the acquisition date in excess of the fair value of loan or pool are considered to be accretable yield, which is recognized as interest income over the life of the loan or pool using a level yield method if the timing and amount of the future cash flows of the loan or pool is reasonably estimable. The cash flows expected over the life of the PCI loan or pool are estimated quarterly using an external cash flow model that projects cash flows and calculates the carrying values of the loans or pools, book yields, effective interest income and impairment, if any, based on loan or pool level events. Assumptions as to default rates, loss severity and prepayment speeds are utilized to calculate the expected cash flows. To the extent actual or projected cash flows are less than previously estimated, additional provisions for loan losses on the purchased loan portfolios will be recognized immediately into earnings. To the extent actual or projected cash flows are more than previously estimated, the increase in cash flows is recognized immediately as a recapture of provision for loan losses up to the amount of any provision previously recognized for that loan or pool, if any, then prospectively recognized in interest income as a yield adjustment. Any disposals of a loan in a pool, including sale of a loan, payment in full or foreclosure results in the removal of the loan from the loan pool at the carrying amount. Loans accounted for under FASB ASC 310-30 are generally considered accruing and performing loans as the loans accrete interest income over the estimated life of the loan when cash flows are reasonably estimable. Accordingly, PCI loans that are contractually past due are still considered to be accruing and performing loans. If the timing and amount of cash flows is not reasonably estimable, the loans may be classified as nonaccrual loans and interest income may be recognized on a cash basis or all cash payments may be accounted for a as a reduction of the principal amount outstanding. Loans purchased that are not accounted for under FASB ASC 310-30 are accounted for under FASB ASC 310-20, Receivables—Nonrefundable fees and Other Costs . These loans are identified as non-PCI loans, and are initially recorded at their fair value, which is estimated using an external cash flow model and assumptions similar to the FASB ASC 310-30 loans. The difference between the estimated fair value and the unpaid principal balance at acquisition date is recognized as interest income over the life of the loan using an effective interest method for non-revolving credits or a straight-line method, which approximates the effective interest method, for revolving credits. Any unrecognized discount for a loan that is subsequently repaid in full will be recognized immediately into income. Loans are generally recorded at the unpaid principal balance, net of premiums, unearned discounts and net deferred loan origination fees and costs. The premiums and unearned discounts may include values determined in purchase accounting. Interest on loans is calculated using the simple interest method based on the daily balance of the principal amount outstanding and is credited to income as earned. Loans are considered past due or delinquent when principal or interest payments are past due 30 days or more. The Company's policies for determining past due or delinquency status, placing loans on nonaccrual status, recording payments received on nonaccrual loans, resuming accrual of interest, and charging off uncollectible loans generally do not differ by loan segments or classes. Any differences are denoted in the applicable sections below. Delinquent Loans : Commercial loans are serviced by the relationship manger assigned to the account. System generated delinquency reports are provided to all relationship managers monthly, and relationship managers take follow up action as needed, including contacting the borrower and transferring seriously delinquent loans to the Bank’s Special Assets Department for collection. Consumer loans are monitored by the Bank’s Consumer Collections Department, with initial delinquency notices sent after 15 days, with follow up notices at 30 and 45 days. The Consumer Collections Department attempts to make direct contact with the borrower to establish a plan to bring the loan current. Consumer loans that become 90 days delinquent are charged off. Nonaccrual and Charged-off Loans : Loans on which the accrual of interest has been discontinued are designated as nonaccrual loans. Delinquent loans may remain on accrual status between 30 days and 89 days past due. The accrual of interest is generally discontinued at the time the loan is 90 days delinquent unless the credit is well secured and in the process of collection. Loans are placed on nonaccrual at an earlier date if collection of the contractual principal or interest is doubtful. All interest accrued but not collected on loans deemed nonaccrual during the period is reversed against interest income in that period. The interest payments received on nonaccrual loans are generally accounted for on the cost-recovery method whereby the interest payment is applied to the principal balances. Loans may be returned to accrual status when improvements in credit quality eliminate the doubt as to the full collectability of both interest and principal and a period of sustained performance has occurred. Substantially all loans that are nonaccrual are also considered impaired. Income recognition on impaired loans conforms to that used on nonaccrual loans. Loans are generally charged-off if collection of the contractual principal or interest as scheduled in the loan agreement is doubtful. Credit card loans and other consumer loans are typically charged-off no later than 180 days past due. Impaired Loans : The Bank routinely tests its classified loans for potential impairment. Classified loans that may be impaired are identified using the Bank's normal loan review procedures, which include post-approval reviews, quarterly reviews by credit administration of criticized loan reports, scheduled internal reviews, underwriting during extensions and renewals, and the analysis of information routinely received on a borrower’s financial performance. A loan is considered impaired when, based on current information and events, it is probable the Bank will be unable to collect the scheduled payments of principal or interest when due according to the original contractual terms of the loan agreement. Factors considered by management in determining impairment include payment status, collateral value, and the probability of collecting scheduled principal and interest payments when due. Loans that experience insignificant payment delays and payment shortfalls generally are not classified as impaired. Management determines the significance of payment delays and payment shortfalls on a case-by-case basis, taking into consideration all of the circumstances surrounding the loan and the borrowers, including length of the delay, the reasons for the delay, the borrower’s prior payment record, and the amounts of the shortfall in relation to the principal and interest owed. Impairment is measured on a loan-by-loan basis by either the present value of expected future cash flows discounted at the loan’s effective interest rate, or as a practical expedient the loan’s observable market price or the fair value of the collateral (less cost to sell) if the loan is collateral dependent. Income recognition on impaired loans conforms to that used on nonaccrual loans. Subsequent to an initial measure of impairment and based on new information received, if there is a significant change in the amount or timing of a loan’s expected future cash flows or a change in the value of collateral or market price of a loan, the impairment is recalculated. However, the net carrying value of a loan never exceeds the recorded investment in the loan. Troubled Debt Restructures : A troubled debt restructured loan (“TDR”) is a restructuring in which the Bank, for economic or legal reasons related to a borrower’s financial difficulties, grants a concession to a borrower that it would not otherwise consider. These concessions may include changes of the interest rate, forbearance of the outstanding principal or accrued interest, extension of the maturity date, delay in the timing of the regular payment, or any other actions intended to minimize potential losses. The Bank does not forgive principal for a majority of its TDRs, but in those situations where principal is forgiven, the entire amount of such principal forgiveness is immediately charged off to the extent not done so prior to the modification. The Bank also considers insignificant delays in payments when determining if a loan should be classified as a TDR. The Company has implemented more stringent definitions of concessions and impairment measures for PCI loans which are not in pools as these loans have known credit deteriorations and are generally accreting income at a lower discounted rate as compared to the contractual note rate based on the guidance of FASB ASC 310-30. Modifications of PCI loans which are not in pools are considered TDRs if they result in a decrease in expected cash flows when compared to the pre-modification expected cash flows, without any other changes to the agreement to consider. A loan that has been placed on nonaccrual status that is subsequently restructured will usually remain on nonaccrual status until the borrower is able to demonstrate repayment performance in compliance with the restructured terms for a sustained period, typically for six months. A restructured loan may return to accrual status sooner based on other significant events or mitigating circumstances. A loan that has not been placed on nonaccrual status may be restructured and such loan may remain on accrual status after such restructuring. In these circumstances, the borrower has made payments before the restructuring and is expected to continue to perform after the restructuring. Generally, this type of restructuring involves a reduction in the loan interest rate and/or a change to interest-only payments for a period of time. The restructured loan is considered impaired despite the accrual status and a specific valuation allowance, if any, is calculated in the manner previously described. A TDR is considered defaulted if, during the 12-month period after the restructure, the loan has not performed in accordance to the restructured terms. Defaults include loans whose payments are 90 days or more past due and loans whose revised maturity date passed and no further modifications will be granted for that borrower. A loan may subsequently be excluded from the TDR disclosures if: (i) the restructured interest rate was greater than or equal to the interest rate of a new loan with comparable risk at the time of the restructure, and (ii) the loan is no longer impaired based on the terms of the restructured agreement. The Bank's policy is that the borrower must demonstrate a sustained period, typically six consecutive months, of payments in accordance with the modified loan before it can be reviewed for removal from the TDR disclosure under the second criteria. However, the loan must be reported as a TDR in at least one annual report on Form 10-K. Once a loan has been classified as a TDR, it will continue to be disclosed as an impaired loan until paid off or charged-off, even if the loan subsequently is no longer disclosed as a TDR. Unfunded Loan Commitments : Unfunded loan commitments are generally related to the unused portion of the total commitment of a loan or providing credit facilities to clients of the Bank and are not actively traded financial instruments. These unfunded commitments are disclosed as financial instruments with off-balance sheet risk in Note (14) Commitments and Contingencies and Note (18) Fair Value Measurements in the Notes to Consolidated Financial Statements.
Loan Fees and Costs	Loan Fees and Costs Loan origination fees and certain direct origination costs are deferred and amortized as an adjustment of the yields of the loans over their contractual lives, adjusted for prepayment of the loans, using the effective interest method or the straight-line method, which approximates the effective interest method. In the event loans are sold, the unamortized net deferred loan origination fees or costs are recognized as a component of the gain or loss on the sale of loans.
Allowance for Loan Losses	Allowance for Loan Losses Allowance for Loan Losses : The allowance for loan losses is a reserve established through a provision for loan losses charged to expense, which represents management’s best estimate of probable losses that have been incurred within the existing portfolio of loans. Loan losses are charged against the allowance when management believes the uncollectibility of a loan balance is confirmed. Subsequent recoveries, if any, are credited to the allowance. The allowance for loan losses on loans designated as non-PCI loans is similar to the methodology described below except that for non-PCI loans, the remaining unaccreted discounts resulting from the fair value adjustments recorded at the time the loans were purchased are additionally factored into the allowance methodology. The allowance for loan losses on PCI loans is described in the “Allowance for Loan Losses on Purchased Credit Impaired Loans” section below. The allowance, in the judgment of management, is necessary to reserve for estimated loan losses from risks inherent in the loan portfolio. The Company’s allowance for loan losses methodology includes allowance allocations calculated in accordance with FASB ASC 310, Receivables and allowance allocations calculated in accordance with FASB ASC 450, Contingencies . Accordingly, the methodology is based on historical loss experience by type of credit, specific homogeneous risk pools and specific loss allocations, with adjustments for current events and conditions. The Company’s process for determining the appropriate level of the allowance for loan losses is designed to account for credit deterioration as it occurs. The provision for loan losses reflects loan quality trends, including the levels of and trends related to nonaccrual loans, past due loans, classified loans and net charge-offs or recoveries, among other factors. The provision for loan losses also reflects all actions taken on all loans for a particular period. Therefore, the amount of the provision reflects not only the necessary increases in the allowance for loan losses related to newly identified criticized loans, but it also reflects actions taken related to other loans including, among other things, any necessary increases or decreases in specific valuation allowances for impaired loans or loan pools. The level of the allowance reflects management’s continuing evaluation of known and inherent risks in the loan portfolio. Portions of the allowance may be allocated for specific credits; however, the entire allowance is available for any credit that, in management’s judgment, could be charged off. Loans which management determines are impaired are individually evaluated for impairment, and specific valuation allowances are recorded, if any, on these loans based on the methodology previously described. Loans that are determined not to meet management's definition of impaired are collectively evaluated for impairment based on (i) historical loss factors determined in accordance with FASB ASC 450 based on historical loan loss experience for similar loans with similar characteristics and trends; and (ii) environmental loss factors that reflect the impact of current conditions, as determined in accordance with FASB ASC 450 based on general economic conditions and other qualitative risk factors both internal and external to the Company. The historical loss factors and environmental loss factors are combined and multiplied against the unguaranteed outstanding principal balances of loans in pools of similar loans with similar characteristics. The Company evaluates specific loans for credit quality indicators and performs regular analysis and evaluation of problem loans. Loans are classified based on an internal credit risk grading process that evaluates, among other things: (i) the obligor’s ability to repay; (ii) the underlying collateral, if any; and (iii) the economic environment and industry in which the borrower operates. This analysis is performed at the loan officer level for all loans. When a loan is performing, but has an assigned risk grade other than pass, the loan officer analyzes the loan to determine an appropriate monitoring and collection strategy. When a loan is nonperforming or has been classified as a nonaccrual loan, a member from the special assets department will analyze the loan to determine if it is impaired. If the loan is considered impaired, the special assets department will evaluate the need for a specific valuation allowance on the loan. Specific valuation allowances are determined by analyzing the borrower’s ability to repay amounts owed, collateral deficiencies and economic conditions affecting the borrower’s industry, among other things. Historical loss factors are calculated based on the historical loss experience and recovery experience of specific classes of loans. The Company calculates historical loss ratios for the classes of loans based on the proportion of actual charge-offs and recoveries experienced to the total loans in the pool for a rolling twelve-quarter average. Environmental loss factors are based on general economic conditions and other qualitative risk factors both internal and external to the Company. In general, such valuation allowances are determined by evaluating, among other things: (i) levels of and trends in delinquencies, classified and impaired loans; (ii) levels of and trends in charge-offs and recoveries; (iii) trends in volume and terms of loans (iv) effects of changes in risk selection and underwriting standards, and other changes in lending policies, procedures, and practices; (v) experience, ability, and depth of lending management and other relevant staff; (vi) national and local economic trends and conditions; (vii) other external factors such as competition, legal, and regulatory; (viii) effects of changes in credit concentrations, and (ix) other factors. Management evaluates the degree of risk that each one of these components has on the quality of the loan portfolio on a quarterly basis. Each component is determined to be on a scale of risk. The results are then utilized in a matrix to determine an appropriate environmental loss factor for each class of loan. The allowance for loan losses evaluation is inherently subjective, as it requires estimates that are susceptible to significant revision as more information becomes available. While management utilizes its best judgment and information available to recognize losses on loans, future additions to the allowance may be necessary based on declines in local and national economic conditions. In addition, various regulatory agencies, as an integral part of their examination process, periodically review the Bank’s allowance for loan losses. Such agencies may require the Bank to make adjustments to the allowance based on their judgments about information available to them at the time of their examinations. The Company believes the allowance for loan losses is appropriate given all of the above considerations. Allowance for Loan Losses on Purchased Credit Impaired Loans: The PCI loans acquired in the Company's mergers and acquisitions are subject to the Company’s internal and external credit review. Under the accounting guidance of FASB ASC 310-30, the allowance for loan losses on PCI loans is measured at each financial reporting period, or measurement date, based on expected cash flows. If and when credit deterioration, or decreases in expected cash flows previously estimated, occurs subsequent to the acquisition date, a provision for loan losses will be charged to earnings as of the measurement date. Allowance for Losses on Unfunded Commitments: The Bank is also party to financial instruments with off-balance sheet risk in the normal course of business to meet the financing needs of its customers. These financial instruments include commitments to extend credit and standby letters of credit. Those instruments involve, to varying degrees, elements of credit risk in excess of the disbursed amounts recognized in the Consolidated Statements of Financial Condition. The Company has a policy in which it evaluates the risk on a quarterly basis, and provides for an allowance for credit losses, as necessary. The methodology is similar to the allowance for loan losses, and includes an estimate of the probability of drawdown of the loan commitment.
Mortgage Banking Operations	Mortgage Banking Operations The Bank sells one-to-four family residential loans on a servicing-released basis. The Bank recognizes a gain or loss to the extent that the sale proceeds of the loan sold differs from the net book value at the time of sale. Income from one-to-four family residential loans brokered to other lenders is recognized into income on date of loan closing. Commitments to sell one-to-four family residential loans are made primarily during the period between the taking of the loan application and the closing of the loan. The timing of making these sale commitments is dependent upon the timing of the borrower’s election to lock-in the mortgage interest rate and fees prior to loan closing. Most of these sale commitments are made on a best-efforts basis whereby the Bank is only obligated to sell the loan if the loan is approved and closed by the Bank. Commitments to fund one-to-four family residential loans (interest rate locks) to be sold into the secondary market and forward commitments for the future delivery of these loans are accounted for as free standing derivatives. Fair values of these mortgage derivatives are estimated based on changes in mortgage interest rates between the date the interest on the loan was locked and the balance sheet date. The Company enters into forward commitments for the future delivery of one-to-four family residential loans when interest rate locks are entered into, in order to hedge the interest rate risk resulting from its commitments to fund the loans. Changes in the fair values of these derivatives are included in other income.
Other Real Estate Owned	Other Real Estate Owned Other real estate acquired by the Company in partial or full satisfaction of a loan obligation is classified as held for sale. When acquired, the property is recorded at the estimated fair value (less the costs to sell) at the date of acquisition, not to exceed net realizable value, and any resulting write-down is charged to the allowance for loan losses. Physical possession of residential real estate property collateralizing a consumer mortgage loan occurs when legal title is obtained upon completion of foreclosure or when the borrower conveys all interest in the properly to satisfy the loan through completion of a deed in lieu of foreclosure or through a similar legal agreement. After acquisition, all costs incurred in maintaining the property are expensed except for costs relating to the development and improvement of the property which are capitalized to the extent of the property’s net realizable value. If the estimated realizable value of the other real estate owned property declines after the acquisition date, the valuation adjustment is charged to other real estate owned expense, net on the Consolidated Statements of Income.
Premises and Equipment	Premises and Equipment Premises and equipment, including leasehold improvements, are stated at cost less accumulated depreciation. Depreciation is computed using the straight-line method over the estimated useful lives of the assets or the lease period, whichever is shorter. The estimated useful lives used to compute depreciation and amortization for buildings and building improvements is 15 to 39 years; and for furniture, fixtures and equipment is three to seven years. The Company reviews buildings, leasehold improvements and equipment for impairment whenever events or changes in the circumstances indicate that the undiscounted cash flows for the property are less than its carrying value. If identified, an impairment loss is recognized through a charge to earnings based on the fair value of the property.
Bank Owned Life Insurance	Bank Owned Life Insurance The Company's bank owned life insurance (“BOLI”) policies insure the lives of certain current or former Bank officers, and name the Bank as beneficiary. Noninterest income is generated tax-free (subject to certain limitations) from the increase in the policies' underlying investments made by the insurance company. The Bank utilizes BOLI to partially offset costs associated with employee compensation and benefit programs with the earnings on the BOLI. The Company records BOLI at the amount that can be realized under the insurance contract at the statement of financial condition date, which is the cash surrender value adjusted for other charges or other amounts due that are probable at settlement.
Other Intangible Assets	Other Intangible Assets The other intangible assets represents the Core Deposit Intangible (“CDI”) acquired in business combinations. The fair value of the CDI stemming from any given business combination is based on the present value of the expected cost savings attributable to the core deposit funding, relative to an alternative source of funding. The CDI is amortized over an estimated useful life which approximates the existing deposit relationships acquired on an accelerated method. The Company evaluates such identifiable intangibles for impairment annually, or more frequently if an indication of impairment exists.
Goodwill	Goodwill The Company’s goodwill represents the excess of the purchase price over the fair value of net assets acquired in certain mergers and acquisitions. Goodwill is assigned to Heritage Bank and is evaluated for impairment at the Bank level (reporting unit) on an annual basis, or more frequently if an indication of impairment exists between the annual tests. Factors to consider may include, among others: a significant change in legal factors or in the general business climate; significant change in the Company’s stock price and market capitalization; unanticipated competition; and an action or assessment by a regulator. For the goodwill impairment assessment, the Company has the option, prior to the two-step process, to first assess qualitative factors to determine whether the existence of events or circumstances leads to a determination that it is more-likely-than-not that the fair value of a reporting unit is less than its carrying value. The Company opted to bypass the qualitative assessment for its 2018 and 2017 annual goodwill impairment testing and proceed directly to the two-step goodwill impairment test. The goodwill impairment two-step process requires the Company to make assumptions and judgments regarding fair value. The first step of the goodwill impairment test is performed by comparing the reporting unit’s aggregate fair value to its carrying value. Absent other indicators of impairment, if the aggregate fair value exceeds the carrying value, goodwill is not considered impaired and no additional analysis is necessary. If the carrying value of the reporting unit were to exceed the aggregate fair value, a second step would be performed to measure the amount of impairment loss, if any. To measure any impairment loss the implied fair value would be determined in the same manner as if the reporting unit were being acquired in a business combination. If the implied fair value of goodwill is less than the recorded goodwill, an impairment charge would be recorded for the difference.
Income Taxes	Income Taxes The Company and the Bank file a United States consolidated federal income tax return and an Oregon State income tax return. Income tax expense is the total of the current year income tax due or refundable and the change in deferred tax assets and liabilities. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the consolidated financial statement carrying amounts of existing assets and liabilities and their respective tax bases. Deferred tax assets and liabilities are measured using enacted tax rates applicable to taxable income in the periods in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rate is recognized in income in the period that includes the enactment date. A valuation allowance, if needed, reduces deferred tax assets to the amounts expected to be realized. A tax position is recognized as a benefit only if it is “more likely than not” that the tax position would be sustained in a tax examination, with a tax examination being presumed to occur. The amount recognized is the largest amount of tax benefit that is greater than 50% likely of being realized on examination. For tax positions not meeting the “more likely than not” test, no tax benefit is recorded. The Company’s policy is to recognize interest and penalties on unrecognized tax benefits in “income taxes” in the Consolidated Statements of Income as the amounts are generally insignificant each year.
Stock-Based Compensation and Deferred Compensation Plans	Stock-Based Compensation The Company maintains a number of stock-based incentive programs, which are discussed in more detail in Note (19) Stock-Based Compensation . Compensation cost is recognized for stock options, restricted stock awards and restricted stock units issued to employees and directors based on the fair value of these awards at the date of grant. Compensation cost is generally recognized over the requisite service period, generally defined as the vesting period, on a straight-line basis. Compensation cost for restricted stock units with market-based vesting is recognized over the service period to the extent the restricted stock units are expected to vest. Forfeitures are recognized as they occur. The market price of the Company’s common stock at the date of grant is used to determine the fair value of the restricted stock awards and restricted stock units. The fair value of stock options granted is estimated based on the date of grant using the Black-Scholes-Merton option pricing model. Certain restricted stock unit grants are subject to performance-based vesting as well as other approved vesting conditions and cliff-vest based on those conditions, and the fair value is estimated using a Monte Carlo simulation pricing model. The assumptions used in the Black-Scholes-Merton option pricing model and the Monte Carlo simulation pricing model include the expected term based on the valuation date and the remaining contractual term of the award; the risk-free interest rate based on the U.S. Treasury curve at the valuation date of the award; the expected dividend yield based on expected dividends being payable to the holders; and the expected stock price volatility over the expected term based on the historical volatility over the equivalent historical term. Deferred Compensation Plans The Company has a Deferred Compensation Plan and has entered into arrangements with certain executive officers. Under the Deferred Compensation Plan, participants are permitted to elect to defer compensation and the Company has the discretion to make additional contributions to the Deferred Compensation Plan on behalf of any participant based on a number of factors. Such discretionary contributions are generally approved by the Compensation Committee of the Company's Board of Directors. The notional account balances of participants under the Deferred Compensation Plan earn interest on an annual basis. The applicable interest rate is the Moody’s Seasoned Aaa Corporate Bond Yield as of January 1 of each year. Generally, a participant’s account is payable upon the earliest of the participant’s separation from service with the Company, the participant’s death or disability, or a specified date that is elected by the participant in accordance with applicable rules of the Internal Revenue Code. Additionally, in conjunction with the Premier Merger, the Company assumed the Salary Continuation Plan. The Salary Continuation Plan is an unfunded non-qualified deferred compensation plan for select former Premier Commercial executive officers, some of which are current Heritage officers. Under the Salary Continuation Plan, the Company will pay each participant, or their beneficiary, specified amounts over specified periods beginning with the individual's termination of service due to retirement subject to early termination provisions. The Company’s obligation to make payments under the Deferred Compensation Plan and the Salary Continuation Plan is a general obligation of the Company and is to be paid from the Company’s general assets. As such, participants are general unsecured creditors of the Company with respect to their participation under both plans. The Company records a liability within accrued expenses and other liabilities on the Consolidated Statements of Financial Condition and records compensation expense in a systematic and rational manner. Since the amounts earned under the Deferred Compensation Plan are generally based on the Company’s annual performance, the Company records deferred compensation expense each year for an amount calculated based on that year’s financial performance.
Earnings per Share	Earnings per Share The two-class method is used in the calculation of basic and diluted earnings per common share. Basic earnings per common share is net income allocated to common shareholders divided by the weighted average number of common shares outstanding during the period. All outstanding unvested share-based payment awards that contain rights to nonforfeitable dividends are considered participating securities for this calculation. Dividends and undistributed earnings allocated to participating securities are excluded from net income allocated to common shareholders and participating securities are excluded from weighted average common shares outstanding. Diluted earnings per common share is calculated using the treasury stock method and includes the dilutive effect of additional potential common shares issuable under stock options. Earnings and dividends per share are restated for all stock splits and stock dividends through the date of issuance of the financial statements.
Derivative Financial Instruments	Derivative Financial Instruments The commitments to originate mortgage loans held for sale and the related forward delivery contracts are considered derivatives. The Company also utilizes interest rate swap derivative contracts to facilitate the needs of its commercial customers whereby it enters into an interest rate swap with a customer while at the same time entering into an offsetting interest rate swap with another financial institution. In connection with each swap transaction, the Company agrees to pay interest to the customer on a notional amount at a variable interest rate and receive interest from the customer on a similar notional amount at a fixed interest rate. At the same time, the Company agrees to pay another financial institution the same fixed interest rate on the same notional amount and receive the same variable interest rate on the same notional amount. The transaction allows the Company’s customer to effectively convert a variable rate loan to a fixed rate. Because the Company acts as an intermediary for its customer, changes in the fair value of the underlying derivative contracts for the most part offset each other and do not significantly impact the Company’s results of operations. These interest rate swaps are not designated as hedging instruments. The fair value of derivative positions outstanding is included in prepaid expenses and other assets and accrued expenses and other liabilities in the Company's Consolidated Statements of Financial Condition and the net change in each of these financial statement line items is included in the Consolidated Statements of Cash Flows. For non-hedging derivative instruments, gains and losses due to changes in fair value and all cash flows are included in other noninterest income in the Company's Consolidated Statements of Income, but net to zero for the years ended December 31, 2018 and 2017 based on the identical back-to-back interest rate swaps.
Operating Segments	Operating Segments While the Company’s chief decision-makers monitor the revenue streams of the various products and services, operations are managed and financial performance is evaluated on a Company-wide basis. Operating segments are aggregated into one as operating results for all segments are similar. Accordingly, all of the financial service operations are considered by management to be aggregated in one reportable operating segment.
Revenue from Contract with Customers	Revenue from Contracts with Customers The Company's revenues are primarily composed of interest income on financial instruments, such as loans and investment securities, which are excluded from the scope of ASC 606. Descriptions of the Company's revenue-generating activities that are within the scope ASC 606, which are presented in Service Charges and Other Fees and Other Income on the Company’s Consolidated Statement of Income, are as follows: • Service Charges on Deposit Accounts: The Company earns fees from its deposit customers from a variety of deposit products and services. Non-transaction based fees such as account maintenance fees and monthly statement fees are considered to be provided to the customer under a day-to-day contract with ongoing renewals. Revenues for these non-transaction fees are earned over the course of a month, representing the period over which the Company satisfies the performance obligation. Transaction-based fees such as non-sufficient fund charges, stop payment charges and wire fees are recognized at the time the transaction is executed as the contract duration does not extend beyond the service performed. • Wealth Management and Trust Services: The Company earns fees from contracts with customers for fiduciary and brokerage activities. Revenues are generally recognized on a monthly basis and are generally based on a percentage of the customer’s assets under management or based on investment or insurance solutions that are implemented for the customer. • Merchant Processing Services and Debit and Credit Card Fees: The Company earns fees from cardholder transactions conducted through third party payment network providers which consist of (i) interchange fees earned from the payment network as a debit card issuer, (ii) referral fee income, and (iii) ongoing merchant fees earned for referring customers to the payment processing provider. These fees are recognized when the transaction occurs, but may settle on a daily or monthly basis.
Recently Issued Accounting Pronouncements	Recently Issued Accounting Pronouncements FASB ASU 2014-09 , Revenue from Contracts with Customers , (as amended by FASB ASU 2015-14; FASB ASU 2016-08; FASB ASU 2016-10 and FASB ASU 2016-12), was issued in May 2014. Under this Accounting Standard Update ("ASU" or "Update"), the Financial Accounting Standards Board ("FASB") created a new Topic 606 which is in response to a joint initiative of FASB and the International Accounting Standards Board to clarify the principles for recognizing revenue and to develop a common revenue standard for U.S. GAAP and international financial reporting standards that would: • Remove inconsistencies and weaknesses in revenue requirements. • Provide a more robust framework for addressing revenue issues. • Improve comparability of revenue recognition practices across entities, industries, jurisdictions and capital markets. • Provide more useful information to users of financial statements through improved disclosure requirements. • Simplify the preparation of financial statements by reducing the number of requirements to which an entity must refer. The Company adopted the revenue recognition guidance, as amended, on January 1, 2018 using the modified retrospective approach. A significant amount of the Company’s revenues are derived from interest income on financial assets, which are excluded from the scope of the amended guidance. With respect to noninterest income and related disclosures, the Company has identified and evaluated the revenue streams and underlying revenue contracts within the scope of the guidance. The Company did not identify any significant changes in the timing of revenue recognition when considering the amended accounting guidance. The adoption of the Update did not have a material impact on the Company's Consolidated Financial Statements, but the adoption did change certain disclosure requirements as described in Significant Accounting Policies above. FASB ASU 2016-01 , Recognition and Measurement of Financial Assets and Financial Liabilities (Subtopic 825-10) , was issued in January 2016, to enhance the reporting model for financial instruments to provide users of financial statements with more decision-useful information. This Update contains several provisions, including but not limited to (1) requiring equity investments, with certain exceptions, to be measured at fair value with changes in fair value recognized in net income; (2) simplifying the impairment assessment of equity investments without readily determinable fair values by requiring a qualitative assessment to identify impairment; (3) eliminating the requirement to disclose the method(s) and significant assumptions used to estimate fair value; and (4) requiring separate presentation of financial assets and liabilities by measurement category and form of financial asset on the balance sheet or the accompanying notes to the financial statements. The Update also changes certain financial statement disclosure requirements, including requiring disclosures of the fair value of financial instruments be made on the basis of exit price. The Company adopted this Update effective January 1, 2018 using the cumulative catch-up transition method. This change resulted in a cumulative adjustment of $93,000 from accumulated other comprehensive loss, net to retained earnings for the unrealized gain related to the Company's equity security. The Company's processes and procedures utilized to estimate the fair value of loans receivable and certificate of deposit accounts for disclosure requirements were additionally changed due to adoption of this Update. Previously, the Company valued these items using an entry price notion. This ASU emphasized that these instruments be measured using the exit price notion; accordingly, the Company refined its calculation as part of adopting this Update. Prior period information has not been updated to conform with the new guidance. See the Consolidated Statements of Stockholders' Equity and Note (18) Fair Value Measurements . FASB ASU 2016-02 , Leases (Topic 842), as amended by ASU 2017-13, 2018-01, 2018-10, 2018-11 and ASU 2018-20, was originally issued in February 2016, to increase transparency and comparability of leases among organizations and to disclose key information about leasing arrangements. The Update sets out the principles for the recognition, measurement, presentation and disclosure of leases for both lessees and lessors. The Update requires lessees to apply a dual approach, classifying leases as either a finance or operating lease. This classification will determine whether the lease expense is recognized based on an effective interest method or on a straight-line basis over the term of the lease. A lessee is also required to record a right-of-use asset and a lease liability for all leases with a term greater than 12 months regardless of their classification. All cash payments will be classified within operating activities in the statement of cash flows. In transition, lessees and lessors are required to recognize and measure leases at the beginning of the earliest period presented using a modified retrospective approach. The Update is effective for public entities for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. During 2018, management developed its methodology to estimate the right-of use assets and lease liabilities and selected a vendor to assist with implementation and calculation of the impact under the modified retrospective approach. The Company adopted the Update on January 1, 2019 and elected an exclusion accounting policy for lease assets and lease liabilities for leases with a term of twelve months or less. The adoption of this ASU resulted in the recognition of operating lease assets and liabilities of approximately $29.3 million and $30.2 million , respectively. FASB ASU 2016-13 , Financial Instruments: Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments , as amended by ASU 2018-19, was issued in June 2016. Commonly referred to as the current expected credit loss model ("CECL"), this Update requires financial assets measured at amortized cost basis to be presented at the net amount expected to be collected. The allowance for credit losses is a valuation account that is deducted from the amortized cost basis of the financial asset to present the net carrying value at the amount expected to be collected on the financial asset. The measurement of expected credit losses is based on relevant information about past events including historical experience, current conditions and reasonable and supportable forecasts that affect the collectibility of the reported amount. The amendment affects loans, debt securities, trade receivables, net investments in leases, off-balance-sheet credit exposures, reinsurance receivables and any other financial asset not excluded from the scope that have the contractual right to receive cash. The Update replaces the incurred loss impairment methodology, which generally only considered past events and current conditions, with a methodology that reflects the expected credit losses and required consideration of a broader range of reasonable and supportable information to estimate all expected credit losses. The Update additionally addresses purchased assets and introduces the purchased financial asset with a more-than-insignificant amount of credit deterioration since origination ("PCD"). The accounting for these PCD assets is similar to the existing accounting guidance of FASB ASC 310-30, Loans and Debt Securities Acquired with Deteriorated Credit Quality , for PCI assets, except the subsequent improvements in estimated cash flows will be immediately recognized into income, similar to the immediate recognition of subsequent deteriorations in cash flows. Current guidance only allows for the prospective recognition of these cash flow improvements. Because the terminology has been changed to a "more-than-insignificant" amount of credit deterioration, the presumption is that more assets might qualify for this accounting under the Update than those under current guidance. For public business entities, the Update is effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years with early adoption permitted for fiscal years after December 15, 2018. An entity will apply the Update through a cumulative-effect adjustment to retained earnings as of the beginning of the first reporting period in which the guidance is adopted. A prospective transition approach is required for debt securities. An entity that has previously applied the guidance of FASB ASC 310-30 will prospectively apply the guidance in this Update for PCD assets. A prospective transition approach should be used for PCD assets where upon adoption, the amortized cost basis should be adjusted to reflect the addition of the allowance for credit losses. The Company is anticipating adopting the Update on January 1, 2020. Upon adoption, the Company expects a change in the processes, internal controls and procedures to calculate the allowance for loan losses, including changes in assumptions and estimates to consider expected credit losses over the life of the loan versus the current accounting practice that utilizes the incurred loss model. The new guidance may result in an increase in the allowance for loan losses which will also reflect the new requirement to include the nonaccretable principal differences on PCI loans; however, the Company is still in the process of determining the magnitude of the increase and its impact on the Consolidated Financial Statements. In addition, the current accounting policy and procedures for other-than-temporary impairment on investment securities available for sale will be replaced with an allowance approach. During 2017, the Company's management created a CECL steering committee to ensure it is fully compliant with the amendments at the adoption date. During 2018, the CECL steering committee selected a vendor to assist the Company in the adoption, completed the implementation discovery sessions, and selected appropriate methodologies. The CECL steering committee is in the process of refining key data to process through its CECL models and developing formal CECL processes and procedures. The Company anticipates running parallel existing ALLL and CECL models by second quarter 2019. FASB ASU 2016-15 , Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments , was issued in August 2016. The Update addresses eight specific cash flow issues with the objective of reducing the existing diversity in practice. For public business entities, the guidance was effective for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years, and must be applied using a retrospective transitional method to each period presented. The Company adopted this Update on January 1, 2018. The adoption did not have a significant impact on its Consolidated Financial Statements as cash proceeds received from the settlement of bank-owned life insurance policies and cash payments for premiums on bank-owned life insurance policies were previously classified as cash inflows and outflows, respectively, from investing activities in the Consolidated Statements of Cash Flows. FASB ASU 2017-04 , Goodwill (Topic 350) , was issued in January 2017 and eliminates Step 2 from the goodwill impairment test. Under the amendments, an entity should perform its goodwill impairment test by comparing the fair value of a reporting unit with its carrying amount. An entity should recognize an impairment charge for the amount by which the carrying amount exceeds the reporting unit’s fair value. The loss recognized, however, should not exceed the total amount of goodwill allocated to that reporting unit. Additionally, an entity should consider income tax effects from any tax deductible goodwill on the carrying amount of the reporting unit when measuring the goodwill impairment loss, if applicable. The Update is effective for annual periods or any interim goodwill impairment tests beginning after December 15, 2019 using a prospective transition method and early adoption is permitted. The Company does not expect the Update will have a material impact on its Consolidated Financial Statements. FASB ASU 2017-08 , Receivables—Nonrefundable Fees and Other Costs (Subtopic 310-20): Premium Amortization on Purchased Callable Debt Securities was issued in March 2017 and changes the accounting for certain purchased callable debt securities held at a premium to shorten the amortization period for the premium to the earliest call date rather than to the maturity date. Accounting for purchased callable debt securities held at a discount does not change. The discount would continue to amortize to the maturity date. The Update is effective for reporting periods beginning after December 15, 2018, with early adoption permitted. The Company adopted this Update in January 2018. The adoption did not have a material impact on its Consolidated Financial Statements as the Company had been accounting for premiums as prescribed under this guidance. FASB ASU 2017-09 , Compensation—Stock Compensation (Topic 718): Scope of Modification Accounting was issued in May 2017 to provide clarity as to when to apply modification accounting when there is a change in the terms or conditions of a share-based payment award. According to this Update, an entity should account for the effects of a modification unless the fair value, vesting conditions and balance sheet classification of the award is the same after the modification as compared to the original award prior to the modification. The Update was effective for reporting periods beginning after December 15, 2017. The Company adopted the Update on January 1, 2018. The adoption did not have a material impact on its Consolidated Financial Statements because no share-based payment award was modified during the year ended December 31, 2018 . The Company will apply this Update prospectively for any subsequent modifications of share-based payment awards. FASB ASU 2018-02 , Income Statement - Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income was issued to address the income tax accounting treatment of the stranded tax effects within other comprehensive income due to the prohibition of backward tracing due to an income tax rate change that was initially recorded in other comprehensive income. This issue came about from the enactment of the Tax Cuts and Jobs Act on December 22, 2017 ("Tax Cuts and Jobs Act") that changed the Company’s income tax rate from 35% to 21%. The Update changed current accounting whereby an entity may elect to reclassify the stranded tax effect from accumulated other comprehensive income (loss) to retained earnings. The Update is effective for periods beginning after December 15, 2018 and early adoption was permitted. The Company early adopted ASU 2018-02 effective December 31, 2017 and elected a portfolio policy to reclassify the stranded tax effects of the change in the federal corporate tax rate of the net unrealized gains on its available-for-sale investment securities of $218,000 from accumulated other comprehensive loss, net to retained earnings. See the Consolidated Statements of Stockholders' Equity. FASB ASU 2018-05 , Income Taxes (Topic 740): Amendments to SEC Paragraphs Pursuant to SEC Staff Accounting Bulletin No. 118 was issued to provide guidance on the income tax accounting implications of the Tax Cuts and Jobs Act, and allows for entities to report provisional amounts for specific income tax effects of the Tax Cuts and Jobs Act for which the accounting under ASC Topic 740 was not yet complete but a reasonable estimate could be determined. A measurement period of one-year is allowed to complete the accounting effects under ASC Topic 740 and revise any previous estimates reported. Any provisional amounts or subsequent adjustments included in an entity’s financial statements during the measurement period should be included in income from continuing operations as an adjustment to tax expense in the reporting period the amounts are determined. The Company adopted this Update with the provisional adjustments as reported in the Consolidated Financial Statements on Form 10-K as of December 31, 2017. As of December 31, 2018 , the Company did not incur any adjustments to the provisional recognition. FASB ASU 2018-13 , Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement, was issued in August 2018 and modifies the disclosure requirements on fair value measurements in Topic 820. The amendments in this Update are effective for all entities for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2019. The Company does not expect the Update will have a material impact on its Consolidated Financial Statements.

Business Combinations (Tables)

Business Combinations (Tables)	12 Months Ended
	Dec. 31, 2018
Business Combinations [Abstract]
Preliminary fair value estimates of assets acquired and liabilities assumed and adjustments	The fair value estimates of the assets acquired and liabilities assumed in the Premier and Puget Mergers were as follows: Premier Merger Puget Sound Merger (In thousands) Assets Cash and cash equivalents $ 22,534 $ 25,889 Interest earning deposits 3,309 54,247 Investment securities available for sale 4,493 80,353 Loans receivable (1) 330,158 388,462 Other real estate owned 1,796 — Premises and equipment, net 3,053 732 Federal Home Loan Bank stock, at cost 1,120 623 Bank owned life insurance 10,852 6,264 Accrued interest receivable 1,006 1,448 Prepaid expenses and other assets 1,603 1,354 Other intangible assets 7,075 11,270 Total assets acquired $ 386,999 $ 570,642 Liabilities Deposits $ 318,717 $ 505,885 Federal Home Loan Bank advances 16,000 — Securities sold under agreement to repurchase 462 — Accrued expenses and other liabilities 5,935 2,504 Total liabilities acquired $ 341,114 $ 508,389 Fair value of net assets acquired $ 45,885 $ 62,253 (1) The outstanding loan balance acquired in the Premier Merger and Puget Sound Merger was $335.4 million and $392.7 million , respectively, at the acquisition date. A summary of the net assets purchased and the estimated fair value adjustments and resulting goodwill recognized from the Premier and Puget Sound Mergers are presented in the following tables. Goodwill represents the excess of the consideration transferred over the estimated fair value of the net assets acquired and liabilities assumed. Premier Merger Puget Sound Merger (In thousands) Consideration transferred $ 99,275 $ 130,773 Cost basis of net assets on merger date $ 40,629 $ 54,405 Fair value adjustments: Investment securities (135 ) (348 ) Total loans receivable, net (111 ) 1,400 Other real estate owned (1,017 ) — Premises and equipment 1,312 (121 ) Other intangible assets 7,075 9,207 Prepaid expenses and other assets (1,912 ) (2,282 ) Deposits (310 ) (62 ) Accrued expenses and other liabilities 354 54 Fair value of net assets on merger date $ 45,885 $ 62,253 Goodwill recognized from the mergers $ 53,390 $ 68,520
Summary of results of operations of acquired business	The table below presents only the significant results for the acquired businesses since the July 2, 2018 and January 16, 2018 merger dates: Premier Merger (1) Puget Sound Merger (1) Total Year ended December 31, 2018 (In thousands) Interest income: Interest and fees on loans (2) $ 10,462 $ 21,898 $ 32,360 Interest income: Interest and fees on investments (3) 76 59 135 Interest income: Other interest earning assets 174 113 287 Interest expense (445 ) (682 ) (1,127 ) Provision for loan losses for loans (700 ) (850 ) (1,550 ) Noninterest income 125 472 597 Noninterest expense (4) (7,558 ) (11,230 ) (18,788 ) Net effect, pre-tax $ 2,134 $ 9,780 $ 11,914 (1) The Premier Merger was completed on July 2, 2018. The Puget Sound Merger was completed on January 16, 2018. (2) Includes the accretion of the discount on the purchased loans of $4.1 million during the year ended December 31, 2018 . (3) All securities acquired in the Puget Sound Merger were sold with trade date of January 16, 2018 and settlement dates on or before February 14, 2018. (4) Excludes certain compensation and employee benefits for management as it is impracticable to determine due to the integration of the operations for this merger. Also includes certain acquisition-related costs incurred by the Company.
Unaudited pro forma information	The following table presents certain pro forma information, for illustrative purposes only, for the years ended December 31, 2018 and 2017 as if the Premier and Puget Mergers had occurred on January 1, 2017. The estimated pro forma information combines the historical results of Premier Commercial and Puget Sound with the Company's consolidated historical results and includes certain adjustments reflecting the estimated impact of certain fair value adjustments for the respective periods. The pro forma information is not indicative of what would have occurred had the Premier and Puget Mergers occurred on January 1, 2017. In particular, the pro forma information does not consider any changes to the provision for loan losses resulting from recorded loans at fair value. Additionally, Heritage expects to achieve further operating savings and other business synergies, including interest income growth, as a result of the Premier and Puget Mergers which are not reflected in the pro forma amounts in the following table. As a result, actual amounts will differ from the pro forma information presented. Pro Forma for the Year Ended December 31, 2018 2017 (Dollars in thousands, except per share amounts) Net interest income $ 194,989 $ 174,190 Net income 69,515 41,551 Basic earnings per common share $ 1.88 $ 1.12 Dilutive Earnings per common share $ 1.87 $ 1.12

Investment Securities (Tables)

Investment Securities (Tables)	12 Months Ended
	Dec. 31, 2018
Investments, Debt and Equity Securities [Abstract]
Reconciliation of available for sale securities	The amortized cost, gross unrealized gains, gross unrealized losses and fair values of investment securities available for sale at the dates indicated were as follows: Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value (In thousands) December 31, 2018 U.S. Treasury and U.S. Government-sponsored agencies $ 101,595 $ 155 $ (147 ) $ 101,603 Municipal securities 158,461 1,209 (806 ) 158,864 Mortgage-backed securities and collateralized mortgage obligations (1) : Residential 337,295 426 (6,119 ) 331,602 Commercial 338,250 1,035 (5,524 ) 333,761 Corporate obligations 25,662 36 (135 ) 25,563 Other asset-backed securities 24,278 424 — 24,702 Total $ 985,541 $ 3,285 $ (12,731 ) $ 976,095 December 31, 2017 U.S. Treasury and U.S. Government-sponsored agencies $ 13,460 $ 6 $ (24 ) $ 13,442 Municipal securities 247,358 3,720 (1,063 ) 250,015 Mortgage-backed securities and collateralized mortgage obligations (1) : Residential 282,724 422 (2,935 ) 280,211 Commercial 219,696 444 (3,061 ) 217,079 Collateralized loan obligations 4,561 19 — 4,580 Corporate obligations 16,594 220 (44 ) 16,770 Other securities (2) 27,781 652 — 28,433 Total $ 812,174 $ 5,483 $ (7,127 ) $ 810,530 (1) Issued and guaranteed by U.S. Government-sponsored agencies. (2) Primarily asset-backed securities.
Schedule of securities available for sale	The amortized cost and fair value of investment securities available for sale at December 31, 2018 , by contractual maturity, are set forth below. Actual maturities may differ from contractual maturities because certain borrowers have the right to call or prepay obligations with or without call or prepayment penalties. Amortized Cost Fair Value (In thousands) Due in one year or less $ 38,547 $ 38,478 Due after one year through five years 193,191 192,556 Due after five years through ten years 272,408 268,779 Due after ten years 481,395 476,282 Total $ 985,541 $ 976,095
Schedule of fair value and unrealized losses of available for sale investment securities	The following table shows the gross unrealized losses and fair value of the Company's investment securities available for sale that are not deemed to be other-than-temporarily impaired, aggregated by investment category and length of time that the individual securities have been in continuous unrealized loss positions as of December 31, 2018 and December 31, 2017 : Less than 12 Months 12 Months or Longer Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses (In thousands) December 31, 2018 U.S. Treasury and U.S. Government-sponsored agencies $ 46,992 $ (58 ) $ 7,350 $ (89 ) $ 54,342 $ (147 ) Municipal securities 31,157 (159 ) 38,792 (647 ) 69,949 (806 ) Mortgage-backed securities and collateralized mortgage obligations (1) : Residential 66,620 (247 ) 193,726 (5,872 ) 260,346 (6,119 ) Commercial 43,531 (272 ) 190,585 (5,252 ) 234,116 (5,524 ) Corporate obligations 13,736 (87 ) 1,951 (48 ) 15,687 (135 ) Total $ 202,036 $ (823 ) $ 432,404 $ (11,908 ) $ 634,440 $ (12,731 ) December 31, 2017 U.S. Treasury and U.S. Government-sponsored agencies $ 11,436 $ (24 ) $ — $ — $ 11,436 $ (24 ) Municipal securities 39,298 (384 ) 26,509 (679 ) 65,807 (1,063 ) Mortgage-backed securities and collateralized mortgage obligations (1) : Residential 175,847 (1,296 ) 66,380 (1,639 ) 242,227 (2,935 ) Commercial 75,121 (700 ) 90,822 (2,361 ) 165,943 (3,061 ) Corporate obligations 3,472 (44 ) — — 3,472 (44 ) Total $ 305,174 $ (2,448 ) $ 183,711 $ (4,679 ) $ 488,885 $ (7,127 ) (1) Issued and guaranteed by U.S. Government-sponsored agencies.
Gross realized gains and losses on sale of securities available for sale	he following table presents the gross realized gains and losses on the sale of securities available for sale for the years ended December 31, 2018 , 2017 and 2016 : Year ended December 31, 2018 2017 2016 (In thousands) Gross realized gains $ 273 $ 193 $ 1,518 Gross realized losses (136 ) (187 ) (203 ) Net realized gains $ 137 $ 6 $ 1,315
Scheduled of amortized cost and fair value of securities pledged as collateral	The following table summarizes the amortized cost and fair value of investment securities available for sale that are pledged as collateral for the following obligations at December 31, 2018 and December 31, 2017 : December 31, 2018 December 31, 2017 Amortized Cost Fair Value Amortized Cost Fair Value (In thousands) Washington and Oregon state to secure public deposits $ 199,026 $ 196,786 $ 206,377 $ 206,425 Repurchase agreements 48,173 47,407 48,750 48,237 Other securities pledged 20,778 20,482 12,484 12,498 Total $ 267,977 $ 264,675 $ 267,611 $ 267,160

Loans Receivable (Tables)

Loans Receivable (Tables)	12 Months Ended
	Dec. 31, 2018
Loans and Leases Receivable Disclosure [Abstract]
Schedule of loans receivable	Loans receivable at December 31, 2018 and December 31, 2017 consisted of the following portfolio segments and classes: December 31, 2018 December 31, 2017 (In thousands) Commercial business: Commercial and industrial $ 853,606 $ 645,396 Owner-occupied commercial real estate 779,814 622,150 Non-owner occupied commercial real estate 1,304,463 986,594 Total commercial business 2,937,883 2,254,140 One-to-four family residential 101,763 86,997 Real estate construction and land development: One-to-four family residential 102,730 51,985 Five or more family residential and commercial properties 112,730 97,499 Total real estate construction and land development 215,460 149,484 Consumer 395,545 355,091 Gross loans receivable 3,650,651 2,845,712 Net deferred loan costs 3,509 3,359 Loans receivable, net 3,654,160 2,849,071 Allowance for loan losses (35,042 ) (32,086 ) Total loans receivable, net $ 3,619,118 $ 2,816,985
Loans receivable by credit quality indicator	The following tables present the balance of the loans receivable by credit quality indicator as of December 31, 2018 and December 31, 2017 . December 31, 2018 Pass OAEM Substandard Doubtful/Loss Total (In thousands) Commercial business: Commercial and industrial $ 788,395 $ 16,168 $ 49,043 $ — $ 853,606 Owner-occupied commercial real estate 741,227 27,724 10,863 — 779,814 Non-owner occupied commercial real estate 1,283,077 9,438 11,948 — 1,304,463 Total commercial business 2,812,699 53,330 71,854 — 2,937,883 One-to-four family residential 100,401 — 1,362 — 101,763 Real estate construction and land development: One-to-four family residential 101,519 258 953 — 102,730 Five or more family residential and commercial properties 112,678 52 — — 112,730 Total real estate construction and land development 214,197 310 953 — 215,460 Consumer 390,808 — 4,213 524 395,545 Gross loans receivable $ 3,518,105 $ 53,640 $ 78,382 $ 524 $ 3,650,651 December 31, 2017 Pass OAEM Substandard Doubtful/Loss Total (In thousands) Commercial business: Commercial and industrial $ 597,697 $ 19,536 $ 28,163 $ — $ 645,396 Owner-occupied commercial real estate 595,455 12,668 14,027 — 622,150 Non-owner occupied commercial real estate 955,450 10,494 20,650 — 986,594 Total commercial business 2,148,602 42,698 62,840 — 2,254,140 One-to-four family residential 85,762 — 1,235 — 86,997 Real estate construction and land development: One-to-four family residential 49,925 537 1,523 — 51,985 Five or more family residential and commercial properties 96,404 707 388 — 97,499 Total real estate construction and land development 146,329 1,244 1,911 — 149,484 Consumer 349,590 — 4,976 525 355,091 Gross loans receivable $ 2,730,283 $ 43,942 $ 70,962 $ 525 $ 2,845,712
Schedule of nonaccrual loans	Nonaccrual loans, segregated by segments and classes of loans, were as follows as of December 31, 2018 and December 31, 2017 : December 31, 2018 December 31, 2017 (In thousands) Commercial business: Commercial and industrial $ 6,639 $ 3,110 Owner-occupied commercial real estate 4,212 4,090 Non-owner occupied commercial real estate 1,713 1,898 Total commercial business 12,564 9,098 One-to-four family residential 71 81 Real estate construction and land development: One-to-four family residential 899 1,247 Total real estate construction and land development 899 1,247 Consumer 169 277 Nonaccrual loans $ 13,703 $ 10,703
Past due financing receivables	The balances of past due loans, segregated by segments and classes of loans, as of December 31, 2018 and December 31, 2017 were as follows: December 31, 2018 30-89 Days 90 Days or Greater Total Past Due Current Total (In thousands) Commercial business: Commercial and industrial $ 2,988 $ 2,281 $ 5,269 $ 848,337 $ 853,606 Owner-occupied commercial real estate 563 600 1,163 778,651 779,814 Non-owner occupied commercial real estate 5,347 1,461 6,808 1,297,655 1,304,463 Total commercial business 8,898 4,342 13,240 2,924,643 2,937,883 One-to-four family residential 227 — 227 101,536 101,763 Real estate construction and land development: One-to-four family residential 665 234 899 101,831 102,730 Five or more family residential and commercial properties — — — 112,730 112,730 Total real estate construction and land development 665 234 899 214,561 215,460 Consumer 2,568 — 2,568 392,977 395,545 Gross loans receivable $ 12,358 $ 4,576 $ 16,934 $ 3,633,717 $ 3,650,651 December 31, 2017 30-89 Days 90 Days or Greater Total Past Due Current Total (In thousands) Commercial business: Commercial and industrial $ 2,993 $ 1,172 $ 4,165 $ 641,231 $ 645,396 Owner-occupied commercial real estate 1,277 1,225 2,502 619,648 622,150 Non-owner occupied commercial real estate 870 3,314 4,184 982,410 986,594 Total commercial business 5,140 5,711 10,851 2,243,289 2,254,140 One-to-four family residential 513 — 513 86,484 86,997 Real estate construction and land development: One-to-four family residential 84 1,331 1,415 50,570 51,985 Five or more family residential and commercial properties 40 — 40 97,459 97,499 Total real estate construction and land development 124 1,331 1,455 148,029 149,484 Consumer 1,939 687 2,626 352,465 355,091 Gross loans receivable $ 7,716 $ 7,729 $ 15,445 $ 2,830,267 $ 2,845,712
Schedule of impaired loans, including restructured	Impaired loans include nonaccrual loans and performing TDR loans. The balances of impaired loans as of December 31, 2018 and December 31, 2017 are set forth in the following tables: December 31, 2018 Recorded Investment With No Specific Valuation Allowance Recorded Investment With Specific Valuation Allowance Total Recorded Investment Unpaid Contractual Principal Balance Related Specific Valuation Allowance (In thousands) Commercial business: Commercial and industrial $ 2,523 $ 20,119 $ 22,642 $ 24,176 $ 2,607 Owner-occupied commercial real estate 816 5,000 5,816 6,150 1,142 Non-owner occupied commercial real estate 3,352 2,924 6,276 6,414 206 Total commercial business 6,691 28,043 34,734 36,740 3,955 One-to-four family residential — 279 279 293 76 Real estate construction and land development: One-to-four family residential 899 — 899 1,662 — Total real estate construction and land development 899 — 899 1,662 — Consumer — 527 527 538 139 Total $ 7,590 $ 28,849 $ 36,439 $ 39,233 $ 4,170 December 31, 2017 Recorded Investment With No Specific Valuation Allowance Recorded Investment With Specific Valuation Allowance Total Recorded Investment Unpaid Contractual Principal Balance Related Specific Valuation Allowance (In thousands) Commercial business: Commercial and industrial $ 2,127 $ 9,872 $ 11,999 $ 12,489 $ 1,326 Owner-occupied commercial real estate 2,452 4,356 6,808 7,054 621 Non-owner occupied commercial real estate 4,722 11,297 16,019 16,172 1,222 Total commercial business 9,301 25,525 34,826 35,715 3,169 One-to-four family residential — 299 299 308 93 Real estate construction and land development: One-to-four family residential 938 309 1,247 2,200 2 Five or more family residential and commercial properties — 645 645 645 37 Total real estate construction and land development 938 954 1,892 2,845 39 Consumer 160 282 442 466 54 Total $ 10,399 $ 27,060 $ 37,459 $ 39,334 $ 3,355
Schedule of average recorded investment impaired loans including restructuring loans	The average recorded investment of impaired loans for the year ended December 31, 2018 , 2017 and 2016 are set forth in the following table: Year Ended December 31, 2018 2017 2016 (In thousands) Commercial business: Commercial and industrial $ 16,773 $ 11,310 $ 10,207 Owner-occupied commercial real estate 11,312 5,401 4,540 Non-owner occupied commercial real estate 9,465 12,162 11,709 Total commercial business 37,550 28,873 26,456 One-to-four family residential 290 309 279 Real estate construction and land development: One-to-four family residential 1,091 2,315 3,305 Five or more family residential and commercial properties 129 903 1,656 Total real estate construction and land development 1,220 3,218 4,961 Consumer 428 351 645 Total $ 39,488 $ 32,751 $ 32,341
Recorded investment balance and related allowance for loan losses of accruing and non-accruing TDRs	The recorded investment balance and related allowance for loan losses of performing and nonaccrual TDR loans as of December 31, 2018 and December 31, 2017 were as follows: December 31, 2018 December 31, 2017 Performing TDRs Nonaccrual TDRs Performing Nonaccrual (In thousands) TDR loans $ 22,736 $ 6,943 $ 26,757 $ 5,193 Allowance for loan losses on TDR loans 2,257 658 2,635 379
Troubled debt restructurings on financing receivables	Loans that were modified as TDR loans during the years ended December 31, 2018 , 2017 and 2016 are set forth in the following table: Year Ended December 31, 2018 2017 2016 Number of Contracts (1) Recorded Investment (1) (2) Number of Contracts (1) Recorded Investment (1) (2) Number of Contracts (1) Recorded Investment (1) (2) (Dollars in thousands) Commercial business: Commercial and industrial 31 $ 16,129 19 $ 7,212 19 $ 7,398 Owner-occupied commercial real estate 4 2,521 3 1,366 2 569 Non-owner occupied commercial real estate 3 2,944 4 9,574 2 2,121 Total commercial business 38 21,594 26 18,152 23 10,088 Real estate construction and land development: One-to-four family residential 2 665 2 938 5 2,206 Five or more family residential and commercial properties — — — — 1 1,078 Total real estate construction and land development 2 665 2 938 6 3,284 Consumer 13 236 8 110 6 66 Total TDR loans 53 $ 22,495 36 $ 19,200 35 $ 13,438 (1) Number of contracts and outstanding principal balance represent loans which have balances as of period end as certain loans may have been paid-down or charged-off during the years ended December 31, 2018 , 2017 and 2016 . (2) Includes subsequent payments after modifications and reflects the balance as of period end. As the Bank did not forgive any principal or interest balance as part of the loan modification, the Bank’s recorded investment in each loan at the date of modification (pre-modification) did not change as a result of the modification (post-modification), except when the modification was the initial advance on a one-to-four family residential real estate construction and land development loan under a master guidance line. There were no advances on these types of loans during the years ended December 31, 2018 , 2017 and 2016 .
Troubled debt restructuring loans, subsequently defaulted	Loans that were modified during the previous twelve months that subsequently defaulted during the years ended December 31, 2018 , 2017 and 2016 are included in the following table: Year Ended December 31, 2018 2017 2016 Number of Contracts Recorded Investment (1) Number of Recorded Investment (1) Number of Recorded Investment (1) (Dollars in thousands) Commercial business: Commercial and industrial 5 $ 1,890 1 $ 283 — $ — Owner-occupied commercial real estate 1 65 1 80 1 488 Total commercial business 6 1,955 2 363 1 488 Real estate construction and land development: One-to-four family residential 2 665 2 938 2 1,143 Total real estate construction and land development 2 665 2 938 2 1,143 Consumer — — 1 7 — — Total 8 $ 2,620 5 $ 1,308 3 $ 1,631 (1) Number of contracts and outstanding principal balance represent loans which have balances as of period end as certain loans may have been paid-down or charged-off during the years ended December 31, 2018 , 2017 and 2016 .
Purchased impaired loans	The following table reflects the outstanding principal balance and recorded investment of the PCI loans at December 31, 2018 and December 31, 2017 : December 31, 2018 December 31, 2017 Outstanding Principal Recorded Investment Outstanding Principal Recorded Investment (In thousands) Commercial business: Commercial and industrial $ 6,319 $ 3,433 $ 8,818 $ 2,912 Owner-occupied commercial real estate 7,830 7,215 12,230 11,515 Non-owner occupied commercial real estate 8,685 7,059 14,295 13,342 Total commercial business 22,834 17,707 35,343 27,769 One-to-four family residential 3,169 3,315 4,120 5,255 Real estate construction and land development: One-to-four family residential 67 380 841 89 Five or more family residential and commercial properties 188 43 2,361 2,035 Total real estate construction and land development 255 423 3,202 2,124 Consumer 2,203 3,462 3,974 5,455 Gross PCI loans $ 28,461 $ 24,907 $ 46,639 $ 40,603
Schedule of impaired purchased loans accretable yield	The following table summarizes the accretable yield on the PCI loans for the years ended December 31, 2018 , 2017 and 2016 . Year Ended December 31, 2018 2017 2016 (In thousands) Balance at the beginning of the year $ 11,224 $ 13,860 $ 17,592 Accretion (2,674 ) (3,471 ) (4,962 ) Disposal and other (2,871 ) (2,758 ) (3,329 ) Reclassification from (to) nonaccreatable difference 3,814 3,593 4,559 Balance at the end of the year $ 9,493 $ 11,224 $ 13,860
Activity in related party loans	Activity in related party loans for the years ended December 31, 2018 , 2017 and 2016 was as follows: Year Ended December 31, 2018 2017 2016 (in thousands) Balance outstanding at the beginning of year $ 8,460 $ 19,917 $ 20,775 Elimination of outstanding loan balance due to change in related party status — (10,930 ) — Principal additions 211 — 738 Principal reductions (304 ) (527 ) (1,596 ) Balance outstanding at the end of year $ 8,367 $ 8,460 $ 19,917
Mortgage banking activities	The following table presents information concerning the origination and sale of the Bank's one-to-four family residential loans and the gains from the sale of loans as a result of the Bank's mortgage banking activities: Year Ended December 31, 2018 2017 2016 (In thousands) One-to-four family residential loans: Originated (1) $ 121,998 $ 144,066 $ 178,169 Sold 76,834 113,786 141,127 Gain on sale of loans, net (2) 2,403 3,412 3,723 (1) Includes loans originated for sale in the secondary market or for the Bank's loan portfolio. (2) Excludes net gains on sales of SBA and other loans.
Contractual amounts of commitments to sell and fund with off-balance sheet risk	The contractual amounts of commitments to sell and fund with off-balance sheet risk at December 31, 2018 and 2017 were as follows: December 31, 2018 December 31, 2017 (In thousands) Commitments to sell mortgage loans $ 3,910 $ 10,140 Commitments to fund mortgage loans (at interest rates approximating market rates) for portfolio or for sale: Fixed rate $ 6,593 $ 10,894 Variable or adjustable rate 1,008 56 Total commitments to fund mortgage loans $ 7,601 $ 10,950
Details of SBNA loans serviced	Details of certain SBA loans serviced are as follows: December 31, 2018 December 31, 2017 (In thousands) SBA loans serviced for others with participating interest, gross loan balance $ 54,335 $ 53,809 SBA loans serviced for others with participating interest, participation balance owned by Bank (1) 12,715 12,394 (1) Included in the balances of total loans receivable, net on the Company's Consolidated Statements of Financial Condition.

Allowance for Loan Losses (Tabl

Allowance for Loan Losses (Tables)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Receivables [Abstract]
Schedule of changes in allowance for loan losses	A summary of the changes in the allowance for loan losses during the years ended December 31, 2018 , 2017 and 2016 is as follows: Year Ended December 31, 2018 2017 2016 (In thousands) Balance at the beginning of the year $ 32,086 $ 31,083 $ 29,746 Charge-offs (3,605 ) (4,838 ) (6,085 ) Recoveries of loans previously charged-off 1,432 1,621 2,491 Provision for loan losses 5,129 4,220 4,931 Balance at the end of the year $ 35,042 $ 32,086 $ 31,083 The following table details the activity in the allowance for loan losses disaggregated by segment and class for the year ended December 31, 2018 : Balance at Beginning of Year Charge-offs Recoveries Provision for Loan Losses Balance at End of Year (In thousands) Commercial business: Commercial and industrial $ 9,910 $ (1,250 ) $ 901 $ 1,782 $ 11,343 Owner-occupied commercial real estate 3,992 (1 ) 7 900 4,898 Non-owner occupied commercial real estate 8,097 (149 ) — (478 ) 7,470 Total commercial business 21,999 (1,400 ) 908 2,204 23,711 One-to-four family residential 1,056 (45 ) — 192 1,203 Real estate construction and land development: One-to-four family residential 862 — 11 367 1,240 Five or more family residential and commercial properties 1,190 — — (236 ) 954 Total real estate construction and land development 2,052 — 11 131 2,194 Consumer 6,081 (2,160 ) 513 2,147 6,581 Unallocated 898 — — 455 1,353 Total $ 32,086 $ (3,605 ) $ 1,432 $ 5,129 $ 35,042 The following table details the activity in the allowance for loan losses disaggregated by segment and class for the year ended December 31, 2016 : Balance at Beginning of Year Charge-offs Recoveries Provision for Loan Losses Balance at End of Year (In thousands) Commercial business: Commercial and industrial $ 9,972 $ (3,265 ) $ 1,844 $ 2,417 $ 10,968 Owner-occupied commercial real estate 4,370 (538 ) — (171 ) 3,661 Non-owner occupied commercial real estate 7,722 (350 ) — 381 7,753 Total commercial business 22,064 (4,153 ) 1,844 2,627 22,382 One-to-four family residential 1,157 — 2 (144 ) 1,015 Real estate construction and land development: One-to-four family residential 1,058 (100 ) 83 (244 ) 797 Five or more family residential and commercial properties 813 (54 ) — 600 1,359 Total real estate construction and land development 1,871 (154 ) 83 356 2,156 Consumer 4,309 (1,778 ) 562 1,931 5,024 Unallocated 345 — — 161 506 Total $ 29,746 $ (6,085 ) $ 2,491 $ 4,931 $ 31,083	The following table details the activity in the allowance for loan losses disaggregated by segment and class for the year ended December 31, 2017 : Balance at Beginning of Year Charge-offs Recoveries Provision for Loan Losses Balance at End of Year (In thousands) Commercial business: Commercial and industrial $ 10,968 $ (859 ) $ 792 $ (991 ) $ 9,910 Owner-occupied commercial real estate 3,661 (1,579 ) 155 1,755 3,992 Non-owner occupied commercial real estate 7,753 — — 344 8,097 Total commercial business 22,382 (2,438 ) 947 1,108 21,999 One-to-four family residential 1,015 (30 ) 2 69 1,056 Real estate construction and land development: One-to-four family residential 797 (556 ) 202 419 862 Five or more family residential and commercial properties 1,359 — — (169 ) 1,190 Total real estate construction and land development 2,156 (556 ) 202 250 2,052 Consumer 5,024 (1,814 ) 470 2,401 6,081 Unallocated 506 — — 392 898 Total $ 31,083 $ (4,838 ) $ 1,621 $ 4,220 $ 32,086
Schedule of loan receivables on the basis of impairment method	The following table details the allowance for loan losses disaggregated on the basis of the Company's impairment method as of December 31, 2017 : Loans Individually Evaluated for Impairment Loans Collectively Evaluated for Impairment PCI Loans Total Allowance for Loan Losses (In thousands) Commercial business: Commercial and industrial $ 1,326 $ 7,558 $ 1,026 $ 9,910 Owner-occupied commercial real estate 621 2,557 814 3,992 Non-owner occupied commercial real estate 1,222 5,919 956 8,097 Total commercial business 3,169 16,034 2,796 21,999 One-to-four family residential 93 798 165 1,056 Real estate construction and land development: One-to-four family residential 2 635 225 862 Five or more family residential and commercial properties 37 1,064 89 1,190 Total real estate construction and land development 39 1,699 314 2,052 Consumer 54 5,303 724 6,081 Unallocated — 898 — 898 Total $ 3,355 $ 24,732 $ 3,999 $ 32,086 The following table details the recorded investment balance of the loan receivables disaggregated on the basis of the Company’s impairment method as of December 31, 2017 : Loans Individually Evaluated for Impairment Loans Collectively Evaluated for Impairment PCI Loans Total Gross Loans Receivable (In thousands) Commercial business: Commercial and industrial $ 11,999 $ 630,485 $ 2,912 $ 645,396 Owner-occupied commercial real estate 6,808 603,827 11,515 622,150 Non-owner occupied commercial real estate 16,019 957,233 13,342 986,594 Total commercial business 34,826 2,191,545 27,769 2,254,140 One-to-four family residential 299 81,443 5,255 86,997 Real estate construction and land development: One-to-four family residential 1,247 50,649 89 51,985 Five or more family residential and commercial properties 645 94,819 2,035 97,499 Total real estate construction and land development 1,892 145,468 2,124 149,484 Consumer 442 349,194 5,455 355,091 Total $ 37,459 $ 2,767,650 $ 40,603 $ 2,845,712 The following table details the allowance for loan losses disaggregated on the basis of the Company's impairment method as of December 31, 2018 : Loans Individually Evaluated for Impairment Loans Collectively Evaluated for Impairment PCI Loans Total Allowance for Loan Losses (In thousands) Commercial business: Commercial and industrial $ 2,607 $ 7,913 $ 823 $ 11,343 Owner-occupied commercial real estate 1,142 3,063 693 4,898 Non-owner occupied commercial real estate 206 6,630 634 7,470 Total commercial business 3,955 17,606 2,150 23,711 One-to-four family residential 76 1,015 112 1,203 Real estate construction and land development: One-to-four family residential — 1,040 200 1,240 Five or more family residential and commercial properties — 875 79 954 Total real estate construction and land development — 1,915 279 2,194 Consumer 139 5,965 477 6,581 Unallocated — 1,353 — 1,353 Total $ 4,170 $ 27,854 $ 3,018 $ 35,042 The following table details the recorded investment balance of the loan receivables disaggregated on the basis of the Company’s impairment method as of December 31, 2018 : Loans Individually Evaluated for Impairment Loans Collectively Evaluated for Impairment PCI Loans Total Gross Loans Receivable (In thousands) Commercial business: Commercial and industrial $ 22,642 $ 827,531 $ 3,433 $ 853,606 Owner-occupied commercial real estate 5,816 766,783 7,215 779,814 Non-owner occupied commercial real estate 6,276 1,291,128 7,059 1,304,463 Total commercial business 34,734 2,885,442 17,707 2,937,883 One-to-four family residential 279 98,169 3,315 101,763 Real estate construction and land development: One-to-four family residential 899 101,451 380 102,730 Five or more family residential and commercial properties — 112,687 43 112,730 Total real estate construction and land development 899 214,138 423 215,460 Consumer 527 391,556 3,462 395,545 Total $ 36,439 $ 3,589,305 $ 24,907 $ 3,650,651

Other Real Estate Owned (Tables

Other Real Estate Owned (Tables)	12 Months Ended
	Dec. 31, 2018
Banking and Thrift [Abstract]
Changes in other real estate owned	Changes in other real estate owned during the years ended December 31, 2018 , 2017 and 2016 were as follows: Year Ended December 31, 2018 2017 2016 (In thousands Balance at the beginning of the year $ — $ 754 $ 2,019 Additions 434 32 1,431 Additions from acquisitions 1,796 — — Proceeds from dispositions (198 ) (930 ) (2,486 ) Gain on sale, net — 144 173 Valuation adjustment (49 ) — (383 ) Balance at the end of the year $ 1,983 $ — $ 754

Premises and Equipment (Tables)

Premises and Equipment (Tables)	12 Months Ended
	Dec. 31, 2018
Property, Plant and Equipment [Abstract]
Schedule of premises and equipment	A summary of premises and equipment is as follows: December 31, 2018 December 31, 2017 (In thousands) Land $ 22,954 $ 21,483 Buildings and building improvements 69,315 50,984 Furniture, fixtures and equipment 25,354 20,894 Total premises and equipment 117,623 93,361 Less: Accumulated depreciation 36,523 33,036 Premises and equipment, net $ 81,100 $ 60,325

Goodwill and Other Intangible_2

Goodwill and Other Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Change in goodwill	The following table presents the change in goodwill for the periods indicated: Year Ended December 31, 2018 2017 2016 (In thousands) Balance at the beginning of the period $ 119,029 $ 119,029 $ 119,029 Additions as a result of acquisitions (1) 121,910 — — Balance at the end of the period $ 240,939 $ 119,029 $ 119,029 (1) See Note (2) Business Combinations
Change in other intangible assets	The following table presents the change in other intangible assets for the periods indicated: Year Ended December 31, 2018 2017 2016 (In thousands) Balance at the beginning of the year $ 6,088 $ 7,374 $ 8,789 Additions as a result of acquisitions (1) 18,345 — — Amortization (3,819 ) (1,286 ) (1,415 ) Balance at the end of the year $ 20,614 $ 6,088 $ 7,374 (1) See Note (2) Business Combinations
Estimated aggregate amortization expense for future years	The estimated aggregate amortization expense related to these intangible assets for future years is as follows: Year Ending December 31, (In thousands) 2019 $ 4,001 2020 3,525 2021 3,111 2022 2,750 2023 2,435 Thereafter 4,792 $ 20,614

Deposits (Tables)

Deposits (Tables)	12 Months Ended
	Dec. 31, 2018
Deposits [Abstract]
Schedule of deposits	Deposits consisted of the following: December 31, 2018 December 31, 2017 Amount Percent Amount Percent (Dollars in thousands) Noninterest demand deposits $ 1,362,268 30.7 % $ 944,791 27.8 % Interest bearing demand deposits 1,317,513 29.7 1,051,752 31.1 Money market accounts 765,316 17.3 499,618 14.7 Savings accounts 520,413 11.8 498,501 14.7 Total non-maturity deposits 3,965,510 89.5 2,994,662 88.3 Certificate of deposit accounts 466,892 10.5 398,398 11.7 Total deposits $ 4,432,402 100.0 % $ 3,393,060 100.0 %
Schedule of interest expense, by category	Interest expense, by category, was as follows: Year Ended December 31, 2018 2017 2016 (In thousands) Interest bearing demand deposits $ 2,728 $ 1,812 $ 1,569 Money market accounts 1,654 682 749 Savings accounts 2,056 1,311 756 Certificate of deposit accounts 3,959 2,244 1,936 $ 10,397 $ 6,049 $ 5,010
Schedule of maturities of certificates of deposit	Scheduled maturities of certificates of deposit for future years are as follows: Year Ending December 31, (In thousands) 2019 $ 313,830 2020 93,675 2021 14,608 2022 24,914 2023 19,847 Thereafter 18 $ 466,892

Repurchase Agreements (Tables)

Repurchase Agreements (Tables)	12 Months Ended
	Dec. 31, 2018
Disclosure of Repurchase Agreements [Abstract]
Repurchase agreement obligation by class of collateral pledged	The following table presents the Company's repurchase agreement obligations by class of collateral pledged: December 31, 2018 December 31, 2017 (In thousands) U.S. Treasury and U.S. Government-sponsored agencies $ 4,878 $ — Mortgage-backed securities and collateralized mortgage obligations (1) : Residential 9,335 11,239 Commercial 17,274 20,582 Total repurchase agreements $ 31,487 $ 31,821 (1) Issued and guaranteed by U.S. Government-sponsored agencies.

Other Borrowings (Tables)

Other Borrowings (Tables)	12 Months Ended
	Dec. 31, 2018
Debt Disclosure [Abstract]
Schedule of FHLB advances	The following table sets forth the details of FHLB advances during and as of the years ended December 31, 2018 and 2017 : December 31, 2018 December 31, 2017 (In thousands) FHLB Advances: Average balance during the year $ 33,913 $ 105,646 Maximum month-end balance during the year $ 154,500 $ 137,450 Weighted average rate during the year 1.98 % 1.16 % Weighted average rate at the end of year n/a 1.56 %

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Schedule of estimated future minimum annual rental commitments under noncancelable leases	The estimated future minimum annual rental commitments under noncancelable leases having an original or remaining term of more than one year are as follows: Year Ending December 31, (In thousands) 2019 $ 4,766 2020 4,251 2021 2,477 2022 1,704 2023 1,568 Thereafter 1,788 $ 16,554
Summary of outstanding commitments to extend credit, including letters of credit	The following table presents outstanding commitments to extend credit, including letters of credit, at the dates indicated: December 31, 2018 December 31, 2017 (In thousands) Commercial business: Commercial and industrial $ 568,215 $ 363,272 Owner-occupied commercial real estate 13,065 6,815 Non-owner occupied commercial real estate 13,621 13,543 Total commercial business 594,901 383,630 One-to-four family residential — — Real estate construction and land development: One-to-four family residential 59,772 38,160 Five or more family residential and commercial properties 95,535 86,787 Total real estate construction and land development 155,307 124,947 Consumer 239,822 204,625 Total outstanding commitments $ 990,030 $ 713,202

Derivative Financial Instrume_2

Derivative Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of notional amounts and estimated fair values of interest rate derivative contracts	The notional amounts and estimated fair values of interest rate derivative contracts outstanding at December 31, 2018 and December 31, 2017 are presented in the following table: December 31, 2018 December 31, 2017 Notional Amounts Estimated Fair Value Notional Amounts Estimated Fair Value (In thousands) Non-hedging interest rate derivatives Interest rate swaps with customer (1) $ 171,798 $ (1,643 ) $ 146,537 $ (882 ) Interest rate swap with third party (1) 171,798 1,643 146,537 882 (1) The estimated fair value of the derivative included in prepaid and other assets on the Consolidated Statements of Financial Condition was $5.1 million and $3.4 million as of December 31, 2018 and 2017 , respectively. The estimated fair value of the derivative included in accrued expenses and other liabilities on the Consolidated Statements of Financial Condition was $5.1 million and $3.4 million as of December 31, 2018 and 2017 , respectively.

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2018
Stockholders' Equity Note [Abstract]
Schedule of earnings per share reconciliation	The following table illustrates the reconciliation of weighted average shares used for earnings per common share computations for the years ended December 31, 2018 , 2017 and 2016 : Year Ended December 31, 2018 2017 2016 (In thousands) Net income: Net income $ 53,057 $ 41,791 $ 38,918 Dividends and undistributed earnings allocated to participating securities (321 ) (293 ) (358 ) Net income allocated to common shareholders $ 52,736 $ 41,498 $ 38,560 Basic: Weighted average common shares outstanding 35,281,408 29,937,400 29,963,365 Restricted stock awards (87,405 ) (179,581 ) (285,063 ) Total basic weighted average common shares outstanding 35,194,003 29,757,819 29,678,302 Diluted: Basic weighted average common shares outstanding 35,194,003 29,757,819 29,678,302 Effect of potentially dilutive common shares (1) 177,587 91,512 13,851 Total diluted weighted average common shares outstanding 35,371,590 29,849,331 29,692,153 (1) Represents the effect of the assumed exercise of stock options and vesting of restricted stock awards and units.
Schedule of dividends activity	The following table summarizes the dividend activity for the years ended December 31, 2018 , 2017 and 2016 : Declared Cash Dividend per Share Record Date Paid Date January 27, 2016 $0.11 February 10, 2016 February 24, 2016 April 20, 2016 $0.12 May 5, 2016 May 19, 2016 July 20, 2016 $0.12 August 4, 2016 August 18, 2016 October 26, 2016 $0.12 November 8, 2016 November 22, 2016 October 26, 2016 $0.25 November 8, 2016 November 22, 2016 * January 25, 2017 $0.12 February 9, 2017 February 23, 2017 April 25, 2017 $0.13 May 10, 2017 May 24, 2017 July 25, 2017 $0.13 August 10, 2017 August 24, 2017 October 25, 2017 $0.13 November 8, 2017 November 22, 2017 October 25, 2017 $0.10 November 8, 2017 November 22, 2017 * January 24, 2018 $0.15 February 7, 2018 February 21, 2018 April 25, 2018 $0.15 May 10, 2018 May 24, 2018 July 24, 2018 $0.15 August 9, 2018 August 23, 2018 October 24, 2018 $0.17 November 7, 2018 November 21, 2018 October 24, 2018 $0.10 November 7, 2018 November 21, 2018 * * Denotes a special dividend.
Schedule of repurchased shares	The following table provides total repurchased shares for the periods indicated: Year Ended December 31, 2018 2017 2016 Repurchased shares to pay withholding taxes (1) 53,256 29,429 29,512 Stock repurchase to pay withholding taxes average share price $ 31.99 $ 25.01 $ 17.82 (1) During the year ended December 31, 2018 , the Company repurchased 26,741 shares related to the withholding taxes due on the accelerated vesting of the restricted stock units of Puget Sound which were converted to Heritage common stock shares with a share price of $31.80 under the terms of the Puget Sound Merger. See Note (2) Business Combinations . There were no shares repurchased as a result of the accelerated vesting of the restricted stock awards related to the Premier Merger.

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Loss (Tables)	12 Months Ended
	Dec. 31, 2018
Equity [Abstract]
Changes in accumulated other comprehensive income (loss)	The changes in accumulated other comprehensive (loss) income (“AOCI”), all of which are due to changes in the fair value of available for sale securities and are net of tax, during the years ended December 31, 2018 , 2017 and 2016 are as follows: December 31, 2018 December 31, 2017 December 31, 2016 (In thousands) Balance of AOCI at the beginning of the year $ (1,298 ) $ (2,606 ) $ 2,559 Other comprehensive (loss) income before reclassification (5,956 ) 1,530 (4,311 ) Amounts reclassified from AOCI for gain on sale of investment securities included in net income (108 ) (4 ) (854 ) Net current period other comprehensive (loss) income (6,064 ) 1,526 (5,165 ) ASU 2016-01 and 2018-02 Implementations (93 ) (218 ) — Balance of AOCI at the end of the year $ (7,455 ) $ (1,298 ) $ (2,606 )

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Fair value measurements of assets on a recurring basis	The following tables summarize the balances of assets and liabilities measured at fair value on a recurring basis as of December 31, 2018 and December 31, 2017 : December 31, 2018 Total Level 1 Level 2 Level 3 (In thousands) Assets Investment securities available for sale: U.S. Treasury and U.S. Government-sponsored agencies $ 101,603 $ 15,936 $ 85,667 $ — Municipal securities 158,864 — 158,864 — Mortgage backed securities and collateralized mortgage obligations: Residential 331,602 — 331,602 — Commercial 333,761 — 333,761 — Corporate obligations 25,563 — 25,563 — Other asset-backed securities 24,702 24,702 — Total investment securities available for sale 976,095 15,936 960,159 — Derivative assets - interest rate swaps 5,095 — 5,095 — Liabilities Derivative liabilities - interest rate swaps $ 5,095 $ — $ 5,095 $ — December 31, 2017 Total Level 1 Level 2 Level 3 (In thousands) Assets Investment securities available for sale: U.S. Treasury and U.S. Government-sponsored agencies $ 13,442 $ — $ 13,442 $ — Municipal securities 250,015 — 250,015 — Mortgage backed securities and collateralized mortgage obligations: Residential 280,211 — 280,211 — Commercial 217,079 — 217,079 — Collateralized loan obligations 4,580 — 4,580 — Corporate obligations 16,770 — 16,770 — Other securities 28,433 146 28,287 — Total investment securities available for sale 810,530 146 810,384 — Derivative assets - interest rate swaps 3,418 — 3,418 — Liabilities Derivative liabilities - interest rate swaps $ 3,418 $ — $ 3,418 $ —
Fair value measurements of assets on a nonrecurring basis	The tables below represent assets measured at fair value on a nonrecurring basis at December 31, 2018 and December 31, 2017 and the net losses recorded in earnings during years ended December 31, 2018 and 2017 : Basis (1) Fair Value at December 31, 2018 Total Level 1 Level 2 Level 3 Net Losses Recorded in Earnings During the Year Ended December 31, 2018 (In thousands) Impaired loans: Commercial business: Commercial and industrial $ 117 $ 107 $ — $ — $ 107 $ 10 Non-owner occupied commercial real estate 1,378 1,102 — — 1,102 150 Total commercial business 1,495 1,209 — — 1,209 160 Consumer 9 7 — — 7 8 Total assets measured at fair value on a nonrecurring basis $ 1,504 $ 1,216 $ — $ — $ 1,216 $ 168 (1) Basis represents the unpaid principal balance of impaired loans. Basis (1) Fair Value at December 31, 2017 Total Level 1 Level 2 Level 3 Net Losses (Gains) Recorded in Earnings During the Year Ended December 31, 2017 (In thousands) Impaired loans: Real estate construction and land development: One-to-four family residential $ 976 $ 307 $ — $ — $ 307 $ (558 ) Total assets measured at fair value on a nonrecurring basis $ 976 $ 307 $ — $ — $ 307 $ (558 ) (1) Basis represents the unpaid principal balance of impaired loans.
Fair value measurements for financial instruments measured at fair value on a non-recurring basis	The following table presents quantitative information about Level 3 fair value measurements for financial instruments measured at fair value on a non-recurring basis at December 31, 2018 and December 31, 2017 : December 31, 2018 Fair Value Valuation Technique(s) Unobservable Input(s) Range of Inputs; Weighted Average (Dollars in thousands) Impaired loans $ 1,216 Market approach Adjustment for differences between the comparable sales 10.4% - (37.3%); (10.9%) December 31, 2017 Fair Value Valuation Technique(s) Unobservable Input(s) Range of Inputs; Weighted Average (Dollars in thousands) Impaired loans $ 307 Market approach Adjustment for differences between the comparable sales (91.5%) - (14.4%); (44.0%)
Schedule of carrying value and fair value of financial instruments	The tables below present the carrying value amount of the Company’s financial instruments and their corresponding estimated fair values at the dates indicated: December 31, 2018 Carrying Value Fair Value Fair Value Measurements Using: Level 1 Level 2 Level 3 (In thousands) Financial Assets: Cash and cash equivalents $ 161,910 $ 161,910 $ 161,910 $ — $ — Investment securities available for sale 976,095 976,095 15,936 960,159 — Federal Home Loan Bank stock 6,076 N/A N/A N/A N/A Loans held for sale 1,555 1,605 — 1,605 — Total loans receivable, net 3,619,118 3,614,348 — — 3,614,348 Accrued interest receivable 15,403 15,403 68 4,091 11,244 Derivative assets - interest rate swaps 5,095 5,095 — 5,095 — Equity security 114 114 114 — — Financial Liabilities: Noninterest deposits, interest bearing demand deposits, money market accounts and savings accounts $ 3,965,510 $ 3,965,510 $ 3,965,510 $ — $ — Certificate of deposit accounts 466,892 470,222 — 470,222 — Securities sold under agreement to repurchase 31,487 31,487 31,487 — — Junior subordinated debentures 20,302 20,500 — — 20,500 Accrued interest payable 191 191 63 81 47 Derivative liabilities - interest rate swaps 5,095 5,095 — 5,095 — December 31, 2017 Carrying Value Fair Value Fair Value Measurements Using: Level 1 Level 2 Level 3 (In thousands) Financial Assets: Cash and cash equivalents $ 103,015 $ 103,015 $ 103,015 $ — $ — Investment securities available for sale 810,530 810,530 146 810,384 — Federal Home Loan Bank stock 8,347 N/A N/A N/A N/A Loans held for sale 2,288 2,364 — 2,364 — Total loans receivable, net 2,816,985 2,810,401 — — 2,810,401 Accrued interest receivable 12,244 12,244 23 3,772 8,449 Derivative assets - interest rate swaps 3,418 3,418 — 3,418 — Financial Liabilities: Noninterest deposits, interest bearing demand deposits, money market accounts and savings accounts $ 2,994,662 $ 2,994,662 $ 2,994,662 $ — $ — Certificate of deposit accounts 398,398 397,039 — 397,039 — Federal Home Loan Bank advances 92,500 92,500 — 92,500 — Securities sold under agreement to repurchase 31,821 31,821 31,821 — — Junior subordinated debentures 20,009 18,500 — — 18,500 Accrued interest payable 162 162 45 79 38 Derivative liabilities - interest rate swaps 3,418 3,418 — 3,418 —

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of stock option activity	The following table summarizes the stock option activity for the years ended December 31, 2018 , 2017 and 2016 : Shares Weighted-Average Exercise Price Weighted-Average Remaining Contractual Term (In years) Aggregate Intrinsic Value (In thousands) Outstanding at December 31, 2015 79,408 $ 14.19 Exercised (37,713 ) 14.31 Forfeited or expired (4,200 ) 16.80 Outstanding at December 31, 2016 37,495 13.77 Exercised (12,662 ) 12.97 Forfeited or expired (1,602 ) 13.76 Outstanding at December 31, 2017 23,231 14.21 Exercised (9,842 ) 13.45 Forfeited or expired (831 ) 14.77 Outstanding, vested and expected to vest and exercisable at December 31, 2018 12,558 $ 14.77 1.39 $ 188
Schedule of restricted stock award activity	The following table summarizes the restricted stock award activity for the years ended December 31, 2018 , 2017 and 2016 : Shares Weighted-Average Grant Date Fair Value Nonvested at December 31, 2015 264,521 $ 15.92 Granted 121,039 17.60 Vested (112,516 ) 15.62 Forfeited (11,748 ) 16.62 Nonvested at December 31, 2016 261,296 16.80 Vested (113,479 ) 16.55 Forfeited (10,418 ) 16.80 Nonvested at December 31, 2017 137,399 17.00 Vested (67,877 ) 16.74 Forfeited (3,489 ) 16.92 Nonvested at December 31, 2018 66,033 $ 17.28
Schedule of assumptions of PRSUs granted	The Company used the following assumptions to estimate the fair value of PRSUs granted during February 2018 and 2017: 2018 2017 Shares issued 5,550 6,089 Expected Term in Years 2.84 2.85 Weighted-Average Risk Free Interest Rate 2.39 % 1.40 % Expected Dividend Yield — % — % Weighted-Average Fair Value 27.69 24.39 Correlation coefficient ABA NASDAQ Community Bank Index ABA NASDAQ Community Bank Index Range of peer company volatilities 18.99% - 51.42% 17.8% - 63.1% Range of peer company correlation coefficients 28.16% - 94.29% 8.24% - 89.79% Heritage volatility 22.30 % 21.80 % Heritage correlation coefficient 76.44 % 75.93 %
Summary of RSU activity	The following table summarizes the unit activity for the year ended December 31, 2018 and 2017 : Units Weighted-Average Grant Date Fair Value Nonvested at December 31, 2016 — $ — Granted 92,356 25.31 Forfeited (1,812 ) 25.35 Nonvested at December 31, 2017 90,544 25.31 Granted 125,633 30.62 Vested (32,375 ) 25.44 Forfeited (4,617 ) 27.82 Nonvested at December 31, 2018 179,185 $ 28.94

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Schedule of income tax expense	Income tax expense for the years ended December 31, 2018 , 2017 and 2016 consisted of the following: Year Ended December 31, 2018 2017 2016 (In thousands) Current tax expense $ 9,658 $ 12,171 $ 6,885 Deferred tax expense 1,372 6,185 6,918 Income tax expense $ 11,030 $ 18,356 $ 13,803
Reconciliation of effective income tax rate	A reconciliation of the Company's effective income tax rate with the Federal statutory income tax rate of 35% for the years 2017 and 2016 and 21% for the year 2018 is as follows: Year Ended December 31, 2018 2017 2016 (In thousands) Income tax expense at Federal statutory rate $ 13,502 $ 21,051 $ 18,452 Tax-exempt instruments (1,879 ) (3,212 ) (3,198 ) Non-deductible acquisition costs 336 210 — Federal tax credits and other benefits (1) (515 ) (1,510 ) (931 ) Effects of BOLI (330 ) (531 ) (511 ) Revaluation of net deferred tax assets 2,568 — Other, net (84 ) (220 ) (9 ) Income tax expense $ 11,030 $ 18,356 $ 13,803 (1) Federal tax credits are provided for under the NMTC program and LIHTC programs as described in Note (14) Commitments and Contingencies . Tax benefits related to these credits were recognized for financial reporting purposes in the same period that the credits were recognized in the Company's income tax returns. Other benefits include the proportional amortization of the LIHTC of $3.1 million , $2.2 million and $523,000 , for the years ended December 31, 2018 , 2017 and 2016 , respectively.
Components of deferred income tax asset (liability)	The following table presents major components of the deferred income tax asset (liability) resulting from differences between financial reporting and tax basis: December 31, 2018 December 31, 2017 (In thousands) Deferred tax assets: Allowance for loan losses $ 6,941 $ 6,699 Accrued compensation 3,379 1,779 Stock compensation 769 660 Net unrealized losses charged to other comprehensive income on securities 2,070 347 Market discount on purchased loans 1,054 539 Foregone interest on nonaccrual loans 811 471 Net operating loss carryforward acquired from NCB 336 270 Other Real Estate Owned 754 — Other deferred tax assets 364 763 Total deferred tax assets 16,478 11,528 Deferred tax liabilities: Deferred loan fees, net (3,333 ) (2,518 ) Premises and equipment (1,819 ) (1,091 ) FHLB stock (569 ) (557 ) Goodwill and other intangible assets (3,526 ) (304 ) Federal tax credits (1,457 ) (1,107 ) Junior subordinated debentures (1,176 ) (1,215 ) Other deferred tax liabilities (540 ) (847 ) Total deferred tax liabilities (12,420 ) (7,639 ) Deferred tax asset, net $ 4,058 $ 3,889

Regulatory Capital Requiremen_2

Regulatory Capital Requirements (Tables)	12 Months Ended
	Dec. 31, 2018
Regulatory Capital Requirements [Abstract]
Minimum capital requirements to maintain leverage ratio	Minimum Well- Actual $ % $ % $ % (Dollars in thousands) As of December 31, 2018: The Company consolidated Common equity Tier 1 capital to risk-weighted assets $ 197,189 4.5 % N/A N/A $ 510,618 11.7 % Tier 1 leverage capital to average assets 201,920 4.0 N/A N/A 530,920 10.5 Tier 1 capital to risk-weighted assets 262,918 6.0 N/A N/A 530,920 12.1 Total capital to risk-weighted assets 350,558 8.0 N/A N/A 566,268 12.9 Heritage Bank Common equity Tier 1 capital to risk-weighted assets 197,004 4.5 284,561 6.5 513,993 11.7 Tier 1 leverage capital to average assets 203,339 4.0 254,174 5.0 513,993 10.1 Tier 1 capital to risk-weighted assets 262,671 6.0 350,229 8.0 513,993 11.7 Total capital to risk-weighted assets 350,229 8.0 437,786 10.0 549,341 12.5 As of December 31, 2017: The Company consolidated Common equity Tier 1 capital to risk-weighted assets $ 154,522 4.5 % N/A N/A $ 386,689 11.3 % Tier 1 leverage capital to average assets 159,494 4.0 N/A N/A 406,687 10.2 Tier 1 capital to risk-weighted assets 206,029 6.0 N/A N/A 406,687 11.8 Total capital to risk-weighted assets 274,706 8.0 N/A N/A 439,044 12.8 Heritage Bank Common equity Tier 1 capital to risk-weighted assets 154,400 4.5 223,023 6.5 391,092 11.4 Tier 1 leverage capital to average assets 159,300 4.0 199,125 5.0 391,092 9.8 Tier 1 capital to risk-weighted assets 205,867 6.0 274,490 8.0 391,092 11.4 Total capital to risk-weighted assets 274,490 8.0 343,112 10.0 423,348 12.3

Heritage Financial Corporatio_2

Heritage Financial Corporation (Parent Company Only) (Tables)	12 Months Ended
	Dec. 31, 2018
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Condensed statements of financial condition	HERITAGE FINANCIAL CORPORATION (PARENT COMPANY ONLY) Condensed Statements of Financial Condition December 31, 2018 December 31, 2017 (In thousands) ASSETS Cash and interest earning deposits $ 14,602 $ 11,904 Investment in subsidiary bank 764,097 512,655 Other assets 2,520 4,696 Total assets $ 781,219 $ 529,255 LIABILITIES AND STOCKHOLDERS’ EQUITY Junior subordinated debentures $ 20,302 $ 20,009 Other liabilities 194 941 Total stockholders’ equity 760,723 508,305 Total liabilities and stockholders’ equity $ 781,219 $ 529,255
Condensed statements of income	HERITAGE FINANCIAL CORPORATION (PARENT COMPANY ONLY) Condensed Statements of Income Year Ended December 31, 2018 2017 2016 (In thousands) INTEREST INCOME: Interest and dividends on interest earning deposits and other assets $ 7 $ 44 $ 34 Total interest income 7 44 34 INTEREST EXPENSE: Junior subordinated debentures 1,263 1,014 880 Total interest expense 1,263 1,014 880 Net interest expense (1,256 ) (970 ) (846 ) NONINTEREST INCOME: Dividends from subsidiary bank 30,000 23,000 30,000 Equity in undistributed income of subsidiary bank 29,258 21,755 11,848 Other income 22 — — Total noninterest income 59,280 44,755 41,848 NONONTEREST EXPENSE: Professional services 3,063 768 385 Other expense 3,833 3,726 3,437 Total noninterest expense 6,896 4,494 3,822 Income before income taxes 51,128 39,291 37,180 Income tax benefit (1,929 ) (2,500 ) (1,738 ) Net income $ 53,057 $ 41,791 $ 38,918
Condensed statements of cash flows	HERITAGE FINANCIAL CORPORATION (PARENT COMPANY ONLY) Condensed Statements of Cash Flows Year Ended December 31, 2018 2017 2016 (In thousands) Cash flows from operating activities: Net income $ 53,057 $ 41,791 $ 38,918 Adjustments to reconcile net income to net cash provided by operating activities: Equity in undistributed income of subsidiary bank (29,258 ) (21,755 ) (11,848 ) Net excess tax benefit from exercise of stock options and vesting of restricted stock — — (123 ) Stock-based compensation expense 2,744 2,103 1,840 Net change in other assets and liabilities 1,735 (1,925 ) (1,141 ) Net cash provided by operating activities 28,278 20,214 27,646 Cash flows from investing activities: Net cash received from acquisitions 1,782 — — Net cash provided by investing activities 1,782 — — Cash flows from financing activities: Common stock cash dividends paid (25,791 ) (18,305 ) (21,569 ) Proceeds from exercise of stock options 133 164 540 Net excess tax benefit from exercise of stock options and vesting of restricted stock — — 123 Repurchase of common stock (1,704 ) (737 ) (2,894 ) Net cash used in financing activities (27,362 ) (18,878 ) (23,800 ) Net increase in cash and cash equivalents 2,698 1,336 3,846 Cash and cash equivalents at the beginning of year 11,904 10,568 6,722 Cash and cash equivalents at the end of year $ 14,602 $ 11,904 $ 10,568 Supplemental non-cash disclosures of cash flow information: Common stock issued for business combinations $ 230,043 $ — $ — Capital contribution of net assets acquired in business combinations to Bank 228,261 — —

Selected Quarterly Financial _2

Selected Quarterly Financial Data (Tables)	12 Months Ended
	Dec. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
Results of operations on a quarterly basis	Results of operations on a quarterly basis were as follows: Year Ended December 31, 2018 First Quarter Second Quarter Third Quarter Fourth Quarter (Dollars in thousands, except per share amounts) Interest income $ 43,247 $ 46,671 $ 54,576 $ 54,865 Interest expense 2,410 2,928 3,480 3,595 Net interest income 40,837 43,743 51,096 51,270 Provision for loan losses 1,152 1,750 1,065 1,162 Net interest income after provision for loan losses 39,685 41,993 50,031 50,108 Noninterest income 7,548 7,573 8,080 8,464 Noninterest expense 36,747 35,706 39,597 37,345 Income before provision for income taxes 10,486 13,860 18,514 21,227 Income tax expense 1,399 2,003 3,010 4,618 Net income $ 9,087 $ 11,857 $ 15,504 $ 16,609 Basic earnings per common share $ 0.27 $ 0.35 $ 0.42 $ 0.45 Diluted earnings per common share 0.27 0.35 0.42 0.45 Cash dividends declared on common stock 0.15 0.15 0.15 0.27 Year Ended December 31, 2017 First Quarter Second Quarter Third Quarter Fourth Quarter (Dollars in thousands, except per share amounts) Interest income $ 34,849 $ 36,041 $ 37,275 $ 39,544 Interest expense 1,717 1,907 2,333 2,389 Net interest income 33,132 34,134 34,942 37,155 Provision for loan losses 867 1,131 884 1,338 Net interest income after provision for loan losses 32,265 33,003 34,058 35,817 Noninterest income 7,363 10,709 8,443 9,064 Noninterest expense 27,223 27,809 27,955 27,588 Income before provision for income taxes 12,405 15,903 14,546 17,293 Income tax expense 3,089 4,075 3,922 7,270 Net income $ 9,316 $ 11,828 $ 10,624 $ 10,023 Basic earnings per common share $ 0.31 $ 0.40 $ 0.35 $ 0.33 Diluted earnings per common share 0.31 0.40 0.35 0.33 Cash dividends declared on common stock 0.12 0.13 0.13 0.23

Description of Business, Basi_3

Description of Business, Basis of Presentation and Significant Accounting Policies and Recently Issued Accounting Pronouncements - Description of Business (Details)	Dec. 31, 2018branch
Heritage Bank
Business Description and Basis of Presentation [Line Items]
Number of branches operating	64

Description of Business, Basi_4

Description of Business, Basis of Presentation and Significant Accounting Policies and Recently Issued Accounting Pronouncements - Allowance for Loan Losses (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Allowance for off-balance sheet financial instruments	$ 306	$ 170

Description of Business, Basi_5

Description of Business, Basis of Presentation and Significant Accounting Policies and Recently Issued Accounting Pronouncements - Mortgage Banking Operations (Details) - USD ($)	Dec. 31, 2018	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Fair value of derivative instruments	$ 0	$ 0

Description of Business, Basi_6

Description of Business, Basis of Presentation and Significant Accounting Policies and Recently Issued Accounting Pronouncements - Premises and Equipment (Details)	12 Months Ended
	Dec. 31, 2018
Minimum | Buildings and building improvements
Property, Plant and Equipment [Line Items]
Useful lives	15 years
Minimum | Furniture, fixtures and equipment
Property, Plant and Equipment [Line Items]
Useful lives	3 years
Maximum | Buildings and building improvements
Property, Plant and Equipment [Line Items]
Useful lives	39 years
Maximum | Furniture, fixtures and equipment
Property, Plant and Equipment [Line Items]
Useful lives	7 years

Description of Business, Basi_7

Description of Business, Basis of Presentation and Significant Accounting Policies and Recently Issued Accounting Pronouncements - Operating Segments (Details)	12 Months Ended
	Dec. 31, 2018segment
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of operating segments	1

Description of Business, Basi_8

Description of Business, Basis of Presentation and Significant Accounting Policies and Recently Issued Accounting Pronouncements - Recently Issued Accounting Pronouncements (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Jan. 01, 2019	Jan. 01, 2018	Jan. 01, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of new accounting principle			$ 0	$ 0
ASU 2016-01
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of new accounting principle			$ 93
ASU 2016-02 | Subsequent Event
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease assets		$ 29,300
Operating lease liabilities		$ 30,200
ASU 2018-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification of stranded tax effects from accumulated other comprehensive loss to retained earnings	$ 218

Business Combinations - Textual

Business Combinations - Textuals (Details) - USD ($) $ / shares in Units, $ in Thousands	Jul. 02, 2018	Jan. 16, 2018	Dec. 31, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Jun. 29, 2018	Jan. 12, 2018
Business Acquisition [Line Items]
Share price (in usd per share)			$ 31.80	$ 31.80
Number of shares forfeited to pay applicable taxes (in shares)			26,741	26,741
Goodwill				$ 121,910	$ 0	$ 0
Puget Sound
Business Acquisition [Line Items]
Number of shares issued (in shares)		1.1688
Number of shares issued		4,112,258
Share price (in usd per share)		$ 31.80						$ 31.80
Fair value of shares issued		$ 130,800
Share price paid in cash (in usd per share)		$ 3,000
Total consideration paid		$ 130,773
Total fair value of shares forfeited to pay applicable taxes		$ 851
Number of shares forfeited to pay applicable taxes (in shares)		26,741
Acquisition-related costs				5,400	$ 810
Goodwill		$ 68,520		68,500
Premier Commercial
Business Acquisition [Line Items]
Number of shares issued (in shares)	0.4863
Number of shares issued	2,848,579
Share price (in usd per share)	$ 34.85						$ 34.85
Fair value of shares issued	$ 99,300
Share price paid in cash (in usd per share)	$ 2,000
Total consideration paid	$ 99,275
Acquisition-related costs				4,900
Goodwill	$ 53,390			$ 53,400
Goodwill, purchase accounting adjustment			$ 102

Business Combinations - Fair Va

Business Combinations - Fair Value Estimates of Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Jul. 02, 2018	Jan. 16, 2018	Dec. 31, 2017
Liabilities
Gross loans receivable	$ 3,650,651			$ 2,845,712
Premier Merger
Assets
Cash and cash equivalents		$ 22,534
Interest earning deposits		3,309
Investment securities available for sale		4,493
Loans receivable		330,158
Other real estate owned		1,796
Premises and equipment, net		3,053
Federal Home Loan Bank stock, at cost		1,120
Bank owned life insurance		10,852
Accrued interest receivable		1,006
Prepaid expenses and other assets		1,603
Other intangible assets		7,075
Total assets acquired		386,999
Liabilities
Deposits		318,717
Federal Home Loan Bank advances		16,000
Securities sold under agreement to repurchase		462
Total liabilities acquired		5,935
Total liabilities acquired		341,114
Fair value of net assets acquired		45,885
Gross loans receivable		$ 335,400
Puget Sound Merger
Assets
Cash and cash equivalents			$ 25,889
Interest earning deposits			54,247
Investment securities available for sale			80,353
Loans receivable			388,462
Other real estate owned			0
Premises and equipment, net			732
Federal Home Loan Bank stock, at cost			623
Bank owned life insurance			6,264
Accrued interest receivable			1,448
Prepaid expenses and other assets			1,354
Other intangible assets			11,270
Total assets acquired			570,642
Liabilities
Deposits			505,885
Federal Home Loan Bank advances			0
Securities sold under agreement to repurchase			0
Total liabilities acquired			2,504
Total liabilities acquired			508,389
Fair value of net assets acquired			62,253
Gross loans receivable			$ 392,700

Business Combinations - Summary

Business Combinations - Summary of Fair Value Adjustments and Goodwill (Details) - USD ($) $ in Thousands	Jul. 02, 2018	Jan. 16, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Fair value adjustments:
Goodwill recognized from the mergers			$ 121,910	$ 0	$ 0
Premier Merger
Business Acquisition [Line Items]
Consideration transferred	$ 99,275
Cost basis of net assets on merger date	40,629
Fair value adjustments:
Investment securities	(135)
Total loans receivable, net	(111)
Other real estate owned	(1,017)
Premises and equipment	1,312
Other intangible assets	7,075
Prepaid expenses and other assets	(1,912)
Deposits	(310)
Accrued expenses and other liabilities	354
Fair value of net assets on merger date	45,885
Goodwill recognized from the mergers	$ 53,390		53,400
Puget Sound Merger
Business Acquisition [Line Items]
Consideration transferred		$ 130,773
Cost basis of net assets on merger date		54,405
Fair value adjustments:
Investment securities		(348)
Total loans receivable, net		1,400
Other real estate owned		0
Premises and equipment		(121)
Other intangible assets		9,207
Prepaid expenses and other assets		(2,282)
Deposits		(62)
Accrued expenses and other liabilities		54
Fair value of net assets on merger date		62,253
Goodwill recognized from the mergers		$ 68,520	$ 68,500

Business Combinations - Results

Business Combinations - Results of Operations of Acquired Business (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Business Acquisition [Line Items]
Interest income: Interest and fees on loans									$ 175,466	$ 129,213	$ 122,147
Interest income: Interest and fees on investments									17,602	12,688	11,215
Interest income: Other interest earning assets									1,642	539	280
Interest expense	$ (3,595)	$ (3,480)	$ (2,928)	$ (2,410)	$ (2,389)	$ (2,333)	$ (1,907)	$ (1,717)	(12,413)	(8,346)	(6,006)
Provision for loan losses for loans	(1,162)	(1,065)	(1,750)	(1,152)	(1,338)	(884)	(1,131)	(867)	(5,129)	(4,220)	(4,931)
Noninterest income	8,464	8,080	7,573	7,548	9,064	8,443	10,709	7,363	31,665	35,579	31,619
Noninterest expense	(37,345)	(39,597)	(35,706)	(36,747)	(27,588)	(27,955)	(27,809)	(27,223)	(149,395)	(110,575)	(106,473)
Income before income taxes	$ 21,227	$ 18,514	$ 13,860	$ 10,486	$ 17,293	$ 14,546	$ 15,903	$ 12,405	64,087	$ 60,147	$ 52,721
Accretion of discount on purchased loans									4,100
Premier Merger
Business Acquisition [Line Items]
Interest income: Interest and fees on loans									10,462
Interest income: Interest and fees on investments									76
Interest income: Other interest earning assets									174
Interest expense									(445)
Provision for loan losses for loans									(700)
Noninterest income									125
Noninterest expense									(7,558)
Income before income taxes									2,134
Puget Sound Merger
Business Acquisition [Line Items]
Interest income: Interest and fees on loans									21,898
Interest income: Interest and fees on investments									59
Interest income: Other interest earning assets									113
Interest expense									(682)
Provision for loan losses for loans									(850)
Noninterest income									472
Noninterest expense									(11,230)
Income before income taxes									9,780
Premier and Puget Mergers
Business Acquisition [Line Items]
Interest income: Interest and fees on loans									32,360
Interest income: Interest and fees on investments									135
Interest income: Other interest earning assets									287
Interest expense									(1,127)
Provision for loan losses for loans									(1,550)
Noninterest income									597
Noninterest expense									(18,788)
Income before income taxes									$ 11,914

Business Combinations - Unaudit

Business Combinations - Unaudited Pro Forma (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Business Combinations [Abstract]
Net interest income	$ 194,989	$ 174,190
Net income	$ 69,515	$ 41,551
Basic earnings per common share (in usd per share)	$ 1.88	$ 1.12
Diluted earnings per common share (in usd per share)	$ 1.87	$ 1.12

Investment Securities - Reconci

Investment Securities - Reconciliation (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 985,541	$ 812,174
Gross Unrealized Gains	3,285	5,483
Gross Unrealized Losses	12,731	7,127
Fair Value	976,095	810,530
U.S. Treasury and U.S. Government-sponsored agencies
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	101,595	13,460
Gross Unrealized Gains	155	6
Gross Unrealized Losses	147	24
Fair Value	101,603	13,442
Municipal securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	158,461	247,358
Gross Unrealized Gains	1,209	3,720
Gross Unrealized Losses	806	1,063
Fair Value	158,864	250,015
Residential mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	337,295	282,724
Gross Unrealized Gains	426	422
Gross Unrealized Losses	6,119	2,935
Fair Value	331,602	280,211
Commercial mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	338,250	219,696
Gross Unrealized Gains	1,035	444
Gross Unrealized Losses	5,524	3,061
Fair Value	333,761	217,079
Collateralized loan obligations
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		4,561
Gross Unrealized Gains		19
Gross Unrealized Losses		0
Fair Value		4,580
Corporate obligations
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	25,662	16,594
Gross Unrealized Gains	36	220
Gross Unrealized Losses	135	44
Fair Value	25,563	16,770
Other securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	24,278	27,781
Gross Unrealized Gains	424	652
Gross Unrealized Losses	0	0
Fair Value	$ 24,702	$ 28,433

Investment Securities - Textual

Investment Securities - Textuals (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Investments, Debt and Equity Securities [Abstract]
Securities classified as trading	$ 0	$ 0
Securities classified as held to maturity	0	0
OTTI, unrealized losses	$ 0	$ 0	$ 0

Investment Securities - Contrac

Investment Securities - Contractual Maturities (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Amortized Cost
Due in one year or less	$ 38,547
Due after one year through five years	193,191
Due after five years through ten years	272,408
Due after ten years	481,395
Amortized Cost	985,541
Fair Value
Due in one year or less	38,478
Due after one year through five years	192,556
Due after five years through ten years	268,779
Due after ten years	476,282
Fair Value	$ 976,095	$ 810,530

Investment Securities - Unreali

Investment Securities - Unrealized Losses (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Fair Value
Less than 12 Months	$ 202,036	$ 305,174
12 Months or Longer	432,404	183,711
Total	634,440	488,885
Unrealized Losses
Less than 12 Months	(823)	(2,448)
12 Months or Longer	(11,908)	(4,679)
Total	(12,731)	(7,127)
U.S. Treasury and U.S. Government-sponsored agencies
Fair Value
Less than 12 Months	46,992	11,436
12 Months or Longer	7,350	0
Total	54,342	11,436
Unrealized Losses
Less than 12 Months	(58)	(24)
12 Months or Longer	(89)	0
Total	(147)	(24)
Municipal securities
Fair Value
Less than 12 Months	31,157	39,298
12 Months or Longer	38,792	26,509
Total	69,949	65,807
Unrealized Losses
Less than 12 Months	(159)	(384)
12 Months or Longer	(647)	(679)
Total	(806)	(1,063)
Residential mortgage-backed securities
Fair Value
Less than 12 Months	66,620	175,847
12 Months or Longer	193,726	66,380
Total	260,346	242,227
Unrealized Losses
Less than 12 Months	(247)	(1,296)
12 Months or Longer	(5,872)	(1,639)
Total	(6,119)	(2,935)
Commercial mortgage-backed securities
Fair Value
Less than 12 Months	43,531	75,121
12 Months or Longer	190,585	90,822
Total	234,116	165,943
Unrealized Losses
Less than 12 Months	(272)	(700)
12 Months or Longer	(5,252)	(2,361)
Total	(5,524)	(3,061)
Corporate obligations
Fair Value
Less than 12 Months	13,736	3,472
12 Months or Longer	1,951	0
Total	15,687	3,472
Unrealized Losses
Less than 12 Months	(87)	(44)
12 Months or Longer	(48)	0
Total	$ (135)	$ (44)

Investment Securities - Realize

Investment Securities - Realized Gains and Losses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Investments, Debt and Equity Securities [Abstract]
Gross realized gains	$ 273	$ 193	$ 1,518
Gross realized losses	136	187	203
Net realized gains	$ 137	$ 6	$ 1,315

Investment Securities - Amortiz

Investment Securities - Amortized Cost and Fair Value (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Investment Holdings [Line Items]
Amortized Cost	$ 267,977	$ 267,611
Fair Value	264,675	267,160
Washington and Oregon state to secure public deposits
Investment Holdings [Line Items]
Amortized Cost	199,026	206,377
Fair Value	196,786	206,425
Repurchase agreements
Investment Holdings [Line Items]
Amortized Cost	48,173	48,750
Fair Value	47,407	48,237
Other securities pledged
Investment Holdings [Line Items]
Amortized Cost	20,778	12,484
Fair Value	$ 20,482	$ 12,498

Investment Securities - Equity

Investment Securities - Equity Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Investments, Debt and Equity Securities [Abstract]
Equity security with readily determinable fair value	$ 114	$ 146

Loans Receivable - Textuals (De

Loans Receivable - Textuals (Details)	12 Months Ended
	Dec. 31, 2018segment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loan segments	4
Maximum percentage consumer loans (percent)	80.00%
One-to-four family residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Maximum percent of appraised value or underlying collateral mortgage (not to exceed 80%) residential loans (percent)	80.00%
One-to-four family residential | Minimum
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan term	15 years
One-to-four family residential | Maximum
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan term	30 years

Loans Receivable - Components o

Loans Receivable - Components of Loans Receivable (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans receivable	$ 3,650,651	$ 2,845,712
Net deferred loan costs	3,509	3,359
Loans receivable, net	3,654,160	2,849,071
Allowance for loan losses	(35,042)	(32,086)	$ (31,083)	$ (29,746)
Total loans receivable, net	3,619,118	2,816,985
Commercial business
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans receivable	2,937,883	2,254,140
Allowance for loan losses	(23,711)	(21,999)	(22,382)	(22,064)
Commercial business | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans receivable	853,606	645,396
Allowance for loan losses	(11,343)	(9,910)	(10,968)	(9,972)
Commercial business | Owner-occupied commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans receivable	779,814	622,150
Allowance for loan losses	(4,898)	(3,992)	(3,661)	(4,370)
Commercial business | Non-owner occupied commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans receivable	1,304,463	986,594
Allowance for loan losses	(7,470)	(8,097)	(7,753)	(7,722)
One-to-four family residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans receivable	101,763	86,997
Allowance for loan losses	(1,203)	(1,056)	(1,015)	(1,157)
Real estate construction and land development
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans receivable	215,460	149,484
Allowance for loan losses	(2,194)	(2,052)	(2,156)	(1,871)
Real estate construction and land development | One-to-four family residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans receivable	102,730	51,985
Allowance for loan losses	(1,240)	(862)	(797)	(1,058)
Real estate construction and land development | Five or more family residential and commercial properties
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans receivable	112,730	97,499
Allowance for loan losses	(954)	(1,190)	(1,359)	(813)
Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans receivable	395,545	355,091
Allowance for loan losses	$ (6,581)	$ (6,081)	$ (5,024)	$ (4,309)

Loans Receivable - Concentratio

Loans Receivable - Concentrations of Credit (Details)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Receivables [Abstract]
Concentration of loans greater than 10%	0	0
Percentage of concentrations of loans in any industry (in excess of 10%) (percent)	10.00%	10.00%

Loans Receivable - Credit Quali

Loans Receivable - Credit Quality Indicators (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Financing Receivable, Recorded Investment [Line Items]
Pass	$ 3,518,105	$ 2,730,283
OAEM	53,640	43,942
Substandard	78,382	70,962
Doubtful/Loss	524	525
Total	3,650,651	2,845,712
Potential problem loans receivable	101,300	83,500
Commercial business
Financing Receivable, Recorded Investment [Line Items]
Pass	2,812,699	2,148,602
OAEM	53,330	42,698
Substandard	71,854	62,840
Doubtful/Loss	0	0
Total	2,937,883	2,254,140
Commercial business | Commercial and industrial
Financing Receivable, Recorded Investment [Line Items]
Pass	788,395	597,697
OAEM	16,168	19,536
Substandard	49,043	28,163
Doubtful/Loss	0	0
Total	853,606	645,396
Commercial business | Owner-occupied commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Pass	741,227	595,455
OAEM	27,724	12,668
Substandard	10,863	14,027
Doubtful/Loss	0	0
Total	779,814	622,150
Commercial business | Non-owner occupied commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Pass	1,283,077	955,450
OAEM	9,438	10,494
Substandard	11,948	20,650
Doubtful/Loss	0	0
Total	1,304,463	986,594
One-to-four family residential
Financing Receivable, Recorded Investment [Line Items]
Pass	100,401	85,762
OAEM	0	0
Substandard	1,362	1,235
Doubtful/Loss	0	0
Total	101,763	86,997
Real estate construction and land development
Financing Receivable, Recorded Investment [Line Items]
Pass	214,197	146,329
OAEM	310	1,244
Substandard	953	1,911
Doubtful/Loss	0	0
Total	215,460	149,484
Real estate construction and land development | One-to-four family residential
Financing Receivable, Recorded Investment [Line Items]
Pass	101,519	49,925
OAEM	258	537
Substandard	953	1,523
Doubtful/Loss	0	0
Total	102,730	51,985
Real estate construction and land development | Five or more family residential and commercial properties
Financing Receivable, Recorded Investment [Line Items]
Pass	112,678	96,404
OAEM	52	707
Substandard	0	388
Doubtful/Loss	0	0
Total	112,730	97,499
Consumer
Financing Receivable, Recorded Investment [Line Items]
Pass	390,808	349,590
OAEM	0	0
Substandard	4,213	4,976
Doubtful/Loss	524	525
Total	$ 395,545	$ 355,091

Loans Receivable - Nonaccrual L

Loans Receivable - Nonaccrual Loans (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross nonaccrual loans	$ 13,703	$ 10,703
Commercial business
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross nonaccrual loans	12,564	9,098
Commercial business | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross nonaccrual loans	6,639	3,110
Commercial business | Owner-occupied commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross nonaccrual loans	4,212	4,090
Commercial business | Non-owner occupied commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross nonaccrual loans	1,713	1,898
One-to-four family residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross nonaccrual loans	71	81
Real estate construction and land development
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross nonaccrual loans	899	1,247
Real estate construction and land development | One-to-four family residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross nonaccrual loans	899	1,247
Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross nonaccrual loans	$ 169	$ 277

Loans Receivable - Past Due Loa

Loans Receivable - Past Due Loans (Details) - USD ($)	Dec. 31, 2018	Dec. 31, 2017
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	$ 16,934,000	$ 15,445,000
Current	3,633,717,000	2,830,267,000
Total	3,650,651,000	2,845,712,000
90 Days or More and Still Accruing	0	0
30-89 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	12,358,000	7,716,000
90 Days or Greater
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	4,576,000	7,729,000
Commercial business
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	13,240,000	10,851,000
Current	2,924,643,000	2,243,289,000
Total	2,937,883,000	2,254,140,000
Commercial business | 30-89 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	8,898,000	5,140,000
Commercial business | 90 Days or Greater
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	4,342,000	5,711,000
Commercial business | Commercial and industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	5,269,000	4,165,000
Current	848,337,000	641,231,000
Total	853,606,000	645,396,000
Commercial business | Commercial and industrial | 30-89 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	2,988,000	2,993,000
Commercial business | Commercial and industrial | 90 Days or Greater
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	2,281,000	1,172,000
Commercial business | Owner-occupied commercial real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,163,000	2,502,000
Current	778,651,000	619,648,000
Total	779,814,000	622,150,000
Commercial business | Owner-occupied commercial real estate | 30-89 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	563,000	1,277,000
Commercial business | Owner-occupied commercial real estate | 90 Days or Greater
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	600,000	1,225,000
Commercial business | Non-owner occupied commercial real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	6,808,000	4,184,000
Current	1,297,655,000	982,410,000
Total	1,304,463,000	986,594,000
Commercial business | Non-owner occupied commercial real estate | 30-89 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	5,347,000	870,000
Commercial business | Non-owner occupied commercial real estate | 90 Days or Greater
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,461,000	3,314,000
One-to-four family residential
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	227,000	513,000
Current	101,536,000	86,484,000
Total	101,763,000	86,997,000
One-to-four family residential | 30-89 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	227,000	513,000
One-to-four family residential | 90 Days or Greater
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
Real estate construction and land development
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	899,000	1,455,000
Current	214,561,000	148,029,000
Total	215,460,000	149,484,000
Real estate construction and land development | 30-89 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	665,000	124,000
Real estate construction and land development | 90 Days or Greater
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	234,000	1,331,000
Real estate construction and land development | One-to-four family residential
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	899,000	1,415,000
Current	101,831,000	50,570,000
Total	102,730,000	51,985,000
Real estate construction and land development | One-to-four family residential | 30-89 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	665,000	84,000
Real estate construction and land development | One-to-four family residential | 90 Days or Greater
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	234,000	1,331,000
Real estate construction and land development | Five or more family residential and commercial properties
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	40,000
Current	112,730,000	97,459,000
Total	112,730,000	97,499,000
Real estate construction and land development | Five or more family residential and commercial properties | 30-89 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	40,000
Real estate construction and land development | Five or more family residential and commercial properties | 90 Days or Greater
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
Consumer
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	2,568,000	2,626,000
Current	392,977,000	352,465,000
Total	395,545,000	355,091,000
Consumer | 30-89 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	2,568,000	1,939,000
Consumer | 90 Days or Greater
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	$ 0	$ 687,000

Loans Receivable - Impaired Loa

Loans Receivable - Impaired Loans (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Specific Valuation Allowance	$ 7,590	$ 10,399
Recorded Investment With Specific Valuation Allowance	28,849	27,060
Total Recorded Investment	36,439	37,459
Unpaid Contractual Principal Balance	39,233	39,334
Related Specific Valuation Allowance	4,170	3,355
Commercial business
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Specific Valuation Allowance	6,691	9,301
Recorded Investment With Specific Valuation Allowance	28,043	25,525
Total Recorded Investment	34,734	34,826
Unpaid Contractual Principal Balance	36,740	35,715
Related Specific Valuation Allowance	3,955	3,169
Commercial business | Commercial and industrial
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Specific Valuation Allowance	2,523	2,127
Recorded Investment With Specific Valuation Allowance	20,119	9,872
Total Recorded Investment	22,642	11,999
Unpaid Contractual Principal Balance	24,176	12,489
Related Specific Valuation Allowance	2,607	1,326
Commercial business | Owner-occupied commercial real estate
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Specific Valuation Allowance	816	2,452
Recorded Investment With Specific Valuation Allowance	5,000	4,356
Total Recorded Investment	5,816	6,808
Unpaid Contractual Principal Balance	6,150	7,054
Related Specific Valuation Allowance	1,142	621
Commercial business | Non-owner occupied commercial real estate
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Specific Valuation Allowance	3,352	4,722
Recorded Investment With Specific Valuation Allowance	2,924	11,297
Total Recorded Investment	6,276	16,019
Unpaid Contractual Principal Balance	6,414	16,172
Related Specific Valuation Allowance	206	1,222
One-to-four family residential
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Specific Valuation Allowance	0	0
Recorded Investment With Specific Valuation Allowance	279	299
Total Recorded Investment	279	299
Unpaid Contractual Principal Balance	293	308
Related Specific Valuation Allowance	76	93
Real estate construction and land development
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Specific Valuation Allowance	899	938
Recorded Investment With Specific Valuation Allowance	0	954
Total Recorded Investment	899	1,892
Unpaid Contractual Principal Balance	1,662	2,845
Related Specific Valuation Allowance	0	39
Real estate construction and land development | One-to-four family residential
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Specific Valuation Allowance	899	938
Recorded Investment With Specific Valuation Allowance	0	309
Total Recorded Investment	899	1,247
Unpaid Contractual Principal Balance	1,662	2,200
Related Specific Valuation Allowance	0	2
Real estate construction and land development | Five or more family residential and commercial properties
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Specific Valuation Allowance		0
Recorded Investment With Specific Valuation Allowance		645
Total Recorded Investment		645
Unpaid Contractual Principal Balance		645
Related Specific Valuation Allowance		37
Consumer
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Specific Valuation Allowance	0	160
Recorded Investment With Specific Valuation Allowance	527	282
Total Recorded Investment	527	442
Unpaid Contractual Principal Balance	538	466
Related Specific Valuation Allowance	$ 139	$ 54

Loans Receivable - Average Reco

Loans Receivable - Average Recorded Investment of Impaired Loans (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Financing Receivable, Modifications [Line Items]
Average recorded investment of impaired loans	$ 39,488,000	$ 32,751,000	$ 32,341,000
Nonaccrual
Financing Receivable, Modifications [Line Items]
Interest income recognized	0	0	0
Restructured performing
Financing Receivable, Modifications [Line Items]
Interest income recognized	1,400,000	1,200,000	651,000
Commercial business
Financing Receivable, Modifications [Line Items]
Average recorded investment of impaired loans	37,550,000	28,873,000	26,456,000
Commercial business | Commercial and industrial
Financing Receivable, Modifications [Line Items]
Average recorded investment of impaired loans	16,773,000	11,310,000	10,207,000
Commercial business | Owner-occupied commercial real estate
Financing Receivable, Modifications [Line Items]
Average recorded investment of impaired loans	11,312,000	5,401,000	4,540,000
Commercial business | Non-owner occupied commercial real estate
Financing Receivable, Modifications [Line Items]
Average recorded investment of impaired loans	9,465,000	12,162,000	11,709,000
One-to-four family residential
Financing Receivable, Modifications [Line Items]
Average recorded investment of impaired loans	290,000	309,000	279,000
Real estate construction and land development
Financing Receivable, Modifications [Line Items]
Average recorded investment of impaired loans	1,220,000	3,218,000	4,961,000
Real estate construction and land development | One-to-four family residential
Financing Receivable, Modifications [Line Items]
Average recorded investment of impaired loans	1,091,000	2,315,000	3,305,000
Real estate construction and land development | Five or more family residential and commercial properties
Financing Receivable, Modifications [Line Items]
Average recorded investment of impaired loans	129,000	903,000	1,656,000
Consumer
Financing Receivable, Modifications [Line Items]
Average recorded investment of impaired loans	$ 428,000	$ 351,000	$ 645,000

Loans Receivable - Performing a

Loans Receivable - Performing and Nonaccrual TDR (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Receivables [Abstract]
Performing TDRs	$ 22,736	$ 26,757
Nonaccrual TDRs	6,943	5,193
Performing TDR loans, Allowance for loan losses	2,257	2,635
Nonaccrual TDR loans, Allowance for loan losses	658	379
Unfunded commitment to borrowers related to TDR loans	$ 943	$ 1,200

Loans Receivable - Modified TDR

Loans Receivable - Modified TDRs (Details) - Troubled Debt Restructured Loans	12 Months Ended
	Dec. 31, 2018USD ($)contract	Dec. 31, 2017USD ($)contract	Dec. 31, 2016USD ($)contract
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	53	36	35
Outstanding Principal Balance	$ 22,495,000	$ 19,200,000	$ 13,438,000
Commercial business
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	38	26	23
Outstanding Principal Balance	$ 21,594,000	$ 18,152,000	$ 10,088,000
Commercial business | Commercial and industrial
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	31	19	19
Outstanding Principal Balance	$ 16,129,000	$ 7,212,000	$ 7,398,000
Commercial business | Owner-occupied commercial real estate
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	4	3	2
Outstanding Principal Balance	$ 2,521,000	$ 1,366,000	$ 569,000
Commercial business | Non-owner occupied commercial real estate
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	3	4	2
Outstanding Principal Balance	$ 2,944,000	$ 9,574,000	$ 2,121,000
Real estate construction and land development
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	2	2	6
Outstanding Principal Balance	$ 665,000	$ 938,000	$ 3,284,000
Real estate construction and land development | One-to-four family residential
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	2	2	5
Outstanding Principal Balance	$ 665,000	$ 938,000	$ 2,206,000
Initial advance at the time of modification	$ 0	$ 0	$ 0
Real estate construction and land development | Five or more family residential and commercial properties
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	0	0	1
Outstanding Principal Balance	$ 0	$ 0	$ 1,078,000
Consumer
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	13	8	6
Outstanding Principal Balance	$ 236,000	$ 110,000	$ 66,000

Loans Receivable - TDRs Textual

Loans Receivable - TDRs Textuals (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2018USD ($)contract	Dec. 31, 2017USD ($)contract	Dec. 31, 2016USD ($)contract
Financing Receivable, Modifications [Line Items]
Related specific valuation allowance for TDRs	$ 4,170	$ 3,355
Commercial business
Financing Receivable, Modifications [Line Items]
Related specific valuation allowance for TDRs	3,955	3,169
Commercial business | Commercial and industrial
Financing Receivable, Modifications [Line Items]
Related specific valuation allowance for TDRs	2,607	1,326
Consumer
Financing Receivable, Modifications [Line Items]
Related specific valuation allowance for TDRs	$ 139	$ 54
Troubled Debt Restructured Loans
Financing Receivable, Modifications [Line Items]
Number of contracts modified that subsequently defaulted | contract	8	5	3
Loans modified during the previous twelve months and subsequently defaulted	$ 2,620	$ 1,308	$ 1,631
Troubled Debt Restructured Loans | Past modified maturity date
Financing Receivable, Modifications [Line Items]
Number of contracts modified that subsequently defaulted | contract	7	4
Troubled Debt Restructured Loans | Commercial business
Financing Receivable, Modifications [Line Items]
Number of contracts modified that subsequently defaulted | contract	6	2	1
Loans modified during the previous twelve months and subsequently defaulted	$ 1,955	$ 363	$ 488
Troubled Debt Restructured Loans | Commercial business | Commercial and industrial
Financing Receivable, Modifications [Line Items]
Number of contracts modified that subsequently defaulted | contract	5	1	0
Loans modified during the previous twelve months and subsequently defaulted	$ 1,890	$ 283	$ 0
Troubled Debt Restructured Loans | Commercial business | Commercial and industrial | Past modified maturity date
Financing Receivable, Modifications [Line Items]
Number of contracts modified that subsequently defaulted | contract	1
Loans modified during the previous twelve months and subsequently defaulted	$ 882
Troubled Debt Restructured Loans | Commercial business | Commercial and industrial | 30-89 days past due
Financing Receivable, Modifications [Line Items]
Number of contracts modified that subsequently defaulted | contract			3
Troubled Debt Restructured Loans | Consumer
Financing Receivable, Modifications [Line Items]
Number of contracts modified that subsequently defaulted | contract	0	1	0
Loans modified during the previous twelve months and subsequently defaulted	$ 0	$ 7	$ 0
Troubled Debt Restructured Loans | Consumer | Past modified maturity date
Financing Receivable, Modifications [Line Items]
Number of contracts modified that subsequently defaulted | contract		1
Troubled Debt Restructured Loans | Modified during the year
Financing Receivable, Modifications [Line Items]
Related specific valuation allowance for TDRs	2,300	$ 1,800
Troubled Debt Restructured Loans | Modified subsequently
Financing Receivable, Modifications [Line Items]
Related specific valuation allowance for TDRs	$ 260	$ 1	$ 111

Loans Receivable - TDRs Subsequ

Loans Receivable - TDRs Subsequently Defaulted (Details) - Troubled Debt Restructured Loans $ in Thousands	12 Months Ended
	Dec. 31, 2018USD ($)contract	Dec. 31, 2017USD ($)contract	Dec. 31, 2016USD ($)contract
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	8	5	3
Recorded Investment | $	$ 2,620	$ 1,308	$ 1,631
Commercial business
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	6	2	1
Recorded Investment | $	$ 1,955	$ 363	$ 488
Commercial business | Commercial and industrial
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	5	1	0
Recorded Investment | $	$ 1,890	$ 283	$ 0
Commercial business | Owner-occupied commercial real estate
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	1	1	1
Recorded Investment | $	$ 65	$ 80	$ 488
Real estate construction and land development
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	2	2	2
Recorded Investment | $	$ 665	$ 938	$ 1,143
Real estate construction and land development | One-to-four family residential
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	2	2	2
Recorded Investment | $	$ 665	$ 938	$ 1,143
Consumer
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	0	1	0
Recorded Investment | $	$ 0	$ 7	$ 0

Loans Receivable - Purchased Cr

Loans Receivable - Purchased Credit Impaired Loans (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Financing Receivable, Impaired [Line Items]
Outstanding Principal	$ 28,461	$ 46,639
Recorded Investment	24,907	40,603
Commercial business
Financing Receivable, Impaired [Line Items]
Outstanding Principal	22,834	35,343
Recorded Investment	17,707	27,769
Commercial business | Commercial and industrial
Financing Receivable, Impaired [Line Items]
Outstanding Principal	6,319	8,818
Recorded Investment	3,433	2,912
Commercial business | Owner-occupied commercial real estate
Financing Receivable, Impaired [Line Items]
Outstanding Principal	7,830	12,230
Recorded Investment	7,215	11,515
Commercial business | Non-owner occupied commercial real estate
Financing Receivable, Impaired [Line Items]
Outstanding Principal	8,685	14,295
Recorded Investment	7,059	13,342
One-to-four family residential
Financing Receivable, Impaired [Line Items]
Outstanding Principal	3,169	4,120
Recorded Investment	3,315	5,255
Real estate construction and land development
Financing Receivable, Impaired [Line Items]
Outstanding Principal	255	3,202
Recorded Investment	423	2,124
Real estate construction and land development | One-to-four family residential
Financing Receivable, Impaired [Line Items]
Outstanding Principal	67	841
Recorded Investment	380	89
Real estate construction and land development | Five or more family residential and commercial properties
Financing Receivable, Impaired [Line Items]
Outstanding Principal	188	2,361
Recorded Investment	43	2,035
Consumer
Financing Receivable, Impaired [Line Items]
Outstanding Principal	2,203	3,974
Recorded Investment	$ 3,462	$ 5,455

Loans Receivable - Change in Ac

Loans Receivable - Change in Accretable Yield (Details) - PCI Loans - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield Movement Schedule [Roll Forward]
Balance at the beginning of the year	$ 11,224	$ 13,860	$ 17,592
Accretion	(2,674)	(3,471)	(4,962)
Disposal and other	(2,871)	(2,758)	(3,329)
Change in accretable yield	3,814	3,593	4,559
Balance at the end of the year	$ 9,493	$ 11,224	$ 13,860

Loans Receivable - Related Part

Loans Receivable - Related Party Loans (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Loans and Leases Receivable, Related Parties [Roll Forward]
Balance outstanding at beginning of year	$ 8,460,000	$ 19,917,000	$ 20,775,000
Elimination of outstanding loan balance due to change in related party status	0	(10,930,000)	0
Principal additions	211,000	0	738,000
Principal reductions	(304,000)	(527,000)	(1,596,000)
Balance outstanding at end of year	8,367,000	8,460,000	$ 19,917,000
Unfunded commitments to related parties	592,000	750,000
Borrowings from related parties	$ 0	$ 0

Loans Receivable - Mortgage Ban

Loans Receivable - Mortgage Banking Activities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Receivables [Abstract]
Loans held for sale	$ 1,555	$ 2,288
One-to-four family residential
One-to-four family residential loans:
Originated	121,998	144,066	$ 178,169
Sold	76,834	113,786	141,127
Gains on sales of loans, net	2,403	3,412	$ 3,723
Contractual amounts of commitments to sell and fund with off-balance sheet risk:
Commitments to sell mortgage loans	3,910	10,140
Commitments to fund mortgage loans (at interest rates approximating market rates) for portfolio or for sale:
Fixed rate	6,593	10,894
Variable or adjustable rate	1,008	56
Total commitments to fund mortgage loans	$ 7,601	$ 10,950

Loans Receivable - SBA Loans (D

Loans Receivable - SBA Loans (Details) - SBA Loans - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
SBA Loans [Line Items]
SBA loans serviced for others with participating interest, gross loan balance	$ 54,335	$ 53,809
SBA loans serviced for others with participating interest, participation balance owned by Bank	12,715	12,394
Servicing fee income and fees from SBA loans serviced for others	$ 506	$ 467	$ 460

Allowance for Loan Losses - Sum

Allowance for Loan Losses - Summary of Changes in Loan Allowance (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Schedule of changes in allowance for loan losses
Balance at the beginning of the year				$ 32,086				$ 31,083	$ 32,086	$ 31,083	$ 29,746
Charge-offs									(3,605)	(4,838)	(6,085)
Recoveries of loans previously charged-off									1,432	1,621	2,491
Provision for loan losses	$ 1,162	$ 1,065	$ 1,750	$ 1,152	$ 1,338	$ 884	$ 1,131	$ 867	5,129	4,220	4,931
Balance at the end of the year	$ 35,042				$ 32,086				$ 35,042	$ 32,086	$ 31,083

Allowance for Loan Losses - Act

Allowance for Loan Losses - Activity in Allowance for Losses Disaggregated on Basis of Impairment (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Schedule of allowance for loan losses on the basis of impairment method
Balance at the beginning of the year				$ 32,086				$ 31,083	$ 32,086	$ 31,083	$ 29,746
Charge-offs									(3,605)	(4,838)	(6,085)
Recoveries									1,432	1,621	2,491
Provision for loan losses	$ 1,162	$ 1,065	$ 1,750	1,152	$ 1,338	$ 884	$ 1,131	867	5,129	4,220	4,931
Balance at the end of the year	35,042				32,086				35,042	32,086	31,083
Commercial business
Schedule of allowance for loan losses on the basis of impairment method
Balance at the beginning of the year				21,999				22,382	21,999	22,382	22,064
Charge-offs									(1,400)	(2,438)	(4,153)
Recoveries									908	947	1,844
Provision for loan losses									2,204	1,108	2,627
Balance at the end of the year	23,711				21,999				23,711	21,999	22,382
Commercial business | Commercial and industrial
Schedule of allowance for loan losses on the basis of impairment method
Balance at the beginning of the year				9,910				10,968	9,910	10,968	9,972
Charge-offs									(1,250)	(859)	(3,265)
Recoveries									901	792	1,844
Provision for loan losses									1,782	(991)	2,417
Balance at the end of the year	11,343				9,910				11,343	9,910	10,968
Commercial business | Owner-occupied commercial real estate
Schedule of allowance for loan losses on the basis of impairment method
Balance at the beginning of the year				3,992				3,661	3,992	3,661	4,370
Charge-offs									(1)	(1,579)	(538)
Recoveries									7	155	0
Provision for loan losses									900	1,755	(171)
Balance at the end of the year	4,898				3,992				4,898	3,992	3,661
Commercial business | Non-owner occupied commercial real estate
Schedule of allowance for loan losses on the basis of impairment method
Balance at the beginning of the year				8,097				7,753	8,097	7,753	7,722
Charge-offs									(149)	0	(350)
Recoveries									0	0	0
Provision for loan losses									(478)	344	381
Balance at the end of the year	7,470				8,097				7,470	8,097	7,753
One-to-four family residential
Schedule of allowance for loan losses on the basis of impairment method
Balance at the beginning of the year				1,056				1,015	1,056	1,015	1,157
Charge-offs									(45)	(30)	0
Recoveries									0	2	2
Provision for loan losses									192	69	(144)
Balance at the end of the year	1,203				1,056				1,203	1,056	1,015
Real estate construction and land development
Schedule of allowance for loan losses on the basis of impairment method
Balance at the beginning of the year				2,052				2,156	2,052	2,156	1,871
Charge-offs									0	(556)	(154)
Recoveries									11	202	83
Provision for loan losses									131	250	356
Balance at the end of the year	2,194				2,052				2,194	2,052	2,156
Real estate construction and land development | One-to-four family residential
Schedule of allowance for loan losses on the basis of impairment method
Balance at the beginning of the year				862				797	862	797	1,058
Charge-offs									0	(556)	(100)
Recoveries									11	202	83
Provision for loan losses									367	419	(244)
Balance at the end of the year	1,240				862				1,240	862	797
Real estate construction and land development | Five or more family residential and commercial properties
Schedule of allowance for loan losses on the basis of impairment method
Balance at the beginning of the year				1,190				1,359	1,190	1,359	813
Charge-offs									0	0	(54)
Recoveries									0	0	0
Provision for loan losses									(236)	(169)	600
Balance at the end of the year	954				1,190				954	1,190	1,359
Consumer
Schedule of allowance for loan losses on the basis of impairment method
Balance at the beginning of the year				6,081				5,024	6,081	5,024	4,309
Charge-offs									(2,160)	(1,814)	(1,778)
Recoveries									513	470	562
Provision for loan losses									2,147	2,401	1,931
Balance at the end of the year	6,581				6,081				6,581	6,081	5,024
Unallocated
Schedule of allowance for loan losses on the basis of impairment method
Balance at the beginning of the year				$ 898				$ 506	898	506	345
Charge-offs									0	0	0
Recoveries									0	0	0
Provision for loan losses									455	392	161
Balance at the end of the year	$ 1,353				$ 898				$ 1,353	$ 898	$ 506

Allowance for Loan Losses - Rec

Allowance for Loan Losses - Recorded Investment Disaggregated on Basis of Impairment (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Allowance for Loan Losses Disaggregated:
Loans Individually Evaluated for Impairment	$ 4,170	$ 3,355
Loans Collectively Evaluated for Impairment	27,854	24,732
PCI Loans	3,018	3,999
Total Allowance for Loan Losses	35,042	32,086	$ 31,083	$ 29,746
Loan Receivables, Disaggregated:
Loans Individually Evaluated for Impairment	36,439	37,459
Loans Collectively Evaluated for Impairment	3,589,305	2,767,650
PCI Loans	24,907	40,603
Total Gross Loans Receivable	3,650,651	2,845,712
Commercial business
Allowance for Loan Losses Disaggregated:
Loans Individually Evaluated for Impairment	3,955	3,169
Loans Collectively Evaluated for Impairment	17,606	16,034
PCI Loans	2,150	2,796
Total Allowance for Loan Losses	23,711	21,999	22,382	22,064
Loan Receivables, Disaggregated:
Loans Individually Evaluated for Impairment	34,734	34,826
Loans Collectively Evaluated for Impairment	2,885,442	2,191,545
PCI Loans	17,707	27,769
Total Gross Loans Receivable	2,937,883	2,254,140
Commercial business | Commercial and industrial
Allowance for Loan Losses Disaggregated:
Loans Individually Evaluated for Impairment	2,607	1,326
Loans Collectively Evaluated for Impairment	7,913	7,558
PCI Loans	823	1,026
Total Allowance for Loan Losses	11,343	9,910	10,968	9,972
Loan Receivables, Disaggregated:
Loans Individually Evaluated for Impairment	22,642	11,999
Loans Collectively Evaluated for Impairment	827,531	630,485
PCI Loans	3,433	2,912
Total Gross Loans Receivable	853,606	645,396
Commercial business | Owner-occupied commercial real estate
Allowance for Loan Losses Disaggregated:
Loans Individually Evaluated for Impairment	1,142	621
Loans Collectively Evaluated for Impairment	3,063	2,557
PCI Loans	693	814
Total Allowance for Loan Losses	4,898	3,992	3,661	4,370
Loan Receivables, Disaggregated:
Loans Individually Evaluated for Impairment	5,816	6,808
Loans Collectively Evaluated for Impairment	766,783	603,827
PCI Loans	7,215	11,515
Total Gross Loans Receivable	779,814	622,150
Commercial business | Non-owner occupied commercial real estate
Allowance for Loan Losses Disaggregated:
Loans Individually Evaluated for Impairment	206	1,222
Loans Collectively Evaluated for Impairment	6,630	5,919
PCI Loans	634	956
Total Allowance for Loan Losses	7,470	8,097	7,753	7,722
Loan Receivables, Disaggregated:
Loans Individually Evaluated for Impairment	6,276	16,019
Loans Collectively Evaluated for Impairment	1,291,128	957,233
PCI Loans	7,059	13,342
Total Gross Loans Receivable	1,304,463	986,594
One-to-four family residential
Allowance for Loan Losses Disaggregated:
Loans Individually Evaluated for Impairment	76	93
Loans Collectively Evaluated for Impairment	1,015	798
PCI Loans	112	165
Total Allowance for Loan Losses	1,203	1,056	1,015	1,157
Loan Receivables, Disaggregated:
Loans Individually Evaluated for Impairment	279	299
Loans Collectively Evaluated for Impairment	98,169	81,443
PCI Loans	3,315	5,255
Total Gross Loans Receivable	101,763	86,997
Real estate construction and land development
Allowance for Loan Losses Disaggregated:
Loans Individually Evaluated for Impairment	0	39
Loans Collectively Evaluated for Impairment	1,915	1,699
PCI Loans	279	314
Total Allowance for Loan Losses	2,194	2,052	2,156	1,871
Loan Receivables, Disaggregated:
Loans Individually Evaluated for Impairment	899	1,892
Loans Collectively Evaluated for Impairment	214,138	145,468
PCI Loans	423	2,124
Total Gross Loans Receivable	215,460	149,484
Real estate construction and land development | One-to-four family residential
Allowance for Loan Losses Disaggregated:
Loans Individually Evaluated for Impairment	0	2
Loans Collectively Evaluated for Impairment	1,040	635
PCI Loans	200	225
Total Allowance for Loan Losses	1,240	862	797	1,058
Loan Receivables, Disaggregated:
Loans Individually Evaluated for Impairment	899	1,247
Loans Collectively Evaluated for Impairment	101,451	50,649
PCI Loans	380	89
Total Gross Loans Receivable	102,730	51,985
Real estate construction and land development | Five or more family residential and commercial properties
Allowance for Loan Losses Disaggregated:
Loans Individually Evaluated for Impairment	0	37
Loans Collectively Evaluated for Impairment	875	1,064
PCI Loans	79	89
Total Allowance for Loan Losses	954	1,190	1,359	813
Loan Receivables, Disaggregated:
Loans Individually Evaluated for Impairment	0	645
Loans Collectively Evaluated for Impairment	112,687	94,819
PCI Loans	43	2,035
Total Gross Loans Receivable	112,730	97,499
Consumer
Allowance for Loan Losses Disaggregated:
Loans Individually Evaluated for Impairment	139	54
Loans Collectively Evaluated for Impairment	5,965	5,303
PCI Loans	477	724
Total Allowance for Loan Losses	6,581	6,081	5,024	4,309
Loan Receivables, Disaggregated:
Loans Individually Evaluated for Impairment	527	442
Loans Collectively Evaluated for Impairment	391,556	349,194
PCI Loans	3,462	5,455
Total Gross Loans Receivable	395,545	355,091
Unallocated
Allowance for Loan Losses Disaggregated:
Loans Individually Evaluated for Impairment	0	0
Loans Collectively Evaluated for Impairment	1,353	898
PCI Loans	0	0
Total Allowance for Loan Losses	$ 1,353	$ 898	$ 506	$ 345

Other Real Estate Owned - Chang

Other Real Estate Owned - Changes in Other Real Estate Owned (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Changes in other real estate owned
Balance at the beginning of the year	$ 0	$ 754	$ 2,019
Additions	434	32	1,431
Additions from acquisitions	1,796	0	0
Proceeds from dispositions	(198)	(930)	(2,486)
Gain on sale, net	0	144	173
Valuation adjustment	(49)	0	(383)
Balance at the end of the year	$ 1,983	$ 0	$ 754

Other Real Estate Owned - Textu

Other Real Estate Owned - Textuals (Details)	Dec. 31, 2018USD ($)
Mortgage Loans on Real Estate [Line Items]
Mortgage loans secured by residential real estate properties	$ 0
One-to-four family residential
Mortgage Loans on Real Estate [Line Items]
Carrying amount of other real estate owned from foreclosure	$ 434,000

Premises and Equipment (Details

Premises and Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Total premises and equipment	$ 117,623	$ 93,361
Less: Accumulated depreciation	36,523	33,036
Premises and equipment, net	81,100	60,325
Depreciation	4,400	3,900	$ 3,900
Land
Property, Plant and Equipment [Line Items]
Total premises and equipment	22,954	21,483
Buildings and building improvements
Property, Plant and Equipment [Line Items]
Total premises and equipment	69,315	50,984
Furniture, fixtures and equipment
Property, Plant and Equipment [Line Items]
Total premises and equipment	$ 25,354	$ 20,894

Goodwill and Other Intangible_3

Goodwill and Other Intangible Assets - Change in Goodwill (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Goodwill [Roll Forward]
Balance at the beginning of the period	$ 119,029	$ 119,029	$ 119,029
Additions as a result of acquisitions	121,910	0	0
Balance at the end of the period	$ 240,939	$ 119,029	$ 119,029

Goodwill and Other Intangible_4

Goodwill and Other Intangible Assets - Textuals (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill impairment charges	$ 0	$ 0	$ 0
Premier Commercial | Core Deposits
Finite-Lived Intangible Assets [Line Items]
Useful life	10 years
Puget Sound | Core Deposits
Finite-Lived Intangible Assets [Line Items]
Useful life	10 years
Washington Banking | Core Deposits
Finite-Lived Intangible Assets [Line Items]
Useful life	10 years
Valley Community Bancshares | Core Deposits
Finite-Lived Intangible Assets [Line Items]
Useful life	10 years
Northwest Commercial Bank | Core Deposits
Finite-Lived Intangible Assets [Line Items]
Useful life	5 years

Goodwill and Other Intangible_5

Goodwill and Other Intangible Assets - Change in Other Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Finite-lived Intangible Assets [Roll Forward]
Balance at the beginning of the year	$ 6,088	$ 7,374	$ 8,789
Additions as a result of acquisitions	18,345	0	0
Amortization	(3,819)	(1,286)	(1,415)
Balance at the end of the year	$ 20,614	$ 6,088	$ 7,374

Goodwill and Other Intangible_6

Goodwill and Other Intangible Assets - Future Amortization Expense (Details) $ in Thousands	Dec. 31, 2018USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
2,019	$ 4,001
2,020	3,525
2,021	3,111
2,022	2,750
2,023	2,435
Thereafter	4,792
Intangible assets, net	$ 20,614

Deposits - Components of Deposi

Deposits - Components of Deposits (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Amount
Noninterest demand deposits	$ 1,362,268	$ 944,791
Interest bearing demand deposits	1,317,513	1,051,752
Money market accounts	765,316	499,618
Savings accounts	520,413	498,501
Total non-maturity deposits	3,965,510	2,994,662
Certificate of deposit accounts	466,892	398,398
Total deposits	$ 4,432,402	$ 3,393,060
Percent
Noninterest demand deposits (as a percent)	30.70%	27.80%
Interest bearing demand deposits (as a percent)	29.70%	31.10%
Money market accounts (as a percent)	17.30%	14.70%
Savings accounts (as a percent)	11.80%	14.70%
Total non-maturity deposits (as a percent)	89.50%	88.30%
Certificate of deposit accounts (as a percent)	10.50%	11.70%
Total deposits (as a percent)	100.00%	100.00%

Deposits - Textuals (Details)

Deposits - Textuals (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Deposits [Abstract]
Accrued interest payable on deposits	$ 144	$ 124
Certificates of deposit equal to or in excess of $250,000	$ 146,200	$ 113,700

Deposits - Schedule of Interest

Deposits - Schedule of Interest Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Deposits [Abstract]
Interest bearing demand deposits	$ 2,728	$ 1,812	$ 1,569
Money market accounts	1,654	682	749
Savings accounts	2,056	1,311	756
Certificate of deposit accounts	3,959	2,244	1,936
Total interest expense	$ 10,397	$ 6,049	$ 5,010

Deposits - Schedule of Maturiti

Deposits - Schedule of Maturities (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Deposits [Abstract]
2,019	$ 313,830
2,020	93,675
2,021	14,608
2,022	24,914
2,023	19,847
Thereafter	18
Certificates of deposit	$ 466,892	$ 398,398

Junior Subordinated Debentures

Junior Subordinated Debentures (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2007	May 01, 2014
Debt Instrument [Line Items]
Issued amount				$ 25,000
Debt term				30 years
Adjustable rate of trust preferred securities	4.37%
Junior subordinated debentures	$ 20,302	$ 20,009
Junior Subordinated Debentures
Debt Instrument [Line Items]
Weighted average rate	6.27%	5.11%	4.50%
LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate (as a percent)				1.56%
Washington Banking
Debt Instrument [Line Items]
Assumed trust preferred securities and junior subordinated debentures, fair value					$ 18,900

Repurchase Agreements (Details)

Repurchase Agreements (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Assets Sold under Agreements to Repurchase [Line Items]
Maturity period	1 day
Repurchase agreement obligations	$ 31,487	$ 31,821
U.S. Treasury and U.S. Government-sponsored agencies
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase agreement obligations	4,878	0
Residential mortgage-backed securities
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase agreement obligations	9,335	11,239
Commercial mortgage-backed securities
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase agreement obligations	$ 17,274	$ 20,582

Other Borrowings - FHLB Advance

Other Borrowings - FHLB Advances (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Debt Disclosure [Abstract]
Credit facility with the FHLB	$ 921,700,000
Advances outstanding	0	$ 92,500,000
FHLB Advances:
Average balance during the year	33,913,000	105,646,000
Maximum month-end balance during the year	$ 154,500,000	$ 137,450,000
Weighted average rate during the year	1.98%	1.16%
Weighted average rate at the end of year		1.56%
Minimum
Federal Home Loan Bank, Advances [Line Items]
Unencumbered collateral in amount equal to varying percentages	100.00%
Maximum
Federal Home Loan Bank, Advances [Line Items]
Unencumbered collateral in amount equal to varying percentages	160.00%

Other Borrowings - Federal Fund

Other Borrowings - Federal Funds Purchased (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Debt Disclosure [Abstract]
Advance line maintained to purchase federal funds	$ 90,000,000
Federal funds purchased	$ 0	$ 0

Other Borrowings - Credit Facil

Other Borrowings - Credit Facilities (Details) - Federal Reserve Bank Advances - USD ($)	Dec. 31, 2018	Dec. 31, 2017
Line of Credit Facility [Line Items]
Credit facility, maximum borrowing capacity	$ 37,400,000
Borrowings outstanding	$ 0	$ 0

Employee Benefit Plans (Details

Employee Benefit Plans (Details)	12 Months Ended
	Dec. 31, 2018USD ($)hour	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]
Percentage of employer contribution fully vested	100.00%
Carrying value of obligation related to deferred compensation plan	$ 3,700,000	$ 2,800,000
Salary Continuation Plan expense	184,000	0	$ 0
Accrued expenses and other liabilities
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]
Salary Continuation Plan	4,600,000
Accrued expenses and other liabilities | Washington Banking
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]
Carrying value of obligation	$ 268,000	250,000
401(k) Plan and Trust Salary Saving Plan
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]
Minimum service days required for eligibility under the plan	30 days
Employer matching contribution, percent of employee's gross pay	50.00%
Maximum annual contributions per employee, percent	3.00%
Defined contribution plan, employer matching contribution amount	$ 1,400,000	1,100,000	1,000,000
401(k) Plan and Trust
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]
Minimum hours of service required for eligibility under the plan | hour	1,000
Minimum age required for eligibility under the plan	18 years
Employer profit sharing contributions	$ 0	0	0
Deferred Compensation Plan
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]
Compensation expense	810,000	652,000	540,000
Company's contributions	$ 583,000	$ 453,000	$ 521,000

Commitments and Contingencies -

Commitments and Contingencies - Lease Commitments (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Rental expense	$ 6.1	$ 3.8	$ 4.4

Commitments and Contingencies_2

Commitments and Contingencies - Future Minimum Rental Payments (Details) $ in Thousands	Dec. 31, 2018USD ($)
Commitments and Contingencies Disclosure [Abstract]
2,019	$ 4,766
2,020	4,251
2,021	2,477
2,022	1,704
2,023	1,568
Thereafter	1,788
Future minimum annual rental commitments	$ 16,554

Commitments and Contingencies_3

Commitments and Contingencies - Outstanding Commitments to Extend Credit (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Other Commitments [Line Items]
Total outstanding commitments	$ 990,030	$ 713,202
Commercial business
Other Commitments [Line Items]
Total outstanding commitments	594,901	383,630
Commercial business | Commercial and industrial
Other Commitments [Line Items]
Total outstanding commitments	568,215	363,272
Commercial business | Owner-occupied commercial real estate
Other Commitments [Line Items]
Total outstanding commitments	13,065	6,815
Commercial business | Non-owner occupied commercial real estate
Other Commitments [Line Items]
Total outstanding commitments	13,621	13,543
One-to-four family residential
Other Commitments [Line Items]
Total outstanding commitments	0	0
Real estate construction and land development
Other Commitments [Line Items]
Total outstanding commitments	155,307	124,947
Real estate construction and land development | One-to-four family residential
Other Commitments [Line Items]
Total outstanding commitments	59,772	38,160
Real estate construction and land development | Five or more family residential and commercial properties
Other Commitments [Line Items]
Total outstanding commitments	95,535	86,787
Consumer
Other Commitments [Line Items]
Total outstanding commitments	$ 239,822	$ 204,625

Commitments and Contingencies_4

Commitments and Contingencies - Variable Interests (Details)	12 Months Ended
	Dec. 31, 2018USD ($)investmenttranch	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2034USD ($)	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)
Variable Interest Entity [Line Items]
Number of equity investments in LIHTCs | investment	2
Investments in unconsolidated LIHTCs	$ 50,900,000	$ 54,000,000
Tax benefits	2,400,000	2,900,000	$ 640,000
Commitments	31,500,000	39,800,000
Impairment losses on LIHTC investments	0	0	0
Carrying value of NMTC	25,700,000	25,800,000
Investment income	708,000	$ 735,000	$ 740,000
Subsidiaries | Investment Tax Credit Carryforward
Variable Interest Entity [Line Items]
Qualified Equity Investments	$ 25,000,000
Number of tranches | tranch	3
Percentage of tranche required to fund to claim the entire tax credit	85.00%
Subsidiaries | Investment Tax Credit Carryforward | 2020
Variable Interest Entity [Line Items]
Gross tax credits related to the Company's CDEs	$ 9,800,000
Forecast
Variable Interest Entity [Line Items]
Qualified Affordable Housing Project Investments, future commitment				$ 4,500,000	$ 523,000	$ 26,400,000

Derivative Financial Instrume_3

Derivative Financial Instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Prepaid expenses and other assets
Derivative [Line Items]
Estimated Fair Value - Interest rate swaps with customer	$ 5,100	$ 3,400
Accrued expenses and other liabilities
Derivative [Line Items]
Estimated Fair Value - Interest rate swap with third party	5,100	3,400
Non-hedging interest rate derivatives | Interest rate swaps
Derivative [Line Items]
Notional Amounts - Interest rate swaps with customer	171,798	146,537
Notional Amounts - Interest rate swap with third party	171,798	146,537
Estimated Fair Value - Interest rate swaps with customer	(1,643)	(882)
Estimated Fair Value - Interest rate swap with third party	$ 1,643	$ 882

Stockholders' Equity - Reconcil

Stockholders' Equity - Reconciliation of Weighted Average Shares (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Net income:
Net income	$ 16,609	$ 15,504	$ 11,857	$ 9,087	$ 10,023	$ 10,624	$ 11,828	$ 9,316	$ 53,057	$ 41,791	$ 38,918
Dividends and undistributed earnings allocated to participating securities									(321)	(293)	(358)
Net income allocated to common shareholders									$ 52,736	$ 41,498	$ 38,560
Basic:
Weighted average common shares outstanding (in shares)									35,281,408	29,937,400	29,963,365
Restricted stock awards (in shares)									(87,405)	(179,581)	(285,063)
Total basic weighted average common shares outstanding (in shares)									35,194,003	29,757,819	29,678,302
Diluted:
Basic weighted average common shares outstanding (in shares)									35,194,003	29,757,819	29,678,302
Effect of potentially dilutive common shares (in shares)									177,587	91,512	13,851
Total diluted weighted average common shares outstanding (in shares)									35,371,590	29,849,331	29,692,153

Stockholders' Equity - Earnings

Stockholders' Equity - Earnings Per Common Share, Textuals (Details) - shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Stockholders' Equity Note [Abstract]
Anti-dilutive securities excluded from computation	0	0	436

Stockholders' Equity - Dividend

Stockholders' Equity - Dividends (Details) - $ / shares

Oct. 24, 2018

Jul. 24, 2018

Apr. 25, 2018

Jan. 24, 2018

Oct. 25, 2017

Jul. 25, 2017

Apr. 25, 2017

Jan. 25, 2017

Oct. 26, 2016

Jul. 20, 2016

Apr. 20, 2016

Jan. 27, 2016

Dec. 31, 2018

Sep. 30, 2018

Jun. 30, 2018

Mar. 31, 2018

Dec. 31, 2017

Sep. 30, 2017

Jun. 30, 2017

Mar. 31, 2017

Dec. 31, 2018

Dec. 31, 2017

Dec. 31, 2016

Subsequent Event [Line Items]

Declared

Oct. 24, 2018

Jul. 24, 2018

Apr. 25, 2018

Jan. 24, 2018

Oct. 25, 2017

Jul. 25, 2017

Apr. 25, 2017

Jan. 25, 2017

Oct. 26, 2016

Jul. 20, 2016

Apr. 20, 2016

Jan. 27, 2016

Cash Dividend per Share (in usd per share)

$ 0.17

$ 0.15

$ 0.15

$ 0.15

$ 0.13

$ 0.13

$ 0.13

$ 0.12

$ 0.12

$ 0.12

$ 0.12

$ 0.11

$ 0.27

$ 0.15

$ 0.15

$ 0.15

$ 0.23

$ 0.13

$ 0.13

$ 0.12

$ 0.72

$ 0.61

$ 0.72

Record Date

Nov. 7, 2018

Aug. 9, 2018

May 10, 2018

Feb. 7, 2018

Nov. 8, 2017

Aug. 10, 2017

May 10, 2017

Feb. 9, 2017

Nov. 8, 2016

Aug. 4, 2016

May 5, 2016

Feb. 10, 2016

Paid Date

Nov. 21, 2018

Aug. 23, 2018

May 24, 2018

Feb. 21, 2018

Nov. 22, 2017

Aug. 24, 2017

May 24, 2017

Feb. 23, 2017

Nov. 22, 2016

Aug. 18, 2016

May 19, 2016

Feb. 24, 2016

Special Dividend

Subsequent Event [Line Items]

Declared

Oct. 24, 2018

Oct. 25, 2017

Oct. 26, 2016

Cash Dividend per Share (in usd per share)

$ 0.10

$ 0.10

$ 0.25

Record Date

Nov. 7, 2018

Nov. 8, 2017

Nov. 8, 2016

Paid Date

Nov. 21, 2018

Nov. 22, 2017

Nov. 22, 2016

Stockholders' Equity - Stock Re

Stockholders' Equity - Stock Repurchase Program (Details) - $ / shares	Oct. 23, 2014	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2018
Eleventh Plan
Class of Stock [Line Items]
Outstanding share, percent	5.00%
Outstanding common shares in the plan	1,513,000
Eleventh Plan
Class of Stock [Line Items]
Repurchased shares		0	138,000	579,996
Average price of shares repurchased (in usd per share)			$ 17.16	$ 16.67

Stockholders' Equity - Shares R

Stockholders' Equity - Shares Repurchased (Details) - $ / shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Equity, Class of Treasury Stock [Line Items]
Number of shares repurchased related to withholding taxes due on accelerated vesting of RSUs (in shares)	26,741
Average share price (in usd per share)	$ 31.80
Shares Related to Withholding Taxes on the Vesting of Restricted Stock
Equity, Class of Treasury Stock [Line Items]
Repurchased shares to pay withholding taxes (in shares)	53,256	29,429	29,512
Stock repurchase to pay withholding taxes average share price (in usd per share)	$ 31.99	$ 25.01	$ 17.82

Stockholders' Equity - Issuance

Stockholders' Equity - Issuance of Common Stock (Details) - USD ($) $ / shares in Units, $ in Millions	Jul. 02, 2018	Jan. 16, 2018	Dec. 31, 2018	Jun. 29, 2018	Jan. 12, 2018
Business Acquisition [Line Items]
Share price (in usd per share)			$ 31.80
Premier Merger
Business Acquisition [Line Items]
Number of shares issued	2,848,579
Share price (in usd per share)	$ 34.85			$ 34.85
Fair value of shares issued	$ 99.3
Puget Sound Merger
Business Acquisition [Line Items]
Number of shares issued		4,112,258
Share price (in usd per share)		$ 31.80			$ 31.80
Fair value of shares issued		$ 130.8

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Jan. 01, 2018	Jan. 01, 2017
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at the beginning of the year	$ 508,305	$ 481,763	$ 469,970
Other comprehensive (loss) income	(6,064)	1,526	(5,165)
ASU Implementation				$ 0	$ 0
Balance at the end of the year	760,723	508,305	481,763
AOCI attributable to parent
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at the beginning of the year	(1,298)	(2,606)	2,559
Other comprehensive (loss) income before reclassification	(5,956)	1,530	(4,311)
Amounts reclassified from AOCI for gain on sale of investment securities included in net income	(108)	(4)	(854)
Other comprehensive (loss) income	(6,064)	1,526	(5,165)
ASU Implementation	(93)	(218)	0	$ (93)	$ (218)
Balance at the end of the year	$ (7,455)	$ (1,298)	$ (2,606)

Fair Value Measurements - Fair

Fair Value Measurements - Fair Value Measurement on Recurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Assets
Fair Value	$ 976,095	$ 810,530
U.S. Treasury and U.S. Government-sponsored agencies
Assets
Fair Value	101,603	13,442
Municipal securities
Assets
Fair Value	158,864	250,015
Residential mortgage-backed securities
Assets
Fair Value	331,602	280,211
Commercial mortgage-backed securities
Assets
Fair Value	333,761	217,079
Collateralized loan obligations
Assets
Fair Value		4,580
Corporate obligations
Assets
Fair Value	25,563	16,770
Other securities
Assets
Fair Value	24,702	28,433
Recurring
Assets
Fair Value	976,095	810,530
Derivative assets - interest rate swaps	5,095	3,418
Liabilities
Derivative liabilities - interest rate swaps	5,095	3,418
Recurring | U.S. Treasury and U.S. Government-sponsored agencies
Assets
Fair Value	101,603	13,442
Recurring | Municipal securities
Assets
Fair Value	158,864	250,015
Recurring | Residential mortgage-backed securities
Assets
Fair Value	331,602	280,211
Recurring | Commercial mortgage-backed securities
Assets
Fair Value	333,761	217,079
Recurring | Collateralized loan obligations
Assets
Fair Value		4,580
Recurring | Corporate obligations
Assets
Fair Value	25,563	16,770
Recurring | Other securities
Assets
Fair Value	24,702	28,433
Recurring | Level 1
Assets
Fair Value	15,936	146
Derivative assets - interest rate swaps	0	0
Liabilities
Derivative liabilities - interest rate swaps	0	0
Recurring | Level 1 | U.S. Treasury and U.S. Government-sponsored agencies
Assets
Fair Value	15,936	0
Recurring | Level 1 | Municipal securities
Assets
Fair Value	0	0
Recurring | Level 1 | Residential mortgage-backed securities
Assets
Fair Value	0	0
Recurring | Level 1 | Commercial mortgage-backed securities
Assets
Fair Value	0	0
Recurring | Level 1 | Collateralized loan obligations
Assets
Fair Value		0
Recurring | Level 1 | Corporate obligations
Assets
Fair Value	0	0
Recurring | Level 1 | Other securities
Assets
Fair Value		146
Recurring | Level 2
Assets
Fair Value	960,159	810,384
Derivative assets - interest rate swaps	5,095	3,418
Liabilities
Derivative liabilities - interest rate swaps	5,095	3,418
Recurring | Level 2 | U.S. Treasury and U.S. Government-sponsored agencies
Assets
Fair Value	85,667	13,442
Recurring | Level 2 | Municipal securities
Assets
Fair Value	158,864	250,015
Recurring | Level 2 | Residential mortgage-backed securities
Assets
Fair Value	331,602	280,211
Recurring | Level 2 | Commercial mortgage-backed securities
Assets
Fair Value	333,761	217,079
Recurring | Level 2 | Collateralized loan obligations
Assets
Fair Value		4,580
Recurring | Level 2 | Corporate obligations
Assets
Fair Value	25,563	16,770
Recurring | Level 2 | Other securities
Assets
Fair Value	24,702	28,287
Recurring | Level 3
Assets
Fair Value	0	0
Derivative assets - interest rate swaps	0	0
Liabilities
Derivative liabilities - interest rate swaps	0	0
Recurring | Level 3 | U.S. Treasury and U.S. Government-sponsored agencies
Assets
Fair Value	0	0
Recurring | Level 3 | Municipal securities
Assets
Fair Value	0	0
Recurring | Level 3 | Residential mortgage-backed securities
Assets
Fair Value	0	0
Recurring | Level 3 | Commercial mortgage-backed securities
Assets
Fair Value	0	0
Recurring | Level 3 | Collateralized loan obligations
Assets
Fair Value		0
Recurring | Level 3 | Corporate obligations
Assets
Fair Value	0	0
Recurring | Level 3 | Other securities
Assets
Fair Value	$ 0	$ 0

Fair Value Measurements - Textu

Fair Value Measurements - Textuals (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Fair value assets transfers between level 1 and level 2 transfer amount	$ 0	$ 0

Fair Value Measurements - Fai_2

Fair Value Measurements - Fair Value Measurement on Nonrecurring Basis (Details) - Nonrecurring - Impaired Loans - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Basis	$ 1,504	$ 976
Fair Value	1,216	307
Net Losses (Gains) Recorded in Earnings	168	(558)
Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value	0	0
Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value	0	0
Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value	1,216	307
One-to-four family residential
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Basis		976
Fair Value		307
Net Losses (Gains) Recorded in Earnings		(558)
One-to-four family residential | Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value		0
One-to-four family residential | Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value		0
One-to-four family residential | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value		$ 307
Commercial business
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Basis	1,495
Fair Value	1,209
Net Losses (Gains) Recorded in Earnings	160
Commercial business | Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value	0
Commercial business | Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value	0
Commercial business | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value	1,209
Commercial business | Commercial and industrial
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Basis	117
Fair Value	107
Net Losses (Gains) Recorded in Earnings	10
Commercial business | Commercial and industrial | Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value	0
Commercial business | Commercial and industrial | Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value	0
Commercial business | Commercial and industrial | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value	107
Commercial business | Non-owner occupied commercial real estate
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Basis	1,378
Fair Value	1,102
Net Losses (Gains) Recorded in Earnings	150
Commercial business | Non-owner occupied commercial real estate | Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value	0
Commercial business | Non-owner occupied commercial real estate | Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value	0
Commercial business | Non-owner occupied commercial real estate | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value	1,102
Consumer
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Basis	9
Fair Value	7
Net Losses (Gains) Recorded in Earnings	8
Consumer | Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value	0
Consumer | Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value	0
Consumer | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value	$ 7

Fair Value Measurements - Quant

Fair Value Measurements - Quantitative Information, Level 3 (Details) - Impaired Loans - Nonrecurring $ in Thousands	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Fair value measurements for financial instruments measured at fair value on a non-recurring basis
Impaired loans	$ 1,216	$ 307
Level 3
Fair value measurements for financial instruments measured at fair value on a non-recurring basis
Impaired loans	$ 1,216	$ 307
Level 3 | Comparability Adjustment | Minimum
Fair value measurements for financial instruments measured at fair value on a non-recurring basis
Range of Inputs	0.104	(0.915)
Level 3 | Comparability Adjustment | Maximum
Fair value measurements for financial instruments measured at fair value on a non-recurring basis
Range of Inputs	(0.373)	(0.144)
Level 3 | Comparability Adjustment | Weighted Average
Fair value measurements for financial instruments measured at fair value on a non-recurring basis
Range of Inputs	(0.109)	(0.440)

Fair Value Measurements - Carry

Fair Value Measurements - Carrying Value and Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Financial Assets:
Equity security	$ 114	$ 146
Carrying Value
Financial Assets:
Cash and cash equivalents	161,910	103,015
Investment securities available for sale	976,095	810,530
Federal Home Loan Bank stock	6,076	8,347
Loans held for sale	1,555	2,288
Total loans receivable, net	3,619,118	2,816,985
Accrued interest receivable	15,403	12,244
Derivative assets - interest rate swaps	5,095	3,418
Equity security	114
Financial Liabilities:
Noninterest deposits, interest bearing demand deposits, money market accounts and savings accounts	3,965,510	2,994,662
Certificate of deposit accounts	466,892	398,398
Federal Home Loan Bank advances		92,500
Securities sold under agreement to repurchase	31,487	31,821
Junior subordinated debentures	20,302	20,009
Accrued interest payable	191	162
Derivative liabilities - interest rate swaps	5,095	3,418
Fair Value
Financial Assets:
Cash and cash equivalents	161,910	103,015
Investment securities available for sale	976,095	810,530
Loans held for sale	1,605	2,364
Total loans receivable, net	3,614,348	2,810,401
Accrued interest receivable	15,403	12,244
Derivative assets - interest rate swaps	5,095	3,418
Equity security	0
Financial Liabilities:
Noninterest deposits, interest bearing demand deposits, money market accounts and savings accounts	3,965,510	2,994,662
Certificate of deposit accounts	470,222	397,039
Federal Home Loan Bank advances		92,500
Securities sold under agreement to repurchase	31,487	31,821
Junior subordinated debentures	20,500	18,500
Accrued interest payable	191	162
Derivative liabilities - interest rate swaps	5,095	3,418
Fair Value | Level 1
Financial Assets:
Cash and cash equivalents	161,910	103,015
Investment securities available for sale	15,936	146
Loans held for sale	0	0
Total loans receivable, net	0	0
Accrued interest receivable	68	23
Derivative assets - interest rate swaps	0	0
Equity security	114
Financial Liabilities:
Noninterest deposits, interest bearing demand deposits, money market accounts and savings accounts	3,965,510	2,994,662
Certificate of deposit accounts	0	0
Federal Home Loan Bank advances		0
Securities sold under agreement to repurchase	31,487	31,821
Junior subordinated debentures	0	0
Accrued interest payable	63	45
Derivative liabilities - interest rate swaps	0	0
Fair Value | Level 2
Financial Assets:
Cash and cash equivalents	0	0
Investment securities available for sale	960,159	810,384
Loans held for sale	1,605	2,364
Total loans receivable, net	0	0
Accrued interest receivable	4,091	3,772
Derivative assets - interest rate swaps	5,095	3,418
Equity security	0
Financial Liabilities:
Noninterest deposits, interest bearing demand deposits, money market accounts and savings accounts	0	0
Certificate of deposit accounts	470,222	397,039
Federal Home Loan Bank advances		92,500
Securities sold under agreement to repurchase	0	0
Junior subordinated debentures	0	0
Accrued interest payable	81	79
Derivative liabilities - interest rate swaps	5,095	3,418
Fair Value | Level 3
Financial Assets:
Cash and cash equivalents	0	0
Investment securities available for sale	0	0
Loans held for sale	0	0
Total loans receivable, net	3,614,348	2,810,401
Accrued interest receivable	11,244	8,449
Derivative assets - interest rate swaps	0	0
Equity security	0
Financial Liabilities:
Noninterest deposits, interest bearing demand deposits, money market accounts and savings accounts	0	0
Certificate of deposit accounts	0	0
Federal Home Loan Bank advances		0
Securities sold under agreement to repurchase	0	0
Junior subordinated debentures	20,500	18,500
Accrued interest payable	47	38
Derivative liabilities - interest rate swaps	$ 0	$ 0

Stock-Based Compensation - Text

Stock-Based Compensation - Textuals (Details) - shares	Jul. 24, 2014	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares remain available for future issuances under stock-based compensation plans		955,282
the Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized for issuance	1,500,000

Stock-Based Compensation - Stoc

Stock-Based Compensation - Stock Option Awards, Textuals (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Proceeds from exercise of stock options	$ 133,000	$ 164,000	$ 540,000
Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	0	0
Tax benefit	0	0	0
Intrinsic value of options exercised	202,000	161,000	177,000
Proceeds from exercise of stock options	$ 132,000	$ 164,000	$ 540,000
Option 1 | Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	3 years
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period	5 years
Option 2 | Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	4 years
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period	10 years

Stock-Based Compensation - St_2

Stock-Based Compensation - Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Shares
Outstanding at beginning of period (in shares)	23,231	37,495	79,408
Exercised (in shares)	(9,842)	(12,662)	(37,713)
Forfeited or expired (in shares)	(831)	(1,602)	(4,200)
Outstanding at end of period (in shares)	12,558	23,231	37,495
Vested and expected to vest at end of period (in shares)	12,558
Exercisable at end of period (in shares)	12,558
Weighted-Average Exercise Price
Outstanding at beginning of period (in usd per share)	$ 14.21	$ 13.77	$ 14.19
Exercised (in usd per share)	13.45	12.97	14.31
Forfeited or expired (in usd per share)	14.77	13.76	16.80
Outstanding at end of period (in usd per share)	14.77	$ 14.21	$ 13.77
Vested and expected to vest at end of period (in usd per share)	14.77
Exercisable at end of period (in usd per share)	$ 14.77
Weighted-Average Remaining Contractual Term, Outstanding	1 year 4 months 20 days
Weighted-Average Remaining Contractual Term, Vested and expected to vest	1 year 4 months 20 days
Weighted-Average Remaining Contractual Term, Exercisable	1 year 4 months 20 days
Aggregate Intrinsic Value, Outstanding	$ 188
Aggregate Intrinsic Value, Vested and expected to vest	188
Aggregate Intrinsic Value, Exercisable	$ 188

Stock-Based Compensation - Rest

Stock-Based Compensation - Restricted Stock Awards, Textuals (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock awards issued, net of forfeitures	$ 2,200	$ 2,900	$ 2,000
Restricted Stock Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	907	1,400	1,800
Tax benefit	191	$ 488	$ 644
Total unrecognized compensation expense	$ 556
Weighted average, recognition period	10 months 17 days
Restricted Stock Awards | Award 1
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	4 years
Restricted Stock Awards | Award 2
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	4 years

Stock-Based Compensation - Re_2

Stock-Based Compensation - Restricted Stock Award Activity (Details) - Restricted Stock Awards - $ / shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Shares
Nonvested at beginning of period (in shares)	137,399	261,296	264,521
Granted (in shares)			121,039
Vested (in shares)	(67,877)	(113,479)	(112,516)
Forfeited (in shares)	(3,489)	(10,418)	(11,748)
Nonvested at end of period (in shares)	66,033	137,399	261,296
Weighted-Average Grant Date Fair Value
Nonvested at beginning of period (in usd per share)	$ 17	$ 16.80	$ 15.92
Granted (in usd per share)			17.60
Vested (in usd per share)	16.74	16.55	15.62
Forfeited (in usd per share)	16.92	16.80	16.62
Nonvested at end of period (in usd per share)	$ 17.28	$ 17	$ 16.80

Stock-Based Compensation - Re_3

Stock-Based Compensation - Restricted Stock Units, Textuals (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value of units that vested	$ 2,200,000	$ 2,900,000	$ 2,000,000
RSU
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance period	3 years
Compensation expense	$ 1,800,000	712,000
Tax benefit	387,000	249,000
Total unrecognized compensation expense	$ 3,500,000
Weighted average, recognition period	2 years 2 months 1 day
Fair value of units that vested	$ 1,000,000
PRSU
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance period	3 years
Fair value of units that vested	$ 0	$ 0
PRSU | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Actual payout percentage	0.00%
PRSU | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Actual payout percentage	150.00%

Stock-Based Compensation - Fair

Stock-Based Compensation - Fair Value Assumptions (Details) - PRSU - $ / shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares issued	5,550	6,089
Expected Term in Years	2 years 10 months 2 days	2 years 10 months 6 days
Expected Dividend Yield (as a percent)	0.00%	0.00%
Weighted-Average Fair Value (in usd per share)	$ 27.69	$ 24.39
Correlation Coefficient Rate	76.44%	75.93%
Volatility Rate	22.30%	21.80%
Weighted Average
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-Average Risk Free Interest Rate	2.39%	1.40%
Peer Company
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Volatility Rate, Minimum	18.99%	17.80%
Volatility Rate, Maximum	51.42%	63.10%
Peer Company | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Correlation Coefficient Rate	28.16%	8.24%
Peer Company | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Correlation Coefficient Rate	94.29%	89.79%

Stock-Based Compensation - RSU

Stock-Based Compensation - RSU Activity (Details) - RSU - $ / shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Shares
Nonvested at beginning of period (in shares)	90,544	0
Granted (in shares)	125,633	92,356
Vested (in shares)	(32,375)
Forfeited (in shares)	(4,617)	(1,812)
Nonvested at end of period (in shares)	179,185	90,544
Weighted-Average Grant Date Fair Value
Nonvested at beginning of period (in usd per share)	$ 25.31	$ 0
Granted (in usd per share)	30.62	25.31
Vested (in usd per share)	25.44
Forfeited (in usd per share)	27.82	25.35
Nonvested at end of period (in usd per share)	$ 28.94	$ 25.31

Cash Requirement (Details)

Cash Requirement (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Banking and Thrift [Abstract]
Required reserve balance	$ 9,200	$ 60

Income Taxes - Components of In

Income Taxes - Components of Income Tax Expense (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Current tax expense									$ 9,658	$ 12,171	$ 6,885
Deferred tax expense									1,372	6,185	6,918
Income tax expense	$ 4,618	$ 3,010	$ 2,003	$ 1,399	$ 7,270	$ 3,922	$ 4,075	$ 3,089	$ 11,030	$ 18,356	$ 13,803

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of Effective Income Tax (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Federal statutory tax rate (as a percent)									21.00%	35.00%	35.00%
Income tax expense at Federal statutory rate									$ 13,502	$ 21,051	$ 18,452
Tax-exempt instruments									(1,879)	(3,212)	(3,198)
Non-deductible acquisition costs									336	210	0
Federal tax credits and other benefits									(515)	(1,510)	(931)
Effects of BOLI									(330)	(531)	(511)
Revaluation of net deferred tax assets										2,568	0
Other, net									(84)	(220)	(9)
Income tax expense	$ 4,618	$ 3,010	$ 2,003	$ 1,399	$ 7,270	$ 3,922	$ 4,075	$ 3,089	11,030	18,356	13,803
Amortizaon of LIHTC									$ 3,100	$ 2,200	$ 523

Income Taxes - Deferred Income

Income Taxes - Deferred Income Tax Asset (Liability) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Deferred tax assets:
Allowance for loan losses	$ 6,941	$ 6,699
Accrued compensation	3,379	1,779
Stock compensation	769	660
Net unrealized losses charged to other comprehensive income on securities	2,070	347
Market discount on purchased loans	1,054	539
Foregone interest on nonaccrual loans	811	471
Net operating loss carryforward acquired from NCB	336	270
Other Real Estate Owned	754	0
Other deferred tax assets	364	763
Total deferred tax assets	16,478	11,528
Deferred tax liabilities:
Deferred loan fees, net	(3,333)	(2,518)
Premises and equipment	(1,819)	(1,091)
FHLB stock	(569)	(557)
Goodwill and other intangible assets	(3,526)	(304)
Federal tax credits	(1,457)	(1,107)
Junior subordinated debentures	(1,176)	(1,215)
Other deferred tax liabilities	(540)	(847)
Total deferred tax liabilities	(12,420)	(7,639)
Deferred tax asset, net	$ 4,058	$ 3,889

Income Taxes - Textuals (Detail

Income Taxes - Textuals (Details) - USD ($)	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Net operating loss carryforward	$ 1,600,000	$ 1,300,000
Valuation allowance	0	$ 0
Taxable temporary difference	2,800,000
Deferred tax liability not recognized	$ 980,000

Regulatory Capital Requiremen_3

Regulatory Capital Requirements (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common Equity Tier One Capital Required for Capital Adequacy	$ 197,189	$ 154,522
Common Equity Tier One Capital Required for Capital Adequacy to Average Assets	4.50%	4.50%
Common Equity Tier One Capital	$ 510,618	$ 386,689
Common Equity Tier One Capital to Average Assets	11.70%	11.30%
Tier One Leverage Capital Required for Capital Adequacy	$ 201,920	$ 159,494
Tier One Leverage Capital Required for Capital Adequacy to Average Assets	4.00%	4.00%
Tier One Leverage Capital	$ 530,920	$ 406,687
Tier One Leverage Capital to Average Assets	10.50%	10.20%
Tier One Risk Based Capital Required for Capital Adequacy	$ 262,918	$ 206,029
Tier One Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets	6.00%	6.00%
Tier One Risk Based Capital	$ 530,920	$ 406,687
Tier One Risk Based Capital to Risk Weighted Assets	12.10%	11.80%
Capital Required for Capital Adequacy	$ 350,558	$ 274,706
Capital Required for Capital Adequacy to Risk Weighted Assets	8.00%	8.00%
Capital	$ 566,268	$ 439,044
Capital to Risk Weighted Assets	12.90%	12.80%
Capital conservation buffer, percentage	4.92%
Heritage Bank
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common Equity Tier One Capital Required for Capital Adequacy	$ 197,004	$ 154,400
Common Equity Tier One Capital Required for Capital Adequacy to Average Assets	4.50%	4.50%
Common Equity Tier One Capital Required to be Well-Capitalized	$ 284,561	$ 223,023
Common Equity Tier One Capital Required to be Well Capitalized to Average Assets	6.50%	6.50%
Common Equity Tier One Capital	$ 513,993	$ 391,092
Common Equity Tier One Capital to Average Assets	11.70%	11.40%
Tier One Leverage Capital Required for Capital Adequacy	$ 203,339	$ 159,300
Tier One Leverage Capital Required for Capital Adequacy to Average Assets	4.00%	4.00%
Tier One Leverage Capital Required to be Well Capitalized	$ 254,174	$ 199,125
Tier One Leverage Capital Required to be Well Capitalized to Average Assets	5.00%	5.00%
Tier One Leverage Capital	$ 513,993	$ 391,092
Tier One Leverage Capital to Average Assets	10.10%	9.80%
Tier One Risk Based Capital Required for Capital Adequacy	$ 262,671	$ 205,867
Tier One Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets	6.00%	6.00%
Tier One Risk Based Capital Required to be Well Capitalized	$ 350,229	$ 274,490
Tier One Risk Based Capital Required to be Well Capitalized to Risk Weighted Assets	8.00%	8.00%
Tier One Risk Based Capital	$ 513,993	$ 391,092
Tier One Risk Based Capital to Risk Weighted Assets	11.70%	11.40%
Capital Required for Capital Adequacy	$ 350,229	$ 274,490
Capital Required for Capital Adequacy to Risk Weighted Assets	8.00%	8.00%
Capital Required to be Well Capitalized	$ 437,786	$ 343,112
Capital Required to be Well Capitalized to Risk Weighted Assets	10.00%	10.00%
Capital	$ 549,341	$ 423,348
Capital to Risk Weighted Assets	12.50%	12.30%
Capital conservation buffer, percentage	4.55%

Heritage Financial Corporatio_3

Heritage Financial Corporation (Parent Company Only) - Condensed Statements of Financial Condition (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
ASSETS
Total assets	$ 5,316,927	$ 4,113,270
LIABILITIES AND STOCKHOLDERS’ EQUITY
Junior subordinated debentures	20,302	20,009
Other liabilities	72,013	67,575
Total stockholders’ equity	760,723	508,305	$ 481,763	$ 469,970
Total liabilities and stockholders’ equity	5,316,927	4,113,270
Parent Company
ASSETS
Cash and interest earning deposits	14,602	11,904	$ 10,568	$ 6,722
Investment in subsidiary bank	764,097	512,655
Other assets	2,520	4,696
Total assets	781,219	529,255
LIABILITIES AND STOCKHOLDERS’ EQUITY
Junior subordinated debentures	20,302	20,009
Other liabilities	194	941
Total stockholders’ equity	760,723	508,305
Total liabilities and stockholders’ equity	$ 781,219	$ 529,255

Heritage Financial Corporatio_4

Heritage Financial Corporation (Parent Company Only) - Condensed Statements of Income (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Condensed Income Statements, Captions [Line Items]
Total interest income	$ 54,865	$ 54,576	$ 46,671	$ 43,247	$ 39,544	$ 37,275	$ 36,041	$ 34,849	$ 199,359	$ 147,709	$ 138,512
Junior subordinated debentures									1,263	1,014	880
Total interest expense	3,595	3,480	2,928	2,410	2,389	2,333	1,907	1,717	12,413	8,346	6,006
Net interest income	51,270	51,096	43,743	40,837	37,155	34,942	34,134	33,132	186,946	139,363	132,506
Other income									9,291	8,828	7,102
Total noninterest income	8,464	8,080	7,573	7,548	9,064	8,443	10,709	7,363	31,665	35,579	31,619
Professional services									9,670	4,777	3,606
Other expense									11,385	9,903	9,567
Total noninterest expense	37,345	39,597	35,706	36,747	27,588	27,955	27,809	27,223	149,395	110,575	106,473
Income before income taxes	21,227	18,514	13,860	10,486	17,293	14,546	15,903	12,405	64,087	60,147	52,721
Income tax expense	4,618	3,010	2,003	1,399	7,270	3,922	4,075	3,089	11,030	18,356	13,803
Net income	$ 16,609	$ 15,504	$ 11,857	$ 9,087	$ 10,023	$ 10,624	$ 11,828	$ 9,316	53,057	41,791	38,918
Parent Company
Condensed Income Statements, Captions [Line Items]
Interest and dividends on interest earning deposits and other assets									7	44	34
Total interest income									7	44	34
Junior subordinated debentures									1,263	1,014	880
Total interest expense									1,263	1,014	880
Net interest income									(1,256)	(970)	(846)
Dividends from subsidiary bank									30,000	23,000	30,000
Equity in undistributed income of subsidiary bank									29,258	21,755	11,848
Other income									22	0	0
Total noninterest income									59,280	44,755	41,848
Professional services									3,063	768	385
Other expense									3,833	3,726	3,437
Total noninterest expense									6,896	4,494	3,822
Income before income taxes									51,128	39,291	37,180
Income tax expense									(1,929)	(2,500)	(1,738)
Net income									$ 53,057	$ 41,791	$ 38,918

Heritage Financial Corporatio_5

Heritage Financial Corporation (Parent Company Only) - Condensed Statements of Cash Flows (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash flows from operating activities:
Net income	$ 16,609	$ 15,504	$ 11,857	$ 9,087	$ 10,023	$ 10,624	$ 11,828	$ 9,316	$ 53,057	$ 41,791	$ 38,918
Adjustments to reconcile net income to net cash provided by operating activities:
Stock-based compensation expense									2,744	2,103	1,840
Net cash provided by operating activities									82,447	73,513	53,980
Cash flows from investing activities:
Net cash received from acquisitions									105,974	0	0
Net cash used in investing activities									(101,634)	(241,394)	(252,926)
Cash flows from financing activities:
Common stock cash dividends paid									(25,791)	(18,305)	(21,569)
Proceeds from exercise of stock options									133	164	540
Net excess tax benefit from exercise of stock options and vesting of restricted stock									0	0	123
Repurchase of common stock									(1,704)	(737)	(2,894)
Net cash provided by financing activities									78,082	167,151	176,051
Net increase (decrease) in cash and cash equivalents									58,895	(730)	(22,895)
Parent Company
Cash flows from operating activities:
Net income									53,057	41,791	38,918
Adjustments to reconcile net income to net cash provided by operating activities:
Equity in undistributed income of subsidiary bank									(29,258)	(21,755)	(11,848)
Net excess tax benefit from exercise of stock options and vesting of restricted stock									0	0	(123)
Stock-based compensation expense									2,744	2,103	1,840
Net change in other assets and liabilities									1,735	(1,925)	(1,141)
Net cash provided by operating activities									28,278	20,214	27,646
Cash flows from investing activities:
Net cash received from acquisitions									1,782	0	0
Net cash used in investing activities									1,782	0	0
Cash flows from financing activities:
Common stock cash dividends paid									(25,791)	(18,305)	(21,569)
Proceeds from exercise of stock options									133	164	540
Net excess tax benefit from exercise of stock options and vesting of restricted stock									0	0	123
Repurchase of common stock									(1,704)	(737)	(2,894)
Net cash provided by financing activities									(27,362)	(18,878)	(23,800)
Net increase (decrease) in cash and cash equivalents									2,698	1,336	3,846
Cash and cash equivalents at the beginning of year				$ 11,904				$ 10,568	11,904	10,568	6,722
Cash and cash equivalents at the end of year	$ 14,602				$ 11,904				14,602	11,904	10,568
Supplemental non-cash disclosures of cash flow information:
Common stock issued for business combinations									230,043	0	0
Capital contribution of net assets acquired in business combinations to Bank									$ 228,261	$ 0	$ 0

Selected Quarterly Financial _3

Selected Quarterly Financial Data (Details) - USD ($) $ / shares in Units, $ in Thousands	Oct. 24, 2018	Jul. 24, 2018	Apr. 25, 2018	Jan. 24, 2018	Oct. 25, 2017	Jul. 25, 2017	Apr. 25, 2017	Jan. 25, 2017	Oct. 26, 2016	Jul. 20, 2016	Apr. 20, 2016	Jan. 27, 2016	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Quarterly Financial Information Disclosure [Abstract]
Interest income													$ 54,865	$ 54,576	$ 46,671	$ 43,247	$ 39,544	$ 37,275	$ 36,041	$ 34,849	$ 199,359	$ 147,709	$ 138,512
Interest expense													3,595	3,480	2,928	2,410	2,389	2,333	1,907	1,717	12,413	8,346	6,006
Net interest income													51,270	51,096	43,743	40,837	37,155	34,942	34,134	33,132	186,946	139,363	132,506
Provision for loan losses													1,162	1,065	1,750	1,152	1,338	884	1,131	867	5,129	4,220	4,931
Net interest income after provision for loan losses													50,108	50,031	41,993	39,685	35,817	34,058	33,003	32,265	181,817	135,143	127,575
Noninterest income													8,464	8,080	7,573	7,548	9,064	8,443	10,709	7,363	31,665	35,579	31,619
Noninterest expense													37,345	39,597	35,706	36,747	27,588	27,955	27,809	27,223	149,395	110,575	106,473
Income before income taxes													21,227	18,514	13,860	10,486	17,293	14,546	15,903	12,405	64,087	60,147	52,721
Income tax expense													4,618	3,010	2,003	1,399	7,270	3,922	4,075	3,089	11,030	18,356	13,803
Net income													$ 16,609	$ 15,504	$ 11,857	$ 9,087	$ 10,023	$ 10,624	$ 11,828	$ 9,316	$ 53,057	$ 41,791	$ 38,918
Basic earnings per common share (in usd per share)													$ 0.45	$ 0.42	$ 0.35	$ 0.27	$ 0.33	$ 0.35	$ 0.40	$ 0.31	$ 1.49	$ 1.39	$ 1.30
Diluted earnings per common share (in usd per share)													0.45	0.42	0.35	0.27	0.33	0.35	0.40	0.31	1.49	1.39	1.30
Cash dividends declared on common stock (in usd per share)	$ 0.17	$ 0.15	$ 0.15	$ 0.15	$ 0.13	$ 0.13	$ 0.13	$ 0.12	$ 0.12	$ 0.12	$ 0.12	$ 0.11	$ 0.27	$ 0.15	$ 0.15	$ 0.15	$ 0.23	$ 0.13	$ 0.13	$ 0.12	$ 0.72	$ 0.61	$ 0.72

Uncategorized Items - hfwa-2018

Label	Element	Value
Retained Earnings [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	$ 218,000
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	$ 93,000