Columbia Banking System (COLB) 10-Q 4 May 18 2018 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2018	Apr. 30, 2018
Document Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q1
Entity Registrant Name	COLUMBIA BANKING SYSTEM INC
Entity Central Index Key	887,343
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		73,238,908

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) shares in Thousands, $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
ASSETS
Cash and due from banks	$ 206,532	$ 244,615
Interest-earning deposits with banks	87,124	97,918
Total cash and cash equivalents	293,656	342,533
Available-for-sale Securities, Debt Securities	2,624,045	2,737,751
Equity securities at fair value	5,000	5,080
Federal Home Loan Bank stock at cost	11,640	10,440
Loans held for sale	4,312	5,766
Loans, net of unearned income	8,339,631	8,358,657
Less: allowance for loan and lease losses	79,827	75,646
Loans, net	8,259,804	8,283,011
Interest receivable	41,795	40,881
Premises and equipment, net	168,366	169,490
Other real estate owned	11,507	13,298
Goodwill	765,842	765,842
Other intangible assets, net	54,985	58,173
Other assets	289,684	284,621
Total assets	12,530,636	12,716,886
LIABILITIES AND SHAREHOLDERS' EQUITY
Noninterest-bearing	4,927,226	5,081,901
Interest-bearing	5,468,297	5,450,184
Total deposits	10,395,523	10,532,085
Federal Home Loan Bank advances	41,564	11,579
Securities sold under agreements to repurchase	24,247	79,059
Subordinated Debt	35,601	35,647
Junior Subordinated Notes	0	8,248
Other liabilities	85,778	100,346
Total liabilities	10,582,713	10,766,964
Commitments and contingent liabilities (Note 12)
Shareholders' equity:
Authorized shares	115,000	115,000
Common Stock Shares Issued And Outstanding	73,240	73,020
Common Stock (no par value)	$ 1,634,916	$ 1,634,705
Retained earnings	361,140	337,442
Accumulated other comprehensive loss	(48,133)	(22,225)
Total shareholders’ equity	1,947,923	1,949,922
Total liabilities and shareholders’ equity	$ 12,530,636	$ 12,716,886

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares shares in Thousands	Mar. 31, 2018	Dec. 31, 2017
Common stock, par value	$ 0	$ 0
Authorized shares	115,000	115,000
Common stock, shares outstanding	73,240	73,020

Consolidated Statements of Inco

Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Interest Income
Loans	$ 103,027	$ 74,120
Taxable securities	12,708	10,986
Tax-exempt securities	3,064	2,691
Deposits in banks	345	19
Total interest income	119,144	87,816
Interest Expense
Deposits	2,509	787
Federal Home Loan Bank advances	570	225
Interest Expense, Subordinated Notes and Debentures	468	0
Other borrowings	116	129
Total interest expense	3,663	1,141
Net Interest Income	115,481	86,675
Provision for loan and lease losses	5,852	2,775
Net interest income after provision for loan and lease losses	109,629	83,900
Noninterest Income
Deposit account and treasury management fees	8,740	7,287
Card revenue	5,813	5,723
Financial services and trust revenue	2,730	2,839
Loan revenue	3,186	3,593
Merchant Discount Fees	0	2,019
Bank owned life insurance	1,426	1,280
Gain (Loss) on Investments	22	0
Change in FDIC loss-sharing asset	0	(274)
Other	1,226	2,392
Total noninterest income	23,143	24,859
Noninterest Expense
Compensation and employee benefits	50,570	40,825
Occupancy	10,121	7,191
Merchant processing expense	0	1,049
Advertising and promotion	1,429	817
Data processing	5,270	4,208
Legal and professional fees	3,237	3,369
Taxes, licenses and fees	1,425	1,241
Regulatory premiums	937	776
Net cost (benefit) of operation of other real estate owned	1	152
Amortization of intangibles	3,188	1,349
Other	9,809	8,009
Total noninterest expense	85,987	68,986
Income before income taxes	46,785	39,773
Income tax provision	6,815	10,574
Net Income	$ 39,970	$ 29,199
Earnings per common share
Basic ($ per share)	$ 0.55	$ 0.50
Diluted ($ per share)	0.55	0.50
Dividends paid per common share	$ 0.22	$ 0.22
Weighted average number of common shares outstanding	72,300	57,388
Weighted average number of diluted common shares outstanding	72,305	57,394

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2018	Mar. 31, 2017
Net income		$ 39,970	$ 29,199
Unrealized gain from securities:
Net unrealized holding loss from available for sale securities arising during the period		(26,048)	1,702
Reclassification adjustment of net gain from sale of available for sale securities included in income		(78)	0
Net unrealized gain from securities, net of reclassification adjustment		(26,126)	1,702
Pension plan liability adjustment:
Unrecognized net actuarial gain (loss) during the period		0	4,604
Less: amortization of unrecognized net actuarial loss included in net periodic pension cost		61	87
Pension plan liability adjustment, net		61	4,691
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	[1]	(26,065)	6,393
Total comprehensive income		$ 13,905	$ 35,592
[1]	All amounts are net of tax. Amounts in parenthesis indicate debits.

Consolidated Statements of Com6

Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Net unrealized holding gain (loss) from available for sale securities arising during the period, tax	$ 7,891	$ (968)
Reclassification adjustment of net gain from sale of available for sale securities included in income, tax	24	0
Net unrealized loss from unfunded defined benefit plan liability arising during the period, tax	0	(2,622)
Less: amortization of unrecognized net actuarial loss included in net periodic pension cost, tax	$ (19)	$ (49)

Consolidated Statements of Chan

Consolidated Statements of Changes in Shareholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income [Member]	Preferred Stock [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption | Accounting Standards Update 2016-09 [Member]	$ 67	$ 184	$ (117)
Balance, value at Dec. 31, 2016	1,251,012	$ 995,837	271,957	$ (18,999)	$ 2,217
Balance, shares at Dec. 31, 2016		58,042			9
Net income	29,199		29,199
Other comprehensive income	6,393			6,393
Issuance of common stock - stock option and other plans, value	1,145	$ 1,145
Issuance of common stock - stock option and other plans, shares		28
Issuance of common stock - restricted stock awards, net of cancelled awards, value	2,358	$ 2,358
Conversion of Stock, Shares Converted					(9)
Conversion of Stock, Amount Converted					$ (2,217)
Conversion of Stock, New Issuance		102
Conversion of Stock, Amount Issued	0	$ 2,217
Issuance of common stock - restricted stock awards, net of cancelled awards, shares		207
Stock Repurchased and Retired During Period, Value	(2,039)	$ (2,039)
Stock Repurchased During Period, Shares		(50)
Cash dividends paid on common stock	(12,792)		(12,792)
Balance, value at Mar. 31, 2017	1,275,343	$ 999,702	288,247	(12,606)	$ 0
Balance, shares at Mar. 31, 2017		58,329			0
Cumulative Effect of New Accounting Principle in Period of Adoption | Accounting Standards Update 2016-01 [Member]	(46)		(203)	157
Balance, value at Dec. 31, 2017	1,949,922	$ 1,634,705	337,442	(22,225)	$ 0
Balance, shares at Dec. 31, 2017		73,020			0
Net income	39,970		39,970
Other comprehensive income	(26,065)			(26,065)
Issuance of common stock - stock option and other plans, value	719	$ 719
Issuance of common stock - stock option and other plans, shares		17
Issuance of common stock - restricted stock awards, net of cancelled awards, value	2,064	$ 2,064
Issuance of common stock - restricted stock awards, net of cancelled awards, shares		263
Stock Repurchased and Retired During Period, Value	(2,575)	$ (2,575)
Stock Repurchased During Period, Shares		(60)
Cash dividends paid on common stock	(16,069)		(16,069)
Balance, value at Mar. 31, 2018	1,947,923	$ 1,634,916	$ 361,140	$ (48,133)	$ 0
Balance, shares at Mar. 31, 2018		73,240			0
Stock Adjustment Deferred Compensation - Shares		0
Stock Adjustment Value Deferred Compensation	$ 3	$ 3

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Gain (Loss) on Sale of Insurance Block	$ 0	$ (1,514)
Repayments of junior subordinated debt	8,248	0
Cash Flows From Operating Activities
Net income	39,970	29,199
Adjustments to reconcile net income to net cash provided by operating activities
Provision for loan and lease losses	5,852	2,775
Stock-based compensation expense	2,064	2,358
Depreciation, amortization and accretion	7,618	6,074
Investment securities gains, net	22	0
Net realized (gain) loss on sale of premises and equipment, loans held for investment and other assets	(630)	55
Net realized loss on sale and valuation adjustments of other real estate owned	135	204
Originations of loans held for sale	27,553	31,295
Proceeds from sales of loans held for sale	29,007	33,896
Net change in:
Interest receivable	(914)	(1,271)
Interest payable	452	(9)
Other assets	2,530	(650)
Other liabilities	(15,014)	(3,841)
Net cash provided by operating activities	43,495	35,981
Cash Flows From Investing Activities
Loans originated and acquired, net of principal collected	17,688	(21,936)
Purchases of securities available for sale	(27,497)	(108,958)
Purchases of premises and equipment	(2,099)	(336)
Payments to Acquire Federal Home Loan Bank Stock	(45,080)	(31,400)
Proceeds from FDIC for reimbursement on loss-sharing asset	0	26
Proceeds from sales of securities available for sale	19,761	0
Proceeds from principal repayments and maturities of securities available for sale	82,643	55,369
Proceeds from Sales of Assets, Investing Activities	3,721	6,893
Proceeds from Sale of Federal Home Loan Bank Stock	43,880	31,040
Proceeds from sales of other real estate and other personal property owned	2,062	1,275
Payments to FDIC related to loss-sharing asset	0	(210)
Net cash provided by (used in) investing activities	95,079	(68,237)
Cash Flows From Financing Activities
Net (decrease) increase in deposits	(136,466)	29,433
Net decrease in sweep repurchase agreements	(54,812)	(33,908)
Proceeds from Federal Home Loan Bank advances	1,127,000	785,000
Proceeds from exercise of stock options	719	1,145
Repayment of Federal Home Loan Bank advances	(1,097,000)	(776,000)
Payment of common stock dividends	(16,069)	(12,792)
Purchase and retirement of common stock	2,575	2,039
Net cash used in financing activities	(187,451)	(9,161)
Decrease in cash and cash equivalents	(48,877)	(41,417)
Cash and cash equivalents at beginning of period	342,533	224,238
Cash and cash equivalents at end of period	293,656	182,821
Supplemental Information:
Cash paid for interest	3,211	1,150
Cash paid for income tax	24	0
Non-cash investing and financing activities
Loans transferred to other real estate owned	$ 406	$ 0

Basis of Presentation and Signi

Basis of Presentation and Significant Accounting Policies	3 Months Ended
	Mar. 31, 2018
Basis of Presentation And Significant Accounting Policies
Basis of Presentation and Significant Accounting Policies	Basis of Presentation, Significant Accounting Policies and Recent Developments Basis of Presentation The interim unaudited Consolidated Financial Statements have been prepared in accordance with accounting principles generally accepted in the United States of America for interim financial information and with instructions to Form 10-Q and Article 10 of Regulation S-X. The Consolidated Financial Statements include the accounts of Columbia Banking System, Inc. (“we”, “our”, “Columbia” or the “Company”) and its subsidiaries, including its wholly owned banking subsidiary Columbia State Bank (“Columbia Bank” or the “Bank”) and Columbia Trust Company (“Columbia Trust”). All intercompany transactions and accounts have been eliminated in consolidation. In the opinion of management, all adjustments (consisting only of normal recurring adjustments) considered necessary for a fair statement of the results for the interim periods presented have been included. The results of operations for the three months ended March 31, 2018 are not necessarily indicative of results to be anticipated for the year ending December 31, 2018 . The accompanying interim unaudited Consolidated Financial Statements should be read in conjunction with the financial statements and related notes contained in the Company’s 2017 Annual Report on Form 10-K. Significant Accounting Policies The significant accounting policies used in preparation of our Consolidated Financial Statements are disclosed in our 2017 Annual Report on Form 10-K. There have not been any changes in our significant accounting policies compared to those contained in our 2017 Form 10-K disclosure for the year ended December 31, 2017 . Reclassifications Certain amounts reported in prior periods may have been reclassified in the Consolidated Financial Statements to conform to the current presentation. The reclassifications have no effect on net income or stockholders’ equity as previously reported.

Accounting Pronouncements Recen

Accounting Pronouncements Recently Issued	3 Months Ended
	Mar. 31, 2018
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
Accounting Pronouncements Recently Issued	Accounting Pronouncements Recently Issued In August 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2016-15, Classification of Certain Cash Receipts and Cash Payments . The amendments in this ASU provide specific guidance on several statement of cash flow classification issues to reduce diversity in practice. The amendments in ASU 2016-15 are effective for fiscal years beginning after December 15, 2017 and interim periods within those fiscal years. The Company has reclassified items in the Statement of Cash Flows for the three months ended March 31, 2017 to conform with its current presentation based on its adoption of ASU 2016-15. In June 2016, the FASB issued ASU 2016-13, Measurement of Credit Losses on Financial Instruments . The amendments included in this ASU require an entity to reflect its current estimate of all expected credit losses for assets held at an amortized cost basis. For available for sale debt securities, credit losses will be measured in a manner similar to current GAAP, however, this ASU will require that credit losses be presented as an allowance rather than as a write-down. The amendments in ASU 2016-13 are effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years, and are required to be adopted through a modified retrospective approach, with a cumulative-effect adjustment to retained earnings as of the beginning of the first reporting period in which the ASU is effective. Currently, the Company cannot reasonably estimate the impact that adoption of ASU 2016-13 will have on its Consolidated Financial Statements; however, the impact may be significant. That assessment is based upon the fact that, unlike the incurred loss models in existing GAAP, the current expected credit loss (“CECL”) model in ASU 2016-13 does not specify a threshold for the recognition of an impairment allowance. Rather, the Company will recognize an impairment allowance equal to its estimate of lifetime expected credit losses, adjusted for prepayments, for in-scope financial instruments as of the end of the reporting period. Accordingly, the impairment allowance measured under the CECL model could increase significantly from the impairment allowance measured under the Company’s existing incurred loss model. Significant CECL implementation matters to be addressed by the Company include selecting loss estimation methodologies, identifying, sourcing and storing data, addressing data gaps, defining a reasonable and supportable forecast period, selecting historical loss information which will be reverted to, documenting the CECL estimation process, assessing the impact to internal controls over financial reporting, capital planning and seeking process approval from audit and regulatory stakeholders. In February 2016, the FASB issued ASU 2016-02, Leases . The amendments included in this ASU create a new accounting model for both lessees and lessors. The new guidance requires lessees to recognize lease liabilities, initially measured as the present value of future lease payments, and corresponding right-of-use assets for all leases with lease terms greater than 12 months. This model differs from the current lease accounting model, which does not require such lease liabilities and corresponding right-of-use assets to be recorded for operating leases. The amendments in ASU 2016-02 must be adopted using the modified retrospective approach and will be effective for the first interim or annual period beginning after December 15, 2018. Early adoption is permitted. During 2017, the Company selected a third-party lease accounting application to assist in the implementation of this new guidance. Significant implementation matters to be addressed by the Company include assessing the impact to our internal controls over financial reporting and documenting the new lease accounting process. We do not expect a material impact to our Consolidated Statement of Income as a result of this ASU. See Note 18, “Commitments and Contingent Liabilities” to our 2017 Form 10-K, for more information regarding the minimum future payments related to our operating leases. In January 2016, the FASB issued ASU 2016-01, Recognition and Measurement of Financial Assets and Financial Liabilities . The amendments in ASU 2016-01 require all equity investments to be measured at fair value with changes in the fair value recognized through net income. The amendments in ASU 2016-01 also require an entity to present separately in other comprehensive income the portion of the total change in the fair value of a liability resulting from a change in the instrument-specific credit risk when the entity has elected to measure the liability at fair value in accordance with the fair value option for financial instruments. In addition, the amendments in this update eliminate the requirement to disclose the method(s) and significant assumptions used to estimate the fair value that is required to be disclosed for financial instruments measured at amortized cost on the balance sheet for public business entities. The amendments in ASU 2016-01 are effective for the first interim or annual period beginning after December 15, 2017. The Company adopted the amendments of ASU 2016-01 effective January 1, 2018 and recorded a cumulative effect adjustment of $203 thousand to retained earnings related to the unrealized holding losses on equity securities with readily determinable fair value included in accumulated other comprehensive loss. The Company also added a separate line item on the Consolidated Balance Sheet for equity securities at fair value and reclassified amounts previously included in securities available for sale at fair value to conform to current period presentation. In addition, as required by the ASU, the fair value disclosure for loans is computed using an exit price notion and deposits with no stated maturity are no longer included in the fair value disclosures in Note 15. In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers , which provides revenue recognition guidance that is intended to create greater consistency with respect to how and when revenue from contracts with customers is shown in the income statement. The guidance requires that revenue from contracts with customers be recognized when transfer of control over goods or services is passed to customers in the amount of consideration expected to be received. Subsequent Accounting Standard Updates have been issued clarifying the original pronouncement (ASU 2016-08, ASU 2016-10, ASU 2016-12 and ASU 2016-20). The majority of the Company’s revenue is comprised of interest income from financial assets, which is specifically outside the scope of ASU 2014-09. On January 1, 2018, we adopted the accounting guidance in ASU 2014-09 and all the related amendments (“Topic 606”) using the modified retrospective method for all contracts that have not been completed (i.e. open contracts). Therefore, the comparative information has not been adjusted and continues to be reported under Topic 605. There was no cumulative effect adjustment as of January 1, 2018, and there were no material changes to the timing or amount of revenue recognized for the three months ended March 31, 2018; however, additional disclosures were incorporated in the footnotes upon adoption. See Note 17, “Revenue from Contracts with Customers,” for more information.

Business Combinations

Business Combinations	3 Months Ended
	Mar. 31, 2018
Business Acquisition [Line Items]
Business Combination Disclosure [Text Block]	On November 1, 2017 , the Company completed its acquisition of Pacific Continental Corporation (“Pacific Continental”) and its wholly-owned banking subsidiary Pacific Continental Bank. The Company acquired 100% of the equity interests of Pacific Continental. The primary reasons for the acquisition were to expand in the Eugene, Oregon market and improve branch network efficiencies in the Seattle and Portland markets. The assets acquired and liabilities assumed have been accounted for under the acquisition method of accounting. The assets and liabilities, both tangible and intangible, were recorded at their fair values as of the November 1, 2017 acquisition date. Initial accounting for deferred taxes was incomplete as of March 31, 2018 . The deferred taxes currently recognized in the financial statements have been determined provisionally as the final Pacific Continental tax return has not yet been completed. The application of the acquisition method of accounting resulted in the recognition of goodwill of $383.1 million and a core deposit intangible of $46.9 million , or 2.34% of core deposits. The goodwill represents the excess purchase price over the fair value of the net assets acquired. The goodwill is not deductible for income tax purposes. The table below summarizes the amounts recognized as of the acquisition date for each major class of assets acquired and liabilities assumed: November 1, 2017 (in thousands) Merger consideration $ 637,103 Identifiable net assets acquired, at fair value Assets acquired Cash and cash equivalents $ 81,190 Investment securities 449,291 Federal Home Loan Bank stock 7,084 Loans 1,873,987 Interest receivable 7,827 Premises and equipment 27,343 Other real estate owned 10,279 Core deposit intangible 46,875 Other assets 50,638 Total assets acquired 2,554,514 Liabilities assumed Deposits (2,118,982 ) Federal Home Loan Bank advances (101,127 ) Subordinated debentures (35,678 ) Junior subordinated debentures (14,434 ) Securities sold under agreements to repurchase (1,617 ) Other liabilities (28,653 ) Total liabilities assumed (2,300,491 ) Total fair value of identifiable net assets, at fair value 254,023 Goodwill $ 383,080 See Note 8, “Goodwill and Other Intangible Assets,” for further discussion of the accounting for goodwill and other intangible assets. The operating results of the Company reported herein include the operating results produced by the acquired assets and assumed liabilities for the period January 1, 2018 to March 31, 2018 . Disclosure of the amount of Pacific Continental’s revenue and net income (excluding integration costs) included in Columbia’s Consolidated Statements of Income is impracticable due to the integration of the operations and accounting for this acquisition. For illustrative purposes only, the following table presents certain unaudited pro forma information for the three months ended March 31, 2017 . This unaudited estimated pro forma financial information was calculated as if Pacific Continental had been acquired as of the beginning of the year prior to the date of acquisition. This unaudited pro forma information combines the historical results of Pacific Continental 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 acquisition occurred as of the beginning of the year prior to the acquisition. In particular, no adjustments have been made to eliminate the impact of other-than-temporary impairment losses and losses recognized on the sale of securities that may not have been necessary had the investment securities been recorded at fair value as of the beginning of the year prior to the date of acquisition. The unaudited pro forma information does not consider any changes to the provision for credit losses resulting from recording loan assets at fair value. Additionally, Columbia expects to achieve further operating cost savings and other business synergies, including revenue growth as a result of the acquisition, which are not reflected in the pro forma amounts that follow. As a result, actual amounts would have differed from the unaudited pro forma information presented. Unaudited Pro Forma Three Months Ended March 31, 2017 (in thousands except per share) Total revenues (net interest income plus noninterest income) $ 139,363 Net income $ 37,147 Earnings per share - basic $ 0.52 Earnings per share - diluted $ 0.52 The following table shows the impact of the acquisition-related expenses related to the acquisition of Pacific Continental for the periods indicated to the various components of noninterest expense: Three Months Ended March 31, 2018 2017 (in thousands) Noninterest Expense Compensation and employee benefits $ 1,556 $ — Occupancy 1,004 1 Advertising and promotion 512 6 Data processing 287 — Legal and professional fees 574 1,311 Other 332 46 Total impact of acquisition-related costs to noninterest expense $ 4,265 $ 1,364 As a result of the acquisition of Pacific Continental, we have consolidated assets exceeding $10 billion and we will be subject to the interchange fee cap imposed under the Dodd-Frank Wall Street Reform and Consumer Protection Act beginning July 1, 2018. We currently anticipate a pre-tax annual impact of approximately $10 million because we will no longer qualify for the small issuer exemption.

Securities

Securities	3 Months Ended
	Mar. 31, 2018
Available-for-sale Securities [Abstract]
Securities	Securities The following table summarizes the amortized cost, gross unrealized gains and losses and the resulting fair value of debt securities available for sale: Amortized Gross Gross Fair Value (in thousands) March 31, 2018 U.S. government agency and government-sponsored enterprise mortgage-backed securities and collateralized mortgage obligations $ 1,693,149 $ 698 $ (48,629 ) $ 1,645,218 State and municipal securities 588,218 3,467 (8,937 ) 582,748 U.S. government agency and government-sponsored enterprise securities 402,036 43 (6,247 ) 395,832 U.S. government securities 251 — (4 ) 247 Total $ 2,683,654 $ 4,208 $ (63,817 ) $ 2,624,045 December 31, 2017 U.S. government agency and government-sponsored enterprise mortgage-backed securities and collateralized mortgage obligations $ 1,752,236 $ 1,815 $ (27,326 ) $ 1,726,725 State and municipal securities 593,940 6,023 (3,959 ) 596,004 U.S. government agency and government-sponsored enterprise securities 416,894 642 (2,762 ) 414,774 U.S. government securities 251 — (3 ) 248 Total $ 2,763,321 $ 8,480 $ (34,050 ) $ 2,737,751 The following table provides the proceeds and gross realized gains and losses on sales of debt securities available for sale as well as other securities gains and losses for the periods indicated: Three Months Ended March 31, 2018 2017 (in thousands) Proceeds from sales of debt securities available for sale $ 19,761 $ — Gross realized gains from sales of debt securities available for sale $ 148 $ — Gross realized losses from sales of debt securities available for sale (46 ) — Other securities losses, net (1) (80 ) — Investment securities gains, net $ 22 $ — __________ (1) Other securities losses, net includes net unrealized loss activity associated with equity securities. There were no sales of equity securities during the periods presented. The scheduled contractual maturities of debt securities available for sale at March 31, 2018 are presented as follows: March 31, 2018 Amortized Cost Fair Value (in thousands) Due within one year $ 161,538 $ 161,314 Due after one year through five years 635,254 626,693 Due after five years through ten years 756,950 737,927 Due after ten years 1,129,912 1,098,111 Total debt securities available for sale $ 2,683,654 $ 2,624,045 The following table summarizes the carrying value of securities pledged as collateral to secure public deposits, borrowings and other purposes as permitted or required by law: March 31, 2018 (in thousands) Washington and Oregon State to secure public deposits $ 246,950 Federal Reserve Bank to secure borrowings 52,754 Other securities pledged 102,363 Total securities pledged as collateral $ 402,067 The following table shows the gross unrealized losses and fair value of the Company’s debt securities available for sale with unrealized losses that are not deemed to be other-than-temporarily impaired, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position at March 31, 2018 and December 31, 2017 : Less than 12 Months 12 Months or More Total Fair Unrealized Fair Unrealized Fair Unrealized (in thousands) March 31, 2018 U.S. government agency and government-sponsored enterprise mortgage-backed securities and collateralized mortgage obligations $ 921,993 $ (19,073 ) $ 681,577 $ (29,556 ) $ 1,603,570 $ (48,629 ) State and municipal securities 315,392 (4,972 ) 76,452 (3,965 ) 391,844 (8,937 ) U.S. government agency and government-sponsored enterprise securities 251,626 (3,969 ) 140,455 (2,278 ) 392,081 (6,247 ) U.S. government securities 247 (4 ) — — 247 (4 ) Total $ 1,489,258 $ (28,018 ) $ 898,484 $ (35,799 ) $ 2,387,742 $ (63,817 ) December 31, 2017 U.S. government agency and government-sponsored enterprise mortgage-backed securities and collateralized mortgage obligations $ 816,678 $ (6,710 ) $ 717,211 $ (20,616 ) $ 1,533,889 $ (27,326 ) State and municipal securities 220,019 (1,723 ) 75,172 (2,236 ) 295,191 (3,959 ) U.S. government agency and government-sponsored enterprise securities 184,046 (1,006 ) 155,983 (1,756 ) 340,029 (2,762 ) U.S. government securities 249 (3 ) — — 249 (3 ) Total $ 1,220,992 $ (9,442 ) $ 948,366 $ (24,608 ) $ 2,169,358 $ (34,050 ) At March 31, 2018 , there were 446 U.S. government agency and government-sponsored enterprise mortgage-backed securities and collateralized mortgage obligations securities in an unrealized loss position, of which 117 were in a continuous loss position for 12 months or more. The decline in fair value is attributable to changes in interest rates relative to where these investments fall within the yield curve and their individual characteristics. Because the Company does not intend to sell these securities nor does the Company consider it more likely than not that it will be required to sell these securities before the recovery of amortized cost basis, which may be upon maturity, the Company does not consider these investments to be other-than-temporarily impaired at March 31, 2018 . At March 31, 2018 , there were 406 state and municipal government securities in an unrealized loss position, of which 71 were in a continuous loss position for 12 months or more. The unrealized losses on state and municipal securities were caused by interest rate changes or widening of market spreads subsequent to the purchase of the individual securities. Management monitors published credit ratings of these securities for adverse changes. As of March 31, 2018 , none of the rated obligations of state and local government entities held by the Company had a below investment grade credit rating. Because the credit quality of these securities are investment grade and the Company does not intend to sell these securities nor does the Company consider it more likely than not that it will be required to sell these securities before the recovery of amortized cost basis, which may be upon maturity, the Company does not consider these investments to be other-than-temporarily impaired at March 31, 2018 . At March 31, 2018 , there were 50 U.S. government agency and government-sponsored enterprise securities in an unrealized loss position, of which 16 were in a continuous loss position for 12 months or more. The decline in fair value is attributable to changes in interest rates relative to where these investments fall within the yield curve and their individual characteristics. Because the Company does not currently intend to sell these securities nor does the Company consider it more likely than not that it will be required to sell these securities before the recovery of amortized cost basis, which may be upon maturity, the Company does not consider these investments to be other-than-temporarily impaired at March 31, 2018 . At March 31, 2018 , there was one U.S. government security in an unrealized loss position, which was not in a continuous loss position for 12 months or more. The decline in fair value is attributable to changes in interest rates relative to where this investment falls within the yield curve and its individual characteristics. Because the Company does not currently intend to sell this security nor does the Company consider it more likely than not that it will be required to sell this security before the recovery of amortized cost basis, which may be upon maturity, the Company does not consider this investment to be other-than-temporarily impaired at March 31, 2018 .

Loans

Loans	3 Months Ended
	Mar. 31, 2018
Loans Receivable, Net [Abstract]
Loans	Loans The Company’s loan portfolio includes originated and purchased loans. Originated loans and purchased loans for which there was no evidence of credit deterioration at their acquisition date and it was probable that we would be able to collect all contractually required payments are referred to collectively as loans, excluding purchased credit impaired loans. Purchased loans for which there was, at acquisition date, evidence of credit deterioration since their origination and it was probable that we would be unable to collect all contractually required payments are referred to as purchased credit impaired loans, or “PCI loans.” The following is an analysis of the loan portfolio by segment (net of unearned income): March 31, 2018 December 31, 2017 Loans, excluding PCI loans PCI Loans Total Loans, excluding PCI loans PCI Loans Total (in thousands) Commercial business $ 3,402,162 $ 13,536 $ 3,415,698 $ 3,377,324 $ 12,628 $ 3,389,952 Real estate: One-to-four family residential 182,302 10,684 192,986 188,396 12,395 200,791 Commercial and multifamily residential 3,776,709 73,446 3,850,155 3,825,739 75,594 3,901,333 Total real estate 3,959,011 84,130 4,043,141 4,014,135 87,989 4,102,124 Real estate construction: One-to-four family residential 208,441 171 208,612 200,518 177 200,695 Commercial and multifamily residential 385,339 611 385,950 371,931 607 372,538 Total real estate construction 593,780 782 594,562 572,449 784 573,233 Consumer 323,631 10,851 334,482 334,190 11,269 345,459 Less: Net unearned income (48,252 ) — (48,252 ) (52,111 ) — (52,111 ) Total loans, net of unearned income 8,230,332 109,299 8,339,631 8,245,987 112,670 8,358,657 Less: Allowance for loan and lease losses (74,162 ) (5,665 ) (79,827 ) (68,739 ) (6,907 ) (75,646 ) Total loans, net $ 8,156,170 $ 103,634 $ 8,259,804 $ 8,177,248 $ 105,763 $ 8,283,011 Loans held for sale $ 4,312 $ — $ 4,312 $ 5,766 $ — $ 5,766 At March 31, 2018 and December 31, 2017 , the Company had no material foreign activities. Substantially all of the Company’s loans and unfunded commitments are geographically concentrated in its service areas within the states of Washington, Oregon and Idaho. The Company has made loans to executive officers and directors of the Company and related interests. These loans are made on the same terms, including interest rates and collateral, as those prevailing at the time for comparable transactions with unrelated persons and do not involve more than the normal risk of collectability. The aggregate dollar amount of these loans was $9.9 million and $10.0 million at March 31, 2018 and December 31, 2017 , respectively. During the first three months of 2018 , there were no advances and $86 thousand in repayments. At March 31, 2018 and December 31, 2017 , $2.28 billion and $2.25 billion of commercial and residential real estate loans were pledged as collateral on Federal Home Loan Bank of Des Moines (“FHLB”) borrowings and additional borrowing capacity. The Company has also pledged $72.5 million and $70.2 million of commercial loans to the Federal Reserve Bank for additional borrowing capacity at March 31, 2018 and December 31, 2017 , respectively. The following is an analysis of nonaccrual loans as of March 31, 2018 and December 31, 2017 : March 31, 2018 December 31, 2017 Recorded Unpaid Principal Recorded Unpaid Principal (in thousands) Commercial business: Secured $ 57,504 $ 69,056 $ 45,410 $ 56,865 Unsecured 115 115 50 49 Real estate: One-to-four family residential 1,054 1,426 785 1,182 Commercial & multifamily residential: Commercial land 3,192 3,201 2,628 2,623 Income property 3,980 4,264 4,284 5,410 Owner occupied 7,367 7,621 7,029 7,270 Real estate construction: One-to-four family residential: Land and acquisition — — 25 26 Residential construction 1,210 1,210 1,829 1,828 Consumer 4,042 4,378 4,149 4,633 Total $ 78,464 $ 91,271 $ 66,189 $ 79,886 Loans, excluding purchased credit impaired loans The following is an aging of the recorded investment of the loan portfolio as of March 31, 2018 and December 31, 2017 : Current 30 - 59 60 - 89 Greater Total Nonaccrual Total Loans March 31, 2018 (in thousands) Commercial business: Secured $ 3,189,473 $ 16,410 $ 2,872 $ — $ 19,282 $ 57,504 $ 3,266,259 Unsecured 119,863 50 51 — 101 115 120,079 Real estate: One-to-four family residential 179,174 340 — — 340 1,054 180,568 Commercial & multifamily residential: Commercial land 283,973 2,299 — — 2,299 3,192 289,464 Income property 1,867,450 1,929 815 — 2,744 3,980 1,874,174 Owner occupied 1,570,051 10,751 2,772 — 13,523 7,367 1,590,941 Real estate construction: One-to-four family residential: Land and acquisition 5,937 318 285 — 603 — 6,540 Residential construction 199,756 112 — — 112 1,210 201,078 Commercial & multifamily residential: Income property 295,067 11,070 — — 11,070 — 306,137 Owner occupied 73,016 — — — — — 73,016 Consumer 316,557 1,229 248 — 1,477 4,042 322,076 Total $ 8,100,317 $ 44,508 $ 7,043 $ — $ 51,551 $ 78,464 $ 8,230,332 Current 30 - 59 60 - 89 Greater Total Nonaccrual Total Loans December 31, 2017 (in thousands) Commercial business: Secured $ 3,185,321 $ 2,530 $ 2,400 $ — $ 4,930 $ 45,410 $ 3,235,661 Unsecured 123,524 100 501 — 601 50 124,175 Real estate: One-to-four family residential 184,256 1,111 402 — 1,513 785 186,554 Commercial & multifamily residential: Commercial land 292,680 92 — 581 673 2,628 295,981 Income property 1,898,655 2,426 971 — 3,397 4,284 1,906,336 Owner occupied 1,590,004 2,485 468 — 2,953 7,029 1,599,986 Real estate construction: One-to-four family residential: Land and acquisition 9,882 — — — — 25 9,907 Residential construction 187,862 — — — — 1,829 189,691 Commercial & multifamily residential: Income property 293,028 — — — — — 293,028 Owner occupied 72,443 — — — — — 72,443 Consumer 325,928 1,446 702 — 2,148 4,149 332,225 Total $ 8,163,583 $ 10,190 $ 5,444 $ 581 $ 16,215 $ 66,189 $ 8,245,987 The following is an analysis of impaired loans as of March 31, 2018 and December 31, 2017 : Recorded Investment Recorded Investment Impaired Loans With Impaired Loans Without Recorded Unpaid Related Recorded Unpaid March 31, 2018 (in thousands) Commercial business: Secured $ 3,221,659 $ 44,600 $ 13,836 $ 18,931 $ 5,657 $ 30,764 $ 33,785 Unsecured 120,056 23 23 23 2 — — Real estate: One-to-four family residential 179,700 868 428 715 22 440 1,017 Commercial & multifamily residential: Commercial land 286,613 2,851 — — — 2,851 2,860 Income property 1,870,614 3,560 — — — 3,560 3,623 Owner occupied 1,582,385 8,556 3,399 4,821 5 5,157 5,269 Real estate construction: One-to-four family residential: Land and acquisition 6,540 — — — — — — Residential construction 199,868 1,210 — — — 1,210 1,210 Commercial & multifamily residential: Income property 306,137 — — — — — — Owner occupied 68,966 4,050 — — — 4,050 4,050 Consumer 315,845 6,231 5,439 5,707 171 792 860 Total $ 8,158,383 $ 71,949 $ 23,125 $ 30,197 $ 5,857 $ 48,824 $ 52,674 Recorded Investment Recorded Investment Impaired Loans With Impaired Loans Without Recorded Unpaid Related Recorded Unpaid December 31, 2017 (in thousands) Commercial business: Secured $ 3,195,649 $ 40,012 $ 3,808 $ 3,937 $ 1,867 $ 36,204 $ 42,314 Unsecured 124,150 25 25 24 3 — — Real estate: One-to-four family residential 185,659 895 867 1,408 103 28 337 Commercial & multifamily residential: Commercial land 293,694 2,287 — — — 2,287 2,282 Income property 1,901,313 5,023 2,768 3,328 185 2,255 2,601 Owner occupied 1,591,298 8,688 77 80 3 8,611 10,077 Real estate construction: One-to-four family residential: Land and acquisition 9,907 — — — — — — Residential construction 188,481 1,210 — — — 1,210 1,210 Commercial & multifamily residential: Income property 293,028 — — — — — — Owner occupied 68,393 4,050 — — — 4,050 4,050 Consumer 325,210 7,015 5,303 5,568 199 1,712 1,864 Total $ 8,176,782 $ 69,205 $ 12,848 $ 14,345 $ 2,360 $ 56,357 $ 64,735 The following table provides additional information on impaired loans for the three month periods indicated: Three Months Ended March 31, 2018 2017 Average Recorded Interest Recognized Average Recorded Interest Recognized (in thousands) Commercial business: Secured $ 42,306 $ 12 $ 8,303 $ 19 Unsecured 24 — — — Real estate: One-to-four family residential 881 7 521 2 Commercial & multifamily residential: Commercial land 2,569 — 1,504 — Income property 4,292 31 4,059 1 Owner occupied 8,622 84 4,462 — Real estate construction: One-to-four family residential: Land and acquisition — — 7 — Residential construction 1,210 — 168 — Commercial & multifamily residential: Owner occupied 4,050 51 — — Consumer 6,623 54 5,370 27 Total $ 70,577 $ 239 $ 24,394 $ 49 The following is an analysis of loans classified as troubled debt restructurings (“TDR”) during the three months ended March 31, 2018 and 2017 : Three months ended March 31, 2018 Three months ended March 31, 2017 Number of TDR Modifications Pre-Modification Post-Modification Number of TDR Modifications Pre-Modification Post-Modification (dollars in thousands) Commercial business: Secured 1 $ 450 $ 450 3 $ 356 $ 356 Real estate: Commercial and multifamily residential: Income property 1 891 891 — — — Consumer 7 1,143 1,143 10 1,546 1,546 Total 9 $ 2,484 $ 2,484 13 $ 1,902 $ 1,902 The Company’s loans classified as TDR are loans that have been modified or the borrower has been granted special concessions due to financial difficulties that, if not for the challenges of the borrower, the Company would not otherwise consider. The TDR modifications or concessions are made to increase the likelihood that these borrowers with financial difficulties will be able to satisfy their debt obligations as amended. The concessions granted in the restructurings summarized in the table above largely consisted of maturity extensions, interest rate modifications or a combination of both. In limited circumstances, a reduction in the principal balance of the loan could also be made as a concession. Credit losses for loans classified as TDR are measured on the same basis as impaired loans. For impaired loans, an allowance is established when the collateral value less selling costs (or discounted cash flows or observable market price) of the impaired loan is lower than the recorded investment of that loan. The Company had commitments to lend $121 thousand of additional funds on loans classified as TDR as of March 31, 2018 . The Company had $506 thousand of such commitments at December 31, 2017 . The Company did not have any loans modified as TDR that defaulted within 12 months of being modified as TDR during the three months ended March 31, 2018 and 2017 . Purchased Credit Impaired Loans Purchased credit impaired (“PCI”) loans are accounted for under ASC 310-30 and initially measured at fair value based on expected future cash flows over the life of the loans. Loans that have common risk characteristics are aggregated into pools. The Company remeasures contractual and expected cash flows, at the pool-level, on a quarterly basis. Contractual cash flows are calculated based upon the loan pool terms after applying a prepayment factor. Calculation of the applied prepayment factor for contractual cash flows is the same as described below for expected cash flows. Inputs to the determination of expected cash flows include cumulative default and prepayment data as well as loss severity and recovery lag information. Cumulative default and prepayment data are calculated via a transition matrix, which utilizes probability values of a loan pool transitioning into a particular delinquency state (e.g. 0-30 days past due, 31 to 60 days, etc.) given its delinquency state at the remeasurement date. Loss severity factors are based upon either actual charge-off data within the loan pools or industry averages, and recovery lags are based upon the collateral within the loan pools. The excess of cash flows expected to be collected over the initial fair value of purchased credit impaired loans is referred to as the accretable yield and is accreted into interest income over the estimated life of the acquired loans using the effective yield method. Other adjustments to the accretable yield include changes in the estimated remaining life of the acquired loans, changes in expected cash flows and changes of indices for acquired loans with variable interest rates. The following is an analysis of our PCI loans, net of related allowance for losses and remaining valuation discounts as of March 31, 2018 and December 31, 2017 : March 31, 2018 December 31, 2017 (in thousands) Commercial business $ 14,201 $ 13,753 Real estate: One-to-four family residential 12,738 14,610 Commercial and multifamily residential 77,400 79,211 Total real estate 90,138 93,821 Real estate construction: One-to-four family residential 171 177 Commercial and multifamily residential 589 595 Total real estate construction 760 772 Consumer 11,989 12,412 Subtotal of PCI loans 117,088 120,758 Less: Valuation discount resulting from acquisition accounting 7,789 8,088 Allowance for loan losses 5,665 6,907 PCI loans, net of allowance for loan losses $ 103,634 $ 105,763 The following table shows the changes in accretable yield for PCI loans for the three months ended March 31, 2018 and 2017 : Three Months Ended March 31, 2018 2017 (in thousands) Balance at beginning of period $ 31,176 $ 45,191 Accretion (2,265 ) (4,182 ) Disposals (159 ) (158 ) Reclassifications from (to) nonaccretable difference 603 (2,407 ) Balance at end of period $ 29,355 $ 38,444

Allowance for Loan and Lease Lo

Allowance for Loan and Lease Losses and Unfunded Commitments and Letters of Credit	3 Months Ended
	Mar. 31, 2018
Allowance For Loan And Lease Losses And Unfunded Loan Commitments And Letters Of Credit
Allowance For Loan And Lease Losses And Unfunded Loan Commitments And Letters Of Credit Text Block	Allowance for Loan and Lease Losses and Unfunded Commitments and Letters of Credit We record an allowance for loan and lease losses (the “allowance”) to recognize management’s estimate of credit losses incurred in the loan portfolio at each balance sheet date. We have used the same methodology for allowance calculations during the three months ended March 31, 2018 and 2017 . The following tables show a detailed analysis of the allowance for the three months ended March 31, 2018 and 2017 : Beginning Charge-offs Recoveries Provision (Recovery) Ending Specific General Three months ended March 31, 2018 (in thousands) Commercial business: Secured $ 29,341 $ (2,414 ) $ 553 $ 9,851 $ 37,331 $ 5,657 $ 31,674 Unsecured 2,000 (63 ) 249 409 2,595 2 2,593 Real estate: One-to-four family residential 701 — 172 (315 ) 558 22 536 Commercial & multifamily residential: Commercial land 4,265 — 6 (526 ) 3,745 — 3,745 Income property 5,672 (223 ) 141 (888 ) 4,702 — 4,702 Owner occupied 5,459 — 12 (722 ) 4,749 5 4,744 Real estate construction: One-to-four family residential: Land and acquisition 963 — 16 (67 ) 912 — 912 Residential construction 3,709 — 3 924 4,636 — 4,636 Commercial & multifamily residential: Income property 7,053 — — 421 7,474 — 7,474 Owner occupied 4,413 — — (2,490 ) 1,923 — 1,923 Consumer 5,163 (264 ) 260 57 5,216 171 5,045 Purchased credit impaired 6,907 (1,343 ) 1,224 (1,123 ) 5,665 — 5,665 Unallocated — — — 321 321 — 321 Total $ 75,646 $ (4,307 ) $ 2,636 $ 5,852 $ 79,827 $ 5,857 $ 73,970 Beginning Charge-offs Recoveries Provision (Recovery) Ending Specific General Three months ended March 31, 2017 (in thousands) Commercial business: Secured $ 36,050 $ (1,109 ) $ 297 $ 434 $ 35,672 $ — $ 35,672 Unsecured 960 (18 ) 68 178 1,188 — 1,188 Real estate: One-to-four family residential 599 (307 ) 117 236 645 11 634 Commercial & multifamily residential: Commercial land 1,797 — — 491 2,288 — 2,288 Income property 7,342 — 35 (574 ) 6,803 26 6,777 Owner occupied 6,439 — 43 52 6,534 — 6,534 Real estate construction: One-to-four family residential: Land and acquisition 316 (14 ) 20 187 509 — 509 Residential construction 669 — 9 431 1,109 — 1,109 Commercial & multifamily residential: Income property 404 — — 378 782 — 782 Owner occupied 1,192 — — 576 1,768 — 1,768 Consumer 3,534 (428 ) 285 (31 ) 3,360 57 3,303 Purchased credit impaired 10,515 (1,939 ) 1,144 (325 ) 9,395 — 9,395 Unallocated 226 — — 742 968 — 968 Total $ 70,043 $ (3,815 ) $ 2,018 $ 2,775 $ 71,021 $ 94 $ 70,927 Changes in the allowance for unfunded commitments and letters of credit, a component of “Other liabilities” in the Consolidated Balance Sheets, are summarized as follows: Three Months Ended March 31, 2018 2017 (in thousands) Balance at beginning of period $ 3,130 $ 2,705 Net changes in the allowance for unfunded commitments and letters of credit 1,200 850 Balance at end of period $ 4,330 $ 3,555 Risk Elements The extension of credit in the form of loans or other credit products to individuals and businesses is one of our principal business activities. Our policies and applicable laws and regulations require risk analysis as well as ongoing portfolio and credit management. We manage our credit risk through lending limit constraints, credit review, approval policies and extensive, ongoing internal monitoring. We also manage credit risk through diversification of the loan portfolio by type of loan, type of industry and type of borrower and by limiting the aggregation of debt to a single borrower. Risk ratings are reviewed and updated whenever appropriate, with more periodic reviews as the risk and dollar value of loss on the loan increases. In the event full collection of principal and interest is not reasonably assured, the loan is appropriately downgraded and, if warranted, placed on nonaccrual status even though the loan may be current as to principal and interest payments. Additionally, we assess whether an impairment of a loan warrants specific reserves or a write-down of the loan. Pass rated loans are generally considered to have sufficient sources of repayment in order to repay the loan in full in accordance with all terms and conditions. Special Mention rated loans have potential weaknesses that, if left uncorrected, may result in deterioration of the repayment prospects for the asset or in the Company’s credit position at some future date. Loans with a risk rating of Substandard or worse are reported as classified loans in our allowance analysis. We review these loans to assess the ability of our borrowers to service all interest and principal obligations and, as a result, the risk rating may be adjusted accordingly. Loans risk rated as Substandard reflect loans where a loss is possible if loan weaknesses are not corrected. Doubtful rated loans have a high probability of loss; however, the amount of loss has not yet been determined. Loss rated loans are considered uncollectable and when identified, are charged off. The following is an analysis of the credit quality of our loan portfolio, excluding PCI loans, as of March 31, 2018 and December 31, 2017 : Pass Special Mention Substandard Doubtful Loss Total March 31, 2018 (in thousands) Loans, excluding PCI loans: Commercial business: Secured $ 3,067,417 $ 47,672 $ 151,170 $ — $ — $ 3,266,259 Unsecured 119,416 — 663 — — 120,079 Real estate: One-to-four family residential 177,122 1,208 2,238 — — 180,568 Commercial and multifamily residential: Commercial land 279,949 1,288 8,227 — — 289,464 Income property 1,837,613 19,863 16,698 — — 1,874,174 Owner occupied 1,542,605 8,986 39,350 — — 1,590,941 Real estate construction: One-to-four family residential: Land and acquisition 6,540 — — — — 6,540 Residential construction 199,868 — 1,210 — — 201,078 Commercial and multifamily residential: Income property 303,079 — 3,058 — — 306,137 Owner occupied 67,672 — 5,344 — — 73,016 Consumer 314,223 — 7,853 — — 322,076 Total $ 7,915,504 $ 79,017 $ 235,811 $ — $ — 8,230,332 Less: Allowance for loan and lease losses 74,162 Loans, excluding PCI loans, net $ 8,156,170 Pass Special Mention Substandard Doubtful Loss Total December 31, 2017 (in thousands) Loans, excluding PCI loans: Commercial business: Secured $ 3,049,031 $ 64,600 $ 122,030 $ — $ — $ 3,235,661 Unsecured 123,621 — 554 — — 124,175 Real estate: One-to-four family residential 183,312 1,186 2,056 — — 186,554 Commercial and multifamily residential: Commercial land 283,673 5,204 7,104 — — 295,981 Income property 1,857,832 17,181 31,323 — — 1,906,336 Owner occupied 1,546,775 7,380 45,831 — — 1,599,986 Real estate construction: One-to-four family residential: Land and acquisition 9,882 — 25 — — 9,907 Residential construction 187,863 — 1,828 — — 189,691 Commercial and multifamily residential: Income property 293,028 — — — — 293,028 Owner occupied 68,393 — 4,050 — — 72,443 Consumer 323,129 — 9,096 — — 332,225 Total $ 7,926,539 $ 95,551 $ 223,897 $ — $ — 8,245,987 Less: Allowance for loan and lease losses 68,739 Loans, excluding PCI loans, net $ 8,177,248 The following is an analysis of the credit quality of our PCI loan portfolio as of March 31, 2018 and December 31, 2017 : Pass Special Mention Substandard Doubtful Loss Total March 31, 2018 (in thousands) PCI loans: Commercial business: Secured $ 12,582 $ — $ 728 $ — $ — $ 13,310 Unsecured 891 — — — — 891 Real estate: One-to-four family residential 11,967 — 771 — — 12,738 Commercial and multifamily residential: Commercial land 12,223 — — — — 12,223 Income property 22,384 — — — — 22,384 Owner occupied 41,874 — 919 — — 42,793 Real estate construction: One-to-four family residential: Land and acquisition 164 — 7 — — 171 Commercial and multifamily residential: Income property 589 — — — — 589 Consumer 11,514 — 475 — — 11,989 Total $ 114,188 $ — $ 2,900 $ — $ — 117,088 Less: Valuation discount resulting from acquisition accounting 7,789 Allowance for loan losses 5,665 PCI loans, net $ 103,634 Pass Special Mention Substandard Doubtful Loss Total December 31, 2017 (in thousands) PCI loans: Commercial business: Secured $ 11,918 $ — $ 723 $ — $ — $ 12,641 Unsecured 1,045 — 67 — — 1,112 Real estate: One-to-four family residential 13,817 — 793 — — 14,610 Commercial and multifamily residential: Commercial land 9,460 349 — — — 9,809 Income property 25,981 — 35 — — 26,016 Owner occupied 42,617 — 769 — — 43,386 Real estate construction: One-to-four family residential: Land and acquisition 169 — 8 — — 177 Commercial and multifamily residential: Income property 595 — — — — 595 Consumer 11,705 — 707 — — 12,412 Total $ 117,307 $ 349 $ 3,102 $ — $ — 120,758 Less: Valuation discount resulting from acquisition accounting 8,088 Allowance for loan losses 6,907 PCI loans, net $ 105,763

Other Real Estate Owned

Other Real Estate Owned	3 Months Ended
	Mar. 31, 2018
Other Real Estate, Foreclosed Assets, and Repossessed Assets [Abstract]
Other Real Estate Owned	Other Real Estate Owned (“OREO”) The following tables set forth activity in OREO for the three months ended March 31, 2018 and 2017 : Three Months Ended March 31, 2018 2017 (in thousands) Balance, beginning of period $ 13,298 $ 5,998 Transfers in 406 — Valuation adjustments (92 ) (193 ) Proceeds from sale of OREO property (2,062 ) (1,275 ) Loss on sale of OREO, net (43 ) (11 ) Balance, end of period $ 11,507 $ 4,519 At March 31, 2018 , there were $433 thousand in foreclosed residential real estate properties held as OREO and the recorded investment of consumer mortgage loans secured by residential real estate properties for which formal foreclosure proceedings were in process was $638 thousand .

Goodwill and Intangible Assets

Goodwill and Intangible Assets	3 Months Ended
	Mar. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets	Goodwill and Other Intangible Assets In accordance with the Intangibles – Goodwill and Other topic of the FASB ASC, goodwill is not amortized but is reviewed for potential impairment at the reporting unit level. Management analyzes its goodwill for impairment on an annual basis on July 31 and between annual tests in certain circumstances such as material adverse changes in legal, business, regulatory and economic factors. An impairment loss is recorded to the extent that the carrying amount of goodwill exceeds its implied fair value. The core deposit intangible (“CDI”) is evaluated for impairment if events and circumstances indicate a possible impairment. The CDI is amortized on an accelerated basis over an estimated life of 10 years . The following table sets forth activity for goodwill and other intangible assets for the periods indicated: Three Months Ended March 31, 2018 2017 (in thousands) Goodwill Total goodwill (1) $ 765,842 $ 382,762 Other intangible assets, net Core deposit intangible: Gross core deposit intangible balance at beginning of period 105,473 58,598 Accumulated amortization at beginning of period (48,219 ) (41,886 ) Core deposit intangible, net at beginning of period 57,254 16,712 CDI current period amortization (3,188 ) (1,349 ) Total core deposit intangible, net at end of period 54,066 15,363 Intangible assets not subject to amortization 919 919 Other intangible assets, net at end of period 54,985 16,282 Total goodwill and other intangible assets at end of period $ 820,827 $ 399,044 __________ (1) See Note 3, “Business Combinations,” for additional information regarding goodwill and intangible assets recorded related to the acquisition of Pacific Continental on November 1, 2017. The following table provides the estimated future amortization expense of core deposit intangibles for the remaining nine months ending December 31, 2018 and the succeeding four years: Amount (in thousands) Year ending December 31, 2018 $ 9,048 2019 10,479 2020 8,724 2021 7,264 2022 5,880

Subordinated debentures

Subordinated debentures	3 Months Ended
	Mar. 31, 2018
Subordinated Borrowing [Line Items]
Subordinated Borrowings Disclosure [Text Block]	Subordinated Debentures On November 1, 2017, with its acquisition of Pacific Continental, the Company assumed $35.0 million in aggregate principal amount of fixed-to-floating rate subordinated debentures (the “Notes”). The Notes are callable at par on June 30, 2021, have a stated maturity of June 30, 2026 and bear interest at a fixed annual rate of 5.875% per year, from and including June 27, 2016, but excluding June 30, 2021. From and including June 30, 2021 through the maturity date or early redemption date, the interest rate will reset quarterly to an annual interest rate equal to the then-current three-month LIBOR plus 471.5 basis points.

Junior subordinated debt

Junior subordinated debt	3 Months Ended
	Mar. 31, 2018
Junior subordinated debt [Abstract]
Junior subordinated debentures [Text Block]	Junior Subordinated Debentures On November 1, 2017, with its acquisition of Pacific Continental, the Company assumed $14.4 million of trust preferred obligations. The Company redeemed $6.2 million of these obligations during 2017. The remaining $8.2 million of obligations were redeemed in January 2018.

Derivatives and Balance Sheet O

Derivatives and Balance Sheet Offsetting	3 Months Ended
	Mar. 31, 2018
General Discussion of Derivative Instruments and Hedging Activities [Abstract]
Derivatives and Hedging Activities	Derivatives and Balance Sheet Offsetting The Company periodically enters into certain commercial loan interest rate swap agreements in order to provide commercial loan customers the ability to convert from variable to fixed interest rates. Under these agreements, the Company enters into a variable-rate loan agreement with a customer in addition to a swap agreement. This swap agreement effectively converts the customer’s variable rate loan into a fixed rate. The Company then enters into a corresponding swap agreement with a third-party in order to offset its exposure on the variable and fixed components of the customer agreement. As the interest rate swap agreements with the customers and third parties are not designated as hedges under the Derivatives and Hedging topic of the FASB ASC, the instruments are marked to market in earnings. The notional amount of open interest rate swap agreements at March 31, 2018 and December 31, 2017 was $393.8 million and $384.7 million , respectively. During the three months ended March 31, 2018 and March 31, 2017 , mark-to-market gain s of $6 thousand and $4 thousand , respectively, were recorded to “Other” noninterest expense. The following table presents the fair value of derivatives not designated as hedging instruments at March 31, 2018 and December 31, 2017 : Asset Derivatives Liability Derivatives March 31, 2018 December 31, 2017 March 31, 2018 December 31, 2017 Balance Sheet Fair Value Balance Sheet Fair Value Balance Sheet Fair Value Balance Sheet Fair Value (in thousands) Interest rate contracts Other assets $ 7,406 Other assets $ 6,707 Other liabilities $ 7,409 Other liabilities $ 6,714 The Company is party to interest rate contracts and repurchase agreements that are subject to enforceable master netting arrangements or similar agreements. Under these agreements, the Company may have the right to net settle multiple contracts with the same counterparty. The following tables show the gross interest rate swap agreements and repurchase agreements in the Consolidated Balance Sheets and the respective collateral received or pledged in the form of other financial instruments, which are generally marketable securities. The collateral amounts in these tables are limited to the outstanding balances of the related asset or liability. Therefore, instances of overcollateralization are not shown. Gross Amounts of Recognized Assets/Liabilities Gross Amounts Offset in the Consolidated Balance Sheets Net Amounts of Assets/Liabilities Presented in the Consolidated Balance Sheets Gross Amounts Not Offset in the Consolidated Balance Sheets Collateral Posted Net Amount March 31, 2018 (in thousands) Assets Interest rate contracts $ 7,406 $ — $ 7,406 $ — $ 7,406 Liabilities Interest rate contracts $ 7,409 $ — $ 7,409 $ (1,190 ) $ 6,219 Repurchase agreements $ 24,247 $ — $ 24,247 $ (24,247 ) $ — December 31, 2017 Assets Interest rate contracts $ 6,707 $ — $ 6,707 $ — $ 6,707 Liabilities Interest rate contracts $ 6,714 $ — $ 6,714 $ (6,714 ) $ — Repurchase agreements $ 79,059 $ — $ 79,059 $ (79,059 ) $ — The following table presents the class of collateral pledged for repurchase agreements as well as the remaining contractual maturity of the repurchase agreements: Remaining contractual maturity of the agreements Overnight and continuous Up to 30 days 30 - 90 days Greater than 90 days Total March 31, 2018 (in thousands) Class of collateral pledged for repurchase agreements U.S. government agency and government-sponsored enterprise mortgage-backed securities and collateralized mortgage obligations $ 24,247 $ — $ — $ — $ 24,247 Gross amount of recognized liabilities for repurchase agreements 24,247 Amounts related to agreements not included in offsetting disclosure $ — The collateral utilized for the Company’s repurchase agreements is subject to market fluctuations as well as prepayments of principal. The Company monitors the risk of the fair value of its pledged collateral falling below acceptable amounts based on the type of the underlying repurchase agreement. The pledged collateral related to the Company’s $24.2 million sweep repurchase agreements, which mature on an overnight basis, is monitored on a daily basis as the underlying sweep accounts can have frequent transaction activity and the amount of pledged collateral is adjusted as necessary.

Commitments and Contingent Liab

Commitments and Contingent Liabilities	3 Months Ended
	Mar. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies Disclosure [Text Block]	Commitments and Contingent Liabilities Lease Commitments: The Company’s lease commitments consist primarily of leased locations under various non-cancellable operating leases that expire between 2018 and 2043 . The majority of the leases contain renewal options and provisions for increases in rental rates based on an agreed upon index or predetermined escalation schedule. Financial Instruments with Off-Balance Sheet Risk: In the normal course of business, the Company makes loan commitments (typically unfunded loans and unused lines of credit) and issues standby letters of credit to accommodate the financial needs of its customers. At March 31, 2018 and December 31, 2017 , the Company’s loan commitments amounted to $2.58 billion and $2.62 billion , respectively. Standby letters of credit commit the Company to make payments on behalf of customers under specified conditions. Historically, no significant losses have been incurred by the Company under standby letters of credit. Both arrangements have credit risk essentially the same as that involved in extending loans to customers and are subject to the Company’s normal credit policies, including collateral requirements, where appropriate. Standby letters of credit were $41.9 million and $51.3 million at March 31, 2018 and December 31, 2017 , respectively. In addition, commitments under commercial letters of credit used to facilitate customers’ trade transactions and other off-balance sheet liabilities amounted to $58 thousand and $159 thousand at March 31, 2018 and December 31, 2017 , respectively. Legal Proceedings: The Company and its subsidiaries are from time to time defendants in and are threatened with various legal proceedings arising from their regular business activities. Management, after consulting with legal counsel, is of the opinion that the ultimate liability, if any, resulting from these pending or threatened actions and proceedings will not have a material effect on the financial statements of the Company.

Shareholders' Equity

Shareholders' Equity	3 Months Ended
	Mar. 31, 2018
Stockholders' Equity Note [Abstract]
Shareholders' Equity	Shareholders’ Equity Dividends: On January 25, 2018 , the Company declared a quarterly cash dividend of $0.22 per common share payable on February 21, 2018 to shareholders of record at the close of business on February 7, 2018 . Subsequent to quarter end, on April 25, 2018 , the Company declared a regular quarterly cash dividend of $0.26 per common share payable on May 23, 2018 to shareholders of record at the close of business on May 9, 2018 . The payment of cash dividends is subject to federal regulatory requirements for capital levels and other restrictions. In addition, the cash dividends paid by Columbia Bank to the Company are subject to both federal and state regulatory requirements.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income	3 Months Ended
	Mar. 31, 2018
Accumulated Other Comprehensive Income (Loss) [Abstract]
Accumulated Other Comprehensive Income	Accumulated Other Comprehensive Loss The following table shows changes in accumulated other comprehensive income (loss) by component for the three month periods ended March 31, 2018 and 2017 : Unrealized Gains and Losses on Available-for-Sale Securities (1) Unrealized Gains and Losses on Pension Plan Liability (1) Total (1) Three months ended March 31, 2018 (in thousands) Beginning balance $ (19,779 ) $ (2,446 ) $ (22,225 ) Adjustment pursuant to adoption of ASU 2016-01 157 — 157 Other comprehensive loss before reclassifications (26,048 ) — (26,048 ) Amounts reclassified from accumulated other comprehensive loss (78 ) 61 (17 ) Net current-period other comprehensive income (loss) (26,126 ) 61 (26,065 ) Ending balance $ (45,748 ) $ (2,385 ) $ (48,133 ) Three months ended March 31, 2017 Beginning balance $ (12,704 ) $ (6,295 ) $ (18,999 ) Other comprehensive income before reclassifications 1,702 4,604 6,306 Amounts reclassified from accumulated other comprehensive income — 87 87 Net current-period other comprehensive income 1,702 4,691 6,393 Ending balance $ (11,002 ) $ (1,604 ) $ (12,606 ) __________ (1) All amounts are net of tax. Amounts in parenthesis indicate debits. The following table shows details regarding the reclassifications from accumulated other comprehensive income (loss) for the three month periods ended March 31, 2018 and 2017 : Amount Reclassified from Accumulated Other Comprehensive Income (Loss) Three Months Ended March 31, Affected line Item in the Consolidated 2018 2017 Statement of Income (in thousands) Unrealized gains and losses on available-for-sale securities Investment securities gains $ 102 $ — Investment securities gains, net 102 — Total before tax (24 ) — Income tax provision $ 78 $ — Net of tax Amortization of pension plan liability Actuarial losses $ (80 ) $ (136 ) Compensation and employee benefits (80 ) (136 ) Total before tax 19 49 Income tax benefit $ (61 ) $ (87 ) Net of tax

Fair Value Accounting and Measu

Fair Value Accounting and Measurement	3 Months Ended
	Mar. 31, 2018
Fair Value Disclosures [Abstract]
Fair Value Accounting and Measurement	Fair Value Accounting and Measurement The Fair Value Measurements and Disclosures topic of the FASB ASC defines fair value, establishes a consistent framework for measuring fair value and expands disclosure requirements about fair value. We hold fixed and variable rate interest-bearing securities, investments in marketable equity securities and certain other financial instruments, which are carried at fair value. Fair value is determined based upon quoted prices when available or through the use of alternative approaches, such as matrix or model pricing, when market quotes are not readily accessible or available. The valuation techniques are based upon observable and unobservable inputs. Observable inputs reflect market data obtained from independent sources, while unobservable inputs reflect our own market assumptions. These two types of inputs create the following fair value hierarchy: Level 1 – Quoted prices for identical instruments in active markets that are accessible at the measurement date. Level 2 – Quoted prices for similar instruments in active markets; quoted prices for identical or similar instruments in markets that are not active; and model derived valuations whose inputs are observable or whose significant value drivers are observable. Level 3 – Prices or valuation techniques that require inputs that are both significant to the fair value measurement and unobservable. Fair values are determined as follows: Securities at fair value are priced using a combination of market activity, industry recognized information sources, yield curves, discounted cash flow models and other factors. These fair value calculations are considered a Level 2 input method under the provisions of the Fair Value Measurements and Disclosures topic of the FASB ASC for all securities other than U.S. Treasury Notes and equity securities, which are considered a Level 1 input method. Interest rate contract positions are valued in models, which use as their basis, readily observable market parameters and are classified within Level 2 of the valuation hierarchy. The following table sets forth the Company’s financial assets and liabilities that were accounted for at fair value on a recurring basis at March 31, 2018 and December 31, 2017 by level within the fair value hierarchy. Financial assets and liabilities are classified in their entirety based on the lowest level of input that is significant to the fair value measurement: Fair value Fair Value Measurements at Reporting Date Using Level 1 Level 2 Level 3 March 31, 2018 (in thousands) Assets Debt securities available for sale: U.S. government agency and government-sponsored enterprise mortgage-back securities and collateralized mortgage obligations $ 1,645,218 $ — $ 1,645,218 $ — State and municipal debt securities 582,748 — 582,748 — U.S. government agency and government-sponsored enterprise securities 395,832 — 395,832 — U.S. government securities 247 247 — — Total debt securities available for sale $ 2,624,045 $ 247 $ 2,623,798 $ — Equity securities $ 5,000 $ 5,000 $ — $ — Other assets (Interest rate contracts) $ 7,406 $ — $ 7,406 $ — Liabilities Other liabilities (Interest rate contracts) $ 7,409 $ — $ 7,409 $ — Fair value Fair Value Measurements at Reporting Date Using Level 1 Level 2 Level 3 December 31, 2017 (in thousands) Assets Debt securities available for sale: U.S. government agency and government-sponsored enterprise mortgage-back securities and collateralized mortgage obligations $ 1,726,725 $ — $ 1,726,725 $ — State and municipal debt securities 596,004 — 596,004 — U.S. government agency and government-sponsored enterprise securities 414,774 — 414,774 — U.S. government securities 248 248 — — Total debt securities available for sale $ 2,737,751 $ 248 $ 2,737,503 $ — Equity securities $ 5,080 $ 5,080 $ — $ — Other assets (Interest rate contracts) $ 6,707 $ — $ 6,707 $ — Liabilities Other liabilities (Interest rate contracts) $ 6,714 $ — $ 6,714 $ — There were no transfers between Level 1 and Level 2 of the valuation hierarchy during the three month periods ended March 31, 2018 and 2017 . The Company recognizes transfers between levels of the valuation hierarchy based on the valuation level at the end of the reporting period. Nonrecurring Measurements Certain assets and liabilities are measured at fair value on a nonrecurring basis after initial recognition such as loans measured for impairment and OREO. The following methods were used to estimate the fair value of each such class of financial instrument: Impaired loans —A loan is considered to be impaired when, based on current information and events, it is probable that the Company will be unable to collect all amounts due (both interest and principal) according to the contractual terms of the loan agreement. Impaired loans are measured based on the present value of expected future cash flows discounted at the loan’s effective interest rate, a loan’s observable market price, or the fair market value of the collateral less estimated costs to sell if the loan is a collateral-dependent loan. Generally, the Company utilizes the fair market value of the collateral to measure impairment. The impairment evaluations are performed in conjunction with the allowance process on a quarterly basis by officers in the Special Credits group, which reports to the Chief Credit Officer. The Real Estate Appraisal Services Department (“REASD”), which also reports to the Chief Credit Officer, is responsible for obtaining appraisals from third-parties or performing internal evaluations. If an appraisal is obtained from a third-party, the REASD reviews the appraisal to evaluate the adequacy of the appraisal report, including its scope, methods, accuracy and reasonableness. Other real estate owned —OREO is real property that the Bank has taken ownership of in partial or full satisfaction of a loan or loans. OREO is generally measured based on the property’s fair market value as indicated by an appraisal or a letter of intent to purchase. OREO is initially recorded at the fair value less estimated costs to sell. This amount becomes the property’s new basis. Any fair value adjustments based on the property’s fair value less estimated costs to sell at the date of acquisition are charged to the allowance, or in the event of a write-up without previous losses charged to the allowance, a credit to earnings is recorded. Management periodically reviews OREO in an effort to ensure the property is recorded at its fair value, net of estimated costs to sell. Any fair value adjustments subsequent to acquisition are charged or credited to earnings. The initial and subsequent evaluations are performed by officers in the Special Credits group, which reports to the Chief Credit Officer. The REASD obtains appraisals from third-parties for OREO and performs internal evaluations. If an appraisal is obtained from a third-party, the REASD reviews the appraisal to evaluate the adequacy of the appraisal report, including its scope, methods, accuracy and reasonableness. The following tables set forth information related to the Company’s assets that were measured using fair value estimates on a nonrecurring basis during the current and prior year quarterly periods: Fair value at Fair Value Measurements at Reporting Date Using Losses During the Three Months Ended Level 1 Level 2 Level 3 (in thousands) Impaired loans $ 7,820 $ — $ — $ 7,820 $ 5,058 OREO 160 — — 160 51 $ 7,980 $ — $ — $ 7,980 $ 5,109 Fair value at Fair Value Measurements at Reporting Date Using Losses During the Three Months Ended Level 1 Level 2 Level 3 (in thousands) OREO $ 1,260 $ — $ — $ 1,260 $ 193 $ 1,260 $ — $ — $ 1,260 $ 193 The losses on impaired loans disclosed above represent the amount of the specific reserve and/or charge-offs during the period applicable to loans held at period end. The amount of the specific reserve is included in the allowance for loan and lease losses. The losses on OREO disclosed above represent the write-downs taken at foreclosure that were charged to the allowance for loan and lease losses, as well as subsequent changes in any valuation allowances from updated appraisals that were recorded to earnings. Quantitative information about Level 3 fair value measurements The range and weighted-average of the significant unobservable inputs used to fair value our Level 3 nonrecurring assets, along with the valuation techniques used, are shown in the following table: Fair value at Valuation Technique Unobservable Input Range (Weighted Average) (1) (dollars in thousands) Impaired loans - collateral-dependent (3) $ 7,512 Fair Market Value of Collateral Adjustment to Stated Value 0.00% - 100.00% (41.33%) Impaired loans - other (4) $ 308 Discounted Cash Flow Discount Rate 6.00% OREO $ 160 Fair Market Value of Collateral Adjustment to Appraisal Value N/A (2) (1) Discount rate applied to discounted cash flow valuation or appraisal value and stated value (in the case of accounts receivable, fixed assets, and inventory). (2) Quantitative disclosures are not provided for OREO because there were no adjustments made to the appraisal values during the current period. (3) Collateral consists of accounts receivable, fixed assets, inventory, and real estate. (4) As there was only one impaired loan remeasured using discounted cash flows, a range of discounts could not be provided. Fair value at Valuation Technique Unobservable Input Range (Weighted Average) (1) (dollars in thousands) OREO $ 1,260 Fair Market Value of Collateral Adjustment to Appraisal Value N/A (2) (1) Discount applied to appraisal value. (2) Quantitative disclosures are not provided for OREO because there were no adjustments made to the appraisal values. The following tables summarize carrying amounts and estimated fair values of selected financial instruments by level within the fair value hierarchy at March 31, 2018 and December 31, 2017 : March 31, 2018 Carrying Fair Level 1 Level 2 Level 3 (in thousands) Assets Cash and due from banks $ 206,532 $ 206,532 $ 206,532 $ — $ — Interest-earning deposits with banks 87,124 87,124 87,124 — — Debt securities available for sale 2,624,045 2,624,045 247 2,623,798 — Equity securities 5,000 5,000 5,000 — — FHLB stock 11,640 11,640 — 11,640 — Loans held for sale 4,312 4,312 — 4,312 — Loans 8,259,804 8,281,010 — — 8,281,010 Interest rate contracts 7,406 7,406 — 7,406 — Liabilities Deposits $ 474,000 $ 465,896 $ — $ 465,896 $ — FHLB advances 41,564 42,090 — 42,090 — Repurchase agreements 24,247 24,247 — 24,247 — Subordinated debentures 35,601 35,486 — 35,486 — Interest rate contracts 7,409 7,409 — 7,409 — December 31, 2017 Carrying Fair Level 1 Level 2 Level 3 (in thousands) Assets Cash and due from banks $ 244,615 $ 244,615 $ 244,615 $ — $ — Interest-earning deposits with banks 97,918 97,918 97,918 — — Debt securities available for sale 2,737,751 2,737,751 248 2,737,503 — Equity securities 5,080 5,080 5,080 — — FHLB stock 10,440 10,440 — 10,440 — Loans held for sale 5,766 5,766 — 5,766 — Loans 8,283,011 8,055,817 — — 8,055,817 Interest rate contracts 6,707 6,707 — 6,707 — Liabilities Deposits $ 10,532,085 $ 10,524,135 $ 10,041,040 $ 483,095 $ — FHLB advances 11,579 12,281 — 12,281 — Repurchase agreements 79,059 79,070 — 79,070 — Subordinated debentures 35,647 35,895 — 35,895 — Junior subordinated debentures 8,248 8,248 — 8,248 — Interest rate contracts 6,714 6,714 — 6,714 —

Earnings per Common Share

Earnings per Common Share	3 Months Ended
	Mar. 31, 2018
Earnings Per Share [Abstract]
Earnings Per Common Share	Earnings per Common Share The Company applies the two-class method of computing basic and diluted EPS. Under the two-class method, EPS is determined for each class of common stock and participating security according to dividends declared and participation rights in undistributed earnings. The Company issues restricted shares under share-based compensation plans and preferred shares which qualify as participating securities. The following table sets forth the computation of basic and diluted earnings per share for the three months ended March 31, 2018 and 2017 : Three Months Ended March 31, 2018 2017 (in thousands except per share) Basic EPS: Net income $ 39,970 $ 29,199 Less: Earnings allocated to participating securities: Preferred shares — 3 Nonvested restricted shares 437 397 Earnings allocated to common shareholders $ 39,533 $ 28,799 Weighted average common shares outstanding 72,300 57,388 Basic earnings per common share $ 0.55 $ 0.50 Diluted EPS: Earnings allocated to common shareholders $ 39,533 $ 28,799 Weighted average common shares outstanding 72,300 57,388 Dilutive effect of equity awards 5 6 Weighted average diluted common shares outstanding 72,305 57,394 Diluted earnings per common share $ 0.55 $ 0.50 Potentially dilutive share options that were not included in the computation of diluted EPS because to do so would be anti-dilutive 12 14

Revenue from Contracts with Cus

Revenue from Contracts with Customers	3 Months Ended
	Mar. 31, 2018
Revenue from Contract with Customer [Abstract]
Revenue from Contract with Customer [Text Block]	Revenue from Contracts with Customers Revenue in the scope of Topic 606, Revenue from Contracts with Customers is measured based on the consideration specified in the contract with a customer and excludes amounts collected on behalf of third parties. The vast majority of the Company’s revenue is specifically out of scope of Topic 606. For in-scope revenue, the following is a description of principal activities, separated by the timing of revenue recognition from which the Company generates its revenue from contracts with customers. a. Revenue earned at a point in time - Examples of revenue earned at a point in time are ATM transaction fees, wire transfer fees, overdraft fees, interchange fees and foreign exchange transaction fees. Revenue is primarily based on the number and type of transactions and is generally derived from transactional information accumulated by our systems and is recognized immediately as the transactions occur or upon providing the service to complete the customer’s transaction. The Company is the principal in each of these contracts, with the exception of interchange fees, in which case we are acting as the agent and record revenue net of expenses paid to the principal. b. Revenue earned over time - The Company earns revenue from contracts with customers in a variety of ways where the revenue is earned over a period of time - generally monthly. Examples of this type of revenue are deposit account maintenance fees, investment advisory fees, merchant revenue and safe deposit box fees. Revenue is generally derived from transactional information accumulated by our systems or those of third-parties and is recognized as the related transactions occur or services are rendered to the customer. The Company recognizes revenue from contracts with customers when it satisfies its performance obligations. The Company’s performance obligations are typically satisfied as services are rendered and our contracts generally do not include multiple performance obligations. As a result, there are no contract balances as payments and services are rendered simultaneously. Payment is generally collected at the time services are rendered, monthly or quarterly. Unsatisfied performance obligations at the report date are not material to our consolidated financial statements. In certain cases, other parties are involved with providing products and services to our customers. If the Company is principal in the transaction (providing goods or services itself), revenues are reported based on the gross consideration received from the customer and any related expenses are reported gross in noninterest expense. If the Company is an agent in the transaction (arranging for another party to provide goods or services), the Company reports its net fee or commission retained as revenue. Rebates, waivers and reversals are recorded as a reduction of the transaction price either when the revenue is recognized by the Company or at the time the rebate, waiver or reversal is earned by the customer. Practical expedients The Company applies the practical expedient in paragraph 606-10-32-18 and does not adjust the consideration from customers for the effects of a significant financing component if at contract inception the period between when the entity transfers the goods or services and when the customer pays for that good or service will be one year or less. The Company pays sales commissions to its employees in accordance with certain incentive plans and in connection with obtaining certain contracts with customer. The Company applies the practical expedient in paragraph 340-40-25-4 and expenses such sales commissions when incurred if the amortization period of the asset the Company otherwise would have recognized is one year or less. Sales commissions are included in compensation and employee benefits expense. For the Company’s contracts that have an original expected duration of one year or less, the Company uses the practical expedient in paragraph 606-10-50-14 and has not disclosed the amount of the transaction price allocated to unsatisfied performance obligations as of the end of each reporting period or when the Company expects to recognize this revenue. Disaggregation of revenue The following table shows the disaggregation of revenue from contracts with customers for the three month period ended March 31, 2018 : Three Months Ended March 31, 2018 (dollars in thousands) Noninterest income: Revenue from contracts with customers: Deposit account and treasury management fees $ 8,740 Card revenue 5,813 Financial services and trust revenue 2,730 Total revenue from contracts with customers 17,283 Other sources of noninterest income 5,860 Total noninterest income $ 23,143

Business Combinations (Tables)

Business Combinations (Tables) - Pacific Continental [Member]	3 Months Ended
	Mar. 31, 2018
Business Acquisition [Line Items]
Schedule of Recognized Identified Assets Acquired and Liabilities Assumed [Table Text Block]	The table below summarizes the amounts recognized as of the acquisition date for each major class of assets acquired and liabilities assumed: November 1, 2017 (in thousands) Merger consideration $ 637,103 Identifiable net assets acquired, at fair value Assets acquired Cash and cash equivalents $ 81,190 Investment securities 449,291 Federal Home Loan Bank stock 7,084 Loans 1,873,987 Interest receivable 7,827 Premises and equipment 27,343 Other real estate owned 10,279 Core deposit intangible 46,875 Other assets 50,638 Total assets acquired 2,554,514 Liabilities assumed Deposits (2,118,982 ) Federal Home Loan Bank advances (101,127 ) Subordinated debentures (35,678 ) Junior subordinated debentures (14,434 ) Securities sold under agreements to repurchase (1,617 ) Other liabilities (28,653 ) Total liabilities assumed (2,300,491 ) Total fair value of identifiable net assets, at fair value 254,023 Goodwill $ 383,080
Business Acquisition, Pro Forma Information [Table Text Block]	For illustrative purposes only, the following table presents certain unaudited pro forma information for the three months ended March 31, 2017 . This unaudited estimated pro forma financial information was calculated as if Pacific Continental had been acquired as of the beginning of the year prior to the date of acquisition. This unaudited pro forma information combines the historical results of Pacific Continental 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 acquisition occurred as of the beginning of the year prior to the acquisition. In particular, no adjustments have been made to eliminate the impact of other-than-temporary impairment losses and losses recognized on the sale of securities that may not have been necessary had the investment securities been recorded at fair value as of the beginning of the year prior to the date of acquisition. The unaudited pro forma information does not consider any changes to the provision for credit losses resulting from recording loan assets at fair value. Additionally, Columbia expects to achieve further operating cost savings and other business synergies, including revenue growth as a result of the acquisition, which are not reflected in the pro forma amounts that follow. As a result, actual amounts would have differed from the unaudited pro forma information presented. Unaudited Pro Forma Three Months Ended March 31, 2017 (in thousands except per share) Total revenues (net interest income plus noninterest income) $ 139,363 Net income $ 37,147 Earnings per share - basic $ 0.52 Earnings per share - diluted $ 0.52
Business Acquisition, Integration, Restructuring and Other Related Costs [Text Block]	The following table shows the impact of the acquisition-related expenses related to the acquisition of Pacific Continental for the periods indicated to the various components of noninterest expense: Three Months Ended March 31, 2018 2017 (in thousands) Noninterest Expense Compensation and employee benefits $ 1,556 $ — Occupancy 1,004 1 Advertising and promotion 512 6 Data processing 287 — Legal and professional fees 574 1,311 Other 332 46 Total impact of acquisition-related costs to noninterest expense $ 4,265 $ 1,364

Securities (Tables)

Securities (Tables)	3 Months Ended
	Mar. 31, 2018
Available-for-sale Securities [Abstract]
Securities Available for Sale	The following table summarizes the amortized cost, gross unrealized gains and losses and the resulting fair value of debt securities available for sale: Amortized Gross Gross Fair Value (in thousands) March 31, 2018 U.S. government agency and government-sponsored enterprise mortgage-backed securities and collateralized mortgage obligations $ 1,693,149 $ 698 $ (48,629 ) $ 1,645,218 State and municipal securities 588,218 3,467 (8,937 ) 582,748 U.S. government agency and government-sponsored enterprise securities 402,036 43 (6,247 ) 395,832 U.S. government securities 251 — (4 ) 247 Total $ 2,683,654 $ 4,208 $ (63,817 ) $ 2,624,045 December 31, 2017 U.S. government agency and government-sponsored enterprise mortgage-backed securities and collateralized mortgage obligations $ 1,752,236 $ 1,815 $ (27,326 ) $ 1,726,725 State and municipal securities 593,940 6,023 (3,959 ) 596,004 U.S. government agency and government-sponsored enterprise securities 416,894 642 (2,762 ) 414,774 U.S. government securities 251 — (3 ) 248 Total $ 2,763,321 $ 8,480 $ (34,050 ) $ 2,737,751
Schedule of gross realized gains and losses on sales and calls of securities available for sale	The following table provides the proceeds and gross realized gains and losses on sales of debt securities available for sale as well as other securities gains and losses for the periods indicated: Three Months Ended March 31, 2018 2017 (in thousands) Proceeds from sales of debt securities available for sale $ 19,761 $ — Gross realized gains from sales of debt securities available for sale $ 148 $ — Gross realized losses from sales of debt securities available for sale (46 ) — Other securities losses, net (1) (80 ) — Investment securities gains, net $ 22 $ — __________ (1) Other securities losses, net includes net unrealized loss activity associated with equity securities. There were no sales of equity securities during the periods presented.
Schedule of Contractual Maturities of Investment Securities Available for Sale	The scheduled contractual maturities of debt securities available for sale at March 31, 2018 are presented as follows: March 31, 2018 Amortized Cost Fair Value (in thousands) Due within one year $ 161,538 $ 161,314 Due after one year through five years 635,254 626,693 Due after five years through ten years 756,950 737,927 Due after ten years 1,129,912 1,098,111 Total debt securities available for sale $ 2,683,654 $ 2,624,045
Carrying Value of Securities Pledged As Collateral	The following table summarizes the carrying value of securities pledged as collateral to secure public deposits, borrowings and other purposes as permitted or required by law: March 31, 2018 (in thousands) Washington and Oregon State to secure public deposits $ 246,950 Federal Reserve Bank to secure borrowings 52,754 Other securities pledged 102,363 Total securities pledged as collateral $ 402,067
Summary of Gross Unrealized Losses and Fair Value of the Investments with Unrealized Losses	The following table shows the gross unrealized losses and fair value of the Company’s debt securities available for sale with unrealized losses that are not deemed to be other-than-temporarily impaired, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position at March 31, 2018 and December 31, 2017 : Less than 12 Months 12 Months or More Total Fair Unrealized Fair Unrealized Fair Unrealized (in thousands) March 31, 2018 U.S. government agency and government-sponsored enterprise mortgage-backed securities and collateralized mortgage obligations $ 921,993 $ (19,073 ) $ 681,577 $ (29,556 ) $ 1,603,570 $ (48,629 ) State and municipal securities 315,392 (4,972 ) 76,452 (3,965 ) 391,844 (8,937 ) U.S. government agency and government-sponsored enterprise securities 251,626 (3,969 ) 140,455 (2,278 ) 392,081 (6,247 ) U.S. government securities 247 (4 ) — — 247 (4 ) Total $ 1,489,258 $ (28,018 ) $ 898,484 $ (35,799 ) $ 2,387,742 $ (63,817 ) December 31, 2017 U.S. government agency and government-sponsored enterprise mortgage-backed securities and collateralized mortgage obligations $ 816,678 $ (6,710 ) $ 717,211 $ (20,616 ) $ 1,533,889 $ (27,326 ) State and municipal securities 220,019 (1,723 ) 75,172 (2,236 ) 295,191 (3,959 ) U.S. government agency and government-sponsored enterprise securities 184,046 (1,006 ) 155,983 (1,756 ) 340,029 (2,762 ) U.S. government securities 249 (3 ) — — 249 (3 ) Total $ 1,220,992 $ (9,442 ) $ 948,366 $ (24,608 ) $ 2,169,358 $ (34,050 )

Loans (Tables)

Loans (Tables)	3 Months Ended
	Mar. 31, 2018
Financing Receivable, Recorded Investment [Line Items]
Analysis of Loan Portfolio by Major Types of Loans	The following is an analysis of the loan portfolio by segment (net of unearned income): March 31, 2018 December 31, 2017 Loans, excluding PCI loans PCI Loans Total Loans, excluding PCI loans PCI Loans Total (in thousands) Commercial business $ 3,402,162 $ 13,536 $ 3,415,698 $ 3,377,324 $ 12,628 $ 3,389,952 Real estate: One-to-four family residential 182,302 10,684 192,986 188,396 12,395 200,791 Commercial and multifamily residential 3,776,709 73,446 3,850,155 3,825,739 75,594 3,901,333 Total real estate 3,959,011 84,130 4,043,141 4,014,135 87,989 4,102,124 Real estate construction: One-to-four family residential 208,441 171 208,612 200,518 177 200,695 Commercial and multifamily residential 385,339 611 385,950 371,931 607 372,538 Total real estate construction 593,780 782 594,562 572,449 784 573,233 Consumer 323,631 10,851 334,482 334,190 11,269 345,459 Less: Net unearned income (48,252 ) — (48,252 ) (52,111 ) — (52,111 ) Total loans, net of unearned income 8,230,332 109,299 8,339,631 8,245,987 112,670 8,358,657 Less: Allowance for loan and lease losses (74,162 ) (5,665 ) (79,827 ) (68,739 ) (6,907 ) (75,646 ) Total loans, net $ 8,156,170 $ 103,634 $ 8,259,804 $ 8,177,248 $ 105,763 $ 8,283,011 Loans held for sale $ 4,312 $ — $ 4,312 $ 5,766 $ — $ 5,766
Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Analysis of Nonaccrual Loans	The following is an analysis of nonaccrual loans as of March 31, 2018 and December 31, 2017 : March 31, 2018 December 31, 2017 Recorded Unpaid Principal Recorded Unpaid Principal (in thousands) Commercial business: Secured $ 57,504 $ 69,056 $ 45,410 $ 56,865 Unsecured 115 115 50 49 Real estate: One-to-four family residential 1,054 1,426 785 1,182 Commercial & multifamily residential: Commercial land 3,192 3,201 2,628 2,623 Income property 3,980 4,264 4,284 5,410 Owner occupied 7,367 7,621 7,029 7,270 Real estate construction: One-to-four family residential: Land and acquisition — — 25 26 Residential construction 1,210 1,210 1,829 1,828 Consumer 4,042 4,378 4,149 4,633 Total $ 78,464 $ 91,271 $ 66,189 $ 79,886
Analysis of the Aged Loan Portfolio	The following is an aging of the recorded investment of the loan portfolio as of March 31, 2018 and December 31, 2017 : Current 30 - 59 60 - 89 Greater Total Nonaccrual Total Loans March 31, 2018 (in thousands) Commercial business: Secured $ 3,189,473 $ 16,410 $ 2,872 $ — $ 19,282 $ 57,504 $ 3,266,259 Unsecured 119,863 50 51 — 101 115 120,079 Real estate: One-to-four family residential 179,174 340 — — 340 1,054 180,568 Commercial & multifamily residential: Commercial land 283,973 2,299 — — 2,299 3,192 289,464 Income property 1,867,450 1,929 815 — 2,744 3,980 1,874,174 Owner occupied 1,570,051 10,751 2,772 — 13,523 7,367 1,590,941 Real estate construction: One-to-four family residential: Land and acquisition 5,937 318 285 — 603 — 6,540 Residential construction 199,756 112 — — 112 1,210 201,078 Commercial & multifamily residential: Income property 295,067 11,070 — — 11,070 — 306,137 Owner occupied 73,016 — — — — — 73,016 Consumer 316,557 1,229 248 — 1,477 4,042 322,076 Total $ 8,100,317 $ 44,508 $ 7,043 $ — $ 51,551 $ 78,464 $ 8,230,332 Current 30 - 59 60 - 89 Greater Total Nonaccrual Total Loans December 31, 2017 (in thousands) Commercial business: Secured $ 3,185,321 $ 2,530 $ 2,400 $ — $ 4,930 $ 45,410 $ 3,235,661 Unsecured 123,524 100 501 — 601 50 124,175 Real estate: One-to-four family residential 184,256 1,111 402 — 1,513 785 186,554 Commercial & multifamily residential: Commercial land 292,680 92 — 581 673 2,628 295,981 Income property 1,898,655 2,426 971 — 3,397 4,284 1,906,336 Owner occupied 1,590,004 2,485 468 — 2,953 7,029 1,599,986 Real estate construction: One-to-four family residential: Land and acquisition 9,882 — — — — 25 9,907 Residential construction 187,862 — — — — 1,829 189,691 Commercial & multifamily residential: Income property 293,028 — — — — — 293,028 Owner occupied 72,443 — — — — — 72,443 Consumer 325,928 1,446 702 — 2,148 4,149 332,225 Total $ 8,163,583 $ 10,190 $ 5,444 $ 581 $ 16,215 $ 66,189 $ 8,245,987
Impaired Financing Receivables	The following is an analysis of impaired loans as of March 31, 2018 and December 31, 2017 : Recorded Investment Recorded Investment Impaired Loans With Impaired Loans Without Recorded Unpaid Related Recorded Unpaid March 31, 2018 (in thousands) Commercial business: Secured $ 3,221,659 $ 44,600 $ 13,836 $ 18,931 $ 5,657 $ 30,764 $ 33,785 Unsecured 120,056 23 23 23 2 — — Real estate: One-to-four family residential 179,700 868 428 715 22 440 1,017 Commercial & multifamily residential: Commercial land 286,613 2,851 — — — 2,851 2,860 Income property 1,870,614 3,560 — — — 3,560 3,623 Owner occupied 1,582,385 8,556 3,399 4,821 5 5,157 5,269 Real estate construction: One-to-four family residential: Land and acquisition 6,540 — — — — — — Residential construction 199,868 1,210 — — — 1,210 1,210 Commercial & multifamily residential: Income property 306,137 — — — — — — Owner occupied 68,966 4,050 — — — 4,050 4,050 Consumer 315,845 6,231 5,439 5,707 171 792 860 Total $ 8,158,383 $ 71,949 $ 23,125 $ 30,197 $ 5,857 $ 48,824 $ 52,674 Recorded Investment Recorded Investment Impaired Loans With Impaired Loans Without Recorded Unpaid Related Recorded Unpaid December 31, 2017 (in thousands) Commercial business: Secured $ 3,195,649 $ 40,012 $ 3,808 $ 3,937 $ 1,867 $ 36,204 $ 42,314 Unsecured 124,150 25 25 24 3 — — Real estate: One-to-four family residential 185,659 895 867 1,408 103 28 337 Commercial & multifamily residential: Commercial land 293,694 2,287 — — — 2,287 2,282 Income property 1,901,313 5,023 2,768 3,328 185 2,255 2,601 Owner occupied 1,591,298 8,688 77 80 3 8,611 10,077 Real estate construction: One-to-four family residential: Land and acquisition 9,907 — — — — — — Residential construction 188,481 1,210 — — — 1,210 1,210 Commercial & multifamily residential: Income property 293,028 — — — — — — Owner occupied 68,393 4,050 — — — 4,050 4,050 Consumer 325,210 7,015 5,303 5,568 199 1,712 1,864 Total $ 8,176,782 $ 69,205 $ 12,848 $ 14,345 $ 2,360 $ 56,357 $ 64,735 The following table provides additional information on impaired loans for the three month periods indicated: Three Months Ended March 31, 2018 2017 Average Recorded Interest Recognized Average Recorded Interest Recognized (in thousands) Commercial business: Secured $ 42,306 $ 12 $ 8,303 $ 19 Unsecured 24 — — — Real estate: One-to-four family residential 881 7 521 2 Commercial & multifamily residential: Commercial land 2,569 — 1,504 — Income property 4,292 31 4,059 1 Owner occupied 8,622 84 4,462 — Real estate construction: One-to-four family residential: Land and acquisition — — 7 — Residential construction 1,210 — 168 — Commercial & multifamily residential: Owner occupied 4,050 51 — — Consumer 6,623 54 5,370 27 Total $ 70,577 $ 239 $ 24,394 $ 49
Analysis of loans classified as Troubled Debt Restructurings (“TDR”)	The following is an analysis of loans classified as troubled debt restructurings (“TDR”) during the three months ended March 31, 2018 and 2017 : Three months ended March 31, 2018 Three months ended March 31, 2017 Number of TDR Modifications Pre-Modification Post-Modification Number of TDR Modifications Pre-Modification Post-Modification (dollars in thousands) Commercial business: Secured 1 $ 450 $ 450 3 $ 356 $ 356 Real estate: Commercial and multifamily residential: Income property 1 891 891 — — — Consumer 7 1,143 1,143 10 1,546 1,546 Total 9 $ 2,484 $ 2,484 13 $ 1,902 $ 1,902
Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Analysis of Loan Portfolio by Major Types of Loans	The following is an analysis of our PCI loans, net of related allowance for losses and remaining valuation discounts as of March 31, 2018 and December 31, 2017 : March 31, 2018 December 31, 2017 (in thousands) Commercial business $ 14,201 $ 13,753 Real estate: One-to-four family residential 12,738 14,610 Commercial and multifamily residential 77,400 79,211 Total real estate 90,138 93,821 Real estate construction: One-to-four family residential 171 177 Commercial and multifamily residential 589 595 Total real estate construction 760 772 Consumer 11,989 12,412 Subtotal of PCI loans 117,088 120,758 Less: Valuation discount resulting from acquisition accounting 7,789 8,088 Allowance for loan losses 5,665 6,907 PCI loans, net of allowance for loan losses $ 103,634 $ 105,763
Changes in Accretable Yield for Acquired Loans	The following table shows the changes in accretable yield for PCI loans for the three months ended March 31, 2018 and 2017 : Three Months Ended March 31, 2018 2017 (in thousands) Balance at beginning of period $ 31,176 $ 45,191 Accretion (2,265 ) (4,182 ) Disposals (159 ) (158 ) Reclassifications from (to) nonaccretable difference 603 (2,407 ) Balance at end of period $ 29,355 $ 38,444

Allowance for Loan and Lease 29

Allowance for Loan and Lease Losses and Unfunded Commitments and Letters of Credit (Tables)	3 Months Ended
	Mar. 31, 2018
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Credit Losses on Financing Receivables	The following tables show a detailed analysis of the allowance for the three months ended March 31, 2018 and 2017 : Beginning Charge-offs Recoveries Provision (Recovery) Ending Specific General Three months ended March 31, 2018 (in thousands) Commercial business: Secured $ 29,341 $ (2,414 ) $ 553 $ 9,851 $ 37,331 $ 5,657 $ 31,674 Unsecured 2,000 (63 ) 249 409 2,595 2 2,593 Real estate: One-to-four family residential 701 — 172 (315 ) 558 22 536 Commercial & multifamily residential: Commercial land 4,265 — 6 (526 ) 3,745 — 3,745 Income property 5,672 (223 ) 141 (888 ) 4,702 — 4,702 Owner occupied 5,459 — 12 (722 ) 4,749 5 4,744 Real estate construction: One-to-four family residential: Land and acquisition 963 — 16 (67 ) 912 — 912 Residential construction 3,709 — 3 924 4,636 — 4,636 Commercial & multifamily residential: Income property 7,053 — — 421 7,474 — 7,474 Owner occupied 4,413 — — (2,490 ) 1,923 — 1,923 Consumer 5,163 (264 ) 260 57 5,216 171 5,045 Purchased credit impaired 6,907 (1,343 ) 1,224 (1,123 ) 5,665 — 5,665 Unallocated — — — 321 321 — 321 Total $ 75,646 $ (4,307 ) $ 2,636 $ 5,852 $ 79,827 $ 5,857 $ 73,970 Beginning Charge-offs Recoveries Provision (Recovery) Ending Specific General Three months ended March 31, 2017 (in thousands) Commercial business: Secured $ 36,050 $ (1,109 ) $ 297 $ 434 $ 35,672 $ — $ 35,672 Unsecured 960 (18 ) 68 178 1,188 — 1,188 Real estate: One-to-four family residential 599 (307 ) 117 236 645 11 634 Commercial & multifamily residential: Commercial land 1,797 — — 491 2,288 — 2,288 Income property 7,342 — 35 (574 ) 6,803 26 6,777 Owner occupied 6,439 — 43 52 6,534 — 6,534 Real estate construction: One-to-four family residential: Land and acquisition 316 (14 ) 20 187 509 — 509 Residential construction 669 — 9 431 1,109 — 1,109 Commercial & multifamily residential: Income property 404 — — 378 782 — 782 Owner occupied 1,192 — — 576 1,768 — 1,768 Consumer 3,534 (428 ) 285 (31 ) 3,360 57 3,303 Purchased credit impaired 10,515 (1,939 ) 1,144 (325 ) 9,395 — 9,395 Unallocated 226 — — 742 968 — 968 Total $ 70,043 $ (3,815 ) $ 2,018 $ 2,775 $ 71,021 $ 94 $ 70,927
Changes in the Allowance for Unfunded Commitments and Letters of Credit	Changes in the allowance for unfunded commitments and letters of credit, a component of “Other liabilities” in the Consolidated Balance Sheets, are summarized as follows: Three Months Ended March 31, 2018 2017 (in thousands) Balance at beginning of period $ 3,130 $ 2,705 Net changes in the allowance for unfunded commitments and letters of credit 1,200 850 Balance at end of period $ 4,330 $ 3,555
Financing Receivable Credit Quality Indicators	The following is an analysis of the credit quality of our loan portfolio, excluding PCI loans, as of March 31, 2018 and December 31, 2017 : Pass Special Mention Substandard Doubtful Loss Total March 31, 2018 (in thousands) Loans, excluding PCI loans: Commercial business: Secured $ 3,067,417 $ 47,672 $ 151,170 $ — $ — $ 3,266,259 Unsecured 119,416 — 663 — — 120,079 Real estate: One-to-four family residential 177,122 1,208 2,238 — — 180,568 Commercial and multifamily residential: Commercial land 279,949 1,288 8,227 — — 289,464 Income property 1,837,613 19,863 16,698 — — 1,874,174 Owner occupied 1,542,605 8,986 39,350 — — 1,590,941 Real estate construction: One-to-four family residential: Land and acquisition 6,540 — — — — 6,540 Residential construction 199,868 — 1,210 — — 201,078 Commercial and multifamily residential: Income property 303,079 — 3,058 — — 306,137 Owner occupied 67,672 — 5,344 — — 73,016 Consumer 314,223 — 7,853 — — 322,076 Total $ 7,915,504 $ 79,017 $ 235,811 $ — $ — 8,230,332 Less: Allowance for loan and lease losses 74,162 Loans, excluding PCI loans, net $ 8,156,170 Pass Special Mention Substandard Doubtful Loss Total December 31, 2017 (in thousands) Loans, excluding PCI loans: Commercial business: Secured $ 3,049,031 $ 64,600 $ 122,030 $ — $ — $ 3,235,661 Unsecured 123,621 — 554 — — 124,175 Real estate: One-to-four family residential 183,312 1,186 2,056 — — 186,554 Commercial and multifamily residential: Commercial land 283,673 5,204 7,104 — — 295,981 Income property 1,857,832 17,181 31,323 — — 1,906,336 Owner occupied 1,546,775 7,380 45,831 — — 1,599,986 Real estate construction: One-to-four family residential: Land and acquisition 9,882 — 25 — — 9,907 Residential construction 187,863 — 1,828 — — 189,691 Commercial and multifamily residential: Income property 293,028 — — — — 293,028 Owner occupied 68,393 — 4,050 — — 72,443 Consumer 323,129 — 9,096 — — 332,225 Total $ 7,926,539 $ 95,551 $ 223,897 $ — $ — 8,245,987 Less: Allowance for loan and lease losses 68,739 Loans, excluding PCI loans, net $ 8,177,248 The following is an analysis of the credit quality of our PCI loan portfolio as of March 31, 2018 and December 31, 2017 : Pass Special Mention Substandard Doubtful Loss Total March 31, 2018 (in thousands) PCI loans: Commercial business: Secured $ 12,582 $ — $ 728 $ — $ — $ 13,310 Unsecured 891 — — — — 891 Real estate: One-to-four family residential 11,967 — 771 — — 12,738 Commercial and multifamily residential: Commercial land 12,223 — — — — 12,223 Income property 22,384 — — — — 22,384 Owner occupied 41,874 — 919 — — 42,793 Real estate construction: One-to-four family residential: Land and acquisition 164 — 7 — — 171 Commercial and multifamily residential: Income property 589 — — — — 589 Consumer 11,514 — 475 — — 11,989 Total $ 114,188 $ — $ 2,900 $ — $ — 117,088 Less: Valuation discount resulting from acquisition accounting 7,789 Allowance for loan losses 5,665 PCI loans, net $ 103,634 Pass Special Mention Substandard Doubtful Loss Total December 31, 2017 (in thousands) PCI loans: Commercial business: Secured $ 11,918 $ — $ 723 $ — $ — $ 12,641 Unsecured 1,045 — 67 — — 1,112 Real estate: One-to-four family residential 13,817 — 793 — — 14,610 Commercial and multifamily residential: Commercial land 9,460 349 — — — 9,809 Income property 25,981 — 35 — — 26,016 Owner occupied 42,617 — 769 — — 43,386 Real estate construction: One-to-four family residential: Land and acquisition 169 — 8 — — 177 Commercial and multifamily residential: Income property 595 — — — — 595 Consumer 11,705 — 707 — — 12,412 Total $ 117,307 $ 349 $ 3,102 $ — $ — 120,758 Less: Valuation discount resulting from acquisition accounting 8,088 Allowance for loan losses 6,907 PCI loans, net $ 105,763

Other Real Estate Owned (Tables

Other Real Estate Owned (Tables)	3 Months Ended
	Mar. 31, 2018
Other Real Estate, Foreclosed Assets, and Repossessed Assets [Abstract]
Summary of Other Real Estate Owned	The following tables set forth activity in OREO for the three months ended March 31, 2018 and 2017 : Three Months Ended March 31, 2018 2017 (in thousands) Balance, beginning of period $ 13,298 $ 5,998 Transfers in 406 — Valuation adjustments (92 ) (193 ) Proceeds from sale of OREO property (2,062 ) (1,275 ) Loss on sale of OREO, net (43 ) (11 ) Balance, end of period $ 11,507 $ 4,519

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	3 Months Ended
	Mar. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Goodwill and Intangible Assets	The following table sets forth activity for goodwill and other intangible assets for the periods indicated: Three Months Ended March 31, 2018 2017 (in thousands) Goodwill Total goodwill (1) $ 765,842 $ 382,762 Other intangible assets, net Core deposit intangible: Gross core deposit intangible balance at beginning of period 105,473 58,598 Accumulated amortization at beginning of period (48,219 ) (41,886 ) Core deposit intangible, net at beginning of period 57,254 16,712 CDI current period amortization (3,188 ) (1,349 ) Total core deposit intangible, net at end of period 54,066 15,363 Intangible assets not subject to amortization 919 919 Other intangible assets, net at end of period 54,985 16,282 Total goodwill and other intangible assets at end of period $ 820,827 $ 399,044
Estimated Future Amortization Expense of Core Deposit Intangibles	The following table provides the estimated future amortization expense of core deposit intangibles for the remaining nine months ending December 31, 2018 and the succeeding four years: Amount (in thousands) Year ending December 31, 2018 $ 9,048 2019 10,479 2020 8,724 2021 7,264 2022 5,880

Derivatives and Balance Sheet32

Derivatives and Balance Sheet Offsetting (Tables)	3 Months Ended
	Mar. 31, 2018
Derivative [Line Items]
Balance Sheet Offsetting [Table Text Block]	The following tables show the gross interest rate swap agreements and repurchase agreements in the Consolidated Balance Sheets and the respective collateral received or pledged in the form of other financial instruments, which are generally marketable securities. The collateral amounts in these tables are limited to the outstanding balances of the related asset or liability. Therefore, instances of overcollateralization are not shown. Gross Amounts of Recognized Assets/Liabilities Gross Amounts Offset in the Consolidated Balance Sheets Net Amounts of Assets/Liabilities Presented in the Consolidated Balance Sheets Gross Amounts Not Offset in the Consolidated Balance Sheets Collateral Posted Net Amount March 31, 2018 (in thousands) Assets Interest rate contracts $ 7,406 $ — $ 7,406 $ — $ 7,406 Liabilities Interest rate contracts $ 7,409 $ — $ 7,409 $ (1,190 ) $ 6,219 Repurchase agreements $ 24,247 $ — $ 24,247 $ (24,247 ) $ — December 31, 2017 Assets Interest rate contracts $ 6,707 $ — $ 6,707 $ — $ 6,707 Liabilities Interest rate contracts $ 6,714 $ — $ 6,714 $ (6,714 ) $ — Repurchase agreements $ 79,059 $ — $ 79,059 $ (79,059 ) $ —
Carrying Value of Securities Pledged As Collateral	The following table summarizes the carrying value of securities pledged as collateral to secure public deposits, borrowings and other purposes as permitted or required by law: March 31, 2018 (in thousands) Washington and Oregon State to secure public deposits $ 246,950 Federal Reserve Bank to secure borrowings 52,754 Other securities pledged 102,363 Total securities pledged as collateral $ 402,067
Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Schedule of Derivative Instruments in Statement of Financial Position, Fair Value	The following table presents the fair value of derivatives not designated as hedging instruments at March 31, 2018 and December 31, 2017 : Asset Derivatives Liability Derivatives March 31, 2018 December 31, 2017 March 31, 2018 December 31, 2017 Balance Sheet Fair Value Balance Sheet Fair Value Balance Sheet Fair Value Balance Sheet Fair Value (in thousands) Interest rate contracts Other assets $ 7,406 Other assets $ 6,707 Other liabilities $ 7,409 Other liabilities $ 6,714
Available-for-sale Securities [Member]
Derivative [Line Items]
Carrying Value of Securities Pledged As Collateral	The following table presents the class of collateral pledged for repurchase agreements as well as the remaining contractual maturity of the repurchase agreements: Remaining contractual maturity of the agreements Overnight and continuous Up to 30 days 30 - 90 days Greater than 90 days Total March 31, 2018 (in thousands) Class of collateral pledged for repurchase agreements U.S. government agency and government-sponsored enterprise mortgage-backed securities and collateralized mortgage obligations $ 24,247 $ — $ — $ — $ 24,247 Gross amount of recognized liabilities for repurchase agreements 24,247 Amounts related to agreements not included in offsetting disclosure $ —

Accumulated Other Comprehensi33

Accumulated Other Comprehensive Income (Tables)	3 Months Ended
	Mar. 31, 2018
Accumulated Other Comprehensive Income (Loss) [Abstract]
Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block]	The following table shows changes in accumulated other comprehensive income (loss) by component for the three month periods ended March 31, 2018 and 2017 : Unrealized Gains and Losses on Available-for-Sale Securities (1) Unrealized Gains and Losses on Pension Plan Liability (1) Total (1) Three months ended March 31, 2018 (in thousands) Beginning balance $ (19,779 ) $ (2,446 ) $ (22,225 ) Adjustment pursuant to adoption of ASU 2016-01 157 — 157 Other comprehensive loss before reclassifications (26,048 ) — (26,048 ) Amounts reclassified from accumulated other comprehensive loss (78 ) 61 (17 ) Net current-period other comprehensive income (loss) (26,126 ) 61 (26,065 ) Ending balance $ (45,748 ) $ (2,385 ) $ (48,133 ) Three months ended March 31, 2017 Beginning balance $ (12,704 ) $ (6,295 ) $ (18,999 ) Other comprehensive income before reclassifications 1,702 4,604 6,306 Amounts reclassified from accumulated other comprehensive income — 87 87 Net current-period other comprehensive income 1,702 4,691 6,393 Ending balance $ (11,002 ) $ (1,604 ) $ (12,606 ) __________ (1) All amounts are net of tax. Amounts in parenthesis indicate debits.
Schedule of reclassifications from accumulated other comprehensive income [Table Text Block]	The following table shows details regarding the reclassifications from accumulated other comprehensive income (loss) for the three month periods ended March 31, 2018 and 2017 : Amount Reclassified from Accumulated Other Comprehensive Income (Loss) Three Months Ended March 31, Affected line Item in the Consolidated 2018 2017 Statement of Income (in thousands) Unrealized gains and losses on available-for-sale securities Investment securities gains $ 102 $ — Investment securities gains, net 102 — Total before tax (24 ) — Income tax provision $ 78 $ — Net of tax Amortization of pension plan liability Actuarial losses $ (80 ) $ (136 ) Compensation and employee benefits (80 ) (136 ) Total before tax 19 49 Income tax benefit $ (61 ) $ (87 ) Net of tax

Fair Value Accounting and Mea34

Fair Value Accounting and Measurement (Tables)	3 Months Ended
	Mar. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial Assets And Liabilities Accounted For Fair Value On Recurring Basis	The following table sets forth the Company’s financial assets and liabilities that were accounted for at fair value on a recurring basis at March 31, 2018 and December 31, 2017 by level within the fair value hierarchy. Financial assets and liabilities are classified in their entirety based on the lowest level of input that is significant to the fair value measurement: Fair value Fair Value Measurements at Reporting Date Using Level 1 Level 2 Level 3 March 31, 2018 (in thousands) Assets Debt securities available for sale: U.S. government agency and government-sponsored enterprise mortgage-back securities and collateralized mortgage obligations $ 1,645,218 $ — $ 1,645,218 $ — State and municipal debt securities 582,748 — 582,748 — U.S. government agency and government-sponsored enterprise securities 395,832 — 395,832 — U.S. government securities 247 247 — — Total debt securities available for sale $ 2,624,045 $ 247 $ 2,623,798 $ — Equity securities $ 5,000 $ 5,000 $ — $ — Other assets (Interest rate contracts) $ 7,406 $ — $ 7,406 $ — Liabilities Other liabilities (Interest rate contracts) $ 7,409 $ — $ 7,409 $ — Fair value Fair Value Measurements at Reporting Date Using Level 1 Level 2 Level 3 December 31, 2017 (in thousands) Assets Debt securities available for sale: U.S. government agency and government-sponsored enterprise mortgage-back securities and collateralized mortgage obligations $ 1,726,725 $ — $ 1,726,725 $ — State and municipal debt securities 596,004 — 596,004 — U.S. government agency and government-sponsored enterprise securities 414,774 — 414,774 — U.S. government securities 248 248 — — Total debt securities available for sale $ 2,737,751 $ 248 $ 2,737,503 $ — Equity securities $ 5,080 $ 5,080 $ — $ — Other assets (Interest rate contracts) $ 6,707 $ — $ 6,707 $ — Liabilities Other liabilities (Interest rate contracts) $ 6,714 $ — $ 6,714 $ —
Financial Assets Accounted For Fair Value On Nonrecurring Basis	The following tables set forth information related to the Company’s assets that were measured using fair value estimates on a nonrecurring basis during the current and prior year quarterly periods: Fair value at Fair Value Measurements at Reporting Date Using Losses During the Three Months Ended Level 1 Level 2 Level 3 (in thousands) Impaired loans $ 7,820 $ — $ — $ 7,820 $ 5,058 OREO 160 — — 160 51 $ 7,980 $ — $ — $ 7,980 $ 5,109 Fair value at Fair Value Measurements at Reporting Date Using Losses During the Three Months Ended Level 1 Level 2 Level 3 (in thousands) OREO $ 1,260 $ — $ — $ 1,260 $ 193 $ 1,260 $ — $ — $ 1,260 $ 193
Fair Value, by Balance Sheet Grouping	The following tables summarize carrying amounts and estimated fair values of selected financial instruments by level within the fair value hierarchy at March 31, 2018 and December 31, 2017 : March 31, 2018 Carrying Fair Level 1 Level 2 Level 3 (in thousands) Assets Cash and due from banks $ 206,532 $ 206,532 $ 206,532 $ — $ — Interest-earning deposits with banks 87,124 87,124 87,124 — — Debt securities available for sale 2,624,045 2,624,045 247 2,623,798 — Equity securities 5,000 5,000 5,000 — — FHLB stock 11,640 11,640 — 11,640 — Loans held for sale 4,312 4,312 — 4,312 — Loans 8,259,804 8,281,010 — — 8,281,010 Interest rate contracts 7,406 7,406 — 7,406 — Liabilities Deposits $ 474,000 $ 465,896 $ — $ 465,896 $ — FHLB advances 41,564 42,090 — 42,090 — Repurchase agreements 24,247 24,247 — 24,247 — Subordinated debentures 35,601 35,486 — 35,486 — Interest rate contracts 7,409 7,409 — 7,409 — December 31, 2017 Carrying Fair Level 1 Level 2 Level 3 (in thousands) Assets Cash and due from banks $ 244,615 $ 244,615 $ 244,615 $ — $ — Interest-earning deposits with banks 97,918 97,918 97,918 — — Debt securities available for sale 2,737,751 2,737,751 248 2,737,503 — Equity securities 5,080 5,080 5,080 — — FHLB stock 10,440 10,440 — 10,440 — Loans held for sale 5,766 5,766 — 5,766 — Loans 8,283,011 8,055,817 — — 8,055,817 Interest rate contracts 6,707 6,707 — 6,707 — Liabilities Deposits $ 10,532,085 $ 10,524,135 $ 10,041,040 $ 483,095 $ — FHLB advances 11,579 12,281 — 12,281 — Repurchase agreements 79,059 79,070 — 79,070 — Subordinated debentures 35,647 35,895 — 35,895 — Junior subordinated debentures 8,248 8,248 — 8,248 — Interest rate contracts 6,714 6,714 — 6,714 —
Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Inputs, Assets, Quantitative Information	The range and weighted-average of the significant unobservable inputs used to fair value our Level 3 nonrecurring assets, along with the valuation techniques used, are shown in the following table: Fair value at Valuation Technique Unobservable Input Range (Weighted Average) (1) (dollars in thousands) Impaired loans - collateral-dependent (3) $ 7,512 Fair Market Value of Collateral Adjustment to Stated Value 0.00% - 100.00% (41.33%) Impaired loans - other (4) $ 308 Discounted Cash Flow Discount Rate 6.00% OREO $ 160 Fair Market Value of Collateral Adjustment to Appraisal Value N/A (2) (1) Discount rate applied to discounted cash flow valuation or appraisal value and stated value (in the case of accounts receivable, fixed assets, and inventory). (2) Quantitative disclosures are not provided for OREO because there were no adjustments made to the appraisal values during the current period. (3) Collateral consists of accounts receivable, fixed assets, inventory, and real estate. (4) As there was only one impaired loan remeasured using discounted cash flows, a range of discounts could not be provided. Fair value at Valuation Technique Unobservable Input Range (Weighted Average) (1) (dollars in thousands) OREO $ 1,260 Fair Market Value of Collateral Adjustment to Appraisal Value N/A (2) (1) Discount applied to appraisal value. (2) Quantitative disclosures are not provided for OREO because there were no adjustments made to the appraisal values.

Earnings per Common Share (Tabl

Earnings per Common Share (Tables)	3 Months Ended
	Mar. 31, 2018
Earnings Per Share [Abstract]
Schedule of Basic and Diluted Earnings Per Share	The following table sets forth the computation of basic and diluted earnings per share for the three months ended March 31, 2018 and 2017 : Three Months Ended March 31, 2018 2017 (in thousands except per share) Basic EPS: Net income $ 39,970 $ 29,199 Less: Earnings allocated to participating securities: Preferred shares — 3 Nonvested restricted shares 437 397 Earnings allocated to common shareholders $ 39,533 $ 28,799 Weighted average common shares outstanding 72,300 57,388 Basic earnings per common share $ 0.55 $ 0.50 Diluted EPS: Earnings allocated to common shareholders $ 39,533 $ 28,799 Weighted average common shares outstanding 72,300 57,388 Dilutive effect of equity awards 5 6 Weighted average diluted common shares outstanding 72,305 57,394 Diluted earnings per common share $ 0.55 $ 0.50 Potentially dilutive share options that were not included in the computation of diluted EPS because to do so would be anti-dilutive 12 14

Revenue from Contracts with C36

Revenue from Contracts with Customers (Tables)	3 Months Ended
	Mar. 31, 2018
Disaggregation of Revenue [Line Items]
Disaggregation of Revenue [Table Text Block]	Disaggregation of revenue The following table shows the disaggregation of revenue from contracts with customers for the three month period ended March 31, 2018 : Three Months Ended March 31, 2018 (dollars in thousands) Noninterest income: Revenue from contracts with customers: Deposit account and treasury management fees $ 8,740 Card revenue 5,813 Financial services and trust revenue 2,730 Total revenue from contracts with customers 17,283 Other sources of noninterest income 5,860 Total noninterest income $ 23,143

Accounting Pronouncements Rec37

Accounting Pronouncements Recently Issued Narrative - Impact of implementation of new accounting standards (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Accounting Standards Update 2016-01 [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	$ (46)
Accounting Standards Update 2016-09 [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption		$ 67
Retained Earnings [Member] | Accounting Standards Update 2016-01 [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	$ (203)
Retained Earnings [Member] | Accounting Standards Update 2016-09 [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption		(117)
Common Stock [Member] | Accounting Standards Update 2016-09 [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption		$ 184

Business Combinations (Details)

Business Combinations (Details) - USD ($) $ / shares in Units, $ in Thousands	Nov. 01, 2017	Mar. 31, 2018	Mar. 31, 2017
Business Acquisition [Line Items]
Threshold for average assets requiring CFPB examination		$ 10,000,000
Estimated pre-tax annual impact of no longer qualifying for the small issuer exemption from interchange fee cap		10,000
Pacific Continental [Member]
Business Acquisition [Line Items]
Business Combination, Acquisition Related Costs		4,265	$ 1,364
Business Acquisition, Pro Forma Revenue			139,363
Business Combination, Consideration Transferred	$ 637,103
Business Acquisition, Effective Date of Acquisition	Nov. 1, 2017
Business Acquisition, Percentage of Voting Interests Acquired	100.00%
Business Combination, Purchase Price Allocation, Goodwill Amount	$ 383,080
Business Combination, Purchase Price Allocation, Amortizable Intangible Assets	46,875
Business Combination, Purchase Price Allocation, Other Assets	50,638
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets	2,554,514
Business Combination, Purchase Price Allocation, Liabilities, Deposits	(2,118,982)
Business Combination, Purchase Price Allocation, Federal Home Loan bank advances	(101,127)
Business Combination, Purchase Price Allocation, Subordinated Debt	(35,678)
Business Combination, Purchase Price Allocation, Junior Subordinated Debentures	(14,434)
Business combination, purchase price allocation, securities sold under agreements to repurchase	(1,617)
Business Combination, Purchase Price Allocation, Other Liabilities	(28,653)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities	(2,300,491)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net	$ 254,023
business combinations, core deposit intangible percentage of core deposits	2.34%
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents	$ 81,190
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Marketable Securities	449,291
Business Combination, Purchase Price Allocation, FHLB Stock	7,084
Business Combination, Acquired Receivable, Fair Value	1,873,987
Business Combination, Purchase Price Allocation, Accrued Interest Receivable	7,827
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment	27,343
Business Combination, Purchase Price Allocation, Other Real Estate Owned	$ 10,279
Business Acquisition, Pro Forma Net Income (Loss)			$ 37,147
Business Acquisition, Pro Forma Earnings Per Share, Basic			$ 0.52
Business Acquisition, Pro Forma Earnings Per Share, Diluted			$ 0.52
Pacific Continental [Member] | Compensation and employee benefits [Member]
Business Acquisition [Line Items]
Business Combination, Acquisition Related Costs		1,556	$ 0
Pacific Continental [Member] | Other noninterest expenses [Member]
Business Acquisition [Line Items]
Business Combination, Acquisition Related Costs		332	46
Pacific Continental [Member] | Legal and professional fees [Member]
Business Acquisition [Line Items]
Business Combination, Acquisition Related Costs		574	1,311
Pacific Continental [Member] | Data processing [Member]
Business Acquisition [Line Items]
Business Combination, Acquisition Related Costs		287	0
Pacific Continental [Member] | Advertising and promotion [Member]
Business Acquisition [Line Items]
Business Combination, Acquisition Related Costs		512	6
Pacific Continental [Member] | Occupancy [Member]
Business Acquisition [Line Items]
Business Combination, Acquisition Related Costs		$ 1,004	$ 1

Securities (Securities Availabl

Securities (Securities Available for Sale) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Gross Realized Gains (Losses), Sale Proceeds	$ 19,761	$ 0
Securities available-for-sale, amortized cost	2,683,654		$ 2,763,321
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain, before Tax	4,208		8,480
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax	63,817		34,050
Available-for-sale Securities, Debt Securities	2,624,045		2,737,751
U.S. Government Agency and Government-Sponsored Enterprise Mortgage-Backed Securities and Collateralized Mortgage Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities available-for-sale, amortized cost	1,693,149		1,752,236
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain, before Tax	698		1,815
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax	48,629		27,326
Available-for-sale Securities, Debt Securities	1,645,218		1,726,725
State and Municipal Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities available-for-sale, amortized cost	588,218		593,940
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain, before Tax	3,467		6,023
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax	8,937		3,959
Available-for-sale Securities, Debt Securities	582,748		596,004
U.S. Government and Government-Sponsored Enterprise Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities available-for-sale, amortized cost	402,036		416,894
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain, before Tax	43		642
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax	6,247		2,762
Available-for-sale Securities, Debt Securities	395,832		414,774
US Government Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities available-for-sale, amortized cost	251		251
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain, before Tax	0		0
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax	4		3
Available-for-sale Securities, Debt Securities	$ 247		$ 248

Securities (Schedule of Contrac

Securities (Schedule of Contractual Maturities of Investment Securities Available for Sale) (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Available-for-sale Securities [Abstract]
Due within one year, Amortized Cost	$ 161,538
Due after one year through five years, Amortized Cost	635,254
Due after five years through ten years, Amortized Cost	756,950
Due after ten years, Amortized Cost	1,129,912
Securities available-for-sale, amortized cost	2,683,654	$ 2,763,321
Due within one year, Fair Value	161,314
Due after one year through five years, Fair Value	626,693
Due after five years through ten years, Fair Value	737,927
Due after ten years, Fair Value	1,098,111
Total investment securities available-for-sale, Fair Value	$ 2,624,045	$ 2,737,751

Securities (Carrying Value of S

Securities (Carrying Value of Securities Pledged as Collateral) (Details) $ in Thousands	Mar. 31, 2018USD ($)
Schedule of Available-for-sale Securities [Line Items]
Carrying amount of securities pledged as collateral	$ 402,067
Washington and Oregon State Public Deposits [Member]
Schedule of Available-for-sale Securities [Line Items]
Carrying amount of securities pledged as collateral	246,950
Federal Reserve Bank Advances [Member]
Schedule of Available-for-sale Securities [Line Items]
Carrying amount of securities pledged as collateral	52,754
Other Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Carrying amount of securities pledged as collateral	$ 102,363

Securities (Summary of Gross Un

Securities (Summary of Gross Unrealized Losses and Fair Value of the Investments with Unrealized Losses) (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months Fair Value	$ 1,489,258	$ 1,220,992
Less than 12 Months Unrealized Losses	(28,018)	(9,442)
12 Months or More Fair Value	898,484	948,366
12 Months or More Unrealized Losses	(35,799)	(24,608)
Total Fair Value	2,387,742	2,169,358
Total Unrealized Losses	(63,817)	(34,050)
U.S. Government Agency and Government-Sponsored Enterprise Mortgage-Backed Securities and Collateralized Mortgage Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months Fair Value	921,993	816,678
Less than 12 Months Unrealized Losses	(19,073)	(6,710)
12 Months or More Fair Value	681,577	717,211
12 Months or More Unrealized Losses	(29,556)	(20,616)
Total Fair Value	1,603,570	1,533,889
Total Unrealized Losses	(48,629)	(27,326)
State and Municipal Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months Fair Value	315,392	220,019
Less than 12 Months Unrealized Losses	(4,972)	(1,723)
12 Months or More Fair Value	76,452	75,172
12 Months or More Unrealized Losses	(3,965)	(2,236)
Total Fair Value	391,844	295,191
Total Unrealized Losses	(8,937)	(3,959)
US Government Corporations and Agencies Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months Fair Value	251,626	184,046
Less than 12 Months Unrealized Losses	(3,969)	(1,006)
12 Months or More Fair Value	140,455	155,983
12 Months or More Unrealized Losses	(2,278)	(1,756)
Total Fair Value	392,081	340,029
Total Unrealized Losses	(6,247)	(2,762)
US Government Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months Fair Value	247	249
Less than 12 Months Unrealized Losses	(4)	(3)
12 Months or More Fair Value	0	0
12 Months or More Unrealized Losses	0	0
Total Fair Value	247	249
Total Unrealized Losses	$ (4)	$ (3)

Securities (Narrative) (Details

Securities (Narrative) (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2018USD ($)security	Mar. 31, 2017USD ($)
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Gross Realized Gains (Losses), Sale Proceeds | $	$ 19,761	$ 0
U.S. Government Agency and Government-Sponsored Enterprise Mortgage-Backed Securities and Collateralized Mortgage Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions	446
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions, Greater than or Equal to One Year	117
Municipal Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions	406
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions, Greater than or Equal to One Year	71
U.S. Government and Government-Sponsored Enterprise Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions	50
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions, Greater than or Equal to One Year	16
US Government Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Number Of Securities In Continuous Loss Position For Twelve Months or More	0
Number Of Securities In Unrealized Loss Position	1

Securities Securities (Summary

Securities Securities (Summary of Gross Realized Gains and Gross Realized Losses (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2018	Mar. 31, 2017
Investments, Debt and Equity Securities [Abstract]
Available-for-sale Securities, Gross Realized Gains (Losses), Sale Proceeds		$ 19,761	$ 0
Available-for-sale Securities, Gross Realized Gains		148	0
Available-for-sale Securities, Gross Realized Losses		(46)	0
Equity Securities, FV-NI, Unrealized Gain (Loss)	[1]	(80)	0
Gain (Loss) on Investments		$ 22	$ 0
[1]	Other securities losses, net includes net unrealized loss activity associated with equity securities. There were no sales of equity securities during the periods presented.

Loans (Narrative) (Details)

Loans (Narrative) (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2018USD ($)contract	Mar. 31, 2017contract	Dec. 31, 2017USD ($)
Financing Receivable, Recorded Investment [Line Items]
Loans to related parties	$ 9,900		$ 10,000
Loans and Leases Receivable, Related Parties, Additions	0
Repayments on related party loans	$ 86
Financing Receivable, Modifications, Subsequent Default, Number of Contracts | contract	0	0
Loans Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Federal Home Loan Bank, Advances, General Debt Obligations, Disclosures, Collateral Pledged	$ 2,280,000		2,250,000
Federal Reserve Bank, Advances, General Debt Obligations, Disclosures, Collateral Pledged	$ 72,500		$ 70,200

Loans (Analysis of Loan Portfol

Loans (Analysis of Loan Portfolio by Major Types of Loans) (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment [Line Items]
Less: unearned income on loans	$ (48,252)	$ (52,111)
Recorded Investment	8,339,631	8,358,657
Allowance for loan losses	(79,827)	(75,646)	$ (71,021)	$ (70,043)
Loans, net	8,259,804	8,283,011
Loans held for sale	4,312	5,766
Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Less: unearned income on loans	(48,252)	(52,111)
Recorded Investment	8,230,332	8,245,987
Allowance for loan losses	(74,162)	(68,739)
Loans, net	8,156,170	8,177,248
Loans held for sale	4,312	5,766
Loans and Leases Receivable, Gross	8,230,332	8,245,987
Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Less: unearned income on loans	0	0
Recorded Investment	109,299	112,670
Allowance for loan losses	(5,665)	(6,907)
Loans, net	103,634	105,763
Loans held for sale	0	0
Loans and Leases Receivable, Gross	117,088	120,758
Acquisition Accounting Valuation Discount on Covered Loans	7,789	8,088
Commercial and Multifamily Residential Construction [Domain] | Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross	589	595
One-to-Four Family Residential [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Consumer, Mortgage	192,986	200,791
Loans and Leases Receivable, Gross, Consumer, Construction	208,612	200,695
Allowance for loan losses	(558)	(701)	(645)	(599)
One-to-Four Family Residential [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Consumer, Mortgage	182,302	188,396
Loans and Leases Receivable, Gross, Consumer, Construction	208,441	200,518
Loans and Leases Receivable, Gross	180,568	186,554
One-to-Four Family Residential [Member] | Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Consumer, Mortgage	10,684	12,395
Loans and Leases Receivable, Gross, Consumer, Construction	171	177
Loans and Leases Receivable, Gross	12,738	14,610
Commercial and Multifamily Residential [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Gross, Commercial, Mortgage	3,850,155	3,901,333
Loans Receivable, Gross, Commercial, Construction	385,950	372,538
Commercial and Multifamily Residential [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Gross, Commercial, Mortgage	3,776,709	3,825,739
Loans Receivable, Gross, Commercial, Construction	385,339	371,931
Commercial and Multifamily Residential [Member] | Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Gross, Commercial, Mortgage	73,446	75,594
Loans Receivable, Gross, Commercial, Construction	611	607
Loans and Leases Receivable, Gross	77,400	79,211
Commercial Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Gross, Commercial and Industrial	3,415,698	3,389,952
Commercial Portfolio Segment [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Gross, Commercial and Industrial	3,402,162	3,377,324
Commercial Portfolio Segment [Member] | Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable, Gross, Commercial and Industrial	13,536	12,628
Loans and Leases Receivable, Gross	14,201	13,753
Real Estate Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable Real Estate Mortgage	4,043,141	4,102,124
Real Estate Portfolio Segment [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable Real Estate Mortgage	3,959,011	4,014,135
Real Estate Portfolio Segment [Member] | Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable Real Estate Mortgage	84,130	87,989
Loans and Leases Receivable, Gross	90,138	93,821
One-to-Four Family Residential Construction [Domain] | Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross	171	177
Real Estate Construction Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable Real Estate Construction	594,562	573,233
Real Estate Construction Portfolio Segment [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable Real Estate Construction	593,780	572,449
Real Estate Construction Portfolio Segment [Member] | Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans Receivable Real Estate Construction	782	784
Loans and Leases Receivable, Gross	760	772
Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Consumer	334,482	345,459
Allowance for loan losses	(5,216)	(5,163)	$ (3,360)	$ (3,534)
Consumer Portfolio Segment [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Consumer	323,631	334,190
Loans and Leases Receivable, Gross	322,076	332,225
Consumer Portfolio Segment [Member] | Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, Gross, Consumer	10,851	11,269
Loans and Leases Receivable, Gross	$ 11,989	$ 12,412

Loans (Analysis of Nonaccrual L

Loans (Analysis of Nonaccrual Loans) (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment Nonaccrual Loans	$ 78,464	$ 66,189
Unpaid Principal Balance Nonaccrual Loans	91,271	79,886
Secured Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment Nonaccrual Loans	57,504	45,410
Unpaid Principal Balance Nonaccrual Loans	69,056	56,865
Unsecured Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment Nonaccrual Loans	115	50
Unpaid Principal Balance Nonaccrual Loans	115	49
One-to-Four Family Residential [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment Nonaccrual Loans	1,054	785
Unpaid Principal Balance Nonaccrual Loans	1,426	1,182
Commercial Land [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment Nonaccrual Loans	3,192	2,628
Unpaid Principal Balance Nonaccrual Loans	3,201	2,623
Income Property Multifamily [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment Nonaccrual Loans	3,980	4,284
Unpaid Principal Balance Nonaccrual Loans	4,264	5,410
Owner Occupied [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment Nonaccrual Loans	7,367	7,029
Unpaid Principal Balance Nonaccrual Loans	7,621	7,270
Land And Acquisition [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment Nonaccrual Loans	0	25
Unpaid Principal Balance Nonaccrual Loans	0	26
Residential Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment Nonaccrual Loans	1,210	1,829
Unpaid Principal Balance Nonaccrual Loans	1,210	1,828
Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment Nonaccrual Loans	4,042	4,149
Unpaid Principal Balance Nonaccrual Loans	$ 4,378	$ 4,633

Loans (Analysis of the Aged Loa

Loans (Analysis of the Aged Loan Portfolio) (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual Loans	$ 78,464	$ 66,189
Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current Loans	8,100,317	8,163,583
Past Due Loans	51,551	16,215
Nonaccrual Loans	78,464	66,189
Loans Receivable, Net	8,230,332	8,245,987
Secured Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual Loans	57,504	45,410
Secured Loans [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current Loans	3,189,473	3,185,321
Past Due Loans	19,282	4,930
Nonaccrual Loans	57,504	45,410
Loans Receivable, Net	3,266,259	3,235,661
Unsecured Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual Loans	115	50
Unsecured Loans [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current Loans	119,863	123,524
Past Due Loans	101	601
Nonaccrual Loans	115	50
Loans Receivable, Net	120,079	124,175
One-to-Four Family Residential [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual Loans	1,054	785
One-to-Four Family Residential [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current Loans	179,174	184,256
Past Due Loans	340	1,513
Nonaccrual Loans	1,054	785
Loans Receivable, Net	180,568	186,554
Commercial Land [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual Loans	3,192	2,628
Commercial Land [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current Loans	283,973	292,680
Past Due Loans	2,299	673
Nonaccrual Loans	3,192	2,628
Loans Receivable, Net	289,464	295,981
Income Property Multifamily [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual Loans	3,980	4,284
Income Property Multifamily [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current Loans	1,867,450	1,898,655
Past Due Loans	2,744	3,397
Nonaccrual Loans	3,980	4,284
Loans Receivable, Net	1,874,174	1,906,336
Owner Occupied [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual Loans	7,367	7,029
Owner Occupied [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current Loans	1,570,051	1,590,004
Past Due Loans	13,523	2,953
Nonaccrual Loans	7,367	7,029
Loans Receivable, Net	1,590,941	1,599,986
Land And Acquisition [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual Loans	0	25
Land And Acquisition [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current Loans	5,937	9,882
Past Due Loans	603	0
Nonaccrual Loans	0	25
Loans Receivable, Net	6,540	9,907
Residential Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual Loans	1,210	1,829
Residential Construction [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current Loans	199,756	187,862
Past Due Loans	112	0
Nonaccrual Loans	1,210	1,829
Loans Receivable, Net	201,078	189,691
Income Property Multifamily Construction [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current Loans	295,067	293,028
Past Due Loans	11,070	0
Nonaccrual Loans	0	0
Loans Receivable, Net	306,137	293,028
Owner Occupied Construction [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current Loans	73,016	72,443
Past Due Loans	0	0
Nonaccrual Loans	0	0
Loans Receivable, Net	73,016	72,443
Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual Loans	4,042	4,149
Consumer Portfolio Segment [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current Loans	316,557	325,928
Past Due Loans	1,477	2,148
Nonaccrual Loans	4,042	4,149
Loans Receivable, Net	322,076	332,225
Financing Receivables, 60 to 89 Days Past Due [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Loans	7,043	5,444
Financing Receivables, 60 to 89 Days Past Due [Member] | Secured Loans [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Loans	2,872	2,400
Financing Receivables, 60 to 89 Days Past Due [Member] | Unsecured Loans [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Loans	51	501
Financing Receivables, 60 to 89 Days Past Due [Member] | One-to-Four Family Residential [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Loans	0	402
Financing Receivables, 60 to 89 Days Past Due [Member] | Commercial Land [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Loans	0	0
Financing Receivables, 60 to 89 Days Past Due [Member] | Income Property Multifamily [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Loans	815	971
Financing Receivables, 60 to 89 Days Past Due [Member] | Owner Occupied [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Loans	2,772	468
Financing Receivables, 60 to 89 Days Past Due [Member] | Land And Acquisition [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Loans	285	0
Financing Receivables, 60 to 89 Days Past Due [Member] | Residential Construction [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Loans	0	0
Financing Receivables, 60 to 89 Days Past Due [Member] | Income Property Multifamily Construction [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Loans	0	0
Financing Receivables, 60 to 89 Days Past Due [Member] | Owner Occupied Construction [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Loans	0	0
Financing Receivables, 60 to 89 Days Past Due [Member] | Consumer Portfolio Segment [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Loans	248	702
Financing Receivables, 30 to 59 Days Past Due [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Loans	44,508	10,190
Financing Receivables, 30 to 59 Days Past Due [Member] | Secured Loans [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Loans	16,410	2,530
Financing Receivables, 30 to 59 Days Past Due [Member] | Unsecured Loans [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Loans	50	100
Financing Receivables, 30 to 59 Days Past Due [Member] | One-to-Four Family Residential [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Loans	340	1,111
Financing Receivables, 30 to 59 Days Past Due [Member] | Commercial Land [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Loans	2,299	92
Financing Receivables, 30 to 59 Days Past Due [Member] | Income Property Multifamily [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Loans	1,929	2,426
Financing Receivables, 30 to 59 Days Past Due [Member] | Owner Occupied [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Loans	10,751	2,485
Financing Receivables, 30 to 59 Days Past Due [Member] | Land And Acquisition [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Loans	318	0
Financing Receivables, 30 to 59 Days Past Due [Member] | Residential Construction [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Loans	112	0
Financing Receivables, 30 to 59 Days Past Due [Member] | Income Property Multifamily Construction [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Loans	11,070	0
Financing Receivables, 30 to 59 Days Past Due [Member] | Owner Occupied Construction [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Loans	0	0
Financing Receivables, 30 to 59 Days Past Due [Member] | Consumer Portfolio Segment [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Loans	1,229	1,446
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Loans	0	581
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Secured Loans [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Loans	0	0
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Unsecured Loans [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Loans	0	0
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | One-to-Four Family Residential [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Loans	0	0
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Commercial Land [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Loans	0	581
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Income Property Multifamily [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Loans	0	0
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Owner Occupied [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Loans	0	0
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Land And Acquisition [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Loans	0	0
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Residential Construction [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Loans	0	0
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Income Property Multifamily Construction [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Loans	0	0
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Owner Occupied Construction [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Loans	0	0
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Consumer Portfolio Segment [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Loans	$ 0	$ 0

Loans (Analysis of Impaired Loa

Loans (Analysis of Impaired Loans) (Details) - Loans, Excluding Purchased Credit Impaired Loans [Member] - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment of Loans Collectively Measured for Contingency Provision	$ 8,158,383		$ 8,176,782
Recorded Investment of Loans Individually Measured for Specific Impairment	71,949		69,205
Recorded Investment	48,824		56,357
Unpaid Principal Balance	52,674		64,735
Related Allowance	5,857		2,360
Average Recorded Investment Impaired Loans	70,577	$ 24,394
Interest Recognized on Impaired Loans	239	49
Secured Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment of Loans Collectively Measured for Contingency Provision	3,221,659		3,195,649
Recorded Investment of Loans Individually Measured for Specific Impairment	44,600		40,012
Recorded Investment	13,836		3,808
Unpaid Principal Balance	18,931		3,937
Related Allowance	5,657		1,867
Average Recorded Investment Impaired Loans	42,306	8,303
Interest Recognized on Impaired Loans	12	19
Unsecured Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment of Loans Collectively Measured for Contingency Provision	120,056		124,150
Recorded Investment of Loans Individually Measured for Specific Impairment	23		25
Recorded Investment	23		25
Unpaid Principal Balance	23		24
Related Allowance	2		3
Average Recorded Investment Impaired Loans	24	0
Interest Recognized on Impaired Loans	0	0
One-to-Four Family Residential [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment of Loans Collectively Measured for Contingency Provision	179,700		185,659
Recorded Investment of Loans Individually Measured for Specific Impairment	868		895
Recorded Investment	428		867
Unpaid Principal Balance	715		1,408
Related Allowance	22		103
Average Recorded Investment Impaired Loans	881	521
Interest Recognized on Impaired Loans	7	2
Commercial Land [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment of Loans Collectively Measured for Contingency Provision	286,613		293,694
Recorded Investment of Loans Individually Measured for Specific Impairment	2,851		2,287
Recorded Investment	0		0
Unpaid Principal Balance	0		0
Related Allowance	0		0
Average Recorded Investment Impaired Loans	2,569	1,504
Interest Recognized on Impaired Loans	0	0
Income Property Multifamily [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment of Loans Collectively Measured for Contingency Provision	1,870,614		1,901,313
Recorded Investment of Loans Individually Measured for Specific Impairment	3,560		5,023
Recorded Investment	0		2,768
Unpaid Principal Balance	0		3,328
Related Allowance	0		185
Average Recorded Investment Impaired Loans	4,292	4,059
Interest Recognized on Impaired Loans	31	1
Owner Occupied [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment of Loans Collectively Measured for Contingency Provision	1,582,385		1,591,298
Recorded Investment of Loans Individually Measured for Specific Impairment	8,556		8,688
Recorded Investment	3,399		77
Unpaid Principal Balance	4,821		80
Related Allowance	5		3
Average Recorded Investment Impaired Loans	8,622	4,462
Interest Recognized on Impaired Loans	84	0
Land And Acquisition [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment of Loans Collectively Measured for Contingency Provision	6,540		9,907
Recorded Investment of Loans Individually Measured for Specific Impairment	0		0
Recorded Investment	0		0
Unpaid Principal Balance	0		0
Related Allowance	0		0
Average Recorded Investment Impaired Loans	0	7
Interest Recognized on Impaired Loans	0	0
Residential Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment of Loans Collectively Measured for Contingency Provision	199,868		188,481
Recorded Investment of Loans Individually Measured for Specific Impairment	1,210		1,210
Recorded Investment	0		0
Unpaid Principal Balance	0		0
Related Allowance	0		0
Average Recorded Investment Impaired Loans	1,210	168
Interest Recognized on Impaired Loans	0	0
Income Property Multifamily Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment of Loans Collectively Measured for Contingency Provision	306,137		293,028
Recorded Investment of Loans Individually Measured for Specific Impairment	0		0
Recorded Investment	0		0
Unpaid Principal Balance	0		0
Related Allowance	0		0
Owner Occupied Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment of Loans Collectively Measured for Contingency Provision	68,966		68,393
Recorded Investment of Loans Individually Measured for Specific Impairment	4,050		4,050
Recorded Investment	0		0
Unpaid Principal Balance	0		0
Related Allowance	0		0
Average Recorded Investment Impaired Loans	4,050	0
Interest Recognized on Impaired Loans	51	0
Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment of Loans Collectively Measured for Contingency Provision	315,845		325,210
Recorded Investment of Loans Individually Measured for Specific Impairment	6,231		7,015
Recorded Investment	5,439		5,303
Unpaid Principal Balance	5,707		5,568
Related Allowance	171		199
Average Recorded Investment Impaired Loans	6,623	5,370
Interest Recognized on Impaired Loans	54	$ 27
Impaired Loans With Recorded Allowance [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment	23,125		12,848
Unpaid Principal Balance	30,197		14,345
Impaired Loans Without Recorded Allowance [Member] | Secured Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment	30,764		36,204
Unpaid Principal Balance	33,785		42,314
Impaired Loans Without Recorded Allowance [Member] | Unsecured Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment	0		0
Unpaid Principal Balance	0		0
Impaired Loans Without Recorded Allowance [Member] | One-to-Four Family Residential [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment	440		28
Unpaid Principal Balance	1,017		337
Impaired Loans Without Recorded Allowance [Member] | Commercial Land [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment	2,851		2,287
Unpaid Principal Balance	2,860		2,282
Impaired Loans Without Recorded Allowance [Member] | Income Property Multifamily [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment	3,560		2,255
Unpaid Principal Balance	3,623		2,601
Impaired Loans Without Recorded Allowance [Member] | Owner Occupied [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment	5,157		8,611
Unpaid Principal Balance	5,269		10,077
Impaired Loans Without Recorded Allowance [Member] | Land And Acquisition [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment	0		0
Unpaid Principal Balance	0		0
Impaired Loans Without Recorded Allowance [Member] | Residential Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment	1,210		1,210
Unpaid Principal Balance	1,210		1,210
Impaired Loans Without Recorded Allowance [Member] | Income Property Multifamily Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment	0		0
Unpaid Principal Balance	0		0
Impaired Loans Without Recorded Allowance [Member] | Owner Occupied Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment	4,050		4,050
Unpaid Principal Balance	4,050		4,050
Impaired Loans Without Recorded Allowance [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment	792		1,712
Unpaid Principal Balance	$ 860		$ 1,864

Loans Loans (Analysis of Troubl

Loans Loans (Analysis of Troubled Debt Restructurings) (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2018USD ($)Modificationscontract	Mar. 31, 2017USD ($)Modificationscontract	Dec. 31, 2017USD ($)
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Number of Contracts | contract	0	0
Loans and Leases Receivable, Related Parties	$ 9,900		$ 10,000
Financing Receivable Modifications Additional Commitment To Lend	$ 121		$ 506
Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | Modifications	9	13
Financing Receivable, Modifications, Pre-Modification Recorded Investment	$ 2,484	$ 1,902
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 2,484	$ 1,902
Loans, Excluding Purchased Credit Impaired Loans [Member] | Secured Loans [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | Modifications	1	3
Financing Receivable, Modifications, Pre-Modification Recorded Investment	$ 450	$ 356
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 450	$ 356
Loans, Excluding Purchased Credit Impaired Loans [Member] | Income Property Multifamily [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | Modifications	1	0
Financing Receivable, Modifications, Pre-Modification Recorded Investment	$ 891	$ 0
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 891	$ 0
Loans, Excluding Purchased Credit Impaired Loans [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | Modifications	7	10
Financing Receivable, Modifications, Pre-Modification Recorded Investment	$ 1,143	$ 1,546
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 1,143	$ 1,546

Loans Loans (Analysis of Purcha

Loans Loans (Analysis of Purchased Credit Impaired Loans - Accretable Yield Rollforward) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017	Dec. 31, 2016
Loans, Analysis of Purchased Credit Impaired Loans, Accretable Yield Rollforward [Abstract]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield	$ 29,355	$ 38,444	$ 31,176	$ 45,191
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield, Accretion	2,265	4,182
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield, Disposals of Loans	159	158
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield, Reclassifications from Nonaccretable Difference	$ 603	$ (2,407)

Allowance for Loan and Lease 52

Allowance for Loan and Lease Losses and Unfunded Commitments and Letters of Credit (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Provision for loan and lease losses	$ 5,852	$ 2,775

Allowance for Loan and Lease 53

Allowance for Loan and Lease Losses and Unfunded Commitments and Letters of Credit (Allowance for Loan and Lease Losses) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	$ 75,646	$ 70,043
Charged-offs	(4,307)	(3,815)
Recoveries	2,636	2,018
Provision for loan and lease losses	5,852	2,775
Ending balance	79,827	71,021
Specific Reserve	5,857	94
General Allocation	73,970	70,927
Secured Loans [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	29,341	36,050
Charged-offs	(2,414)	(1,109)
Recoveries	553	297
Provision for loan and lease losses	9,851	434
Ending balance	37,331	35,672
Specific Reserve	5,657	0
General Allocation	31,674	35,672
Unsecured Loans [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	2,000	960
Charged-offs	(63)	(18)
Recoveries	249	68
Provision for loan and lease losses	409	178
Ending balance	2,595	1,188
Specific Reserve	2	0
General Allocation	2,593	1,188
One-to-Four Family Residential [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	701	599
Charged-offs	0	(307)
Recoveries	172	117
Provision for loan and lease losses	(315)	236
Ending balance	558	645
Specific Reserve	22	11
General Allocation	536	634
Commercial Land [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	4,265	1,797
Charged-offs	0	0
Recoveries	6	0
Provision for loan and lease losses	(526)	491
Ending balance	3,745	2,288
Specific Reserve	0	0
General Allocation	3,745	2,288
Income Property Multifamily [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	5,672	7,342
Charged-offs	(223)	0
Recoveries	141	35
Provision for loan and lease losses	(888)	(574)
Ending balance	4,702	6,803
Specific Reserve	0	26
General Allocation	4,702	6,777
Owner Occupied [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	5,459	6,439
Charged-offs	0	0
Recoveries	12	43
Provision for loan and lease losses	(722)	52
Ending balance	4,749	6,534
Specific Reserve	5	0
General Allocation	4,744	6,534
Land And Acquisition [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	963	316
Charged-offs	0	(14)
Recoveries	16	20
Provision for loan and lease losses	(67)	187
Ending balance	912	509
Specific Reserve	0	0
General Allocation	912	509
Residential Construction [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	3,709	669
Charged-offs	0	0
Recoveries	3	9
Provision for loan and lease losses	924	431
Ending balance	4,636	1,109
Specific Reserve	0	0
General Allocation	4,636	1,109
Income Property Multifamily Construction [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	7,053	404
Charged-offs	0	0
Recoveries	0	0
Provision for loan and lease losses	421	378
Ending balance	7,474	782
Specific Reserve	0	0
General Allocation	7,474	782
Owner Occupied Construction [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	4,413	1,192
Charged-offs	0	0
Recoveries	0	0
Provision for loan and lease losses	(2,490)	576
Ending balance	1,923	1,768
Specific Reserve	0	0
General Allocation	1,923	1,768
Consumer Portfolio Segment [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	5,163	3,534
Charged-offs	(264)	(428)
Recoveries	260	285
Provision for loan and lease losses	57	(31)
Ending balance	5,216	3,360
Specific Reserve	171	57
General Allocation	5,045	3,303
Purchased Credit Impaired Loans [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	6,907	10,515
Charged-offs	(1,343)	(1,939)
Recoveries	1,224	1,144
Provision for loan and lease losses	(1,123)	(325)
Ending balance	5,665	9,395
Specific Reserve	0	0
General Allocation	5,665	9,395
Unallocated Financing Receivables [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	0	226
Charged-offs	0	0
Recoveries	0	0
Provision for loan and lease losses	321	742
Ending balance	321	968
Specific Reserve	0	0
General Allocation	$ 321	$ 968

Allowance for Loan and Lease 54

Allowance for Loan and Lease Losses and Unfunded Commitments and Letters of Credit (Changes in the Allowance for Unfunded Commitments and Letters of Credit) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Allowance For Loan And Lease Losses And Unfunded Loan Commitments And Letters Of Credit
Beginning balance	$ 3,130	$ 2,705
Allowance for Loan and Lease Losses, Net Changes In Unfunded Commitments and Letters Of Credit Allowance	1,200	850
Ending balance	$ 4,330	$ 3,555

Allowance for Loan and Lease 55

Allowance for Loan and Lease Losses and Unfunded Commitments and Letters of Credit (Analysis of Credit Quality of the Loan Portfolio) (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Less: allowance for loan and lease losses	$ 79,827	$ 75,646	$ 71,021	$ 70,043
Loans, net	8,259,804	8,283,011
Loans, Excluding Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	8,230,332	8,245,987
Less: allowance for loan and lease losses	74,162	68,739
Loans, net	8,156,170	8,177,248
Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	117,088	120,758
Acquisition Accounting Valuation Discount on Purchased Credit Impaired Loans	7,789	8,088
Less: allowance for loan and lease losses	5,665	6,907
Loans, net	103,634	105,763
Pass [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	7,915,504	7,926,539
Pass [Member] | Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	114,188	117,307
Special Mention [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	79,017	95,551
Special Mention [Member] | Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	0	349
Substandard [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	235,811	223,897
Substandard [Member] | Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	2,900	3,102
Doubtful [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	0	0
Doubtful [Member] | Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	0	0
Unlikely to be Collected Financing Receivable [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	0	0
Unlikely to be Collected Financing Receivable [Member] | Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	0	0
Secured Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Less: allowance for loan and lease losses	37,331	29,341	35,672	36,050
Secured Loans [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	3,266,259	3,235,661
Secured Loans [Member] | Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	13,310	12,641
Secured Loans [Member] | Pass [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	3,067,417	3,049,031
Secured Loans [Member] | Pass [Member] | Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	12,582	11,918
Secured Loans [Member] | Special Mention [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	47,672	64,600
Secured Loans [Member] | Special Mention [Member] | Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	0	0
Secured Loans [Member] | Substandard [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	151,170	122,030
Secured Loans [Member] | Substandard [Member] | Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	728	723
Secured Loans [Member] | Doubtful [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	0	0
Secured Loans [Member] | Doubtful [Member] | Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	0	0
Secured Loans [Member] | Unlikely to be Collected Financing Receivable [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	0	0
Secured Loans [Member] | Unlikely to be Collected Financing Receivable [Member] | Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	0	0
Unsecured Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Less: allowance for loan and lease losses	2,595	2,000	1,188	960
Unsecured Loans [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	120,079	124,175
Unsecured Loans [Member] | Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	891	1,112
Unsecured Loans [Member] | Pass [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	119,416	123,621
Unsecured Loans [Member] | Pass [Member] | Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	891	1,045
Unsecured Loans [Member] | Special Mention [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	0	0
Unsecured Loans [Member] | Special Mention [Member] | Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	0	0
Unsecured Loans [Member] | Substandard [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	663	554
Unsecured Loans [Member] | Substandard [Member] | Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	0	67
Unsecured Loans [Member] | Doubtful [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	0	0
Unsecured Loans [Member] | Doubtful [Member] | Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	0	0
Unsecured Loans [Member] | Unlikely to be Collected Financing Receivable [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	0	0
Unsecured Loans [Member] | Unlikely to be Collected Financing Receivable [Member] | Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	0	0
One-to-Four Family Residential [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Less: allowance for loan and lease losses	558	701	645	599
One-to-Four Family Residential [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	180,568	186,554
One-to-Four Family Residential [Member] | Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	12,738	14,610
One-to-Four Family Residential [Member] | Pass [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	177,122	183,312
One-to-Four Family Residential [Member] | Pass [Member] | Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	11,967	13,817
One-to-Four Family Residential [Member] | Special Mention [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	1,208	1,186
One-to-Four Family Residential [Member] | Special Mention [Member] | Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	0	0
One-to-Four Family Residential [Member] | Substandard [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	2,238	2,056
One-to-Four Family Residential [Member] | Substandard [Member] | Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	771	793
One-to-Four Family Residential [Member] | Doubtful [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	0	0
One-to-Four Family Residential [Member] | Doubtful [Member] | Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	0	0
One-to-Four Family Residential [Member] | Unlikely to be Collected Financing Receivable [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	0	0
One-to-Four Family Residential [Member] | Unlikely to be Collected Financing Receivable [Member] | Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	0	0
Commercial Land [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Less: allowance for loan and lease losses	3,745	4,265	2,288	1,797
Commercial Land [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	289,464	295,981
Commercial Land [Member] | Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	12,223	9,809
Commercial Land [Member] | Pass [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	279,949	283,673
Commercial Land [Member] | Pass [Member] | Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	12,223	9,460
Commercial Land [Member] | Special Mention [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	1,288	5,204
Commercial Land [Member] | Special Mention [Member] | Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	0	349
Commercial Land [Member] | Substandard [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	8,227	7,104
Commercial Land [Member] | Substandard [Member] | Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	0	0
Commercial Land [Member] | Doubtful [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	0	0
Commercial Land [Member] | Doubtful [Member] | Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	0	0
Commercial Land [Member] | Unlikely to be Collected Financing Receivable [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	0	0
Commercial Land [Member] | Unlikely to be Collected Financing Receivable [Member] | Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	0	0
Income Property Multifamily [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Less: allowance for loan and lease losses	4,702	5,672	6,803	7,342
Income Property Multifamily [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	1,874,174	1,906,336
Income Property Multifamily [Member] | Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	22,384	26,016
Income Property Multifamily [Member] | Pass [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	1,837,613	1,857,832
Income Property Multifamily [Member] | Pass [Member] | Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	22,384	25,981
Income Property Multifamily [Member] | Special Mention [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	19,863	17,181
Income Property Multifamily [Member] | Special Mention [Member] | Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	0	0
Income Property Multifamily [Member] | Substandard [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	16,698	31,323
Income Property Multifamily [Member] | Substandard [Member] | Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	0	35
Income Property Multifamily [Member] | Doubtful [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	0	0
Income Property Multifamily [Member] | Doubtful [Member] | Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	0	0
Income Property Multifamily [Member] | Unlikely to be Collected Financing Receivable [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	0	0
Income Property Multifamily [Member] | Unlikely to be Collected Financing Receivable [Member] | Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	0	0
Owner Occupied [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Less: allowance for loan and lease losses	4,749	5,459	6,534	6,439
Owner Occupied [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	1,590,941	1,599,986
Owner Occupied [Member] | Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	42,793	43,386
Owner Occupied [Member] | Pass [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	1,542,605	1,546,775
Owner Occupied [Member] | Pass [Member] | Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	41,874	42,617
Owner Occupied [Member] | Special Mention [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	8,986	7,380
Owner Occupied [Member] | Special Mention [Member] | Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	0	0
Owner Occupied [Member] | Substandard [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	39,350	45,831
Owner Occupied [Member] | Substandard [Member] | Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	919	769
Owner Occupied [Member] | Doubtful [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	0	0
Owner Occupied [Member] | Doubtful [Member] | Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	0	0
Owner Occupied [Member] | Unlikely to be Collected Financing Receivable [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	0	0
Owner Occupied [Member] | Unlikely to be Collected Financing Receivable [Member] | Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	0	0
Land And Acquisition [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Less: allowance for loan and lease losses	912	963	509	316
Land And Acquisition [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	6,540	9,907
Land And Acquisition [Member] | Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	171	177
Land And Acquisition [Member] | Pass [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	6,540	9,882
Land And Acquisition [Member] | Pass [Member] | Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	164	169
Land And Acquisition [Member] | Special Mention [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	0	0
Land And Acquisition [Member] | Special Mention [Member] | Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	0	0
Land And Acquisition [Member] | Substandard [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	0	25
Land And Acquisition [Member] | Substandard [Member] | Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	7	8
Land And Acquisition [Member] | Doubtful [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	0	0
Land And Acquisition [Member] | Doubtful [Member] | Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	0	0
Land And Acquisition [Member] | Unlikely to be Collected Financing Receivable [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	0	0
Land And Acquisition [Member] | Unlikely to be Collected Financing Receivable [Member] | Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	0	0
Residential Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Less: allowance for loan and lease losses	4,636	3,709	1,109	669
Residential Construction [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	201,078	189,691
Residential Construction [Member] | Pass [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	199,868	187,863
Residential Construction [Member] | Special Mention [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	0	0
Residential Construction [Member] | Substandard [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	1,210	1,828
Residential Construction [Member] | Doubtful [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	0	0
Residential Construction [Member] | Unlikely to be Collected Financing Receivable [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	0	0
Income Property Multifamily Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Less: allowance for loan and lease losses	7,474	7,053	782	404
Income Property Multifamily Construction [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	306,137	293,028
Income Property Multifamily Construction [Member] | Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	589	595
Income Property Multifamily Construction [Member] | Pass [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	303,079	293,028
Income Property Multifamily Construction [Member] | Pass [Member] | Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	589	595
Income Property Multifamily Construction [Member] | Special Mention [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	0	0
Income Property Multifamily Construction [Member] | Special Mention [Member] | Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	0	0
Income Property Multifamily Construction [Member] | Substandard [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	3,058	0
Income Property Multifamily Construction [Member] | Substandard [Member] | Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	0	0
Income Property Multifamily Construction [Member] | Doubtful [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	0	0
Income Property Multifamily Construction [Member] | Doubtful [Member] | Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	0	0
Income Property Multifamily Construction [Member] | Unlikely to be Collected Financing Receivable [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	0	0
Income Property Multifamily Construction [Member] | Unlikely to be Collected Financing Receivable [Member] | Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	0	0
Owner Occupied Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Less: allowance for loan and lease losses	1,923	4,413	1,768	1,192
Owner Occupied Construction [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	73,016	72,443
Owner Occupied Construction [Member] | Pass [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	67,672	68,393
Owner Occupied Construction [Member] | Special Mention [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	0	0
Owner Occupied Construction [Member] | Substandard [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	5,344	4,050
Owner Occupied Construction [Member] | Doubtful [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	0	0
Owner Occupied Construction [Member] | Unlikely to be Collected Financing Receivable [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	0	0
Consumer Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Less: allowance for loan and lease losses	5,216	5,163	$ 3,360	$ 3,534
Consumer Portfolio Segment [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	322,076	332,225
Consumer Portfolio Segment [Member] | Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	11,989	12,412
Consumer Portfolio Segment [Member] | Pass [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	314,223	323,129
Consumer Portfolio Segment [Member] | Pass [Member] | Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	11,514	11,705
Consumer Portfolio Segment [Member] | Special Mention [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	0	0
Consumer Portfolio Segment [Member] | Special Mention [Member] | Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	0	0
Consumer Portfolio Segment [Member] | Substandard [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	7,853	9,096
Consumer Portfolio Segment [Member] | Substandard [Member] | Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	475	707
Consumer Portfolio Segment [Member] | Doubtful [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	0	0
Consumer Portfolio Segment [Member] | Doubtful [Member] | Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	0	0
Consumer Portfolio Segment [Member] | Unlikely to be Collected Financing Receivable [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	0	0
Consumer Portfolio Segment [Member] | Unlikely to be Collected Financing Receivable [Member] | Purchased Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount	$ 0	$ 0

Other Real Estate Owned (Summar

Other Real Estate Owned (Summary of Other Real Estate Owned) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Other Real Estate Owned [Line Items]
Balance, beginning of period	$ 13,298	$ 5,998
Transfers in	406	0
Valuation adjustments	(92)	(193)
Proceeds from Sale of OREO Property	2,062	1,275
Loss on sale of OREO, net	(43)	(11)
Total OREO, end of period	11,507	$ 4,519
Mortgage Loans in Process of Foreclosure, Amount	638
One-to-Four Family Residential [Member]
Other Real Estate Owned [Line Items]
Total OREO, end of period	$ 433

Goodwill and Intangible Asset57

Goodwill and Intangible Assets (Schedule of Goodwill and Intangible Assets) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017	Dec. 31, 2016
Goodwill and Intangible Assets [Roll Forward]
Total goodwill, beginning of period	$ 765,842
Total goodwill, end of period	765,842	$ 382,762
CDI current period amortization	(3,188)	(1,349)
Indefinite-Lived Intangible Assets (Excluding Goodwill)	919	919
Other intangible assets, net	54,985	16,282	$ 58,173
Total goodwill and intangible assets, end of period	$ 820,827	399,044
Core Deposits [Member]
Goodwill and Intangible Assets [Line Items]
Estimated life of CDI, in years	10 years
Goodwill and Intangible Assets [Roll Forward]
Gross core deposit intangible balance, beginning of period			105,473	$ 58,598
Accumulated amortization at beginning of period			$ (48,219)	$ (41,886)
Core deposit intangible, net, beginning of period	$ 57,254	16,712
CDI current period amortization	(3,188)	(1,349)
Total core deposit intangible, end of period	$ 54,066	$ 15,363

Goodwill and Intangible Asset58

Goodwill and Intangible Assets (Estimated Future Amortization Expense of Core Deposit Intangibles) (Details) $ in Thousands	Mar. 31, 2018USD ($)
Future Amortization Expense For Core Deposit Intangibles
2,018	$ 9,048
2,019	10,479
2,020	8,724
2,021	7,264
2,022	$ 5,880

Subordinated debentures (Detail

Subordinated debentures (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Nov. 01, 2017
Subordinated Borrowing [Line Items]
Subordinated Borrowing, Interest Rate	5.875%
Debt Instrument, Interest Rate Terms	471.5
Pacific Continental [Member]
Subordinated Borrowing [Line Items]
Business Combination, Purchase Price Allocation, Subordinated Debt		$ 35

Junior subordinated debt (Detai

Junior subordinated debt (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017	Nov. 01, 2017
junior subordinated debentures [Line Items]
Junior Subordinated Notes	$ 0		$ 8,248
Repayments of junior subordinated debt	$ 8,248	$ 0	$ 6,200
Pacific Continental [Member]
junior subordinated debentures [Line Items]
Business Combination, Purchase Price Allocation, Junior Subordinated Debentures				$ 14,434

Derivatives and Balance Sheet61

Derivatives and Balance Sheet Offsetting (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Derivative [Line Items]
Gain (Loss) on Derivative Instruments, Net, Pretax	$ 6	$ 4
Secured Borrowings, Gross Including Not Subject to Master Netting Arrangement	24,247
Secured Borrowings, Gross, Difference, Amount	0
U.S. Government Agency and Government-Sponsored Enterprise Mortgage-Backed Securities and Collateralized Mortgage Obligations [Member]
Derivative [Line Items]
Secured Borrowings, Gross Including Not Subject to Master Netting Arrangement	24,247
Maturity Overnight [Member] | U.S. Government Agency and Government-Sponsored Enterprise Mortgage-Backed Securities and Collateralized Mortgage Obligations [Member]
Derivative [Line Items]
Secured Borrowings, Gross Including Not Subject to Master Netting Arrangement	24,247
Maturity Less than 30 Days [Member] | U.S. Government Agency and Government-Sponsored Enterprise Mortgage-Backed Securities and Collateralized Mortgage Obligations [Member]
Derivative [Line Items]
Secured Borrowings, Gross Including Not Subject to Master Netting Arrangement	0
Maturity 30 to 90 Days [Member] | U.S. Government Agency and Government-Sponsored Enterprise Mortgage-Backed Securities and Collateralized Mortgage Obligations [Member]
Derivative [Line Items]
Secured Borrowings, Gross Including Not Subject to Master Netting Arrangement	0
Maturity Greater than 90 Days [Member] | U.S. Government Agency and Government-Sponsored Enterprise Mortgage-Backed Securities and Collateralized Mortgage Obligations [Member]
Derivative [Line Items]
Secured Borrowings, Gross Including Not Subject to Master Netting Arrangement	0
Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member]
Derivative [Line Items]
Derivative, Notional Amount	393,800		$ 384,700
Not Designated as Hedging Instrument [Member] | Other Assets [Member] | Interest Rate Contracts [Member]
Derivative [Line Items]
Fair value of asset derivative instruments	7,406		6,707
Not Designated as Hedging Instrument [Member] | Other Liabilities [Member] | Interest Rate Contracts [Member]
Derivative [Line Items]
Fair value of liability derivative instruments	$ 7,409		$ 6,714

Derivatives and Balance Sheet62

Derivatives and Balance Sheet Offsetting Balance Sheet Offsetting (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Balance Sheet Offsetting [Line Items]
Secured Borrowings, Gross Including Not Subject to Master Netting Arrangement	$ 24,247
Repurchase agreements, amounts offset in balance sheet	0	$ 0
Repurchase agreements, net amount presented in statement of financial position	24,247	79,059
Securities Sold under Agreements to Repurchase, Collateral, Right to Reclaim Securities	(24,247)	(79,059)
Securities sold under agreements to repurchase, amount not offset	0	0
Interest Rate Contracts [Member]
Balance Sheet Offsetting [Line Items]
Derivative Assets, Gross Amounts Offset in the Balance Sheets	0	0
Derivative Asset	7,406	6,707
Derivative, Collateral, Obligation to Return Securities	0	0
Derivative Asset, Fair Value, Amount Not Offset Against Collateral	7,406	6,707
Derivative Liability, Gross Amounts Offset in Balance Sheets	0	0
Derivative Liability	7,409	6,714
Derivative, Collateral, Right to Reclaim Securities	(1,190)	(6,714)
Derivative Liability, Fair Value, Amount Not Offset Against Collateral	6,219	0
Available-for-sale Securities [Member]
Balance Sheet Offsetting [Line Items]
Securities Sold under Agreements to Repurchase, Gross	24,247	79,059
Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member] | Other Assets [Member]
Balance Sheet Offsetting [Line Items]
Fair value of asset derivative instruments	7,406	6,707
Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member] | Other Liabilities [Member]
Balance Sheet Offsetting [Line Items]
Fair value of liability derivative instruments	7,409	$ 6,714
U.S. Government Agency and Government-Sponsored Enterprise Mortgage-Backed Securities and Collateralized Mortgage Obligations [Member]
Balance Sheet Offsetting [Line Items]
Secured Borrowings, Gross Including Not Subject to Master Netting Arrangement	24,247
Maturity Overnight [Member] | U.S. Government Agency and Government-Sponsored Enterprise Mortgage-Backed Securities and Collateralized Mortgage Obligations [Member]
Balance Sheet Offsetting [Line Items]
Secured Borrowings, Gross Including Not Subject to Master Netting Arrangement	$ 24,247

Commitments and Contingent Li63

Commitments and Contingent Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Commitments to Extend Credit [Member]
Other Commitments [Line Items]
Fair Value Disclosure, Off-balance Sheet Risks, Amount, Liability	$ 2,580,000	$ 2,620,000
Standby Letters of Credit [Member]
Other Commitments [Line Items]
Fair Value Disclosure, Off-balance Sheet Risks, Amount, Liability	41,900	51,300
Commercial Letter of Credit and other off-balance sheet liabilities [Member]
Other Commitments [Line Items]
Fair Value Disclosure, Off-balance Sheet Risks, Amount, Liability	$ 58	$ 159

Shareholders' Equity (Details)

Shareholders' Equity (Details) - $ / shares	Apr. 25, 2018	Jan. 25, 2018
Class of Stock [Line items]
Declared quarterly cash dividend		$ 0.22
Subsequent Event [Member]
Class of Stock [Line items]
Declared quarterly cash dividend	$ 0.26

Accumulated Other Comprehensi65

Accumulated Other Comprehensive Income (Changes in AOCI by Component) (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance		$ (22,225)	$ (18,999)
Other comprehensive loss before reclassifications	[1]	(26,048)	6,306
Amounts reclassified from accumulated other comprehensive loss	[1]	(17)	87
Net current-period other comprehensive income (loss)	[1]	(26,065)	6,393
Ending balance		(48,133)	(12,606)
Unrealized Gains and Losses on Available-for-Sale Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance		(19,779)	(12,704)
Other comprehensive loss before reclassifications	[1]	(26,048)	1,702
Amounts reclassified from accumulated other comprehensive loss	[1]	(78)	0
Net current-period other comprehensive income (loss)	[1]	(26,126)	1,702
Ending balance		(45,748)	(11,002)
Unrealized Gains and Losses on Pension Plan Liability [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance		(2,446)	(6,295)
Other comprehensive loss before reclassifications	[1]	0	4,604
Amounts reclassified from accumulated other comprehensive loss	[1]	61	87
Net current-period other comprehensive income (loss)	[1]	61	4,691
Ending balance		$ (2,385)	$ (1,604)
Accounting Standards Update 2016-01 [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Cumulative Effect of New Accounting Principle in Period of Adoption				$ (46)
Accounting Standards Update 2016-01 [Member] | Unrealized Gains and Losses on Available-for-Sale Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Cumulative Effect of New Accounting Principle in Period of Adoption				157
Accounting Standards Update 2016-01 [Member] | Unrealized Gains and Losses on Pension Plan Liability [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Cumulative Effect of New Accounting Principle in Period of Adoption				0
Accounting Standards Update 2016-01 [Member] | Accumulated Other Comprehensive Income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Cumulative Effect of New Accounting Principle in Period of Adoption				$ 157
[1]	All amounts are net of tax. Amounts in parenthesis indicate debits.

Accumulated Other Comprehensi66

Accumulated Other Comprehensive Income (Reclassification out of AOCI) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Investment securities gains, net	$ 22	$ 0
Compensation and employee benefits	50,570	40,825
Total before tax	46,785	39,773
Income tax provision	(6,815)	(10,574)
Net income	39,970	29,199
Reclassification out of Accumulated Other Comprehensive Income [Member] | Unrealized Gains and Losses on Available-for-Sale Securities [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Investment securities gains, net	102	0
Total before tax	102	0
Income tax provision	(24)	0
Net income	78	0
Reclassification out of Accumulated Other Comprehensive Income [Member] | Unrealized Gains and Losses on Pension Plan Liability [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Compensation and employee benefits	(80)	(136)
Total before tax	(80)	(136)
Income tax provision	19	49
Net income	$ (61)	$ (87)

Fair Value Accounting and Mea67

Fair Value Accounting and Measurement (Financial Assets And Liabilities Accounted for Fair Value On Recurring Basis) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable Securities, Equity Securities	$ 5,000	$ 5,080
Fair Value, Level 2 to level 1 Transfers, Amount	0
Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	$ 2,624,045	2,737,751
Marketable Securities, Equity Securities	5,000	5,080
Other assets (Interest rate contracts)	7,406	6,707
Other liabilities (Interest rate contracts)	7,409	6,714
Fair Value, Inputs, Level 1 [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	247	248
Marketable Securities, Equity Securities	5,000	5,080
Other assets (Interest rate contracts)	0	0
Other liabilities (Interest rate contracts)	0	0
Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	2,623,798	2,737,503
Marketable Securities, Equity Securities	0	0
Other assets (Interest rate contracts)	7,406	6,707
Other liabilities (Interest rate contracts)	7,409	6,714
Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	0	0
Marketable Securities, Equity Securities	0	0
Other assets (Interest rate contracts)	0	0
Other liabilities (Interest rate contracts)	0	0
U.S. Government Agency and Sponsored Enterprise Mortgage-Back Securities and Collateralized Mortgage Obligations [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	1,645,218	1,726,725
U.S. Government Agency and Sponsored Enterprise Mortgage-Back Securities and Collateralized Mortgage Obligations [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	0	0
U.S. Government Agency and Sponsored Enterprise Mortgage-Back Securities and Collateralized Mortgage Obligations [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	1,645,218	1,726,725
U.S. Government Agency and Sponsored Enterprise Mortgage-Back Securities and Collateralized Mortgage Obligations [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	0	0
State and Municipal Securities [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	582,748	596,004
State and Municipal Securities [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	0	0
State and Municipal Securities [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	582,748	596,004
State and Municipal Securities [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	0	0
U.S. Government Agency [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	395,832	414,774
U.S. Government Agency [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	0	0
U.S. Government Agency [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	395,832	414,774
U.S. Government Agency [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	0	0
US Government Securities [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	247	248
US Government Securities [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	247	248
US Government Securities [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	0	0
US Government Securities [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	$ 0	$ 0

Fair Value Accounting and Mea68

Fair Value Accounting and Measurement (Financial Assets Accounted For Fair Value On Nonrecurring Basis) (Details) - Fair Value, Measurements, Nonrecurring [Member] - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	$ 7,820
Fair Value, Option, Changes in Fair Value, Gain (Loss)	5,109	$ 193
OREO	160	1,260
Assets, Fair Value Disclosure	7,980	1,260
Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	0
OREO	0	0
Assets, Fair Value Disclosure	0	0
Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	0
OREO	0	0
Assets, Fair Value Disclosure	0	0
Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	7,820
OREO	160	1,260
Assets, Fair Value Disclosure	7,980	1,260
Impaired Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Option, Changes in Fair Value, Gain (Loss)	5,058
Other Real Estate Owned [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Option, Changes in Fair Value, Gain (Loss)	$ 51	$ 193

Fair Value Accounting and Mea69

Fair Value Accounting and Measurement (Quantitative Information About Level 3 Fair Value Measurements) (Details) - Fair Value, Measurements, Nonrecurring [Member] - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Impaired loans	$ 7,820
OREO	160	$ 1,260
Fair Value, Inputs, Level 3 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Impaired loans	7,820
OREO	160	$ 1,260
Collateral Pledged [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Impaired loans	$ 7,512
Collateral Pledged [Member] | Market Approach Valuation Technique [Member] | Impaired Loans [Member] | Minimum [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Comparability Adjustments	0.00%
Collateral Pledged [Member] | Market Approach Valuation Technique [Member] | Impaired Loans [Member] | Maximum [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Comparability Adjustments	100.00%
Collateral Pledged [Member] | Market Approach Valuation Technique [Member] | Impaired Loans [Member] | Weighted Average [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Comparability Adjustments	41.33%
Uncollateralized [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Impaired loans	$ 308
Uncollateralized [Member] | Market Approach Valuation Technique [Member] | Impaired Loans [Member] | Minimum [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rate	6.00%
Uncollateralized [Member] | Market Approach Valuation Technique [Member] | Impaired Loans [Member] | Maximum [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rate	6.00%
Uncollateralized [Member] | Market Approach Valuation Technique [Member] | Impaired Loans [Member] | Weighted Average [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Inputs, Discount Rate	6.00%

Fair Value Accounting and Mea70

Fair Value Accounting and Measurement (Carrying Amounts and Estimated Fair Values of Selected Financial Instruments) (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Assets
Interest-earning deposits with banks	$ 87,124	$ 97,918
Available-for-sale Securities, Debt Securities	2,624,045	2,737,751
Marketable Securities, Equity Securities	5,000	5,080
Estimate of Fair Value Measurement [Member]
Assets
Cash and due from banks	206,532	244,615
Interest-earning deposits with banks	87,124	97,918
Available-for-sale Securities, Debt Securities	2,624,045	2,737,751
Marketable Securities, Equity Securities	5,000	5,080
FHLB stock	11,640	10,440
Loans held for sale	4,312	5,766
Loans	8,281,010	8,055,817
Interest rate contracts	7,406	6,707
Liabilities
Deposits	465,896	10,524,135
FHLB Advances	42,090	12,281
Repurchase agreements	24,247	79,070
Interest rate contracts	7,409	6,714
Subordinated Debt Obligations, Fair Value Disclosure	35,486	35,895
Junior subordinated debentures, fair value disclosure		8,248
Reported Value Measurement [Member]
Assets
Cash and due from banks	206,532	244,615
Interest-earning deposits with banks	87,124	97,918
Available-for-sale Securities, Debt Securities	2,624,045	2,737,751
Marketable Securities, Equity Securities	5,000	5,080
FHLB stock	11,640	10,440
Loans held for sale	4,312	5,766
Loans	8,259,804	8,283,011
Interest rate contracts	7,406	6,707
Liabilities
Deposits	474,000	10,532,085
FHLB Advances	41,564	11,579
Repurchase agreements	24,247	79,059
Interest rate contracts	7,409	6,714
Subordinated Debt Obligations, Fair Value Disclosure	35,601	35,647
Junior subordinated debentures, fair value disclosure		8,248
Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value Measurement [Member]
Assets
Cash and due from banks	206,532	244,615
Interest-earning deposits with banks	87,124	97,918
Available-for-sale Securities, Debt Securities	247	248
Marketable Securities, Equity Securities	5,000	5,080
FHLB stock	0	0
Loans held for sale	0	0
Loans	0	0
Interest rate contracts	0	0
Liabilities
Deposits	0	10,041,040
FHLB Advances	0	0
Repurchase agreements	0	0
Interest rate contracts	0	0
Subordinated Debt Obligations, Fair Value Disclosure	0	0
Junior subordinated debentures, fair value disclosure		0
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value Measurement [Member]
Assets
Cash and due from banks	0	0
Interest-earning deposits with banks	0	0
Available-for-sale Securities, Debt Securities	2,623,798	2,737,503
Marketable Securities, Equity Securities	0	0
FHLB stock	11,640	10,440
Loans held for sale	4,312	5,766
Loans	0	0
Interest rate contracts	7,406	6,707
Liabilities
Deposits	465,896	483,095
FHLB Advances	42,090	12,281
Repurchase agreements	24,247	79,070
Interest rate contracts	7,409	6,714
Subordinated Debt Obligations, Fair Value Disclosure	35,486	35,895
Junior subordinated debentures, fair value disclosure		8,248
Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value Measurement [Member]
Assets
Cash and due from banks	0	0
Interest-earning deposits with banks	0	0
Available-for-sale Securities, Debt Securities	0	0
Marketable Securities, Equity Securities	0	0
FHLB stock	0	0
Loans held for sale	0	0
Loans	8,281,010	8,055,817
Interest rate contracts	0	0
Liabilities
Deposits	0	0
FHLB Advances	0	0
Repurchase agreements	0	0
Interest rate contracts	0	0
Subordinated Debt Obligations, Fair Value Disclosure	$ 0	0
Junior subordinated debentures, fair value disclosure		$ 0

Earnings per Common Share (Deta

Earnings per Common Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Net Income	$ 39,970	$ 29,199
Earnings allocated to participating securities - preferred shares	0	3
Earnings allocated to participating securities - nonvested restricted shares	437	397
Earnings allocated to common shareholders, Basic	$ 39,533	$ 28,799
Weighted average common shares outstanding	72,300	57,388
Basic earnings per common share	$ 0.55	$ 0.50
Earnings allocated to common shareholders, Diluted	$ 39,533	$ 28,799
Dilutive effect of equity awards and warrants	5	6
Weighted average diluted common shares outstanding	72,305	57,394
Diluted earnings per common share	$ 0.55	$ 0.50
Potentially dilutive share options that were not included in the computation of diluted EPS because to do so would be anti-dilutive.	12	14

Revenue from Contracts with C72

Revenue from Contracts with Customers (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Revenue from Contract with Customer [Abstract]
Deposit account and treasury management fees	$ 8,740	$ 7,287
Card revenue	5,813	5,723
Financial services and trust revenue	2,730	2,839
Loan revenue	3,186	3,593
Revenue from contracts with customers	17,283
Noninterest income, excluding revenue from contracts with customers	5,860
Noninterest Income	$ 23,143	$ 24,859