Pacific Premier Bancorp (PPBI) 10-K 28 Feb 18 2017 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2017	Feb. 27, 2018	Jun. 30, 2017
Document and Entity Information
Entity Registrant Name	PACIFIC PREMIER BANCORP INC
Entity Central Index Key	1,028,918
Document Type	10-K
Document Period End Date	Dec. 31, 2017
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Public Float			$ 1.5
Entity Common Stock, Shares Outstanding		46,241,238
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	FY

CONSOLIDATED STATEMENTS OF FINA

CONSOLIDATED STATEMENTS OF FINANCIAL CONDITION - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
ASSETS
Cash and due from banks	$ 79,284	$ 14,706
Interest-bearing deposits with financial institutions	120,780	142,151
Cash and cash equivalents	200,064	156,857
Interest-bearing time deposits with financial institutions	3,693	3,944
Investments held-to-maturity, at amortized cost (fair value of $18,082 and $8,461 as of December 31, 2017 and December 31, 2016, respectively)	18,291	8,565
Investment securities available-for-sale, at fair value	787,429	380,963
FHLB, FRB and other stock, at cost	65,881	37,304
Loans held for sale, at lower of cost or fair value	23,426	7,711
Loans held for investment	6,196,468	3,241,613
Allowance for loan losses	(28,936)	(21,296)
Loans held for investment, net	6,167,532	3,220,317
Accrued interest receivable	27,053	13,145
Other real estate owned	326	460
Premises and equipment	53,155	12,014
Deferred income taxes, net	13,265	16,807
Bank owned life insurance	75,976	40,409
Intangible assets	43,014	9,451
Goodwill	493,329	102,490
Other assets	52,067	25,874
Total assets	8,024,501	4,036,311
Deposit accounts:
Noninterest-bearing checking	2,226,848	1,185,768
Interest-bearing:
Checking	365,193	182,893
Money market/savings	2,409,007	1,202,361
Retail certificates of deposit	767,651	375,203
Wholesale/brokered certificates of deposit	317,169	199,356
Total interest-bearing	3,859,020	1,959,813
Total deposits	6,085,868	3,145,581
FHLB advances and other borrowings	536,287	327,971
Subordinated debentures	105,123	69,383
Accrued expenses and other liabilities	55,227	33,636
Total liabilities	6,782,505	3,576,571
STOCKHOLDERS’ EQUITY
Preferred stock, $.01 par value; 1,000,000 shares authorized; no shares issued and outstanding	0	0
Common stock, $.01 par value; 100,000,000 shares authorized; 46,245,050 shares at December 31, 2017 and 100,000,000 shares authorized; 27,798,283 shares at December 31, 2016 issued and outstanding	458	274
Additional paid-in capital	1,063,974	345,138
Retained earnings	177,149	117,049
Accumulated other comprehensive income (loss), net of tax (benefit) of $231 at December 31, 2017 and $(1,978) at December 31, 2016	415	(2,721)
Total stockholders' equity	1,241,996	459,740
Total liabilities and stockholders' equity	$ 8,024,501	$ 4,036,311

CONSOLIDATED STATEMENTS OF FIN3

CONSOLIDATED STATEMENTS OF FINANCIAL CONDITION (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Estimated Fair Value	$ 18,082	$ 8,461
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	1,000,000	1,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	100,000,000	100,000,000
Common stock, shares issued (in shares)	46,245,050	27,798,283
Common stock, shares outstanding (in shares)	46,245,050	27,798,283
Accumulated other comprehensive income (loss), tax (benefit) (in dollars)	$ 231	$ (1,978)

CONSOLIDATED STATEMENTS OF INCO

CONSOLIDATED STATEMENTS OF INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
INTEREST INCOME
Loans	$ 251,027	$ 157,935	$ 111,097
Investment securities and other interest-earning assets	18,978	8,670	7,259
Total interest income	270,005	166,605	118,356
INTEREST EXPENSE
Deposits	13,371	8,391	6,630
FHLB advances and other borrowings	4,411	1,295	1,490
Subordinated debentures	4,721	3,844	3,937
Total interest expense	22,503	13,530	12,057
Net interest income before provision for loan losses	247,502	153,075	106,299
Provision for loan losses	8,640	8,776	6,425
Net interest income after provision for loan losses	238,862	144,299	99,874
NONINTEREST INCOME
Loan servicing fees	787	1,032	371
Deposit fees	3,809	1,697	1,274
Net gain from sales of loans	12,468	9,539	7,970
Net gain from sales of investment securities	2,737	1,797	290
Other income	11,313	5,537	4,483
Total noninterest income	31,114	19,602	14,388
NONINTEREST EXPENSE
Compensation and benefits	84,138	52,836	37,108
Premises and occupancy	14,742	9,838	7,810
Data processing	8,206	4,261	2,816
Other real estate owned operations, net	72	385	68
FDIC insurance premiums	2,151	1,545	1,376
Legal, audit and professional expense	6,101	3,041	2,514
Marketing expense	4,436	3,981	2,305
Office, telecommunications and postage expense	3,117	2,107	2,005
Loan expense	3,299	2,191	1,268
Deposit expense	6,240	4,904	3,643
Merger-related expense	21,002	4,388	4,799
CDI amortization	6,144	2,039	1,350
Other expense	8,102	7,067	6,476
Total noninterest expense	167,750	98,583	73,538
Net income before income taxes	102,226	65,318	40,724
Income tax	42,126	25,215	15,209
Net income	$ 60,100	$ 40,103	$ 25,515
EARNINGS PER SHARE
Basic (in dollars per share)	$ 1.59	$ 1.49	$ 1.21
Diluted (in dollars per share)	$ 1.56	$ 1.46	$ 1.19
WEIGHTED AVERAGE SHARES OUTSTANDING
Basic (in shares)	37,705,556	26,931,634	21,156,668
Diluted (in shares)	38,511,261	27,439,159	21,488,698

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement of Comprehensive Income [Abstract]
Net Income	$ 60,100	$ 40,103	$ 25,515
Other comprehensive income (loss), net of tax:
Unrealized holding gains/(losses) on securities arising during the period, net of income tax (benefits)	4,937	(2,013)	(15)
Reclassification adjustment for net gain on sale of securities included in net income, net of income taxes	(1,801)	(1,040)	(171)
Other comprehensive income (loss), net of tax	3,136	(3,053)	(186)
Comprehensive income, net of tax	$ 63,236	$ 37,050	$ 25,329

CONSOLIDATED STATEMENTS OF COM6

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement of Comprehensive Income [Abstract]
Tax effect on unrealized holding gains (losses) on securities arising during the period	$ 3,100	$ (1,500)	$ (13)
Income tax expense on reclassification adjustment for net gain on sale of securities included in net income	$ 936	$ 757	$ 119

CONSOLIDATED STATEMENTS OF STOC

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Retained Earnings	Accumulated Other Comprehensive Income (Loss)
Balance at Dec. 31, 2014	$ 199,592	$ 169	$ 147,474	$ 51,431	$ 518
Balance (in shares) at Dec. 31, 2014		16,903,884
Increase (Decrease) in Stockholders' Equity
Net Income	25,515			25,515
Other comprehensive income (loss)	(186)				(186)
Share-based compensation expense	1,165		1,165
Issuance of restricted stock, net (in shares)		60,000
Issuance of common stock	72,252	$ 45	72,207
Issuance of common stock (in shares)		4,480,645
Warrants exercised	689	$ 1	688
Warrants exercised (in shares)		125,316
Repurchase of common stock	(116)	$ 0	(116)
Repurchase of common stock (in shares)		(7,165)
Exercise of stock options	69	$ 0	69
Exercise of stock options (in shares)		8,066
Balance at Dec. 31, 2015	298,980	$ 215	221,487	76,946	332
Balance (in shares) at Dec. 31, 2015		21,570,746
Increase (Decrease) in Stockholders' Equity
Net Income	40,103			40,103
Other comprehensive income (loss)	(3,053)				(3,053)
Share-based compensation expense	2,729		2,729
Issuance of restricted stock, net	0
Issuance of restricted stock, net (in shares)		296,236
Issuance of common stock	119,383	$ 58	119,325
Issuance of common stock (in shares)		5,815,051
Goodwill adjustment	379		379
Repurchase of common stock	(126)		(126)
Repurchase of common stock (in shares)		0
Exercise of stock options	1,345	$ 1	1,344
Exercise of stock options (in shares)		116,250
Balance at Dec. 31, 2016	$ 459,740	$ 274	345,138	117,049	(2,721)
Balance (in shares) at Dec. 31, 2016	27,798,283	27,798,283
Increase (Decrease) in Stockholders' Equity
Net Income	$ 60,100			60,100
Other comprehensive income (loss)	3,136				3,136
Share-based compensation expense	5,809		5,809
Issuance of restricted stock, net	0
Issuance of restricted stock, net (in shares)		166,397
Issuance of common stock	709,377	$ 181	709,196
Issuance of common stock (in shares)		17,954,274
Goodwill adjustment	500		500
Repurchase of common stock	(1,258)		(1,258)
Repurchase of common stock (in shares)		(21,537)
Exercise of stock options	4,592	$ 3	4,589
Exercise of stock options (in shares)		347,633
Balance at Dec. 31, 2017	$ 1,241,996	$ 458	$ 1,063,974	$ 177,149	$ 415
Balance (in shares) at Dec. 31, 2017	46,245,050	46,245,050

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash flows from operating activities:
Net income	$ 60,100	$ 40,103	$ 25,515
Adjustments to net income:
Depreciation and amortization expense	4,888	2,854	2,432
Provision for loan losses	8,640	8,776	6,425
Share-based compensation expense	5,809	2,729	1,165
Loss on sale and disposal of premises and equipment	234	656	0
(Gain) loss on sale of or write down of other real estate owned	(46)	321	92
Net amortization on securities available-for-sale	7,601	9,157	3,822
Net accretion of discounts/premiums for loans acquired and deferred loan fees/costs	1,627	1,832	(2,967)
Gain on sale of investment securities available-for-sale	(2,737)	(1,797)	(290)
Other-than-temporary impairment recovery on investment securities, net	0	(205)	0
Originations of loans held for sale	(142,104)	(103,883)	(87,900)
Proceeds from the sales of and principal payments from loans held for sale	140,012	115,877	86,604
Gain on sale of loans	(12,468)	(9,539)	(7,970)
Deferred income tax expense (benefit)	16,866	3,887	(1,395)
Change in accrued expenses and other liabilities, net	5,003	(4,428)	6,786
Income from bank owned life insurance, net	(1,842)	(1,164)	(1,147)
Amortization of core deposit intangible	6,144	2,039	1,350
Change in accrued interest receivable and other assets, net	(13,728)	(3,768)	(8,853)
Net cash (used in) provided by operating activities	83,999	63,447	23,669
Cash flows from investing activities:
Net increase in interest-bearing time deposits with financial institutions	251	0	(1,972)
Increase in loans, net	(519,407)	(263,075)	(247,000)
Purchase of loans held for investment	(13,582)	(271,159)	(43,440)
Change in other real estate owned from sales	507	380	(216)
Purchase of held-to-maturity securities	0	0	(9,642)
Principal payments on securities available-for-sale	76,057	38,935	33,751
Purchase of securities available-for-sale	(317,441)	(190,140)	(90,127)
Proceeds from sale of securities available-for-sale	268,596	230,945	27,642
Proceeds from the sale of premises and equipment	0	10,049	1,506
Investment in bank owned life insurance	198	0	0
Purchases of premises and equipment	(4,165)	(11,970)	(1,887)
Change in FHLB, FRB, and other stock, at cost	(12,838)	(15,012)	(2,856)
Cash acquired in acquisitions	225,945	40,132	2,961
Net cash used in investing activities	(295,879)	(430,915)	(331,280)
Cash flows from financing activities:
Net increase in deposit accounts	187,883	313,770	228,279
Net change in federal funds purchased	0	0	(1,500)
Net change in short-term borrowings	61,120	181,846	47,682
Proceeds from long-term borrowings	12,012	0	0
Repayment of long-term borrowings	(9,262)	(50,927)	0
Proceeds from exercise of stock options and warrants	4,592	1,345	758
Repurchase of common stock	(1,258)	(126)	(116)
Net cash provided by financing activities	255,087	445,908	275,103
Net increase (decrease) in cash and cash equivalents	43,207	78,440	(32,508)
Cash and cash equivalents, beginning of year	156,857	78,417	110,925
Cash and cash equivalents, end of year	200,064	156,857	78,417
Supplemental cash flow disclosures:
Interest paid	21,777	13,564	12,081
Income taxes paid	18,846	13,139	12,127
NONCASH INVESTING ACTIVITIES DURING THE PERIOD
Transfers from loans to other real estate owned	121	197	450
Assets acquired (liabilities assumed) in acquisitions (See Note 25):
Interest-bearing deposits with financial institutions	0	1,972	0
Investment securities	442,923	190,254	56,121
Loans	2,427,589	456,158	332,893
Core deposit intangible	39,703	4,319	2,903
Deferred income tax	14,959	6,748	4,794
Bank owned life insurance	0	0	11,276
Goodwill	391,070	51,658	27,882
Fixed assets	42,097	4,190	2,134
Other assets	74,379	9,362	2,402
Deposits	(2,752,501)	(636,591)	(336,018)
Other borrowings	(180,186)	0	(33,300)
Other liabilities	(16,395)	(8,843)	(1,796)
Common Stock and additional paid-in capital	$ (716,421)	$ (120,174)	$ (79,777)

Description of Business and Sum

Description of Business and Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Description of Business and Summary of Significant Accounting Policies	Description of Business and Summary of Significant Accounting Policies Description of Business —The Corporation, a Delaware corporation organized in 1997, is a California-based bank holding company that owns 100% of the capital stock of the Bank, the Corporation’s principal operating subsidiary. The Bank was incorporated and commenced operations in 1983. The principal business of the Company is attracting deposits from the general public and investing those deposits, together with funds generated from operations and borrowings, primarily in business loans and real estate property loans. At December 31, 2017 , the Company had 33 depository branches located in the counties of Orange, Los Angeles, Riverside, San Bernardino, San Diego, San Luis Obispo and Santa Barbara, California as well as Clark County, Nevada. The Company is subject to competition from other financial institutions. The Company is subject to the regulations of certain governmental agencies and undergoes periodic examinations by those regulatory authorities. Principles of Consolidation —The consolidated financial statements include the accounts of Pacific Premier Bancorp, Inc. (the ‘‘Corporation’’) and its wholly-owned subsidiary, Pacific Premier Bank (the ‘‘Bank’’) (collectively, the ‘‘Company’’). The Company accounts for its investments in its wholly-owned special purpose entities, PPBI Statutory Trust I, Heritage Oaks Capital Trust II, Mission Community Capital Trust I and Santa Lucia Bancorp (CA) Capital Trust, under the equity method whereby the subsidiary’s net earnings are recognized in the Company’s Statement of Income and the investment in these entities is included in Other Assets on the Company’s Consolidated Statements of Financial Condition. The Company is organized and operates as a single reporting segment, principally engaged in the commercial banking business. All significant intercompany accounts and transactions have been eliminated in consolidation. Basis of Financial Statement Presentation —The accompanying consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States ("U.S. GAAP"). Certain amounts in the financial statements and related footnote disclosures for the prior years have been reclassified to conform to the current presentation with no impact to previously reported net income or stockholders' equity. Use of Estimates —The preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements, as well as the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Estimates may change as new information is obtained. The following discussion provides a summary of the Company's significant accounting policies: Cash and Cash Equivalents —Cash and cash equivalents include cash on hand, cash balances due from banks and federal funds sold. Interest bearing deposits with financial institutions represent primarily cash held at the Federal Reserve Bank of San Francisco. At December 31, 2017 , there were no cash reserves required by the Board of Governors of the Federal Reserve System (“Federal Reserve”) for depository institutions based on the amount of deposits held. The Company maintains amounts due from banks that exceed federally insured limits. The Company has not experienced any losses in such accounts. Securities —The Company has established written guidelines and objectives for its investing activities. At the time of purchase, management designates the security as either held to maturity, available-for-sale or held for trading based on the Company’s investment objectives, operational needs and intent. The investments are monitored to ensure that those activities are consistent with the established guidelines and objectives. Securities Held-to-Maturity —Investments in debt securities that management has the positive intent and ability to hold to maturity are reported at cost and adjusted for periodic principal payments and the amortization of premiums and accretion of discounts, which are recognized in interest income using the interest method over the period of time to investment's maturity. Securities Available-for-Sale —Investments in debt securities that management has no immediate plan to sell, but which may be sold in the future, are carried at fair value. Premiums and discounts are amortized using the interest method over the remaining period to the call date for premiums or contractual maturity for discounts and, in the case of mortgage-backed securities the estimated average life, which can fluctuate based on the anticipated prepayments on the underlying collateral of the securities. Unrealized holding gains and losses, net of tax, are recorded in a separate component of stockholders’ equity as accumulated other comprehensive income. Realized gains and losses on the sales of securities are determined on the specific identification method, recorded on a trade date basis based on the amortized cost basis of the specific security and are included in noninterest income as net gain (loss) on investment securities. Impairment of Investments —Quarterly, the Company evaluates investment securities in an unrealized loss position for OTTI. In determining whether a security's decline in fair value is other-than-temporary, the Company considers a number of factors including: (i) the length of time and the extent to which the fair value of the investment has been less than its amortized cost; (ii) the financial condition and near-term prospects of the issuer; (iii) the intent and ability of the Company to hold the investment for a period of time sufficient to allow for an anticipated recovery in fair value; (iv) downgrades in credit ratings; and (v) general market conditions which reflect prospects for the economy as a whole, including interest rates and sector credit spreads. If it is determined that an OTTI exists, and either the Company intends to sell the investment or it is likely the Company will be required to sell the investment before its anticipated recovery, the total amount of the OTTI, which is measured as the amount by which the investment's amortized cost exceeds its fair value, is recognized in current period earnings. If the Company has the intent and ability to hold the investment and it is more likely than not it will be required to sell the investment prior to an anticipated recovery of its amortized cost basis, the Company records in current period earnings the portion of OTTI deemed to be credit related, while the remaining portion of OTTI deemed to be non-credit related is recorded in accumulated other comprehensive income. Credit related losses are determined through a discounted cash flow analysis, which incorporates assumptions concerning the estimated timing and amounts of expected cash flows. Non-credit related OTTI losses result from other factors such as change in interest rates and general market conditions. The presentation of OTTI in the consolidated financial statements is on a gross basis with a reduction in the gross amount for the portion of the loss deemed non-credit related and is recorded in accumulated other comprehensive income. Federal Home Loan Bank Stock —The Bank is a member of the FHLB system. Members are required to own a certain amount of stock based on the level of borrowings and other factors, and may invest in additional amounts. FHLB stock is carried at cost and periodically evaluated for impairment based on ultimate recovery of par value. Both cash and stock dividends are recorded as a component of interest income. Federal Reserve Bank Stock —The Bank is a member of the Federal Reserve Bank of San Francisco. FRB stock is carried at cost, classified as a restricted security, and periodically evaluated for impairment based on ultimate recovery of par value. Both cash and stock dividends are recorded as a component of interest income. Loans Held for Sale —Loans that the Company has the intent to sell prior to maturity have been designated as held for sale at origination and are recorded at lower of cost or fair value. Gains or losses are recognized upon the sale of the loans on a specific identification basis. Loan Servicing Assets —Servicing assets are related to SBA loans sold and are recognized at the time of sale when servicing is retained with the income statement effect recorded in gains on sales of SBA loans. Servicing assets are initially recorded at fair value based on the present value of the contractually specified servicing fee, net of estimated servicing costs, over the estimated life of the loan, using a discount rate. The Company’s servicing costs approximates the industry average servicing costs of approximately 40 basis points. The servicing assets are subsequently amortized into noninterest income in proportion to, and over the period of, the estimated future net servicing income of the underlying loans. The Company periodically evaluates servicing assets for impairment based upon the fair value of the assets as compared to their carrying amount. The Company typically sells the guaranteed portion of SBA loans and retains the unguaranteed portion (“retained interest”). A portion of the premium on sale of SBA loans is recognized as gain on sale of loans at the time of the sale by allocating the carrying amount between the asset sold and the retained interest, based on their relative fair values. The remaining portion of the premium is recorded as a discount on the retained interest and is amortized over the remaining life of the loan as an adjustment to yield. The retained interest, net of any discount, are included in loans held for investment—net of allowance for loan losses in the accompanying consolidated statements of financial condition. Loans Held for Investment —Loans held for investment are loans the Company has the ability and intent to hold until their maturity. The loans are carried at amortized cost, net of discounts and premiums on purchased loans, deferred loan origination fees and costs and ALLL. Net deferred loan origination fees and costs on loans are amortized or accreted using the interest method over the expected life of the loans. Amortization of deferred loan fees and costs are discontinued for loans placed on nonaccrual. Any remaining deferred fees or costs and prepayment fees associated with loans that payoff prior to contractual maturity are included in loan interest income in the period of payoff. Loan commitment fees received to originate or purchase a loan are deferred and, if the commitment is exercised, recognized over the life of the loan using the interest method as an adjustment of yield or, if the commitment expires unexercised, recognized as income upon expiration of the commitment. Interest on loans is recognized using the interest method and is only accrued if deemed collectible. Loans for which the accrual of interest has been discontinued are designated as nonaccrual loans. The accrual of interest on loans is discontinued when principal or interest is past due 90 days based on contractual terms of the loan or when, in the opinion of management, there is reasonable doubt as to collection of principal and or interest. When loans are placed on nonaccrual status, all interest previously accrued but not collected is reversed against current period interest income. Interest income generally is not recognized on nonaccrual loans unless the likelihood of further loss is remote. Interest payments received on nonaccrual loans are applied as a reduction to the loan principal balance. Interest accruals are resumed on such loans only when they are brought current with respect to interest and principal and when, in the judgment of management, the loans are estimated to be fully collectible as to all principal and interest. A loan is considered to be impaired when it is probable that the Company will be unable to collect all amounts due (principal and interest) according to the contractual terms of the loan agreement. The Company reviews loans for impairment when the loan is classified as substandard or worse, delinquent 90 days, determined by management to be collateral dependent, or when the borrower files bankruptcy or is granted concession which qualifies as a troubled debt restructuring. Measurement of impairment is based on the loan’s expected future cash flows discounted at the loan’s effective interest rate, measured by reference to an observable market value, if one exists, or the fair value of the collateral if the loan is deemed collateral dependent. The Company selects the measurement method on a loan-by-loan basis except those loans deemed collateral dependent. Loans for which impairment has been determined are generally charged-off at such time the loan is classified as a loss. Allowance for Loan Losses— The Company maintains an ALLL at a level deemed appropriate by management to provide for known or probable incurred losses in the portfolio as of the date of the consolidated statements of financial condition. The Company has an internal asset review system and loss allowance methodology designed to provide for the detection of problem assets and an appropriate level of allowance to cover loan losses. Management’s determination of the adequacy of the ALLL is based on an evaluation of the composition of the portfolio, actual loss experience, industry charge-off experience on income property loans, current economic conditions, and other relevant factors in the area in which the Company’s lending and real estate activities are based. These factors may affect the borrowers’ ability to pay as well as the value of the underlying collateral securing loans. The allowance is calculated by applying loss factors to loans held for investment according to loan type and loan credit classification. The loss factors are based primarily upon the Bank’s historical loss experience and industry charge-off experience and are evaluated on a quarterly basis. At December 31, 2017 , the following portfolio segments have been identified. Segments are groupings of similar loans at a level, which the Company has adopted systematic methods of documentation for determining its allowance for loan losses: • Commercial and industrial (including Franchise) - Commercial and industrial loans are secured by business assets including inventory, receivables and machinery and equipment to businesses located generally in our primary market area. Loan types includes revolving lines or credit, term loans, seasonal loans and loans secured by liquid collateral such as cash deposits or marketable securities. HOA credit facilities are included in C&I loans. We also issue letters of credit on behalf of our customers. Risk arises primarily due to the difference between expected and actual cash flows of the borrowers. In addition, the recoverability of the Company's investment in these loans is also dependent on other factors primarily dictated by the type of collateral securing these loans. The fair value of the collateral securing these loans may fluctuate as market conditions change. In the case of loans secured by accounts receivable, the recovery of the Company's investment is dependent upon the borrower's ability to collect amounts due from its customers. • Commercial real estate (including owner-occupied and nonowner occupied) - Commercial real estate includes various type of loans which the Company holds real property as collateral. Commercial real estate lending activity is typically restricted to owner-occupied or nonowner-occupied. The primary risks of real estate loans include the borrower's inability to pay, material decreases in the value of the real estate that is being held as collateral and significant increases in interest rates, which may make the real estate loan unprofitable. Real estate loans may be more adversely affected by conditions in the real estate markets or in the general economy. • SBA - We are approved to originate loans under the SBA's Preferred Lenders Program ("PLP"). The PLP lending status affords us a higher level of delegated credit autonomy, translating to a significantly shorter turnaround time from application to funding, which is critical to our marketing efforts. We originate loans nationwide under the SBA's 7(a), SBA Express, International Trade and 504(a) loan programs, in conformity with SBA underwriting and documentation standards. SBA loans are similar to commercial business loans, but have additional credit enhancement provided by the U.S. Small Business Administration, for up to 85 percent of the loan amount for loans up to $150,000 and 75 percent of the loan amount for loans of more than $150,000. The Company originates SBA loans with the intent to sell the guaranteed portion into the secondary market on a quarterly basis. • Agribusiness and farmland - We originate loans to the agricultural community to fund seasonal production and longer term investments in land, buildings, equipment, crops and livestock. Agribusiness loans are for the purpose of financing agricultural production to finance crops and livestock. Farmland loans include all land know to be used or usable for agricultural purposes, such as crop and livestock production and is secured by the land and improvements thereon. • Multi-family - Loans secured by multi-family and commercial real estate properties generally involve a greater degree of credit risk than one-to-four family loans. Because payments on loans secured by multi-family and commercial real estate properties are often dependent on the successful operation or management of the properties, repayment of these loans may be subject to adverse conditions in the real estate market or the economy. • One-to-four family - Although we do not originate, through our bank acquisitions, we have acquired first lien single family loans, we occasionally purchase such loans to diversify our portfolio. The primary risks of one-to-four family loans include the borrower's inability to pay, material decreases in the value of the real estate that is being held as collateral and significant increases in interest rates, which may make loan unprofitable. • Construction and land - We originate loans for the construction of 1-4 family and multi-family residences and CRE properties in our market area. We concentrate our efforts on single homes and small infill projects in established neighborhoods where there is not abundant land available for development. Construction loans are considered to have higher risks due to construction completion and timing risk, and the ultimate repayment being sensitive to interest rate changes, government regulation of real property and the availability of long-term financing. Additionally, economic conditions may impact the Company's ability to recover its investment in construction loans, as adverse economic conditions may negatively impact the real estate market, which could affect the borrower's ability to complete and sell the project. Additionally, the fair value of the underlying collateral may fluctuate as market conditions change. We occasionally originate land loans located predominantly in California for the purpose of facilitating the ultimate construction of a home or commercial building. The primary risks include the borrower's inability to pay and the inability of the Company to recover its investment due to a decline in the fair value of the underlying collateral. • Consumer loans - We originate a limited number of consumer loans, generally for banking customers only, which consist primarily of home equity lines of credit, savings account secured loans and auto loans. Repayment of these loans is dependent on the borrower's ability to pay and the fair value of the underlying collateral. Various regulatory agencies, as an integral part of their examination process, periodically review the Company’s ALLL. Such agencies may require the Company to recognize additions to the allowance based on judgments different from those of management. In the opinion of management, and in accordance with the credit loss allowance methodology, the present allowance is considered adequate to absorb probable incurred credit losses. Additions and reductions to the allowance are reflected in current operations. Charge-offs to the allowance, for all loan segments, are made when specific assets are considered uncollectible or are transferred to other real estate owned and the fair value of the property is less than the loan’s recorded investment. Recoveries are credited to the allowance. Although management uses the best information available to make these estimates, future adjustments to the allowance may be necessary due to economic, operating, regulatory and other conditions that may extend beyond the Company’s control. Purchased Credit Impaired Loans —As part of business acquisitions, the Bank acquires certain loans that have shown evidence of credit deterioration since origination, referred to as purchased credit impaired loans. These loans are recorded at the fair value, such that no ALLL for PCI is established upon their acquisition. The Company has elected to account for such loans individually. The Company estimates the amount and timing of expected cash flows for each purchased loan, and the expected cash flows in excess of the fair value is recorded as interest income over the remaining life of the loan and is referred to as the accretable yield. The excess of the loan’s contractual principal and interest over expected cash flows is not recorded and is referred to as the non-accretable difference. Over the life of the loan, expected cash flows continue to be estimated. Subsequent decreases in expected future cash flows beyond the expected cash flows as of the acquisition date are accounted for through a charge to the provision for loan losses. If subsequent reforecasts indicate there has been a probable and significant increase in the level of expected future cash flows, the Company first reduces any previously established ALLL for PCI loans and then accounts for the remainder of the increase through interest income as a yield adjustment. Other Real Estate Owned— Real estate properties acquired through, or in lieu of, loan foreclosure are recorded at fair value, less cost to sell, with any excess loan balance over the fair value of the property charged against the ALLL. The Company obtains an appraisal and/or market valuation on all other real estate owned at the time of possession. After foreclosure, valuations are periodically performed by management. Any subsequent fair value losses are recorded as a charge to current period earnings with a corresponding write-down to the asset. All legal fees and direct costs, including foreclosure and other related costs are expensed as incurred. Premises and Equipment— Premises and equipment are carried at cost less accumulated depreciation and amortization. Depreciation and amortization are computed using the straight-line method over the estimated useful lives of the assets, which range from forty years for buildings, seven years for furniture, fixtures and equipment, and three years for computer and telecommunication equipment. The cost of leasehold improvements is amortized using the straight-line method over the shorter of the estimated useful life of the asset or the term of the related leases. The Company periodically evaluates the recoverability of long-lived assets, such as premises and equipment, to ensure the carrying value has not been impaired. Assets to be disposed of are reported at the lower of the carrying amount or fair value less costs to sell. Securities Sold Under Agreements to Repurchase— The Company enters into sales of securities under agreement to repurchase. These agreements are treated as financing arrangements and, accordingly, the obligations to repurchase the securities sold are reflected as liabilities in the Company’s consolidated financial statements. The securities collateralizing these agreements are delivered to several major national brokerage firms who arranged the transactions. The securities are reflected as assets in the Company’s consolidated financial statements. The brokerage firms may loan such securities to other parties in the normal course of their operations and agree to return the identical security to the Company at the maturity of the agreements. Bank Owned Life Insurance— Bank owned life insurance is accounted for using the cash surrender value method and is recorded at its realizable value. The change in the net asset value is included in other assets and other noninterest income. Goodwill and Core Deposit Intangible— Goodwill is generally determined as the excess of the fair value of the consideration transferred, plus the fair value of any noncontrolling interests in the acquiree, over the fair value of the net assets acquired and liabilities assumed as of the acquisition date. Goodwill and intangible assets acquired in a purchase business combination and determined to have indefinite useful lives are not amortized, but tested for impairment at least annually or more frequently if events and circumstances exist that indicate the necessity for such impairment tests to be performed. The Company typically performs its annual impairment testing in the fourth quarter. Intangible assets with definite useful lives are amortized over their estimated useful lives to their estimated residual values. Goodwill is the only intangible asset with an indefinite life on our balance sheet. Core deposit intangible assets arising from whole bank acquisitions are amortized on either an accelerated basis, reflecting the pattern in which the economic benefits of the intangible asset is consumed or otherwise used up, or on a straight-line amortization method over their estimated useful lives, which ranges from 6 to 10 years. Loan Commitments and Related Financial Instruments— Financial instruments include off-balance sheet credit instruments, such as commitments to make loans and commercial letters of credit, issued to meet customer financing needs. The face amount for these items represents the exposure to loss, before considering customer collateral or ability to repay. Such financial instruments are recorded when they are funded. Subordinated Debentures— Long-term borrowings are carried at cost, adjusted for amortization of premiums and accretion of discounts, which are recognized in interest expense using the interest method. Debt issuance costs are recognized in interest expense using the interest method over the life of the instrument. Stock-Based Compensation —The Company issues stock-based awards to certain officers and directors of the Company. The related compensation costs are recognized in the income statement based on the grant-date fair value over the grantee's requisite service period (generally the vesting period). A Black-Scholes model is utilized to estimate the fair value of stock options and the market price of the Company's common stock at the date of the grant is used for restricted stock awards. Income Taxes— Deferred tax assets and liabilities are recorded for the expected future tax consequences of events that have been recognized in the Company’s financial statements or tax returns using the asset liability method. In estimating future tax consequences, all expected future events other than enactments of changes in the tax law or rates are considered. The effect on deferred taxes of a change in tax rates is recognized in income in the period that includes the enactment date. Deferred tax assets are to be recognized for temporary differences that will result in deductible amounts in future years and for tax carryforwards if, in the opinion of management, it is more likely than not that the deferred tax assets will be realized. At December 31, 2016, there was no valuation allowance deemed necessary against the Company’s deferred tax asset. At December 31, 2017, a valuation allowance of $380,000 was recorded against the capital loss carryover deferred tax asset, as the Company does not believe it will generate sufficient capital gain before the capital loss carryover expires. A tax position is recognized as a benefit only if it is “more likely than not” that the tax position would be sustained in a tax examination, with a tax examination being presumed to occur. The amount recognized is the largest amount of tax benefit that is greater than 50% likely of being realized on examination. For tax positions not meeting the “more likely than not” test, no tax benefit is recorded. The Company recognizes interest and / or penalties related to income tax matters in income tax expense. Earnings per Share— Earnings per share of common stock is calculated on both a basic and diluted basis based on the weighted average number of common and common equivalent shares outstanding, excluding common shares in treasury. Basic earnings per share excludes dilution and is computed by dividing income available to stockholders by the weighted average number of common shares outstanding for the period. The Company has no outstanding unvested share-based payment awards that contain rights to nonforfeitable dividends that would be considered participating securities for the basic calculation. Diluted earnings per share reflects the potential dilution that could occur if securities or other contracts to issue common stock were exercised or converted into common stock or resulted from the issuance of common stock that then would share in earnings. Comprehensive Income— Comprehensive income is reported in addition to net income for all periods presented. Comprehensive income is a more inclusive financial reporting methodology that includes disclosure of other comprehensive income (loss) that historically has not been recognized in the calculation of net income. Unrealized gains and losses on the Company's available-for-sale investment securities are required to be included in other comprehensive income or loss. Total comprehensive income (loss) and the components of accumulated other comprehensive income or loss are presented in the Consolidated Statement of Stockholders’ Equity and Consolidated Statements of Comprehensive Income. Loss Contingencies— Loss contingencies, including claims and legal action arising in the ordinary course of business, are recorded as liabilities when the likelihood of loss is probable and an amount or range of loss can be reasonably estimated. Management does not believe there now are such matters that will have a material effect on the financial statements. Fair Value of Financial Instruments— Fair values of financial instruments are estimated using relevant market information and other assumptions, as more fully disclosed in a separate note. Fair value estimates involve uncertainties and matters of significant judgment regarding interest rates, credit risk, prepayments, and other factors, especially in the absence of broad markets for particular items. Changes in assumptions or in market conditions could significantly affect these estimates. Accounting Standards Adopted in 2017 In March 2016, the FASB issued Accounting Standards Update ("ASU") 2016-09 , Compensation-Stock Compensation (Topic 718): Improvements to Employee Share-Based Accounting . The amendments simplify several aspects of the accounting for share-based payment award transactions, including accounting for excess tax benefits and tax deficiencies, classifying excess tax benefits on the statement of cash flows, accounting for forfeitures, classifying awards that permit share repurchases to satisfy statutory tax-withholding requirements and classifying tax payments on behalf of employees on the statement of cash flows. For public business entities, the amendment is effective for annual periods beginning after December 15, 2016 and interim periods within those annual periods. Early adoption is permitted for any organization in any interim or annual period. As a result of the adoption of ASU 2016-09, the Company began recognizing the tax effects of exercised or vested awards as discrete items in the reporting period in which they occur, resulting in a $2.0 million tax benefit to the Company for the year ended December 31, 2017. In March 2016, the FASB issued ASU 2016-07, Investments-Equity Method and Joint Ventures (Topic 323): Simplifying the Transition to the Equity Method of Accounting . The amendments elimina

Regulatory Capital Requirements

Regulatory Capital Requirements and Other Regulatory Matters	12 Months Ended
	Dec. 31, 2017
Banking and Thrift [Abstract]
Regulatory Capital Requirements and Other Regulatory Matters	Regulatory Capital Requirements and Other Regulatory Matters The Company and the Bank are subject to various regulatory capital requirements administered by federal banking agencies. Failure to meet minimum capital requirements can initiate certain mandatory, and possibly additional discretionary, actions by regulators that, if undertaken, could have a direct material effect on the Company’s and the Bank’s financial statements. Under capital adequacy guidelines and the regulatory framework for prompt corrective action, the Company and the Bank must meet specific capital guidelines that involve quantitative measures of the Company’s and the Bank’s assets, liabilities and certain off-balance sheet items as calculated under regulatory accounting practices. The Company’s and the Bank’s capital amounts and classification are also subject to qualitative judgments by the regulators about components, risk weightings and other factors. Quantitative measures established by regulation to ensure capital adequacy require the Bank to maintain capital in order to meet certain capital ratios to be considered adequately capitalized or well capitalized under the regulatory framework for prompt corrective action. As of the most recent formal notification from the Federal Reserve, the Bank was categorized as “well capitalized.” There are no conditions or events since that notification that management believes have changed the Bank’s categorization. Final comprehensive regulatory capital rules for U.S. banking organizations pursuant to the capital framework of the Basel Committee on Banking Supervision, generally referred to as “Basel III”, became effective for the Company and the Bank on January 1, 2015, subject to phase-in periods for certain of their components and other provisions, and fully phased in by January 1, 2019. The most significant of the provisions of the Final Capital Rules, which applied to the Company and the Bank were as follows: the phase-out of trust preferred securities from Tier 1 capital, the higher risk-weighting of high volatility and past due real estate loans and the capital treatment of deferred tax assets and liabilities above certain thresholds. Under the Basel III rules, the Company must hold a capital conservation buffer above the adequately capitalized risk-based capital ratios. The capital conservation buffer is being phased in from 0.00% for 2015 to 2.50% by 2019. The capital conservation buffer for 2017 is 1.25% and for 2016 is 0.625%. The net unrealized gain or loss on available-for-sale securities is not included in computing regulatory capital. As defined in applicable regulations and set forth in the table below, which excludes the capital conservation buffer, at December 31, 2017 and 2016 , the Company and the Bank continue to exceed the “well capitalized” standards: Actual Minimum Required for Capital Adequacy Purposes Required to be Well Capitalized Under Prompt Corrective Action Regulations Amount Ratio Amount Ratio Amount Ratio (dollars in thousands) At December 31, 2017 Pacific Premier Bancorp, Inc. Consolidated Tier 1 Leverage Ratio $ 744,233 10.70 % $ 278,183 4.00 % N/A N/A Common Equity Tier 1 to Risk-Weighted Assets 724,205 10.59 % 307,778 4.50 % N/A N/A Tier 1 Capital to Risk-Weighted Assets 744,233 10.88 % 410,371 6.00 % N/A N/A Total Capital to Risk-Weighted Assets 859,442 12.57 % 547,161 8.00 % N/A N/A Pacific Premier Bank Tier 1 Leverage Ratio $ 812,170 11.68 % $ 278,152 4.00 % $ 347,690 5.00 % Common Equity Tier 1 to Risk-Weighted Assets 812,170 11.88 % 307,702 4.50 % 444,458 6.50 % Tier 1 Capital to Risk-Weighted Assets 812,170 11.88 % 410,269 6.00 % 547,025 8.00 % Total Capital to Risk-Weighted Assets 843,005 12.33 % 547,025 8.00 % 683,781 10.00 % At December 31, 2016 Pacific Premier Bancorp, Inc. Consolidated Tier 1 Leverage Ratio $ 366,658 9.78 % $ 150,027 4.00 % N/A N/A Common Equity Tier 1 to Risk-Weighted Assets 356,658 10.12 % 158,574 4.50 % N/A N/A Tier 1 Capital to Risk-Weighted Assets 366,658 10.41 % 211,432 6.00 % N/A N/A Total Capital to Risk-Weighted Assets 448,150 12.72 % 281,909 8.00 % N/A N/A Pacific Premier Bank Tier 1 Leverage Ratio $ 410,524 10.94 % $ 150,107 4.00 % $ 187,634 5.00 % Common Equity Tier 1 to Risk-Weighted Assets 410,524 11.65 % 158,536 4.50 % 228,997 6.50 % Tier 1 Capital to Risk-Weighted Assets 410,524 11.65 % 211,382 6.00 % 281,842 8.00 % Total Capital to Risk-Weighted Assets 432,943 12.29 % 281,842 8.00 % 352,303 10.00 %

Investment Securities

Investment Securities	12 Months Ended
	Dec. 31, 2017
Investments, Debt and Equity Securities [Abstract]
Investment Securities	Investment Securities The amortized cost and estimated fair value of securities were as follows: December 31, 2017 Amortized Cost Unrealized Gain Unrealized Loss Estimated Fair Value (dollars in thousands) Investment securities available-for-sale Agency $ 47,051 $ 236 $ (78 ) $ 47,209 Corporate 78,155 1,585 (194 ) 79,546 Municipal bonds 228,929 3,942 (743 ) 232,128 Collateralized mortgage obligation: residential 33,984 132 (335 ) 33,781 Mortgage-backed securities: residential 398,664 266 (4,165 ) 394,765 Total investment securities available-for-sale 786,783 6,161 (5,515 ) 787,429 Investment securities held-to-maturity Mortgage-backed securities: residential 17,153 — (209 ) 16,944 Other 1,138 — — 1,138 Total investment securities held-to-maturity 18,291 — (209 ) 18,082 Total investment securities $ 805,074 $ 6,161 $ (5,724 ) $ 805,511 December 31, 2016 Amortized Unrealized Unrealized Estimated Cost Gain Loss Fair Value (dollars in thousands) Investment securities available-for-sale Corporate $ 37,475 $ 372 $ (205 ) $ 37,642 Municipal bonds 120,155 338 (1,690 ) 118,803 Collateralized mortgage obligation: residential 31,536 25 (173 ) 31,388 Mortgage-backed securities: residential 196,496 69 (3,435 ) 193,130 Total investment securities available-for-sale 385,662 804 (5,503 ) 380,963 Investment securities held-to-maturity Mortgage-backed securities: residential 7,375 — (104 ) 7,271 Other 1,190 — — 1,190 Total investment securities held-to-maturity 8,565 — (104 ) 8,461 Total investment securities $ 394,227 $ 804 $ (5,607 ) $ 389,424 Unrealized gains and losses on investment securities available-for-sale are recognized in stockholders’ equity as accumulated other comprehensive income or loss. At December 31, 2017 , the Company had accumulated other comprehensive income of $646,000 , or $415,000 net of tax, compared to accumulated other comprehensive loss of $4.7 million or $2.7 million net of tax, at December 31, 2016 . At December 31, 2017 , mortgage-backed securities with an estimated par value of $55.6 million and a fair value of $57.0 million were pledged as collateral for the Bank’s three inverse putable reverse repurchase agreements which totaled $28.5 million and HOA reverse repurchase agreements which totaled $ 17.6 million . At December 31, 2017 and 2016, there were not holdings of securities of any one issuer, other than the U.S. Government and its agencies, in an amount greater than 10% of shareholders' equity. The Company reviews individual securities classified as available-for-sale to determine whether a decline in fair value below the amortized cost basis is temporary (i) those declines were due to interest rate changes and not to a deterioration in the creditworthiness of the issuers of those investment securities, and (ii) we have the ability to hold those securities until there is a recovery in their values or until their maturity. If it is probable that the Company will be unable to collect all amounts due according to contractual terms of the debt security not impaired at acquisition, an other-than-temporary impairment shall be considered to have occurred. If an OTTI occurs, the cost basis of the security will be written down to its fair value as the new cost basis and the write down accounted for as a realized loss. The Company realized OTTI recovery of $2,000 as of December 31, 2017 , which relates to investment income from previously charged-off investments. As of December 31, 2016 , the Company realized OTTI losses net of recoveries of $205,000 . A $207,000 OTTI was taken in the first quarter of 2016, related to a CRA investment purchased in June of 2014 with a par value of $50 , and a book value of $500,000 . In March of 2016, the shareholders of the investment voted to approve a sale of the institution at a per share acquisition price less than the Bank's book value, and the sale closed in July 2016. The Company is currently waiting to receive the proceeds for its outstanding shares. As a result, the Bank's current holdings were written down and the loss recognized. The Company did not realize any OTTI losses in 2015. The table below shows the number, fair value and gross unrealized holding losses of the Company’s investment securities by investment category and length of time that the securities have been in a continuous loss position. December 31, 2017 Less than 12 months 12 months or Longer Total Number Fair Value Gross Unrealized Holding Losses Number Fair Value Gross Unrealized Holding Losses Number Fair Value Gross Unrealized Holding Losses (dollars in thousands) Investment securities available-for-sale Agency 6 $ 13,754 $ (78 ) — $ — $ — 6 $ 13,754 $ (78 ) Corporate 4 10,079 (64 ) 2 6,076 (130 ) 6 16,155 (194 ) Municipal bonds 103 61,313 (268 ) 30 15,658 (475 ) 133 76,971 (743 ) Collateralized mortgage obligation: residential 5 13,971 (149 ) 3 8,943 (186 ) 8 22,914 (335 ) Mortgage-backed securities: residential 66 220,951 (1,600 ) 41 110,062 (2,565 ) 107 331,013 (4,165 ) Total investment securities available-for-sale 184 320,068 (2,159 ) 76 140,739 (3,356 ) 260 460,807 (5,515 ) Investment securities held-to-maturity Mortgage-backed securities: residential 2 10,745 (133 ) 1 6,198 (76 ) 3 16,943 (209 ) Total investment securities held-to-maturity 2 10,745 (133 ) 1 6,198 (76 ) 3 16,943 (209 ) Total investment securities 186 $ 330,813 $ (2,292 ) 77 $ 146,937 $ (3,432 ) 263 $ 477,750 $ (5,724 ) December 31, 2016 Less than 12 months 12 months or Longer Total Number Fair Gross Number Fair Gross Number Fair Gross (dollars in thousands) Investment securities available-for-sale Corporate 3 $ 7,609 $ (205 ) — $ — $ — 3 $ 7,609 $ (205 ) Municipal bonds 152 85,750 (1,690 ) — — — 152 85,750 (1,690 ) Collateralized mortgage obligation: residential 5 19,092 (173 ) — — — 5 19,092 (173 ) Mortgage-backed securities: residential 55 149,740 (2,916 ) 4 16,039 (519 ) 59 165,779 (3,435 ) Total available-for-sale 215 262,191 (4,984 ) 4 16,039 (519 ) 219 278,230 (5,503 ) Investment securities held-to-maturity Mortgage-backed securities: residential 1 7,271 (104 ) — — — 1 7,271 (104 ) Total held-to-maturity 1 7,271 (104 ) — — — 1 7,271 (104 ) Total securities 216 $ 269,462 $ (5,088 ) 4 $ 16,039 $ (519 ) 220 $ 285,501 $ (5,607 ) The amortized cost and estimated fair value of investment securities available for sale at December 31, 2017 , by contractual maturity are shown in the table below. One Year or Less More than One Year to Five Years More than Five Years to Ten Years More than Ten Years Total Amortized Cost Fair Value Amortized Cost Fair Value Amortized Cost Fair Value Amortized Cost Fair Value Amortized Cost Fair Value (dollars in thousands) Investment securities available-for-sale Agency $ — $ — $ — $ — $ 15,156 $ 15,164 $ 31,895 $ 32,045 $ 47,051 $ 47,209 Corporate — — — — 78,155 79,546 — — 78,155 79,546 Municipal bonds 4,124 4,121 32,390 32,424 72,845 73,312 119,570 122,271 228,929 232,128 Collateralized mortgage obligation: residential — — — — 1,069 1,071 32,915 32,710 33,984 33,781 Mortgage-backed securities: residential 2,591 2,583 2,647 2,611 65,541 65,014 327,885 324,557 398,664 394,765 Total investment securities available-for-sale 6,715 6,704 35,037 35,035 232,766 234,107 512,265 511,583 786,783 787,429 Investment securities held-to-maturity Mortgage-backed securities: residential — — — — — — 17,153 16,944 17,153 16,944 Other — — — — — — 1,138 1,138 1,138 1,138 Total investment securities held-to-maturity — — — — — — 18,291 18,082 18,291 18,082 Total investment securities $ 6,715 $ 6,704 $ 35,037 $ 35,035 $ 232,766 $ 234,107 $ 530,556 $ 529,665 $ 805,074 $ 805,511 During the years ended December 31, 2017 , 2016 and 2015 , the Company recognized gross gains on sales of available-for-sale securities in the amount of $3.1 million , $1.8 million and $317,000 , respectively. During the years ended December 31, 2017 , 2016 and 2015 , the Company recognized gross losses on sales of available-for-sale securities in the amount of $386,000 , $9,000 and $27,000 , respectively. The Company had net proceeds from the sale or maturity/call of available-for-sale securities of $269 million , $231 million and $28 million during the years ended December 31, 2017 , 2016 and 2015 , respectively. FHLB, FRB and other stock At December 31, 2017 , the Company had $17.3 million in FHLB stock, $ 25.3 million in FRB stock, and $ 23.3 million in other stock, all carried at cost. During the years ended December 31, 2017 and 2015 , FHLB had repurchased $10.3 million and $16.4 million , respectively, of the Company’s excess FHLB stock through their stock repurchase program. During the year ended December 31, 2016 , FHLB did not repurchase any of the Company’s excess FHLB stock through their stock repurchase program. The Company evaluates its investments in FHLB and other stock for impairment periodically, including their capital adequacy and overall financial condition. No impairment losses have been recorded through December 31, 2017.

Loans

Loans	12 Months Ended
	Dec. 31, 2017
Receivables [Abstract]
Loans	Loans The following table presents the composition of the loan portfolio as of the dates indicated: For the Years Ended December 31, 2017 2016 (dollars in thousands) Business Loans Commercial and industrial $ 1,086,659 $ 563,169 Franchise 660,414 459,421 Commercial owner occupied 1,289,213 454,918 SBA 185,514 88,994 Agribusiness 116,066 — Total business loans 3,337,866 1,566,502 Real Estate Loans Commercial non-owner occupied 1,243,115 586,975 Multi-family 794,384 690,955 One-to-four family 270,894 100,451 Construction 282,811 269,159 Farmland 145,393 — Land 31,233 19,829 Total real estate loans 2,767,830 1,667,369 Consumer Loans Consumer loans 92,931 4,112 Gross loans held for investment 6,198,627 3,237,983 Plus: Deferred loan origination costs/(fees) and premiums/(discounts), net (2,159 ) 3,630 Loans held for investment 6,196,468 3,241,613 Allowance for loan losses (28,936 ) (21,296 ) Loans held for investment, net $ 6,167,532 $ 3,220,317 Loans held for sale, at lower of cost or fair value $ 23,426 $ 7,711 The Company originates SBA loans with the intent to sell the guaranteed portion of the loan prior to maturity and therefore designates them as held for sale. From time to time, the Company may purchase or sell other types of loans in order to manage concentrations, maximize interest income, change risk profiles, improve returns and generate liquidity. Concentration of Credit Risk The Company’s loan portfolio was collateralized by various forms of real estate and business assets located principally in California. The Company’s loan portfolio contains concentrations of credit in commercial non-owner occupied real estate, multi-family real estate and commercial owner occupied business loans. The Company maintains policies approved by the Board of Directors that address these concentrations and continues to diversify its loan portfolio through loan originations and purchases and sales of loans to meet approved concentration levels. While management believes that the collateral presently securing these loans is adequate, there can be no assurances that further significant deterioration in the California real estate market and economy would not expose the Company to significantly greater credit risk. Loans Serviced for Others The Company generally retains the servicing rights of the guaranteed portion of SBA loans sold, for which the Company records a servicing asset at fair value within other assets. At December 31, 2017 and 2016 , the servicing asset total $8.8 million and $5.3 million , respectively and was included in other assets. Servicing rights are evaluated for impairment based upon the fair value of the rights as compared to the carrying amount. Impairment is recognized through a valuation allowance, to the extent the fair value is less than the carrying amount. At December 31, 2017 , and 2016 , the Company determined that no valuation allowance was necessary. Loans serviced for others are not included in the accompanying consolidated statements of financial condition. The unpaid principal balance of loans and participations serviced for others were $635 million at December 31, 2017 and $303 million at December 31, 2016 . Purchased Credit Impaired Loans The Company has purchased loans, for which there was, at acquisition, evidence of deterioration of credit quality since origination and it was probable, at acquisition, that all contractually required payments would not be collected. The carrying amount of those loans at December 31, 2017 , and 2016 was as follows: For the Years Ended December 31, 2017 2016 (dollars in thousands) Business Loans Commercial and industrial $ 3,310 $ 2,586 Commercial owner occupied 1,262 491 SBA 1,802 — Total business loans 6,374 3,077 Real Estate Loans Commercial non-owner occupied 1,650 1,088 One-to-four family 255 1 Construction 517 — Land 83 — Total real estate loans 2,505 1,089 Consumer Loans Consumer loans 10 393 Total purchase credit impaired $ 8,889 $ 4,559 The following table summarizes the accretable yield on the purchased credit impaired for the years ended December 31, 2017 , 2016 and 2015 : For the Years Ended December 31, 2017 2016 2015 (dollars in thousands) Balance at the beginning of period $ 3,747 $ 2,726 $ 1,403 Additions 3,102 788 602 Accretion (2,037 ) (1,354 ) (385 ) Payoffs (2,125 ) 165 (249 ) Reclassification from nonaccretable difference 332 1,422 1,355 Balance at the end of period $ 3,019 $ 3,747 $ 2,726 Impaired Loans The following tables provide a summary of the Company’s investment in impaired loans as of and for the periods indicated: Impaired Loans Recorded Investment Unpaid Principal Balance With Specific Allowance Without Specific Allowance Specific Allowance for Impaired Loans Average Recorded Investment Interest Income Recognized (dollars in thousands) December 31, 2017 Business Loans Commercial and industrial $ 1,160 $ 1,585 $ — $ 1,160 $ — $ 441 $ — Commercial owner occupied 97 98 97 — 55 153 — SBA 1,201 4,329 — 1,201 — 434 — Real Estate Loans Commercial non-owner occupied — — — — — 86 — One-to-four family 817 849 — 817 — 166 — Construction — — — — — 1,017 — Land 9 35 — 9 — 12 — Totals $ 3,284 $ 6,896 $ 97 $ 3,187 $ 55 $ 2,309 $ — December 31, 2016 Business Loans Commercial and industrial $ 250 $ 1,990 $ 250 $ — $ 250 $ 864 $ 76 Franchise — — — — — 1,016 68 Commercial owner occupied 436 847 — 436 — 505 37 SBA 316 3,865 — 316 — 331 23 Real Estate Loans Commercial non-owner occupied — — — — — 1,072 93 One-to-four family 124 291 — 124 — 226 18 Land 15 36 — 15 — 18 2 Totals $ 1,141 $ 7,029 $ 250 $ 891 $ 250 $ 4,032 $ 317 December 31, 2015 Business Loans Commercial and industrial $ 313 $ 578 $ — $ 313 $ — $ 90 $ 29 Franchise 1,630 2,394 1,461 169 731 1,386 3 Commercial owner occupied 536 883 — 536 — 415 67 Real Estate Loans Commercial non-owner occupied 214 329 — 214 — 430 19 One-to-four family 70 98 — 70 — 204 5 Land 21 37 — 21 — 13 — Totals $ 2,784 $ 4,319 $ 1,461 $ 1,323 $ 731 $ 2,538 $ 123 The Company considers a loan to be impaired when, based on current information and events, it is probable the Company will be unable to collect all amounts due according to the contractual terms of the loan agreement or it is determined that the likelihood of the Company receiving all scheduled payments, including interest, when due is remote. The Company has no commitments to lend additional funds to debtors whose loans have been impaired. The Company reviews loans for impairment when the loan is classified as substandard or worse, delinquent 90 days, determined by management to be collateral dependent, or when the borrower files bankruptcy or is granted a troubled debt restructure. Measurement of impairment is based on the loan’s expected future cash flows discounted at the loan’s effective interest rate, measured by reference to an observable market value, if one exists, or the fair value of the collateral if the loan is deemed collateral dependent. Loans are generally charged-off at the time that the loan is classified as a loss. Valuation allowances are determined on a loan-by-loan basis or by aggregating loans with similar risk characteristics. We sometimes modify or restructure loans when the borrower is experiencing financial difficulties by making a concession to the borrower in the form of changes in the amortization terms, reductions in the interest rates, the acceptance of interest only payments and, in limited cases, concessions to the outstanding loan balances. These loans are classified as troubled debt restructurings (“TDRs”) and considered impaired loans. TDRs are loans modified for the purpose of alleviating temporary impairments to the borrower’s financial condition or cash flows. A workout plan between us and the borrower is designed to provide a bridge for borrower cash flow shortfalls in the near term. A TDR loan may be returned to accrual status when the loan is brought current, has performed in accordance with the contractual restructured terms for a time frame of at least six months and the ultimate collectability of the total contractual restructured principal and interest in no longer in doubt. At December 31, 2017 , the Company had a recorded investment in a TDR of $97,000 . The modification of the terms of this relationship included the restructuring of two loans related to one borrower into one loan and an extension of the maturity to three years. There were no TDRs at December 31, 2016 . When loans are placed on nonaccrual status, all accrued interest is reversed from current period earnings. Payments received on nonaccrual loans are generally applied as a reduction to the loan principal balance. If the likelihood of further loss is remote, the Company will recognize interest on a cash basis only. Loans may be returned to accruing status if the Company believes that all remaining principal and interest is fully collectible and there has been at least six months of sustained repayment performance since the loan was placed on nonaccrual. The Company does not accrue interest on loans 90 days or more past due or when, in the opinion of management, there is reasonable doubt as to the collection of interest. The Company had impaired loans on nonaccrual status of $3.3 million , $1.1 million and $4.0 million at December 31, 2017 , 2016 and 2015 , respectively. If such loans had been performing in accordance with their original terms, the Company would have recorded additional loan interest income of $155,000 in 2017 , $360,000 in 2016 , and $279,000 in 2015 . The Company did not record income from the receipt of cash payments related to nonaccruing loans during the years ended December 31, 2017 , 2016 and 2015 . The Company had $1.8 million loans 90 days or more past due and still accruing at December 31, 2017 , majority of which were PCI loans. Income recognition for PCI loans is accounted for in accordance with ASC Subtopic 310-30 Receivables -Loans and Debt Securities Acquired with Deteriorated Credit Quality. There were no loans 90 days or more past due and still accruing at December 31, 2016 . Credit Quality and Credit Risk The Company’s credit quality is maintained and credit risk managed in two distinct areas. The first is the loan origination process, wherein the Bank underwrites credit quality and chooses which risks it is willing to accept. The second is in the ongoing oversight of the loan portfolio, where existing credit risk is measured and monitored, and where performance issues are dealt with in a timely and comprehensive fashion. The Company maintains a comprehensive credit policy, which sets forth minimum and maximum tolerances for key elements of loan risk. The policy identifies and sets forth specific guidelines for analyzing each of the loan products the Company offers from both an individual and portfolio wide basis. The credit policy is reviewed annually by the Bank Board. The Bank's seasoned underwriters and portfolio managers ensure all key risk factors are analyzed with most loan underwriting including a comprehensive global cash flow analysis. Credit risk is managed within the loan portfolio by the Company’s portfolio managers based on a comprehensive credit and portfolio review policy. This policy requires a program of financial data collection and analysis, comprehensive loan reviews, property and/or business inspections and monitoring of portfolio concentrations and trends. The portfolio managers also monitor asset-based lines of credit, loan covenants and other conditions associated with the Company’s business loans as a means to help identify potential credit risk. Individual loans, excluding the homogeneous loan portfolio, are reviewed at least every two years and in most cases, more often, including the assignment of a risk grade. Risk grades are based on a six -grade Pass scale; along with Special Mention, Substandard, Doubtful and Loss classifications, as such classifications are defined by the federal banking regulatory agencies. The assignment of risk grades allows the Company to, among other things, identify the risk associated with each credit in the portfolio, and to provide a basis for estimating probable incurred losses inherent in the portfolio. Risk grades are reviewed regularly by the Company’s Credit and Portfolio Review committee, and are reviewed annually by an independent third-party, as well as by regulatory agencies during scheduled examinations. The following provides brief definitions for risk grades assigned to loans in the portfolio: • Pass classifications represent assets with a level of credit quality, which contain no well-defined deficiency or weakness. • Special Mention assets do not currently expose the Bank to a sufficient risk to warrant classification in one of the adverse categories, but possess correctable deficiencies or potential weaknesses deserving management’s close attention. • Substandard assets are inadequately protected by the current net worth and paying capacity of the obligor or of the collateral pledged, if any. These assets are characterized by the distinct possibility that the Bank will sustain some loss if the deficiencies are not corrected. OREO acquired from foreclosure are also classified as substandard. • Doubtful credits have all the weaknesses inherent in substandard credits, with the added characteristic that the weaknesses make collection or liquidation in full, on the basis of currently existing facts, conditions, and values, highly questionable and improbable. • Loss assets are those that are considered uncollectible and of such little value that their continuance as assets is not warranted. Amounts classified as loss are promptly charged off. The portfolio managers also manage loan performance risks, collections, workouts, bankruptcies and foreclosures. Loan performance risks are mitigated by our portfolio managers acting promptly and assertively to address problem credits when they are identified. Collection efforts are commenced immediately upon non-payment, and the portfolio managers seek to promptly determine the appropriate steps to minimize the Company’s risk of loss. When foreclosure will maximize the Company’s recovery for a non-performing loan, the portfolio managers will take appropriate action to initiate the foreclosure process. When a loan is graded as special mention or substandard or doubtful, the Company obtains an updated valuation of the underlying collateral. If the credit in question is also identified as impaired, a valuation allowance, if necessary, is established against such loan or a loss is recognized by a charge to the allowance for loan losses if management believes that the full amount of the Company’s recorded investment in the loan is no longer collectable. The Company typically continues to obtain or confirm updated valuations of underlying collateral for special mention and classified loans on an annual basis in order to have the most current indication of fair value. Once a loan is identified as impaired, an analysis of the underlying collateral is performed at least quarterly, and corresponding changes in any related valuation allowance are made or balances deemed to be fully uncollectable are charged-off. The following tables stratify the loan portfolio by the Company’s internal risk grading system as well as certain other information concerning the credit quality of the loan portfolio as of the periods indicated: Credit Risk Grades Pass Special Mention Substandard Doubtful Total Gross Loans December 31, 2017 (dollars in thousands) Business Loans Commercial and industrial $ 1,063,452 $ 8,163 $ 15,044 $ — $ 1,086,659 Franchise 660,415 — — — 660,415 Commercial owner occupied 1,273,380 654 21,180 — 1,295,214 SBA 199,468 1 3,469 — 202,938 Agribusiness 108,143 4,079 3,844 — 116,066 Real Estate Loans Commercial non-owner occupied 1,242,045 — 1,070 — 1,243,115 Multi-family 794,156 — 228 — 794,384 One-to-four family 268,776 154 1,964 — 270,894 Construction 282,294 517 — — 282,811 Farmland 144,234 44 1,115 — 145,393 Land 30,979 — 254 — 31,233 Consumer Loans Consumer loans 92,794 — 137 — 92,931 Totals $ 6,160,136 $ 13,612 $ 48,305 $ — $ 6,222,053 Credit Risk Grades Pass Special Mention Substandard Doubtful Total Gross Loans December 31, 2016 (dollars in thousands) Business Loans Commercial and industrial $ 550,919 $ 8,216 $ 3,784 $ 250 $ 563,169 Franchise 459,421 — — — 459,421 Commercial owner occupied 450,416 281 4,221 — 454,918 SBA 96,190 53 462 — 96,705 Real Estate Loans Commercial non-owner occupied 585,093 810 1,072 — 586,975 Multi-family 681,942 6,610 2,403 — 690,955 One-to-four family 100,010 — 441 — 100,451 Construction 269,159 — — — 269,159 Land 19,814 — 15 — 19,829 Consumer Loans Consumer loans 3,719 — 393 — 4,112 Totals $ 3,216,683 $ 15,970 $ 12,791 $ 250 $ 3,245,694 Days Past Due Current 30-59 60-89 90+ Total Gross Loans Non-accruing December 31, 2017 (dollars in thousands) Business Loans Commercial and industrial $ 1,085,770 $ 84 $ 570 $ 235 $ 1,086,659 $ 1,160 Franchise 660,415 — — — 660,415 — Commercial owner occupied 1,291,254 3,474 486 — 1,295,214 97 SBA 200,821 177 — 1,940 202,938 1,201 Agribusiness 116,066 — — — 116,066 — Real Estate Loans Commercial non-owner occupied 1,243,115 — — — 1,243,115 — Multi-family 792,603 1,781 — — 794,384 — One-to-four family 269,725 354 — 815 270,894 817 Construction 282,811 — — — 282,811 — Farmland 145,393 — — — 145,393 — Land 31,141 83 — 9 31,233 9 Consumer Loans Consumer loans 92,880 11 — 40 92,931 — Totals $ 6,211,994 $ 5,964 $ 1,056 $ 3,039 $ 6,222,053 $ 3,284 Days Past Due Current 30-59 60-89 90+ Total Gross Loans Non-accruing December 31, 2016 (dollars in thousands) Business Loans Commercial and industrial $ 562,805 $ 104 $ — $ 260 $ 563,169 $ 250 Franchise 459,421 — — — 459,421 — Commercial owner occupied 454,918 — — — 454,918 436 SBA 96,389 — — 316 96,705 316 Real Estate Loans Commercial non-owner occupied 586,975 — — — 586,975 — Multi-family 690,955 — — — 690,955 — One-to-four family 100,314 18 71 48 100,451 124 Construction 269,159 — — — 269,159 — Land 19,814 — — 15 19,829 15 Consumer Loans Consumer loans 4,112 — — — 4,112 — Totals $ 3,244,862 $ 122 $ 71 $ 639 $ 3,245,694 $ 1,141

Allowance for Loan Losses

Allowance for Loan Losses	12 Months Ended
	Dec. 31, 2017
Provision for Loan and Lease Losses [Abstract]
Allowance for Loan Losses	Allowance for Loan Losses The Company’s ALLL covers estimated credit losses on individually evaluated loans that are determined to be impaired as well as estimated probable incurred losses inherent in the remainder of the loan portfolio. The ALLL is prepared using the information provided by the Company’s credit review process together with data from peer institutions and economic information gathered from published sources. The loan portfolio is segmented into groups of loans with similar risk characteristics. Each segment possesses varying degrees of risk based on, among other things, the type of loan, the type of collateral, and the sensitivity of the borrower or industry to changes in external factors such as economic conditions. An estimated loss rate calculated using the Company’s actual historical loss rates adjusted for current portfolio trends, economic conditions, and other relevant internal and external factors, is applied to each group’s aggregate loan balances. The Company's base ALLL factors are determined by management using the Bank's annualized actual trailing charge-off data over a full credit cycle with the loss emergence period extending on average from 1 to 1.4 years. Adjustments to those base factors are made for relevant internal and external factors. Those factors may include: • Changes in national, regional and local economic conditions, including trends in real estate values and the interest rate environment, • Changes in the nature and volume of the loan portfolio, including new types of lending, • Changes in volume and severity of past due loans, the volume of nonaccrual loans, and the volume and severity of adversely classified or graded loans, and • The existence and effect of concentrations of credit, and changes in the level of such concentrations. For loans risk graded as watch or worse, progressively higher potential loss factors are applied based on migration analysis of risk grading and net charge-offs. The following tables summarize the allocation of the allowance as well as the activity in the allowance attributed to various segments in the loan portfolio as of and for the periods indicated: Commercial and Industrial Franchise Commercial Owner Occupied SBA Agribusiness Warehouse Facilities Commercial Non-owner Occupied Multi-family One-to-four Family Construction Farmland Land Consumer Loans Total (dollars in thousands) Balance, December 31, 2016 $ 6,362 $ 3,845 $ 1,193 $ 1,039 $ — $ — $ 1,715 $ 2,927 $ 365 $ 3,632 $ — $ 198 $ 20 $ 21,296 Charge-offs (1,344 ) — — (8 ) — — — — (10 ) — — — — (1,362 ) Recoveries 94 — 105 127 — — — — 35 — — — 1 362 Provisions for (reduction in) loan losses 4,609 1,952 (531 ) 1,732 1,291 — (449 ) (2,320 ) 413 937 137 795 74 8,640 Balance, December 31, 2017 $ 9,721 $ 5,797 $ 767 $ 2,890 $ 1,291 $ — $ 1,266 $ 607 $ 803 $ 4,569 $ 137 $ 993 $ 95 $ 28,936 Amount of allowance attributed to: Specifically evaluated impaired loans $ — $ — $ 55 $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — $ 55 General portfolio allocation 9,721 5,797 712 2,890 1,291 — 1,266 607 803 4,569 137 993 95 28,881 Loans individually evaluated for impairment 1,160 — 97 1,201 — — — — 817 — — 9 — 3,284 Specific reserves to total loans individually evaluated for impairment — % — % 56.70 % — % — % — % — % — % — % — % — % — % — % 1.67 % Loans collectively evaluated for impairment $ 1,085,499 $ 660,414 $ 1,289,116 $ 184,313 $ 116,066 $ — $ 1,243,115 $ 794,384 $ 270,077 $ 282,811 $ 145,393 $ 31,224 $ 92,931 $ 6,195,343 General reserves to total loans collectively evaluated for impairment 0.90 % 0.88 % 0.06 % 1.57 % 1.11 % — % 0.10 % 0.08 % 0.30 % 1.62 % 0.09 % 3.18 % 0.10 % 0.47 % Total gross loans $ 1,086,659 $ 660,414 $ 1,289,213 $ 185,514 $ 116,066 $ — $ 1,243,115 $ 794,384 $ 270,894 $ 282,811 $ 145,393 $ 31,233 $ 92,931 $ 6,198,627 Total allowance to gross loans 0.89 % 0.88 % 0.06 % 1.56 % 1.11 % — % 0.10 % 0.08 % 0.30 % 1.62 % 0.09 % 3.18 % 0.10 % 0.47 % Commercial and Industrial Franchise Commercial Owner Occupied SBA Agribusiness Warehouse Facilities Commercial Non-owner Occupied Multi-family One-to-four Family Construction Farmland Land Consumer Loans Total (dollars in thousands) Balance, December 31, 2015 $ 3,449 $ 3,124 $ 1,870 $ 1,500 $ — $ 759 $ 2,048 $ 1,583 $ 698 $ 2,030 $ — $ 233 $ 23 $ 17,317 Charge-offs (2,802 ) (980 ) (329 ) (980 ) — — — — (151 ) — — — — (5,242 ) Recoveries 177 — 25 193 — — 21 — 25 — — — 4 445 Provisions for (reduction in) loan losses 5,538 1,701 (373 ) 326 — (759 ) (354 ) 1,344 (207 ) 1,602 — (35 ) (7 ) 8,776 Balance, December 31, 2016 $ 6,362 $ 3,845 $ 1,193 $ 1,039 $ — $ — $ 1,715 $ 2,927 $ 365 $ 3,632 $ — $ 198 $ 20 $ 21,296 Amount of allowance attributed to: Specifically evaluated impaired loans $ 250 $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — $ 250 General portfolio allocation 6,112 3,845 1,193 1,039 — — 1,715 2,927 365 3,632 — 198 20 21,046 Loans individually evaluated for impairment 250 — 436 316 — — — — 124 — — 15 — 1,141 Specific reserves to total loans individually evaluated for impairment 100.00 % — % — % — % — % — % — % — % — % — % — % — % — % 21.91 % Loans collectively evaluated for impairment $ 562,919 $ 459,421 $ 454,482 $ 88,678 $ — $ — $ 586,975 $ 690,955 $ 100,327 $ 269,159 $ — $ 19,814 $ 4,112 $ 3,236,842 General reserves to total loans collectively evaluated for impairment 1.09 % 0.84 % 0.26 % 1.17 % — % — % 0.29 % 0.42 % 0.36 % 1.35 % — % 1.00 % 0.49 % 0.65 % Total gross loans $ 563,169 $ 459,421 $ 454,918 $ 88,994 $ — $ — $ 586,975 $ 690,955 $ 100,451 $ 269,159 $ — $ 19,829 $ 4,112 $ 3,237,983 Total allowance to gross loans 1.13 % 0.84 % 0.26 % 1.17 % — % — % 0.29 % 0.42 % 0.36 % 1.35 % — % 1.00 % 0.49 % 0.66 % Commercial and Industrial Franchise Commercial Owner Occupied SBA Agribusiness Warehouse Facilities Commercial Non-owner Occupied Multi-family One-to-four Family Construction Farmland Land Consumer Loans Total (dollars in thousands) Balance, December 31, 2014 $ 2,646 $ 1,554 $ 1,757 $ 568 $ — $ 546 $ 2,007 $ 1,060 $ 842 $ 1,088 $ — $ 108 $ 24 $ 12,200 Charge-offs (484 ) (764 ) — — — — (116 ) — (16 ) — — — — (1,380 ) Recoveries 47 — — 8 — — 3 — 13 — — — 1 72 Provisions for (reduction in) loan losses 1,240 2,334 113 924 — 213 154 523 (141 ) 942 — 125 (2 ) 6,425 Balance, December 31, 2015 $ 3,449 $ 3,124 $ 1,870 $ 1,500 $ — $ 759 $ 2,048 $ 1,583 $ 698 $ 2,030 $ — $ 233 $ 23 $ 17,317 Amount of allowance attributed to: Specifically evaluated impaired loans $ — $ 731 $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — $ 731 General portfolio allocation 3,449 2,393 1,870 1,500 — 759 2,048 1,583 698 2,030 — 233 23 16,586 Loans individually evaluated for impairment 313 1,630 536 — — — 214 — 70 — — 21 — 2,784 Specific reserves to total loans individually evaluated for impairment — % 44.85 % — % — % — % — % — % — % — % — % — % — % — % 26.26 % Loans collectively evaluated for impairment $ 309,428 $ 327,295 $ 294,190 $ 62,256 $ — $ 143,200 $ 421,369 $ 429,003 $ 79,980 $ 169,748 $ — $ 18,319 $ 5,111 $ 2,259,899 General reserves to total loans collectively evaluated for impairment 1.11 % 0.73 % 0.64 % 2.41 % — % 0.53 % 0.49 % 0.37 % 0.87 % 1.20 % — % 1.27 % 0.45 % 0.73 % Total gross loans $ 309,741 $ 328,925 $ 294,726 $ 53,691 $ — $ 143,200 $ 421,583 $ 429,003 $ 80,050 $ 169,748 $ — $ 18,340 $ 5,111 $ 2,254,118 Total allowance to gross loans 1.11 % 0.95 % 0.63 % 2.79 % — % 0.53 % 0.49 % 0.37 % 0.87 % 1.20 % — % 1.27 % 0.45 % 0.77 %

Other Real Estate Owned

Other Real Estate Owned	12 Months Ended
	Dec. 31, 2017
Other Real Estate [Abstract]
Other Real Estate Owned	Other Real Estate Owned Other real estate owned was $326,000 at December 31, 2017 , $460,000 at December 31, 2016 and $1.2 million at December 31, 2015 . The following summarizes the activity in the other real estate owned for the years ended December 31: 2017 2016 2015 (dollars in thousands) Balance, beginning of year $ 460 $ 1,161 $ 1,037 Additions / foreclosures 326 197 450 Sales (507 ) (577 ) (233 ) Gain (loss) on sale 47 18 (52 ) Write downs — (339 ) (41 ) Balance, end of year $ 326 $ 460 $ 1,161 The Company had $73,000 in consumer mortgage loans collateralized by residential real estate property for which formal foreclosure proceedings were in process as of December 31, 2017 , compared to $41,000 as of December 31, 2016 .

Premises and Equipment

Premises and Equipment	12 Months Ended
	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
Premises and Equipment	Premises and Equipment The Company's premises and equipment consisted of the following at December 31: 2017 2016 (dollars in thousands) Land $ 16,920 $ 200 Premises 19,868 1,707 Leasehold improvements 14,025 8,982 Furniture, fixtures and equipment 20,480 14,565 Automobiles 187 187 Subtotal 71,480 25,641 Less: accumulated depreciation 18,325 13,627 Total $ 53,155 $ 12,014 Depreciation expense for premises and equipment was $4.9 million for 2017 , $2.9 million for 2016 and $2.4 million for 2015 .

Goodwill and Core Deposit Intan

Goodwill and Core Deposit Intangibles	12 Months Ended
	Dec. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Core Deposit Intangibles	Goodwill and Core Deposit Intangibles At December 31, 2017 , the Company had goodwill of $493 million . Additions to goodwill of $391 million included $122 million from the PLZZ acquisition and $269 million from the HEOP acquisition. The following table presents changes in the carrying value of goodwill for the periods indicated: 2017 2016 (dollars in thousands) Balance, beginning of year $ 102,490 $ 50,832 Goodwill acquired during the year 390,839 51,658 Impairment losses — — Balance, end of year $ 493,329 $ 102,490 Accumulated impairment losses at end of year — — The Company’s goodwill was evaluated for impairment during the fourth quarter of 2017 , with no impairment loss recognition considered necessary. At December 31, 2017 , the Company had $43.0 million of CDI. Additions to CDI of $39.7 million included $11.6 million from the PLZZ acquisition and $28.1 million from the HEOP acquisition. The Company's change in the gross amount of core deposit intangibles and the related accumulated amortization consisted of the following at December 31: 2017 2016 2015 (dollars in thousands) Gross amount of CDI: Balance, beginning of year $ 15,102 $ 10,782 $ 7,876 Additions due to acquisitions 39,707 4,320 2,906 Balance, end of year 54,809 15,102 10,782 Accumulated amortization: Balance, beginning of year (5,651 ) (3,612 ) (2,262 ) Amortization (6,144 ) (2,039 ) (1,350 ) Balance, end of year (11,795 ) (5,651 ) (3,612 ) Net CDI, end of year $ 43,014 $ 9,451 $ 7,170 The estimated aggregate amortization expense related to our core deposit intangible assets for each of the next five years is $8.4 million , $7.3 million , $6.5 million , $5.4 million , and $4.5 million . The Company’s core deposit intangibles is evaluated for impairment if events and circumstances indicate possible impairment. Factors that may attribute to impairment include customer attrition and run-off. Management is unaware of any events and/or circumstances that would indicate a possible impairment to the core deposit intangibles.

Bank Owned Life Insurance

Bank Owned Life Insurance	12 Months Ended
	Dec. 31, 2017
Investments, All Other Investments [Abstract]
Bank Owned Life Insurance	Bank Owned Life Insurance At December 31, 2017 and 2016 , the Company had $76.0 million and $40.4 million , respectively of BOLI. The Company recorded noninterest income associated with the BOLI policies of $2.3 million , $1.4 million and $1.3 million for the years ending December 31, 2017 , 2016 and 2015 , respectively. BOLI involves the purchasing of life insurance by the Company on a selected group of employees where the Company is the owner and beneficiary of the policies. BOLI is recorded as an asset at its cash surrender value. Increases in the cash surrender value of these policies, as well as a portion of the insurance proceeds received, are recorded in noninterest income and are not subject to income tax, as long as they are held for the life of the covered parties.

Qualified Affordable Housing Pr

Qualified Affordable Housing Project Investments	12 Months Ended
	Dec. 31, 2017
Equity Method Investments and Joint Ventures [Abstract]
Qualified Affordable Housing Project Investments	Qualified Affordable Housing Project Investments The Company's investment in Qualified Affordable Housing Funds that generate Low Income Housing Tax Credits at December 31, 2017 and 2016 was $11.6 million and $7.0 million , respectively, recorded in other assets. Total unfunded commitments related to the investments in qualified affordable housing funds totaled $1.3 million and $749 thousand at December 31, 2017 and 2016 , respectively. The Company has invested in three separate LIHTC funds, which provide the Company with CRA credit. Additionally, the investment in LIHTC funds provide the Company with tax credits and with operating loss tax benefits over an approximately 10 year period. None of the original investment will be repaid. The investments in the WNC Institutional Tax Credit funds are being accounted for using the cost method, under which the Company amortizes as non-interest expense the initial cost of the investment equally over the expected time period in which tax credits and other tax benefits will be received. The investment in the Sycamore Court fund qualifies for and is being accounted for using the proportional amortization method, which allows for the amortization of the investment to be in proportion to the total of the tax credits and other tax benefits that are allocated to the investor. The tax credits and operating loss tax benefits are recognized in the income statement as a component of income tax expense (benefit) for all LIHTC funds. The following table presents the Company's original investment in the LIHTC funds, the current recorded investment balance, and the unfunded liability balance of each investment at December 31, 2017 and 2016 . In addition, the table reflects the tax credits and tax benefits recorded by the Company during 2017 and 2016 , the amortization of the investment and the net impact to the Company's income tax provision for 2017 and 2016 . Qualified Affordable Housing Funds at Original Investment Value Current Recorded Investment Unfunded Liability Obligation Tax Credits and Tax Deductions (1) Amortization of Investments (2) Net Income Tax Benefit WNC Institutional Tax Credit $ 5,000 $ 2,750 $ 85 $ 455 $ 500 $ (663 ) WNC Institutional Tax Credit 5,000 3,250 288 482 500 (690 ) Sycamore Court 6,181 5,582 927 1,577 599 (782 ) Total - Investments in $ 16,181 $ 11,582 $ 1,300 $ 2,514 $ 1,599 $ (2,135 ) Qualified Affordable Housing Funds at Original Investment Value Current Recorded Investment Unfunded Liability Obligation Tax Credits and Tax Deductions (1) Amortization of Investments (2) Net Income Tax Benefit WNC Institutional Tax Credit $ 5,000 $ 3,250 $ 223 $ 488 $ 542 $ (596 ) WNC Institutional Tax Credit 5,000 3,750 526 473 782 (637 ) Total - Investments in $ 10,000 $ 7,000 $ 749 $ 961 $ 1,324 $ (1,233 ) (1) The amounts reflected in this column represent both the tax credits, as well as the tax benefits generated by the Qualified Affordable Housing Projects operating loss for the year, which are included in the calculation of income tax expense. (2) This amount represents the amortization of the investment cost of the LIHTC.

Deposit Accounts

Deposit Accounts	12 Months Ended
	Dec. 31, 2017
Deposits [Abstract]
Deposit Accounts	Deposit Accounts Deposit accounts and weighted average interest rates consisted of the following at December 31: 2017 Weighted 2016 Weighted (dollars in thousands) Transaction accounts Noninterest-bearing checking $ 2,226,848 — % $ 1,185,768 — % Interest-bearing checking 365,193 0.13 % 182,893 0.11 % Money market 2,181,571 0.48 % 1,100,787 0.34 % Savings 227,436 0.13 % 101,574 0.14 % Total transaction accounts 5,001,048 0.21 % 2,571,022 0.16 % Certificates of deposit accounts Less than 100,000 192,409 0.85 % 121,148 0.74 % $100,000 through $250,000 369,748 1.01 % 153,103 0.82 % Greater than $250,000 522,663 1.26 % 300,308 0.74 % Total certificates of deposit accounts 1,084,820 1.10 % 574,559 0.76 % Total deposits $ 6,085,868 0.33 % $ 3,145,581 0.27 % The aggregate annual maturities of certificates of deposit accounts at December 31, 2017 are as follows: 2017 Balance Weighted Average Interest Rate (dollars in thousands) Within 3 months $ 318,794 0.93 % 4 to 6 months 250,026 1.07 % 7 to 12 months 279,192 1.18 % 13 to 24 months 175,005 1.24 % 25 to 36 months 29,270 1.33 % 37 to 60 months 22,936 1.44 % Over 60 months 9,597 1.13 % Total $ 1,084,820 1.10 % Interest expense on deposit accounts for the years ended December 31 is summarized as follows: 2017 2016 2015 (dollars in thousands) Checking accounts $ 365 $ 200 $ 165 Money market accounts 6,720 3,641 2,426 Savings 251 151 141 Certificates of deposit accounts 6,035 4,399 3,898 Total $ 13,371 $ 8,391 $ 6,630 Accrued interest on deposits, which is included in accrued expenses and other liabilities, was $526,000 at December 31, 2017 and $178,000 at December 31, 2016 .

Federal Home Loan Bank Advances

Federal Home Loan Bank Advances and Other Borrowings	12 Months Ended
	Dec. 31, 2017
Long-term Federal Home Loan Bank Advances [Abstract]
Federal Home Loan Bank Advances and Other Borrowings	Federal Home Loan Bank Advances and Other Borrowings As of December 31, 2017 , the Company has a line of credit with the FHLB that provides for advances totaling up to 45% of the Company’s assets, equating to a credit line of $2.9 billion , of which $677 million was available for borrowing. The available for borrowing was based on collateral pledged by real estate loans with an aggregate balance of $1.4 billion and FHLB stock of $17.3 million . At December 31, 2017 , the Company had $310 million in overnight FHLB advances and $180 million term advances, compared to $278 million in overnight FHLB advances and no term advances at December 31, 2016 . The term advance have maturity dates ranging from January 2018 to June of 2022 and rates ranging from 0.90% to 2.73% . The following table summarizes activities in advances from the FHLB for the periods indicated: Year Ended December 31, 2017 2016 (dollars in thousands) Average balance outstanding $ 290,839 $ 58,814 Maximum amount outstanding at any month-end during the year 490,148 278,000 Balance outstanding at end of year 490,148 278,000 Weighted average interest rate during the year 1.19 % 0.59 % Bank related credit facilities have been established with Citigroup, Barclays Bank and Union Bank. The outstanding credit facilities are secured by pledged investment securities. At December 31, 2017 and 2016 , the Company had borrowings of $18.5 million with Citigroup that mature in September of 2018, $10.0 million with Barclays Bank that mature in February of 2018, which the Company does not intend on renewing, and an unused reverse repurchase facility with Union Bank of $50 million . The outstanding borrowings are secured by MBS with an estimated fair value of $27.3 million . The Company sells certain securities under agreements to repurchase. The agreements are treated as overnight borrowings with the obligations to repurchase securities sold reflected as a liability. The dollar amount of investment securities underlying the agreements remain in the asset accounts. The Company enters into these debt agreements as a service to certain HOA depositors to add protection for deposit amounts above FDIC insurance levels. At December 31, 2017 , the Company sold securities under agreement to repurchase of $17.6 million with weighted average rate of 0.01% and collateralized by investment securities with fair value of approximately $29.7 million . At December 31, 2017 , the Bank had unsecured lines of credit with eight correspondent banks for a total amount of $168 million and access through the Federal Reserve discount window to borrow $3.3 million . At December 31, 2017 and December 31, 2016 , the Company had no outstanding balances against these lines. In addition, the Corporation acquired a line of credit with Wells Fargo Bank in June of 2017, with availability of $15 million . The line was added to provide an additional source of liquidity at the Corporation level and has no outstanding balance at December 31, 2017 and matures in June 2018. The following table summarizes activities in other borrowings for the periods indicated: Year Ended December 31, 2017 2016 (dollars in thousands) Average balance outstanding $ 50,866 $ 48,732 Maximum amount outstanding at any month-end during the year 52,996 53,586 Balance outstanding at end of year 46,139 49,971 Weighted average interest rate during the year 1.86 % 1.94 %

Subordinated Debentures

Subordinated Debentures	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Subordinated Debentures	Subordinated Debentures In August 2014, the Corporation issued $60 million in aggregate principal amount of 5.75% Subordinated Notes Due 2024 (the “Notes”) in a private placement transaction to institutional accredited investors (the “Private Placement”). The Corporation contributed $50 million of net proceeds from the Private Placement to the Bank to support general corporate purposes. The Notes bear interest at an annual fixed rate of 5.75% , with the first interest payment on the Notes occurring on March 3, 2015, and interest will be paid semiannually each March 3 and September 3 through September 2024. The Notes can only be redeemed, partially or in whole, prior to the maturity date if the notes do not constitute Tier 2 Capital (for purposes of capital adequacy guidelines of the Board of Governors of the Federal Reserve). As of December 31, 2017 , the Notes qualify as Tier 2 Capital. Principal and interest are due upon early redemption. In connection with the Private Placement, the Corporation obtained ratings from Kroll Bond Rating Agency (“KBRA”). KBRA assigned investment grade ratings of BBB+ and BBB for the Corporation's senior secured debt and subordinated debt, respectively, and a senior deposit rating of A- for the Bank. The Company's and Bank's ratings were re-affirmed in October of 2017 by KBRA. In March 2004, the Corporation issued $10.3 million of Floating Rate Junior Subordinated Deferrable Interest Debentures (the “Debt Securities”) to PPBI Trust I, a statutory trust created under the laws of the State of Delaware. The Debt Securities are subordinated to effectively all borrowings of the Corporation and are due and payable on April 6, 2034. Interest is payable quarterly on the Debt Securities at 3-month LIBOR plus 2.75% for a rate of 4.11% at December 31, 2017 and 3.63% at December 31, 2016 . The Debt Securities may be redeemed, in part or whole, on or after April 7, 2009 at the option of the Corporation, at par. The Debt Securities can also be redeemed at par if certain events occur that impact the tax treatment or the capital treatment of the issuance. The Corporation also purchased a 3% minority interest totaling $310,000 in PPBI Trust I. The balance of the equity of PPBI Trust I is comprised of mandatorily redeemable preferred securities (“Trust Preferred Securities”) and is included in other assets. PPBI Trust I sold $10,000,000 of Trust Preferred Securities to investors in a private offering. On April 1, 2017, as part of the Heritage Oaks acquisition, the Corporation assumed $5.2 million of floating rate junior subordinated debt securities associated with Heritage Oaks Capital Trust II. Interest is payable quarterly at three-month LIBOR plus 1.72% per annum, for an effective rate of 3.06% per annum as of December 31, 2017 . At December 31, 2017 , the carrying value of these debentures was $3.9 million , which reflects purchase accounting fair value adjustments of $1.3 million . The Corporation also assumed $3.1 million and $5.2 million of floating rate junior subordinated debt associated with Mission Community Capital Trust I and Santa Lucia Bancorp (CA) Capital Trust, respectively. At December 31, 2017 , the carrying value of Mission Community Capital Trust I and Santa Lucia Bancorp (CA) Capital Trust were $2.8 million and $3.8 million , respectively, which reflects purchase accounting fair value adjustments of $327,000 and $1.4 million , respectively. Interest is payable quarterly at three-month LIBOR plus 2.95% per annum, for an effective rate of 4.31% per annum as of December 31, 2017 for Mission Community Capital Trust I. Interest is payable quarterly at three-month LIBOR plus 1.48% per annum, for an effective rate of 2.84% per annum as of December 31, 2017 for Santa Lucia Bancorp (CA) Capital Trust. These three debentures are callable by the Corporation at par. On November 1, 2017, as part of the PLZZ acquisition, the Company assumed three subordinated notes totaling $25 million at a fixed interest rate of 7.125% payable in arrears on a quarterly basis. The notes have a maturity date of June 26, 2025 and are also redeemable in whole or in part from time to time beginning in June 26, 2020 at an amount equal to 103.0% of principal plus accrued unpaid interest. The redemption price decreases 50 basis points each subsequent year. The Corporation is not allowed to consolidate and trust preferred securities into the Company's consolidated financial statements. The resulting effect on the Company’s consolidated financial statements is to report only the Subordinated Debentures as a component of the Company’s liabilities. The following table summarizes activities for our subordinated debentures for the periods indicated: Year Ended December 31, 2017 2016 (dollars in thousands) Average balance outstanding $ 81,466 $ 69,347 Maximum amount outstanding at any month-end during the year 105,123 69,383 Balance outstanding at end of year 105,123 69,383 Weighted average interest rate during the year 5.80 % 5.54 %

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes Income taxes for the years ended December 31 consisted of the following: 2017 2016 2015 (dollars in thousands) Current income tax provision: Federal $ 18,644 $ 16,928 $ 12,460 State 7,062 4,655 4,144 Total current income tax provision 25,706 21,583 16,604 Deferred income tax provision (benefit): Federal 8,294 2,379 (887 ) Effect of Tax Act 5,633 — — State 2,493 1,253 (508 ) Total deferred income tax provision (benefit) 16,420 3,632 (1,395 ) Total income tax provision $ 42,126 $ 25,215 $ 15,209 A reconciliation from statutory federal income taxes, that are based on a statutory rate of 35% , to the Company's effective income taxes for the years ended December 31 is as follows: 2017 2016 2015 (dollars in thousands) Statutory federal income tax provision $ 35,778 $ 22,863 $ 14,253 State taxes, net of federal income tax effect 6,720 4,135 2,886 Cash surrender life insurance (645 ) (407 ) (483 ) Tax exempt interest (1,660 ) (764 ) (742 ) Merger costs 824 533 447 LIHTC investments (1,031 ) (909 ) (871 ) Effect of the Tax Act 5,633 — — Excess tax benefit of stock-based compensation (1,995 ) — — Prior year true-up (1,108 ) — — Other (390 ) (236 ) (281 ) Total income tax provision $ 42,126 $ 25,215 $ 15,209 Deferred tax assets (liabilities) were comprised of the following temporary differences between the financial statement carrying amounts and the tax basis of assets at December 31: 2017 2016 2015 (dollars in thousands) Deferred tax assets: Accrued expenses $ 2,463 $ 2,839 $ 1,717 Net operating loss 4,834 3,977 5,192 Allowance for loan losses, net of bad debt charge-offs 8,400 8,061 6,252 Deferred compensation 3,074 2,348 2,547 State taxes 1,500 1,879 1,451 Depreciation — 1,090 651 Loan discount 8,642 3,477 — Stock-based compensation 1,914 1,108 639 Unrealized loss on available for sale securities — 1,939 — Capital loss carryover 380 — — AMT credit 107 — — Total deferred tax assets 31,314 26,718 18,449 Deferred tax liabilities: Deferred FDIC gain (524 ) (1,675 ) (1,656 ) Core deposit intangibles (11,691 ) (3,331 ) (2,266 ) Loan origination costs (3,368 ) (4,208 ) — Depreciation (699 ) — — Unrealized loss on available for sale securities (188 ) — (231 ) Other (1,199 ) (697 ) (2,785 ) Total deferred tax liabilities (17,669 ) (9,911 ) (6,938 ) Valuation allowance (380 ) — — Net deferred tax asset $ 13,265 $ 16,807 $ 11,511 On December 22, 2017, the U.S. government enacted comprehensive tax legislation commonly referred to as the Tax Cuts and Jobs Act (“Tax Act”). Among other changes, the Tax Act reduces the U.S. federal corporate tax rate from 35% to 21%. The Company has recorded an income tax expense of $5.6 million related to the remeasurement of federal net deferred tax assets resulting from the permanent reduction in the U.S. statutory corporate tax rate to 21% from 35%. The Company is still completing its analysis of the impact of the Tax Act and will record any adjustments to the provisional amount as a component of income tax expense during the measurement period provided for in SAB 118. The Company accounts for income taxes by recognizing deferred tax assets and liabilities based upon temporary differences between the amounts for financial reporting purposes and tax basis of its assets and liabilities. Deferred tax assets are reduced by a valuation allowance when, in the opinion of management, it is more likely than not that some portion, or all, of the deferred tax asset will not be realized. In assessing the realization of deferred tax assets, management evaluates both positive and negative evidence, including the existence of any cumulative losses in the current year and the prior two years, the forecasts of future income, applicable tax planning strategies, and assessments of current and future economic and business conditions. This analysis is updated quarterly and adjusted as necessary. Based on the analysis, the Company has determined that a valuation allowance for deferred tax assets was not required as of December 31, 2016 and December 31, 2015 . As of December 31, 2017 , the Company recorded a valuation allowance of $380,000 against the capital loss carryover deferred tax asset, as the Company does not believe it will generate sufficient capital gain before the capital loss carryover expires. Section 382 of the Internal Revenue Code imposes limitations on a corporation’s ability to use any net unrealized built in losses and other tax attributes, such as net operating loss and tax credit carryforwards, when it undergoes a 50% ownership change over a designated testing period. The Company has a Section 382 limited net operating loss carry forward of approximately $17.4 million for federal income tax purposes, which is scheduled to expire in 2026. In addition, the Company has a Section 382 limited net operating loss carry forward of approximately $14.7 million for California franchise tax purposes, which is scheduled to expire in 2020. The Company is expected to fully utilize the federal and California net operating loss carryforward before it expires with the application of the Section 382 annual limitation. The Company and its subsidiaries are subject to U.S. Federal income tax as well as income and franchise tax in multiple state jurisdictions. The statute of limitations related to the consolidated Federal income tax returns is closed for all tax years up to and including 2013. The expiration of the statute of limitations related to the various state income and franchise tax returns varies by state. The Company is currently not under examination in any taxing jurisdiction. A reconciliation of the beginning and ending amount of unrecognized tax benefits for the years ended December 31, 2017 and 2016 is as follows: 2017 2016 (dollars in thousands) Balance at January 1, $ — $ — Additions based on tax positions related to prior years 2,906 — Balance at December 31, $ 2,906 $ — The total amount of unrecognized tax benefits was $2.9 million and $0 at December 31, 2017 and 2016 and is primarily comprised of unrecognized tax benefits from an acquisition during 2017. The total amount of tax benefits that, if recognized, would favorably impact the effective tax rate was $0 at December 31, 2017 . The Company does not believe that the unrecognized tax benefits will change within the next twelve months. The Company recognizes interest and penalties accrued related to unrecognized tax benefits in income tax expense. The Company had accrued for $104,000 and $0 of the interest and penalties at December 31, 2017 and 2016 , respectively.

Commitments, Contingencies and

Commitments, Contingencies and Concentrations of Risk	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments, Contingencies and Concentrations of Risk	Commitments, Contingencies and Concentrations of Risk Lease Commitments – The Company leases a portion of its facilities from non-affiliates under operating leases expiring at various dates through 2027 . The following schedule shows the minimum annual lease payments, excluding any renewals and extensions, property taxes, and other operating expenses, due under these agreements: Year ending December 31, Amount (dollars in thousands) 2018 $ 7,170 2019 5,476 2020 2,675 2021 1,887 2022 1,421 Thereafter 2,312 Total $ 20,941 Rental expense under all operating leases totaled $4.8 million for 2017 , $4.4 million for 2016 , and $3.8 million for 2015 . Legal Proceedings –The Company is not involved in any material pending legal proceedings other than legal proceedings occurring in the ordinary course of business. Management believes that none of these legal proceedings, individually or in the aggregate, will have a material adverse impact on the results of operations or financial condition of the Company. Employment Agreements— The Company has entered into a three -year employment agreement with its Chief Executive Officer (“CEO”). This agreement provides for the payment of a base salary, a bonus based upon the CEO’s individual performance and the Company’s overall performance, provides a vehicle for the CEO’s use, and provides for the payment of severance benefits upon termination under specified circumstances. Additionally, the Bank has entered into a three years employment agreements with the following executive officers: Chief Banking Officer, the Chief Financial Officer, the Chief Credit Officer and the Chief Operating Officer. The agreements provide for the payment of a base salary, a bonus based upon the individual’s performance and the overall performance of the Bank and the payment of severance benefits upon termination under specified circumstances. Availability of Funding Sources— The Company funds substantially all of the loans, which it originates or purchases, through deposits, internally generated funds, and/or borrowings. The Company competes for deposits primarily on the basis of rates, and, as a consequence, the Company could experience difficulties in attracting deposits to fund its operations if the Company does not continue to offer deposit rates at levels that are competitive with other financial institutions. To the extent that the Company is not able to maintain its currently available funding sources or to access new funding sources, it would have to curtail its loan production activities or sell loans and investment securities earlier than is optimal. Any such event could have a material adverse effect on the Company’s results of operations, financial condition and cash flows.

Benefit Plans

Benefit Plans	12 Months Ended
	Dec. 31, 2017
Retirement Benefits [Abstract]
Benefit Plans	Benefit Plans 401(k) Plan— The Bank maintains an Employee Savings Plan (the “401(k) Plan”) which qualifies under Section 401(k) of the Internal Revenue Code. Under the 401(k) Plan, employees may contribute between 1% to 100% of their compensation. In 2017 , 2016 and 2015 , the Bank matched 100% of contributions for the first three percent contributed and 50% on the next two percent contributed. Contributions made to the 401(k) Plan by the Bank amounted to $1.4 million for 2017 , $959,000 for 2016 and $769,000 for 2015 . Pacific Premier Bancorp, Inc. 2004 Long-Term Incentive Plan (the “2004 Plan”) — The 2004 Plan was approved by the Corporation’s stockholders in May 2004. The 2004 Plan authorized the granting of incentive stock options, nonstatutory stock options, stock appreciation rights and restricted stock (collectively "Awards") equal to 525,500 shares of the common stock of the Corporation for issuances to executive, key employees, officers and directors. The 2004 Plan was in effect for a period of ten years starting in February 25, 2004, the date the 2004 Plan was adopted. Awards granted under the 2004 Plan were made at an exercise price equal to the fair market value of the stock on the date of grant. The Awards granted pursuant to the 2004 Plan vest at a rate of 33.3% per year. The 2004 Plan terminated in February 2014. Heritage Oaks Bancorp, Inc. 2005 Equity Based Compensation Plan (the "2005 Plan") — The 2005 Plan was acquired from Heritage Oaks Bancorp, Inc. on April 1, 2017. The 2005 Plan authorized the granting of Incentive Stock Options, Non-Qualified Stock Options, Stock Appreciation Rights, Restricted Stock Awards, Restricted Stock Units and Performance Share Cash Only Awards. As of December 31, 2016, no further grants can be made from this plan, however Pacific Premier assumed all unvested and unexercised awards. Pacific Premier Bancorp, Inc. 2012 Long-Term Incentive Plan (the “2012 Plan”) — The 2012 Plan was approved by the Corporation’s stockholders in May 2012. The 2012 Plan authorizes the granting of Awards equal to 620,000 shares of the common stock of the Corporation for issuances to executives, key employees, officers, and directors. The 2012 Plan will be in effect for a period of ten years from May 30, 2012, the date the 2012 Plan was adopted. Awards granted under the 2012 Plan will be made at an exercise price equal to the fair market value of the stock on the date of grant. Awards granted to officers and employees may include incentive stock options, non-qualified stock options, restricted stock, restricted stock units, and stock appreciation rights. The awards have vesting periods ranging from 1 to 3 years; vesting in either three equal annual installments or one lump sum at the end of the third year. In May 2014, the Corporation’s stockholders approved an amendment to the 2012 Plan to increase the shares available under the plan by 800,000 shares to total 1,420,000 shares. In May 2015, the Corporation's stockholders approved an amendment to the 2012 Plan to permit the grant of performance-based awards, including equity compensation awards that may not be subject to the deduction limitation of Section 162(m) of the Internal Revenue Code. The performance-based awards include (i) both performance-based equity compensation awards and performance-based cash bonus payments and (ii) restricted stock units. In May 2017, the Corporation’s stockholders approved an amendment to the 2012 Plan to increase the shares available under the plan by 3,580,000 shares to total 5,000,000 shares. Heritage Oaks Bancorp, Inc. 2015 Equity Based Compensation Plan (the "2015 Plan") — The 2015 Plan was acquired from Heritage Oaks Bancorp, Inc. on April 1, 2017. The 2015 plan was approved by the Corporation's stockholders in May 2015. The 2015 Plan authorized the Company to grant various types of share-based compensation awards to the Company's employees and Board of Directors such as stock options, restricted stock awards, and restricted stock units. Under the 2015 Equity Incentive Plan a maximum of 2,500,000 shares of the Company's common stock were made to be issued. Shares issued under this plan, other than stock options and stock appreciation rights, were counted against the plan on a two shares for every one share actually issued basis. Awards that were canceled, expired, forfeited, fail to vest, or otherwise resulted in issued shares not being delivered to the grantee, were made available for the issuance of future share-based compensation awards. Additionally, under this plan, no one individual was to be granted shares in aggregate that exceed more than 250,000 shares during any calendar year. The 2015 Plan is still active and Pacific Premier assumed all unvested and unexercised awards. The Pacific Premier Bancorp, Inc. 2004 Long-Term Incentive Plan, Heritages Oaks Bancorp, Inc. 2005 Equity Based Compensation Plan, Pacific Premier Bancorp, Inc. 2012 Long-Term Incentive Plan and the Heritage Oaks Bancorp, Inc. 2015 Equity Based Compensation Plan are collectively the “Plans.” Stock Options As of December 31, 2017 , there are 114,454 options outstanding on the 2004 Plan with zero available for grant. As of December 31, 2017 , there are 48,532 options outstanding on the 2005 Plan with zero available for grant. As of December 31, 2017 , there are 755,362 options outstanding on the 2012 Plan with 3,594,149 available for grant. As of December 31, 2017 , there are 36,175 options outstanding on the 2015 Plan with zero available for grant. Below is a summary of the stock option activity in the Plans for the year ended December 31, 2017 : 2017 Number of Stock Options Outstanding Weighted Average Exercise Price Per Share Weighted Average Remaining Contractual Term Aggregate Intrinsic value (in years) (dollars in thousands) Outstanding at January 1, 2017 1,083,667 $ 12.61 Granted 210,977 20.40 Exercised (333,959 ) 13.49 Forfeited and Expired (6,162 ) 34.68 Outstanding at December 31, 2017 954,523 $ 13.89 5.8 $ 24,926 Vested and Exercisable at December 31, 2017 749,281 $ 12.47 5.3 $ 20,627 The total intrinsic value of options exercised during the years ended December 31, 2017 , 2016 and 2015 was $7.7 million , $2.0 million and $60,000 , respectively. The amount charged against compensation expense in relation to the stock options was $927,000 for 2017 , $883,000 for 2016 and $514,000 for 2015 . At December 31, 2017 , unrecognized compensation expense related to the options is approximately $814,000 . Options granted under the Option Plans during 2017 , 2016 and 2015 were valued using the Black-Scholes model with the following average assumptions: Year Ended December 31, 2017 2016 2015 Expected volatility 22.43% - 28.77% 21.98% - 26.88% 29.47% Expected term .33 - 6 Years 6.00 Years 6.00 Years Expected dividends None None None Risk free rate 1.03% - 2.02% 1.32% - 1.83% 1.39% Weighted-average grant date fair value $19.66 $5.55 $4.73 The following is the listing of the input variables and the assumptions utilized by the Company for each parameter used in the Black-Scholes option pricing model in prior years: Risk-free Rate – The risk-free rate for periods within the contractual life of the option have been based on the U.S. Treasury rate that matures on the expected assigned life of the option at the date of the grant. Expected Life of Options – The expected life of options is based on the period of time that options granted are expected to be outstanding. Expected Volatility –The expected volatility has been based on the historical volatility for the Company’s shares. Dividend Yield – The dividend yield has been based on historical experience and expected future changes on dividend payouts. The Company does not expect to declare or pay dividends on its common stock within the foreseeable future. Restricted Stock Below is a summary of the restricted stock activity in the Plans for the years ended December 31, 2017 : 2017 Shares Weighted Average Grant-Date Fair Value per share Unvested at the beginning of the year 370,334 $ 23.53 Granted 201,544 38.70 Vested (125,035 ) 26.26 Forfeited — — Unvested at the end of the year 446,843 $ 29.61 Compensation expense for the year ended December 31, 2017 , 2016 and 2015 related to the above restricted stock grants amounted to $5.0 million , $1.8 million and $260,000 , respectively. Restricted stock awards are valued at the closing stock price on the date of grant and are expensed to stock based compensation expense over the period for which the related service is performed. The total grant date fair value of awards was $7.8 million for 2017 awards. At December 31, 2017 , unrecognized compensation expense related to restricted stock is approximately $8.2 million . Other Plans Salary Continuation Plan— The Bank implemented a non-qualified supplemental retirement plan in 2006 (the “Salary Continuation Plan”) for certain executive officers of the Bank. The Salary Continuation Plan is unfunded. Deferred Compensation Plans — Deferred Compensation Plan -The Bank implemented a non-qualified supplemental retirement plan in 2006 (the “Supplemental Executive Retirement Plan” or “SERP”) for certain executive officers of the Bank. The Bank has acquired additional SERPs through the acquisitions of SDTB, IDPK and HEOP. The SERP is unfunded. The expense incurred for the SERP for each of the last three years was $721,000 , $573,000 and $307,000 resulting in a deferred compensation liability of $8.3 million and $5.1 million as of the years ended 2017 and 2016. In addition, with the acquisition of PLZZ, the Company acquired a deferred compensation plan that is unfunded and results in a deferred compensation asset and liability both in the amount of $2.0 million . The amounts expensed in 2017 , 2016 , and 2015 for all of these plans amounted to $721,000 , $573,000 , and $555,000 respectively. As of December 31, 2017 , 2016 and 2015 , $8.4 million , $5.7 million , and $5.4 million , respectively, were recorded in other liabilities on the consolidated statements of condition for each of these plans.

Financial Instruments with Off-

Financial Instruments with Off-Balance Sheet Risk	12 Months Ended
	Dec. 31, 2017
Risks and Uncertainties [Abstract]
Financial Instruments with Off-Balance Sheet Risk	Financial Instruments with Off-Balance Sheet Risk The Company is a party to financial instruments with off-balance sheet risk in the normal course of business to meet the financing needs of its customers. These financial instruments include commitments to extend credit in the form of originating loans or providing funds under existing lines or letters of credit. These commitments are agreements to lend to a customer as long as there is no violation of any condition established in the contract. Commitments generally have fixed expiration dates and may require payment of a fee. Since many commitments are expected to expire, the total commitment amounts do not necessarily represent future cash requirements. Commitments involve, to varying degrees, elements of credit and interest rate risk in excess of the amounts recognized in the accompanying consolidated statements of financial condition. The Company's exposure to credit loss in the event of nonperformance by the other party to the financial instrument for commitments to extend credit is represented by the contractual or notional amount of those instruments. The Company controls credit risk of its commitments to fund loans through credit approvals, limits and monitoring procedures. The Company uses the same credit policies in making commitments and conditional obligations as it does for on-balance sheet instruments. The Company evaluates each customer for creditworthiness. The Company receives collateral to support commitments when deemed necessary. The most significant categories of collateral include real estate properties underlying mortgage loans, liens on personal property and cash on deposit with the Bank. The Company maintains an allowance for credit losses to provide for commitments related to loans associated with undisbursed loan funds and unused lines of credit. The allowance for these commitments was $1.9 million at December 31, 2017 and $1.1 million at December 31, 2016 . The Company’s commitments to extend credit at December 31, 2017 were $1.2 billion and $581 million at December 31, 2016 . The 2017 balance is primarily composed of $ 707 million of undisbursed commitments for C&I loans.

Fair Value of Financial Instrum

Fair Value of Financial Instruments	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments	Fair Value of Financial Instruments The fair value of an asset or liability is the price that would be received to sell that asset or paid to transfer that liability in an orderly transaction occurring in the principal market (or most advantageous market in the absence of a principal market) for such asset or liability. In estimating fair value, the Company utilizes valuation techniques that are consistent with the market approach, the income approach, and/or the cost approach. Such valuation techniques are consistently applied. Inputs to valuation techniques include the assumptions that market participants would use in pricing an asset or liability. ASC Topic 825 requires disclosure of the fair value of financial assets and financial liabilities, including both those financial assets and financial liabilities that are not measured and reported at fair value on a recurring basis and a non-recurring basis. The methodologies for estimating the fair value of financial assets and financial liabilities that are measured at fair value, and for estimating the fair value of financial assets and financial liabilities not recorded at fair value, are discussed below. In accordance with accounting guidance, the Company groups its financial assets and financial liabilities measured at fair value in three levels, based on the markets in which the assets and liabilities are traded and the reliability of the assumptions used to determine fair value. The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1 measurements) and the lowest priority to unobservable inputs (Level 3 measurements). The three levels of the fair value hierarchy are described as follows: Level 1 - Unadjusted quoted prices in active markets that are accessible at the measurement date for identical, unrestricted assets or liabilities. Level 2 - Inputs other than quoted prices included in Level 1 that are observable for the asset or liability, either directly or indirectly. These might include quoted prices for similar instruments in active markets, quoted prices for identical or similar instruments in markets that are not active, inputs other than quoted prices that are observable for the asset or liability (such as interest rates, prepayment speeds, volatilities, etc.) or model-based valuation techniques where all significant assumptions are observable, either directly or indirectly, in the market. Level 3 - Valuation is generated from model-based techniques where one or more significant inputs are not observable, either directly or indirectly, in the market. These unobservable assumptions reflect the Company’s own estimates of assumptions that market participants would use in pricing the asset or liability. Valuation techniques may include use of matrix pricing, discounted cash flow models, and similar techniques. Because no market exists for a significant portion of the Company’s financial instruments, fair value estimates are based on judgments regarding current economic conditions, risk characteristics of various financial instruments, and other factors. These estimates are subjective in nature and involve uncertainties and matters of significant judgment and, therefore, cannot be determined with precision. Changes in assumptions could significantly affect the fair values presented. Management uses its best judgment in estimating the fair value of the Company’s financial instruments; however, there are inherent limitations in any estimation technique. Therefore, for substantially all financial instruments, the fair value estimates presented herein are not necessarily indicative of the amounts the Company could have realized in a sales transaction at December 31, 2017 and December 31, 2016 . A financial instrument’s level within the fair value hierarchy is based on the lowest level of input that is significant to the fair value measurement. Management maximizes the use of observable inputs and attempts to minimize the use of unobservable inputs when determining fair value measurements. The following is a description of both the general and specific valuation methodologies used for certain instruments measured at fair value, as well as the general classification of these instruments pursuant to the valuation hierarchy. Cash and due from banks —The carrying amounts of cash and short-term instruments approximate fair value due to the liquidity of these instruments. Investment securities —Investment securities are generally valued based upon quotes obtained from an independent third-party pricing service, which uses evaluated pricing applications and model processes. Observable market inputs, such as, benchmark yields, reported trades, broker/dealer quotes, issuer spreads, two-sided markets, benchmark securities, bids, offers and reference data are considered as part of the evaluation. The inputs are related directly to the security being evaluated, or indirectly to a similarly situated security. Market assumptions and market data are utilized in the valuation models. The Company reviews the market prices provided by the third-party pricing service for reasonableness based on the Company’s understanding of the market place and credit issues related to the securities. The Company has not made any adjustments to the market quotes provided by them and, accordingly, the Company categorized its investment portfolio within Level 2 of the fair value hierarchy. FHLB, FRB, Other Stock —Due to restrictions placed on its transferability, it is not practical to determine the fair value of the stock. Loans Held for Sale —The fair value of loans held for sale is estimated based upon binding contracts and quotes from third party investors resulting in a Level 2 classification. Loans Held for Investment —The fair value of loans, other than loans on nonaccrual status, was estimated by discounting the remaining contractual cash flows using the estimated current rate at which similar loans would be made to borrowers with similar credit risk characteristics and for the same remaining maturities, reduced by deferred net loan origination fees and the allocable portion of the allowance for loan losses. Accordingly, in determining the estimated current rate for discounting purposes, no adjustment has been made for any change in borrowers’ credit risks since the origination of such loans. Rather, the allocable portion of the allowance for loan losses is considered to provide for such changes in estimating fair value. As a result, this fair value is not necessarily the value, which would be derived using an exit price. These loans are included within Level 3 of the fair value hierarchy. Impaired loans and OREO —Impaired loans and OREO assets are recorded at the fair value less estimated costs to sell at the time of foreclosure. The fair value of impaired loans and OREO assets are generally based on recent real estate appraisals adjusted for estimated selling costs. These appraisals may utilize a single valuation approach or a combination of approaches including comparable sales and the income approach. Adjustments are routinely made in the appraisal process by the appraisers to adjust for differences between the comparable sales and income data available. Such adjustments are typically significant and result in a Level 3 classification of the inputs for determining fair value. Deposit Accounts and Short-term Borrowings— The amounts payable to depositors for demand, savings, and money market accounts, and short-term borrowings are considered to approximate fair value. The fair value of fixed-maturity certificates of deposit is estimated using the rates currently offered for deposits of similar remaining maturities using a discounted cash flow calculation. Interest-bearing deposits and borrowings are included within Level 2 of the fair value hierarchy. Term FHLB Advances and Other Long-term Borrowings— The fair value of long term borrowings is determined using rates currently available for similar borrowings with similar credit risk and for the remaining maturities and are classified as Level 2. Subordinated Debentures —The fair value of subordinated debentures is estimated by discounting the balance by the current three-month LIBOR rate plus the current market spread. The fair value is determined based on the maturity date as the Company does not currently have intentions to call the debenture and is classified as Level 2. Accrued Interest Receivable/Payable— The carrying amounts of accrued interest receivable and accrued interest payable are deemed to approximate fair value. Estimated fair values are disclosed for financial instruments for which it is practicable to estimate fair value. These estimates are made at a specific point in time based on relevant market data and information about the financial instruments. These estimates do not reflect any premium or discount that could result from offering the Company’s entire holdings of a particular financial instrument for sale at one time, nor do they attempt to estimate the value of anticipated future business related to the instruments. In addition, the tax ramifications related to the realization of unrealized gains and losses can have a significant effect on fair value estimates and have not been considered in any of these estimates. The fair value estimates presented herein are based on pertinent information available to management as of December 31, 2017 and 2016 . At December 31, 2017 Carrying Amount Level 1 Level 2 Level 3 Estimated Fair Value (dollars in thousands) Assets: Cash and cash equivalents $ 200,064 $ 200,064 $ — $ — $ 200,064 Interest-bearing time deposits with financial institutions 3,693 3,693 — — 3,693 Investments held to maturity 18,291 — 18,082 — 18,082 Investment securities available-for-sale 787,429 — 787,429 — 787,429 FHLB, FRB and other stock 65,881 N/A N/A N/A N/A Loans held for sale 23,426 — 23,524 — 23,524 Loans held for investment, net 6,167,532 — — 6,269,366 6,269,366 Accrued interest receivable 27,053 27,053 — — 27,053 Liabilities: Deposit accounts 6,085,868 5,001,053 1,074,564 — 6,075,617 FHLB advances 490,148 — 489,823 — 489,823 Other borrowings 46,139 — 46,373 — 46,373 Subordinated debentures 105,123 — 115,159 — 115,159 Accrued interest payable 2,131 2,131 — — 2,131 At December 31, 2016 Carrying Amount Level 1 Level 2 Level 3 Estimated Fair Value (dollars in thousands) Assets: Cash and cash equivalents $ 156,857 $ 156,857 $ — $ — $ 156,857 Interest-bearing time deposits with financial institutions 3,944 3,944 — — 3,944 Investments held to maturity 8,565 — 8,461 — 8,461 Investment securities available for sale 380,963 — 380,963 — 380,963 FHLB, FRB and other stock 37,304 N/A N/A N/A N/A Loans held for sale 7,711 — 8,405 — 8,405 Loans held for investment, net 3,220,317 — — 3,211,154 3,211,154 Accrued interest receivable 13,145 13,145 — — 13,145 Liabilities: Deposit accounts 3,145,581 2,330,579 573,467 — 2,904,046 FHLB advances 278,000 — 277,935 — 277,935 Other borrowings 49,971 — 50,905 — 50,905 Subordinated debentures 69,383 — 69,982 — 69,982 Accrued interest payable 1,481 1,481 — — 1,481 The Company’s valuation methodologies may produce a fair value calculation that may not be indicative of net realizable value or reflective of future fair values. While management believes the Company’s valuation methodologies are appropriate and consistent with other market participants, the use of different methodologies or assumptions to determine the fair value of certain financial instruments could result in a different estimate of fair value at the reporting date. A loan is considered impaired when it is probable that payment of interest and principal will not be made in accordance with the contractual terms of the loan agreement. Impairment is measured based on the fair value of the underlying collateral or the discounted expected future cash flows. The Company measures impairment on all non-accrual loans for which it has reduced the principal balance to the value of the underlying collateral less the anticipated selling cost. As such, the Company records impaired loans as non-recurring Level 3 when the fair value of the underlying collateral is based on an observable market price or current appraised value. When current market prices are not available or the Company determines that the fair value of the underlying collateral is further impaired below appraised values, the Company records impaired loans as Level 3. At December 31, 2017 , substantially all the Company’s impaired loans were evaluated based on the fair value of their underlying collateral based upon the most recent appraisal available to management. The measures of fair value on a non-recurring basis are immaterial at December 31, 2017 and 2016 . The following fair value hierarchy tables present information about the Company’s assets measured at fair value on a recurring basis at the dates indicated: At December 31, 2017 Fair Value Measurement Using Level 1 Level 2 Level 3 Securities at Fair Value (dollars in thousands) Investment securities available for sale: Agency $ — $ 47,209 $ — $ 47,209 Corporate — 79,546 — 79,546 Municipal bonds — 232,128 — 232,128 Collateralized mortgage obligation: residential — 33,781 — 33,781 Mortgage-backed securities: residential — 394,765 — 394,765 Total securities available for sale: $ — $ 787,429 $ — $ 787,429 At December 31, 2016 Fair Value Measurement Using Level 1 Level 2 Level 3 Securities at Fair Value (dollars in thousands) Investment securities available for sale: Corporate $ — $ 37,642 $ — $ 37,642 Municipal bonds — 118,803 — 118,803 Collateralized mortgage obligation: residential — 31,388 — 31,388 Mortgage-backed securities: residential — 193,130 — 193,130 Total securities available for sale: $ — $ 380,963 $ — $ 380,963

Earnings Per Share

Earnings Per Share	12 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
Earnings Per Share	Earnings Per Share Earnings per share of common stock is calculated on both a basic and diluted basis based on the weighted average number of common and common equivalent shares outstanding, excluding common shares in treasury. Basic earnings per share excludes dilution and is computed by dividing income available to stockholders by the weighted average number of common shares outstanding for the period. The Company has no outstanding unvested share-based payment awards that contain rights to nonforfeitable dividends that would be considered participating securities for the basic calculation. Diluted earnings per share reflects the potential dilution that could occur if securities or other contracts to issue common stock were exercised or converted into common stock or resulted from the issuance of common stock that then would share in earnings and excludes common shares in treasury. Stock options exercisable for shares of common stock are excluded from the computation of diluted earnings per share if they are anti-dilutive due to their exercise price exceeding the average market price during the period. The impact of stock options, which are anti-dilutive are excluded from the computations of diluted earnings per share. The dilutive impact of these securities could be included in future computations of diluted earnings per share if the market price of the common stock increases. The weighted average number of stock options excluded was 17,524 for December 31, 2017 , 82,760 for December 31, 2016 and 222,858 for December 31, 2015 . A reconciliation of the numerators and denominators used in basic and diluted earnings per share computations is presented in the table below. Income/(Loss) (numerator) Shares (denominator) Per Share Amount (dollars in thousands, except share data) For the year ended December 31, 2017: Net income applicable to earnings per share $ 60,100 Basic earnings per share: Income available to common stockholders 60,100 37,705,556 $ 1.59 Effect of dilutive securities: Warrants and stock option plans — 805,705 Diluted earnings per share: Income available to common stockholders $ 60,100 38,511,261 $ 1.56 For the year ended December 31, 2016: Net income applicable to earnings per share $ 40,103 Basic earnings per share: Income available to common stockholders 40,103 26,931,634 $ 1.49 Effect of dilutive securities: Warrants and stock option plans — 507,525 Diluted earnings per share: Income available to common stockholders $ 40,103 27,439,159 $ 1.46 For the year ended December 31, 2015: Net income applicable to earnings per share $ 25,515 Basic earnings per share: Income available to common stockholders 25,515 21,156,668 $ 1.21 Effect of dilutive securities: Warrants and stock option plans — 332,030 Diluted earnings per share: Income available to common stockholders $ 25,515 21,488,698 $ 1.19

Derivative Instruments

Derivative Instruments	12 Months Ended
	Dec. 31, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments	Derivative Instruments From time to time, the Company enters into interest rate swap agreements with certain borrowers to assist them in mitigating their interest rate risk exposure associated with the loans they have with the Company. At the same time, the Company enters into identical interest rate swap agreements with another financial institution to mitigate the Company’s interest rate risk exposure associated with the swap agreements it enters into with its borrowers. At December 31, 2017 , the Company had swaps with matched terms with an aggregate notional amount of $58.6 million and a fair value of $1.1 million . The fair values of these swaps are recorded as components of other assets and other liabilities in the Company’s condensed consolidated balance sheet. Changes in the fair value of these swaps, which occur due to changes in interest rates, are recorded in the Company’s income statement as a component of noninterest income. Since the terms of the swap agreements between the Company and its borrowers have been matched with the terms of swap agreements with another financial institution, the adjustments for the change in their fair value offset each other in non-interest income. Although changes in the fair value of swap agreements between the Company and borrowers and the Company and other financial institutions offset each other, changes in the credit risk of these counterparties may result in a difference in the fair value of these swap agreements. Offsetting swap agreements the Company has with other financial institutions are collateralized with cash, and swap agreements with borrowers are secured by the collateral arrangements for the underlying loans these borrowers have with the Company. During the twelve months ended December 31, 2017 , there were no losses recorded on swap agreements, attributable to the change in credit risk associated with a counterparty. All interest rate swap agreements entered into by the Company as of December 31, 2017 are not designated as hedging instruments. The following tables summarize the Company's derivative instruments, included in "other assets" and "other liabilities" in the consolidated statements of financial condition. The Company's derivative instruments were acquired as part of the HEOP acquisition, and the Company did not have any at December 31, 2016: December 31, 2017 Derivative Assets Derivative Liabilities Notional Fair Value Notional Fair Value (dollars in thousands) Derivative instruments not designated as hedging instruments: Interest rate swap contracts $ 58,599 $ 1,135 $ 58,599 $ 1,135 Total derivative instruments $ 58,599 $ 1,135 $ 58,599 $ 1,135

Balance Sheet Offsetting

Balance Sheet Offsetting	12 Months Ended
	Dec. 31, 2017
Offsetting [Abstract]
Balance Sheet Offsetting	Balance Sheet Offsetting Derivative financial instruments may be eligible for offset in the consolidated balance sheets, such as those subject to enforceable master netting arrangements or a similar agreement. Under these agreements, the Company has the right to net settle multiple contracts with the same counterparty. The Company offers an interest rate swap product to qualified customers, which are then paired with derivative contracts the Company enters into with a counterparty bank. While derivative contracts entered into with counterparty banks may be subject to enforceable master netting agreements, derivative contracts with customers may not be subject to enforceable master netting arrangements. Financial instruments that are eligible for offset in the consolidated statements of financial condition as of December 31, 2017 are presented in the table below: December 31, 2017 Gross Amounts Not Offset in the Consolidated Gross Amounts Recognized in the Consolidated Balance Sheets Gross Amounts Offset in the Consolidated Balance Sheets Net Amounts Presented in the Consolidated Balance Sheets Financial Instruments Cash Collateral (1) Net Amount (dollars in thousands) Financial assets: Derivatives not designated as $ 1,833 $ (698 ) $ 1,135 $ — $ — $ 1,135 Total $ 1,833 $ (698 ) $ 1,135 $ — $ — $ 1,135 Financial liabilities: Derivatives not designated as $ 1,135 $ — $ 1,135 $ — $ — $ 1,135 Total $ 1,135 $ — $ 1,135 $ — $ — $ 1,135 (1) Represents cash collateral held with counterparty bank.

Related Parties

Related Parties	12 Months Ended
	Dec. 31, 2017
Related Party Transactions [Abstract]
Related Parties	Related Parties Loans to the Company’s executive officers and directors are made in the ordinary course of business, in accordance with applicable regulations and the Company's policies and procedures. At December 31, 2017 , the Company had related party loans outstanding totaling $6.12 million and at December 31, 2016 , the Company had related party loans outstanding totaling $2.38 million . On January 8, 2018, the Company entered into a new related party loan with a commitment amount of $4.0 million . At the end of 2017 , the Company had related party deposits of $746 million compared to $354 million at the end of 2016 . John J. Carona was appointed to the Board of Directors on March 15, 2013, in connection with the Company's acquisition of FAB. Mr. Carona is the President and Chief Executive Officer of Associa, a Texas corporation that specializes in providing management and related services for homeowners associations located across the United States. At December 31, 2017 and 2016 , $736 million and $352 million , respectively, of the related party deposits were attributable to Associa.

Quarterly Results of Operations

Quarterly Results of Operations (Unaudited)	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Quarterly Results of Operations (Unaudited)	Quarterly Results of Operations (Unaudited) The following is a summary of selected financial data presented below by quarter for the periods indicated: First Quarter Second Quarter Third Quarter Fourth Quarter (dollars in thousands, except per share data) For the year ended December 31, 2017: Interest income $ 45,427 $ 68,733 $ 70,161 $ 85,684 Interest expense 3,724 5,395 5,870 7,514 Provision for loan losses 2,502 1,904 2,049 2,185 Noninterest income 4,683 8,759 8,221 9,451 Noninterest expense 29,747 48,496 39,612 49,895 Income tax provision 4,616 7,521 10,619 19,370 Net income $ 9,521 $ 14,176 $ 20,232 $ 16,171 Earnings per share: Basic $ 0.35 $ 0.36 $ 0.51 $ 0.37 Diluted 0.34 0.35 0.50 0.36 For the year ended December 31, 2016: Interest income $ 37,505 $ 40,874 $ 42,429 $ 45,797 Interest expense 3,304 3,313 3,420 3,493 Provision for loan losses 1,120 1,589 4,013 2,054 Noninterest income 4,848 4,468 5,968 4,318 Noninterest expense 23,633 23,713 25,860 25,377 Income tax provision 5,742 6,358 5,877 7,238 Net income $ 8,554 $ 10,369 $ 9,227 $ 11,953 Earnings per share: Basic $ 0.33 $ 0.38 $ 0.34 $ 0.44 Diluted 0.33 0.37 0.33 0.43

Parent Company Financial Inform

Parent Company Financial Information	12 Months Ended
	Dec. 31, 2017
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Parent Company Financial Information	Parent Company Financial Information The Corporation is a California-based bank holding company organized in 1997 as a Delaware corporation and owns 100% of the capital stock of the Bank, its principal operating subsidiary. The Bank was incorporated and commenced operations in 1983. Condensed financial statements of the Corporation are as follows: PACIFIC PREMIER BANCORP, INC. STATEMENTS OF FINANCIAL CONDITION (Parent company only) At December 31, 2017 2016 (dollars in thousands) Assets Cash and cash equivalents $ 17,097 $ 15,124 Investment in subsidiaries 1,329,961 513,606 Other assets 2,599 2,400 Total Assets $ 1,349,657 $ 531,130 Liabilities Subordinated debentures $ 105,123 $ 69,383 Accrued expenses and other liabilities 2,538 2,007 Total Liabilities 107,661 71,390 Total Stockholders’ Equity 1,241,996 459,740 Total Liabilities and Stockholders’ Equity $ 1,349,657 $ 531,130 PACIFIC PREMIER BANCORP, INC. STATEMENTS OF OPERATIONS (Parent company only) For the Years Ended December 31, 2017 2016 2015 (dollars in thousands) Income Interest income $ 36 $ 31 $ 27 Noninterest income — — — Total income 36 31 27 Expense Interest expense 4,720 3,844 3,937 Noninterest expense 8,956 3,769 2,831 Total expense 13,676 7,613 6,768 Loss before income tax provision (13,640 ) (7,582 ) (6,741 ) Income tax benefit (5,417 ) (2,785 ) (2,783 ) Net loss (parent only) (8,223 ) (4,797 ) (3,958 ) Equity in net earnings of subsidiaries 68,323 44,900 29,473 Net income $ 60,100 $ 40,103 $ 25,515 PACIFIC PREMIER BANCORP, INC. SUMMARY STATEMENTS OF CASH FLOWS (Parent company only) For the Years Ended December 31, 2017 2016 2015 CASH FLOWS FROM OPERATING ACTIVITIES (dollars in thousands) Net income $ 60,100 $ 40,103 $ 25,515 Adjustments to reconcile net income to cash used in operating activities: Share-based compensation expense 5,809 2,729 1,165 Equity in undistributed earnings of subsidiaries and dividends from the bank (68,323 ) (44,901 ) (29,473 ) Increase (decrease) in accrued expenses and other liabilities (365 ) 240 166 (Decrease) increase in current and deferred taxes (896 ) — 3,566 Decrease (increase) in other assets 1,714 4,794 (6,893 ) Net cash (used in) provided by operating activities (1,961 ) 2,965 (5,954 ) CASH FLOWS FROM FINANCING ACTIVITIES: Proceeds from issuance of common stock, net of issuance cost — — — Repurchase of common stock (1,258 ) (125 ) (116 ) Proceeds from exercise of options and warrants 4,592 1,107 758 Capital contribution to Bank 600 7,765 (10,000 ) Proceeds from issuance of subordinated debentures — — — Net cash provided by (used in) financing activities 3,934 8,747 (9,358 ) Net increase (decrease) in cash and cash equivalents 1,973 11,712 (15,312 ) Cash and cash equivalents, beginning of year 15,124 3,412 18,724 Cash and cash equivalents, end of year $ 17,097 $ 15,124 $ 3,412

Acquisitions

Acquisitions	12 Months Ended
	Dec. 31, 2017
Business Combinations [Abstract]
Acquisitions	Acquisitions Plaza Bancorp Acquisition Effective as of November 1, 2017, the Company completed the acquisition of Plaza Bancorp (OTC Market Group Pink Sheets: PLZZ) (“Plaza”), the holding company of Plaza Bank, a California chartered banking corporation headquartered in Irvine, California with $1.3 billion in total assets, $1.1 billion in gross loans and $1.1 billion in total deposits. Pursuant to the terms of the merger agreement, each outstanding share of PLZZ common stock was converted into the right to receive 0.2000 shares of Company common stock. The value of the total deal consideration was approximately $251 million , which included approximately $6.5 million of aggregate cash consideration payable to holders of unexercised options and warrants exercisable for shares of PLZZ common stock, and the issuance of 6,049,373 shares of the Company's common stock, which had a value of $40.40 per share, which was the closing price of the Company's common stock on October 31, 2017, the last trading day prior to the consummation of the acquisition. Goodwill in the amount of $122 million was recognized in the PLZZ acquisition. Goodwill represents the future economic benefits arising from net assets acquired that are not individually identified and separately recognized and is attributable to synergies expected to be derived from the combination of the two entities. Goodwill recognized in this transaction is not deductible for income tax purposes. The following table represents the assets acquired and liabilities assumed of PLZZ as of November 1, 2017 and the fair value adjustments and amounts recorded by the Company in 2017 under the acquisition method of accounting, which are subject to adjustment for up to one year after the merger date: PLZZ Fair Value Fair Book Value Adjustment Value (dollars in thousands) ASSETS ACQUIRED Cash and cash equivalents $ 150,459 $ — $ 150,459 Loans, gross 1,069,359 (6,418 ) 1,062,941 Allowance for loan losses (13,009 ) 13,009 — Fixed assets 7,389 (194 ) 7,195 Core deposit intangible 198 11,382 11,580 Deferred tax assets 11,849 (6,876 ) 4,973 Other assets 19,495 (330 ) 19,165 Total assets acquired $ 1,245,740 $ 10,573 $ 1,256,313 LIABILITIES ASSUMED Deposits $ 1,081,727 $ 1,224 $ 1,082,951 Borrowings 40,755 397 41,152 Other Liabilities 8,956 (622 ) 8,334 Total liabilities assumed 1,131,438 999 1,132,437 Excess of assets acquired over liabilities assumed $ 114,302 $ 9,574 123,876 Consideration paid 250,939 Paid by PLZZ prior to close 6,544 Capitalized merger-related expense 1,366 Goodwill recognized $ 121,885 Heritage Oaks Bancorp Acquisition Effective as of April 1, 2017, the Company completed the acquisition of HEOP, the holding company of Heritage Oaks Bank, a Paso Robles, California based state-chartered bank (“Heritage Oaks Bank”) with $2.0 billion in total assets, $1.4 billion in gross loans and $1.7 billion in total deposits at March 31, 2017. Heritage Oaks Bank operates branches within San Luis Obispo and Santa Barbara Counties and a loan production office in Ventura County. Pursuant to the terms of the merger agreement, each outstanding share of HEOP common stock was converted into the right to receive 0.3471 shares of corporate common stock. The value of the total deal consideration was approximately $465 million , which included approximately $3.9 million of aggregate cash consideration payable to holders of Heritage Oaks share-based compensation awards, and the issuance of 11,959,022 shares of the Corporation's common stock, which had a value of $38.55 per share, which was the closing price of the Corporation's common stock on March 31, 2017, the last trading day prior to the consummation of the acquisition. Goodwill in the amount of $269 million was recognized in the HEOP acquisition. Goodwill represents the future economic benefits arising from net assets acquired that are not individually identified and separately recognized and is attributable to synergies expected to be derived from the combination of the two entities. Goodwill recognized in this transaction is not deductible for income tax purposes. The following table represents the assets acquired and liabilities assumed of HEOP as of April 1, 2017 and the fair value adjustments and amounts recorded by the Company in 2017 under the acquisition method of accounting: HEOP Book Value Fair Value Adjustments Fair Value ASSETS ACQUIRED (dollars in thousands) Cash and cash equivalents $ 78,728 $ — $ 78,728 Investment securities 447,520 (4,597 ) 442,923 Loans, gross 1,387,949 (23,300 ) 1,364,649 Allowance for loan losses (17,200 ) 17,200 — Fixed assets 35,567 (665 ) 34,902 Core deposit intangible — 28,123 28,123 Deferred tax assets 17,850 (6,567 ) 11,283 Other assets 55,223 (9 ) 55,214 Total assets acquired $ 2,005,637 $ 10,185 $ 2,015,822 LIABILITIES ASSUMED Deposits $ 1,668,079 $ 1,471 $ 1,669,550 Borrowings 141,996 (2,962 ) 139,034 Other Liabilities 7,290 771 8,061 Total liabilities assumed 1,817,365 (720 ) 1,816,645 Excess of assets acquired over liabilities assumed $ 188,272 $ 10,905 199,177 Consideration paid 465,482 Capitalized merger-related expense 2,649 Goodwill recognized $ 268,954 The fair values are estimates and are subject to adjustment for up to one year after the merger date. In the third quarter of 2017, the Company made a $1.1 million adjustment to deferred tax assets and the deal consideration. Security Bank Acquisition On January 31, 2016, the Company completed its acquisition of SCAF whereby we acquired $714 million in total assets, $456 million in loans and $637 million in total deposits. Under the terms of the merger agreement, each share of SCAF common stock was converted into the right to receive 0.9629 shares of the Corporation’s common stock. The value of the total deal consideration was $120 million , which includes $788,000 of aggregate cash consideration to the holders of SCAF stock options and the issuance of 5,815,051 shares of the Corporation’s common stock, valued at $119.4 million based on a closing stock price of $20.53 per share on January 29, 2016. SCAF was the holding company of Security Bank of California, a Riverside, California, based state-chartered bank with six branches located in Riverside County, San Bernardino County and Orange County. Goodwill in the amount of $51.7 million was recognized in the SCAF acquisition. Goodwill represents the future economic benefits arising from net assets acquired that are not individually identified and separately recognized and is attributable to synergies expected to be derived from the combination of the two entities. Goodwill recognized in this transaction is not deductible for income tax purposes. The following table represents the assets acquired and liabilities assumed of SCAF as of January 31, 2016 and the fair value adjustments and amounts recorded by the Company in 2016 under the acquisition method of accounting: SCAF Book Value Fair Value Adjustments Fair Value (dollars in thousands) ASSETS ACQUIRED Cash and cash equivalents $ 40,947 $ — $ 40,947 Interest-bearing deposits with financial institutions 1,972 — 1,972 Investment securities 191,881 (1,627 ) 190,254 Loans, gross 467,197 (11,039 ) 456,158 Allowance for loan losses (7,399 ) 7,399 — Fixed assets 5,335 (1,145 ) 4,190 Core deposit intangible 493 3,826 4,319 Deferred tax assets 5,618 1,130 6,748 Other assets 10,589 (1,227 ) 9,362 Total assets acquired $ 716,633 $ (2,683 ) $ 713,950 LIABILITIES ASSUMED Deposits $ 636,450 $ 141 $ 636,591 Borrowings — — — Deferred tax liability — — — Other Liabilities 9,063 (220 ) 8,843 Total liabilities assumed 645,513 (79 ) 645,434 Excess of assets acquired over liabilities assumed $ 71,120 $ (2,604 ) 68,516 Consideration paid 120,174 Goodwill recognized $ 51,658 The Company accounted for these transactions under the acquisition method of accounting in accordance with ASC 805, Business Combinations , which requires purchased assets and liabilities assumed to be recorded at their respective fair values at the date of acquisition. The loan portfolios of SCAF, HEOP and PLZZ were recorded at fair value at the date of each acquisition. A valuation of SCAF, HEOP and PLZZ's loan portfolio was performed as of the acquisition dates to assess the fair value of the loan portfolio. The loan portfolios were both segmented into two groups; loan with credit deterioration and loans without credit deterioration, and then split further by loan type. The fair value was calculated on an individual loan basis using a discounted cash flow analysis. The discount rate utilized was based on a weighted average cost of capital, considering the cost of equity and cost of debt. Also factored into the fair value estimates were loss rates, recovery period and prepayment rates based on industry standards. The Company also determined the fair value of the core deposit intangible, securities and deposits with the assistance of third-party valuations as well as the fair value of OREO was based on recent appraisals of the properties. The core deposit intangible on non-maturing deposit was determined by evaluating the underlying characteristics of the deposit relationships, including customer attrition, deposit interest rates, service charge income, overhead expense and costs of alternative funding. Since the fair value of intangible assets are calculated as if they were stand-alone assets, the presumption is that a hypothetical buyer of the intangible asset would be able to take advantage of potential tax benefits resulting from the asset purchase. The value of the benefit is the present value over the period of the tax benefit, using the discount rate applicable to the asset. In determining the fair value of certificates of deposit, a discounted cash flow analysis was used, which involved present valuing the contractual payments over the remaining life of the certificates of deposit at market-based interest rates. For loans acquired from SCAF, HEOP and PLZZ, the contractual amounts due, expected cash flows to be collected, interest component and fair value as of the respective acquisition dates were as follows: Acquired Loans SCAF HEOP PLZZ (dollars in thousands) Contractual amounts due $ 539,806 $ 1,717,230 $ 1,703,246 Cash flows not expected to be collected 2,765 4,442 20,152 Expected cash flows 537,041 1,712,788 1,683,094 Interest component of expected cash flows 80,883 348,100 625,592 Fair value of acquired loans $ 456,158 $ 1,364,688 $ 1,057,502 In accordance with generally accepted accounting principles, there was no carryover of the allowance for loan losses that had been previously recorded by SCAF, HEOP and PLZZ. The operating results of the Company for the twelve months ending December 31, 2017 include the operating results of SCAF, HEOP and PLZZ since their respective acquisition dates. The following table presents the net interest and other income, net income and earnings per share as if the merger with SCAF, HEOP and PLZZ were effective as of January 1, 2017, 2016 and 2015 for the respective year in which each acquisition was closed. The unaudited pro forma information in the following table is intended for informational purposes only and is not necessarily indicative of our future operating results or operating results that would have occurred had the mergers been completed at the beginning of each respective year. N o assumptions have been applied to the pro forma results of operations regarding possible revenue enhancements, expense efficiencies or asset dispositions. Unaudited pro forma net interest and other income, net income and earnings per share presented below: Year Ended December 31, 2017 2016 2015 Net interest and other income $ 342,159 $ 258,970 $ 246,622 Net income 72,316 71,722 58,257 Basic earnings per share 1.58 1.58 1.30 Diluted earnings per share 1.55 1.56 1.29

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2017
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events Pacific Premier Bancorp, Inc. and Grandpoint Capital, Inc. On February 9, 2018, we entered into a definitive agreement with Grandpoint Capital, Inc. to acquire Grandpoint and its wholly-owned, California-chartered state bank subsidiary, Grandpoint Bank. Grandpoint is headquartered in Los Angeles, California with $3.2 billion in total assets, $2.4 billion in gross loans and $2.4 billion in total deposits at December 31, 2017. Grandpoint operates 14 regional offices in Southern California, Arizona and Vancouver, Washington. Under the terms of the definitive agreement, holders of Grandpoint common stock will have the right to receive 0.4750 shares of Company common stock. The proposed transaction is expected to close in the third quarter of 2018, subject to satisfaction of customary closing conditions, including regulatory approvals and approval of Grandpoint’s and the Corporation’s shareholders. Certain Grandpoint shareholders, as well as Grandpoint's directors and executive officers have entered into agreements with the Corporation pursuant to which they have committed to provide written consents with respect to shares of Grandpoint common stock in favor of the acquisition. Related Party Loan On January 8, 2018, the Company entered into a new related party loan having a commitment amount of $4.0 million .

Description of Business and S35

Description of Business and Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Description of Business	Description of Business —The Corporation, a Delaware corporation organized in 1997, is a California-based bank holding company that owns 100% of the capital stock of the Bank, the Corporation’s principal operating subsidiary. The Bank was incorporated and commenced operations in 1983. The principal business of the Company is attracting deposits from the general public and investing those deposits, together with funds generated from operations and borrowings, primarily in business loans and real estate property loans. At December 31, 2017 , the Company had 33 depository branches located in the counties of Orange, Los Angeles, Riverside, San Bernardino, San Diego, San Luis Obispo and Santa Barbara, California as well as Clark County, Nevada. The Company is subject to competition from other financial institutions. The Company is subject to the regulations of certain governmental agencies and undergoes periodic examinations by those regulatory authorities.
Principles of Consolidation	Principles of Consolidation —The consolidated financial statements include the accounts of Pacific Premier Bancorp, Inc. (the ‘‘Corporation’’) and its wholly-owned subsidiary, Pacific Premier Bank (the ‘‘Bank’’) (collectively, the ‘‘Company’’). The Company accounts for its investments in its wholly-owned special purpose entities, PPBI Statutory Trust I, Heritage Oaks Capital Trust II, Mission Community Capital Trust I and Santa Lucia Bancorp (CA) Capital Trust, under the equity method whereby the subsidiary’s net earnings are recognized in the Company’s Statement of Income and the investment in these entities is included in Other Assets on the Company’s Consolidated Statements of Financial Condition. The Company is organized and operates as a single reporting segment, principally engaged in the commercial banking business. All significant intercompany accounts and transactions have been eliminated in consolidation.
Basis of Financial Statement Presentation	Basis of Financial Statement Presentation —The accompanying consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States ("U.S. GAAP"). Certain amounts in the financial statements and related footnote disclosures for the prior years have been reclassified to conform to the current presentation with no impact to previously reported net income or stockholders' equity.
Use of Estimates	Use of Estimates —The preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements, as well as the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Estimates may change as new information is obtained.
Cash and Cash Equivalents	Cash and Cash Equivalents —Cash and cash equivalents include cash on hand, cash balances due from banks and federal funds sold. Interest bearing deposits with financial institutions represent primarily cash held at the Federal Reserve Bank of San Francisco. At December 31, 2017 , there were no cash reserves required by the Board of Governors of the Federal Reserve System (“Federal Reserve”) for depository institutions based on the amount of deposits held. The Company maintains amounts due from banks that exceed federally insured limits. The Company has not experienced any losses in such accounts.
Securities	Securities —The Company has established written guidelines and objectives for its investing activities. At the time of purchase, management designates the security as either held to maturity, available-for-sale or held for trading based on the Company’s investment objectives, operational needs and intent. The investments are monitored to ensure that those activities are consistent with the established guidelines and objectives.
Securities Held-to-Maturity	Securities Held-to-Maturity —Investments in debt securities that management has the positive intent and ability to hold to maturity are reported at cost and adjusted for periodic principal payments and the amortization of premiums and accretion of discounts, which are recognized in interest income using the interest method over the period of time to investment's maturity.
Securities Available-for-sale	Securities Available-for-Sale —Investments in debt securities that management has no immediate plan to sell, but which may be sold in the future, are carried at fair value. Premiums and discounts are amortized using the interest method over the remaining period to the call date for premiums or contractual maturity for discounts and, in the case of mortgage-backed securities the estimated average life, which can fluctuate based on the anticipated prepayments on the underlying collateral of the securities. Unrealized holding gains and losses, net of tax, are recorded in a separate component of stockholders’ equity as accumulated other comprehensive income. Realized gains and losses on the sales of securities are determined on the specific identification method, recorded on a trade date basis based on the amortized cost basis of the specific security and are included in noninterest income as net gain (loss) on investment securities.
Impairment of Investments	Impairment of Investments —Quarterly, the Company evaluates investment securities in an unrealized loss position for OTTI. In determining whether a security's decline in fair value is other-than-temporary, the Company considers a number of factors including: (i) the length of time and the extent to which the fair value of the investment has been less than its amortized cost; (ii) the financial condition and near-term prospects of the issuer; (iii) the intent and ability of the Company to hold the investment for a period of time sufficient to allow for an anticipated recovery in fair value; (iv) downgrades in credit ratings; and (v) general market conditions which reflect prospects for the economy as a whole, including interest rates and sector credit spreads. If it is determined that an OTTI exists, and either the Company intends to sell the investment or it is likely the Company will be required to sell the investment before its anticipated recovery, the total amount of the OTTI, which is measured as the amount by which the investment's amortized cost exceeds its fair value, is recognized in current period earnings. If the Company has the intent and ability to hold the investment and it is more likely than not it will be required to sell the investment prior to an anticipated recovery of its amortized cost basis, the Company records in current period earnings the portion of OTTI deemed to be credit related, while the remaining portion of OTTI deemed to be non-credit related is recorded in accumulated other comprehensive income. Credit related losses are determined through a discounted cash flow analysis, which incorporates assumptions concerning the estimated timing and amounts of expected cash flows. Non-credit related OTTI losses result from other factors such as change in interest rates and general market conditions. The presentation of OTTI in the consolidated financial statements is on a gross basis with a reduction in the gross amount for the portion of the loss deemed non-credit related and is recorded in accumulated other comprehensive income.
Federal Home Loan Bank Stock	Federal Home Loan Bank Stock —The Bank is a member of the FHLB system. Members are required to own a certain amount of stock based on the level of borrowings and other factors, and may invest in additional amounts. FHLB stock is carried at cost and periodically evaluated for impairment based on ultimate recovery of par value. Both cash and stock dividends are recorded as a component of interest income.
Federal Reserve Bank Stock	Federal Reserve Bank Stock —The Bank is a member of the Federal Reserve Bank of San Francisco. FRB stock is carried at cost, classified as a restricted security, and periodically evaluated for impairment based on ultimate recovery of par value. Both cash and stock dividends are recorded as a component of interest income.
Loans Held for Sale	Loans Held for Sale —Loans that the Company has the intent to sell prior to maturity have been designated as held for sale at origination and are recorded at lower of cost or fair value. Gains or losses are recognized upon the sale of the loans on a specific identification basis.
Loan Servicing Assets	Loan Servicing Assets —Servicing assets are related to SBA loans sold and are recognized at the time of sale when servicing is retained with the income statement effect recorded in gains on sales of SBA loans. Servicing assets are initially recorded at fair value based on the present value of the contractually specified servicing fee, net of estimated servicing costs, over the estimated life of the loan, using a discount rate. The Company’s servicing costs approximates the industry average servicing costs of approximately 40 basis points. The servicing assets are subsequently amortized into noninterest income in proportion to, and over the period of, the estimated future net servicing income of the underlying loans. The Company periodically evaluates servicing assets for impairment based upon the fair value of the assets as compared to their carrying amount. The Company typically sells the guaranteed portion of SBA loans and retains the unguaranteed portion (“retained interest”). A portion of the premium on sale of SBA loans is recognized as gain on sale of loans at the time of the sale by allocating the carrying amount between the asset sold and the retained interest, based on their relative fair values. The remaining portion of the premium is recorded as a discount on the retained interest and is amortized over the remaining life of the loan as an adjustment to yield. The retained interest, net of any discount, are included in loans held for investment—net of allowance for loan losses in the accompanying consolidated statements of financial condition.
Loans Held for Investment	Loans Held for Investment —Loans held for investment are loans the Company has the ability and intent to hold until their maturity. The loans are carried at amortized cost, net of discounts and premiums on purchased loans, deferred loan origination fees and costs and ALLL. Net deferred loan origination fees and costs on loans are amortized or accreted using the interest method over the expected life of the loans. Amortization of deferred loan fees and costs are discontinued for loans placed on nonaccrual. Any remaining deferred fees or costs and prepayment fees associated with loans that payoff prior to contractual maturity are included in loan interest income in the period of payoff. Loan commitment fees received to originate or purchase a loan are deferred and, if the commitment is exercised, recognized over the life of the loan using the interest method as an adjustment of yield or, if the commitment expires unexercised, recognized as income upon expiration of the commitment. Interest on loans is recognized using the interest method and is only accrued if deemed collectible. Loans for which the accrual of interest has been discontinued are designated as nonaccrual loans. The accrual of interest on loans is discontinued when principal or interest is past due 90 days based on contractual terms of the loan or when, in the opinion of management, there is reasonable doubt as to collection of principal and or interest. When loans are placed on nonaccrual status, all interest previously accrued but not collected is reversed against current period interest income. Interest income generally is not recognized on nonaccrual loans unless the likelihood of further loss is remote. Interest payments received on nonaccrual loans are applied as a reduction to the loan principal balance. Interest accruals are resumed on such loans only when they are brought current with respect to interest and principal and when, in the judgment of management, the loans are estimated to be fully collectible as to all principal and interest. A loan is considered to be impaired when it is probable that the Company will be unable to collect all amounts due (principal and interest) according to the contractual terms of the loan agreement. The Company reviews loans for impairment when the loan is classified as substandard or worse, delinquent 90 days, determined by management to be collateral dependent, or when the borrower files bankruptcy or is granted concession which qualifies as a troubled debt restructuring. Measurement of impairment is based on the loan’s expected future cash flows discounted at the loan’s effective interest rate, measured by reference to an observable market value, if one exists, or the fair value of the collateral if the loan is deemed collateral dependent. The Company selects the measurement method on a loan-by-loan basis except those loans deemed collateral dependent. Loans for which impairment has been determined are generally charged-off at such time the loan is classified as a loss.
Allowance for Loan Losses	Allowance for Loan Losses— The Company maintains an ALLL at a level deemed appropriate by management to provide for known or probable incurred losses in the portfolio as of the date of the consolidated statements of financial condition. The Company has an internal asset review system and loss allowance methodology designed to provide for the detection of problem assets and an appropriate level of allowance to cover loan losses. Management’s determination of the adequacy of the ALLL is based on an evaluation of the composition of the portfolio, actual loss experience, industry charge-off experience on income property loans, current economic conditions, and other relevant factors in the area in which the Company’s lending and real estate activities are based. These factors may affect the borrowers’ ability to pay as well as the value of the underlying collateral securing loans. The allowance is calculated by applying loss factors to loans held for investment according to loan type and loan credit classification. The loss factors are based primarily upon the Bank’s historical loss experience and industry charge-off experience and are evaluated on a quarterly basis. At December 31, 2017 , the following portfolio segments have been identified. Segments are groupings of similar loans at a level, which the Company has adopted systematic methods of documentation for determining its allowance for loan losses: • Commercial and industrial (including Franchise) - Commercial and industrial loans are secured by business assets including inventory, receivables and machinery and equipment to businesses located generally in our primary market area. Loan types includes revolving lines or credit, term loans, seasonal loans and loans secured by liquid collateral such as cash deposits or marketable securities. HOA credit facilities are included in C&I loans. We also issue letters of credit on behalf of our customers. Risk arises primarily due to the difference between expected and actual cash flows of the borrowers. In addition, the recoverability of the Company's investment in these loans is also dependent on other factors primarily dictated by the type of collateral securing these loans. The fair value of the collateral securing these loans may fluctuate as market conditions change. In the case of loans secured by accounts receivable, the recovery of the Company's investment is dependent upon the borrower's ability to collect amounts due from its customers. • Commercial real estate (including owner-occupied and nonowner occupied) - Commercial real estate includes various type of loans which the Company holds real property as collateral. Commercial real estate lending activity is typically restricted to owner-occupied or nonowner-occupied. The primary risks of real estate loans include the borrower's inability to pay, material decreases in the value of the real estate that is being held as collateral and significant increases in interest rates, which may make the real estate loan unprofitable. Real estate loans may be more adversely affected by conditions in the real estate markets or in the general economy. • SBA - We are approved to originate loans under the SBA's Preferred Lenders Program ("PLP"). The PLP lending status affords us a higher level of delegated credit autonomy, translating to a significantly shorter turnaround time from application to funding, which is critical to our marketing efforts. We originate loans nationwide under the SBA's 7(a), SBA Express, International Trade and 504(a) loan programs, in conformity with SBA underwriting and documentation standards. SBA loans are similar to commercial business loans, but have additional credit enhancement provided by the U.S. Small Business Administration, for up to 85 percent of the loan amount for loans up to $150,000 and 75 percent of the loan amount for loans of more than $150,000. The Company originates SBA loans with the intent to sell the guaranteed portion into the secondary market on a quarterly basis. • Agribusiness and farmland - We originate loans to the agricultural community to fund seasonal production and longer term investments in land, buildings, equipment, crops and livestock. Agribusiness loans are for the purpose of financing agricultural production to finance crops and livestock. Farmland loans include all land know to be used or usable for agricultural purposes, such as crop and livestock production and is secured by the land and improvements thereon. • Multi-family - Loans secured by multi-family and commercial real estate properties generally involve a greater degree of credit risk than one-to-four family loans. Because payments on loans secured by multi-family and commercial real estate properties are often dependent on the successful operation or management of the properties, repayment of these loans may be subject to adverse conditions in the real estate market or the economy. • One-to-four family - Although we do not originate, through our bank acquisitions, we have acquired first lien single family loans, we occasionally purchase such loans to diversify our portfolio. The primary risks of one-to-four family loans include the borrower's inability to pay, material decreases in the value of the real estate that is being held as collateral and significant increases in interest rates, which may make loan unprofitable. • Construction and land - We originate loans for the construction of 1-4 family and multi-family residences and CRE properties in our market area. We concentrate our efforts on single homes and small infill projects in established neighborhoods where there is not abundant land available for development. Construction loans are considered to have higher risks due to construction completion and timing risk, and the ultimate repayment being sensitive to interest rate changes, government regulation of real property and the availability of long-term financing. Additionally, economic conditions may impact the Company's ability to recover its investment in construction loans, as adverse economic conditions may negatively impact the real estate market, which could affect the borrower's ability to complete and sell the project. Additionally, the fair value of the underlying collateral may fluctuate as market conditions change. We occasionally originate land loans located predominantly in California for the purpose of facilitating the ultimate construction of a home or commercial building. The primary risks include the borrower's inability to pay and the inability of the Company to recover its investment due to a decline in the fair value of the underlying collateral. • Consumer loans - We originate a limited number of consumer loans, generally for banking customers only, which consist primarily of home equity lines of credit, savings account secured loans and auto loans. Repayment of these loans is dependent on the borrower's ability to pay and the fair value of the underlying collateral. Various regulatory agencies, as an integral part of their examination process, periodically review the Company’s ALLL. Such agencies may require the Company to recognize additions to the allowance based on judgments different from those of management. In the opinion of management, and in accordance with the credit loss allowance methodology, the present allowance is considered adequate to absorb probable incurred credit losses. Additions and reductions to the allowance are reflected in current operations. Charge-offs to the allowance, for all loan segments, are made when specific assets are considered uncollectible or are transferred to other real estate owned and the fair value of the property is less than the loan’s recorded investment. Recoveries are credited to the allowance. Although management uses the best information available to make these estimates, future adjustments to the allowance may be necessary due to economic, operating, regulatory and other conditions that may extend beyond the Company’s control.
Purchased Credit Impaired Loans	Purchased Credit Impaired Loans —As part of business acquisitions, the Bank acquires certain loans that have shown evidence of credit deterioration since origination, referred to as purchased credit impaired loans. These loans are recorded at the fair value, such that no ALLL for PCI is established upon their acquisition. The Company has elected to account for such loans individually. The Company estimates the amount and timing of expected cash flows for each purchased loan, and the expected cash flows in excess of the fair value is recorded as interest income over the remaining life of the loan and is referred to as the accretable yield. The excess of the loan’s contractual principal and interest over expected cash flows is not recorded and is referred to as the non-accretable difference. Over the life of the loan, expected cash flows continue to be estimated. Subsequent decreases in expected future cash flows beyond the expected cash flows as of the acquisition date are accounted for through a charge to the provision for loan losses. If subsequent reforecasts indicate there has been a probable and significant increase in the level of expected future cash flows, the Company first reduces any previously established ALLL for PCI loans and then accounts for the remainder of the increase through interest income as a yield adjustment.
Other Real Estate Owned	Other Real Estate Owned— Real estate properties acquired through, or in lieu of, loan foreclosure are recorded at fair value, less cost to sell, with any excess loan balance over the fair value of the property charged against the ALLL. The Company obtains an appraisal and/or market valuation on all other real estate owned at the time of possession. After foreclosure, valuations are periodically performed by management. Any subsequent fair value losses are recorded as a charge to current period earnings with a corresponding write-down to the asset. All legal fees and direct costs, including foreclosure and other related costs are expensed as incurred.
Premises and Equipment	Premises and Equipment— Premises and equipment are carried at cost less accumulated depreciation and amortization. Depreciation and amortization are computed using the straight-line method over the estimated useful lives of the assets, which range from forty years for buildings, seven years for furniture, fixtures and equipment, and three years for computer and telecommunication equipment. The cost of leasehold improvements is amortized using the straight-line method over the shorter of the estimated useful life of the asset or the term of the related leases. The Company periodically evaluates the recoverability of long-lived assets, such as premises and equipment, to ensure the carrying value has not been impaired. Assets to be disposed of are reported at the lower of the carrying amount or fair value less costs to sell.
Securities Sold Under Agreements to Repurchase	Securities Sold Under Agreements to Repurchase— The Company enters into sales of securities under agreement to repurchase. These agreements are treated as financing arrangements and, accordingly, the obligations to repurchase the securities sold are reflected as liabilities in the Company’s consolidated financial statements. The securities collateralizing these agreements are delivered to several major national brokerage firms who arranged the transactions. The securities are reflected as assets in the Company’s consolidated financial statements. The brokerage firms may loan such securities to other parties in the normal course of their operations and agree to return the identical security to the Company at the maturity of the agreements.
Bank Owned Life Insurance	Bank Owned Life Insurance— Bank owned life insurance is accounted for using the cash surrender value method and is recorded at its realizable value. The change in the net asset value is included in other assets and other noninterest income.
Goodwill and Core Deposit Intangible	Goodwill and Core Deposit Intangible— Goodwill is generally determined as the excess of the fair value of the consideration transferred, plus the fair value of any noncontrolling interests in the acquiree, over the fair value of the net assets acquired and liabilities assumed as of the acquisition date. Goodwill and intangible assets acquired in a purchase business combination and determined to have indefinite useful lives are not amortized, but tested for impairment at least annually or more frequently if events and circumstances exist that indicate the necessity for such impairment tests to be performed. The Company typically performs its annual impairment testing in the fourth quarter. Intangible assets with definite useful lives are amortized over their estimated useful lives to their estimated residual values. Goodwill is the only intangible asset with an indefinite life on our balance sheet. Core deposit intangible assets arising from whole bank acquisitions are amortized on either an accelerated basis, reflecting the pattern in which the economic benefits of the intangible asset is consumed or otherwise used up, or on a straight-line amortization method over their estimated useful lives, which ranges from 6 to 10 years.
Loan Commitments and Related Financial Instruments	Loan Commitments and Related Financial Instruments— Financial instruments include off-balance sheet credit instruments, such as commitments to make loans and commercial letters of credit, issued to meet customer financing needs. The face amount for these items represents the exposure to loss, before considering customer collateral or ability to repay. Such financial instruments are recorded when they are funded.
Subordinated Debentures	Subordinated Debentures— Long-term borrowings are carried at cost, adjusted for amortization of premiums and accretion of discounts, which are recognized in interest expense using the interest method. Debt issuance costs are recognized in interest expense using the interest method over the life of the instrument.
Stock-Based Compensation	Stock-Based Compensation —The Company issues stock-based awards to certain officers and directors of the Company. The related compensation costs are recognized in the income statement based on the grant-date fair value over the grantee's requisite service period (generally the vesting period). A Black-Scholes model is utilized to estimate the fair value of stock options and the market price of the Company's common stock at the date of the grant is used for restricted stock awards.
Income Taxes	Income Taxes— Deferred tax assets and liabilities are recorded for the expected future tax consequences of events that have been recognized in the Company’s financial statements or tax returns using the asset liability method. In estimating future tax consequences, all expected future events other than enactments of changes in the tax law or rates are considered. The effect on deferred taxes of a change in tax rates is recognized in income in the period that includes the enactment date. Deferred tax assets are to be recognized for temporary differences that will result in deductible amounts in future years and for tax carryforwards if, in the opinion of management, it is more likely than not that the deferred tax assets will be realized. At December 31, 2016, there was no valuation allowance deemed necessary against the Company’s deferred tax asset. At December 31, 2017, a valuation allowance of $380,000 was recorded against the capital loss carryover deferred tax asset, as the Company does not believe it will generate sufficient capital gain before the capital loss carryover expires. A tax position is recognized as a benefit only if it is “more likely than not” that the tax position would be sustained in a tax examination, with a tax examination being presumed to occur. The amount recognized is the largest amount of tax benefit that is greater than 50% likely of being realized on examination. For tax positions not meeting the “more likely than not” test, no tax benefit is recorded. The Company recognizes interest and / or penalties related to income tax matters in income tax expense.
Earnings per Share	Earnings per Share— Earnings per share of common stock is calculated on both a basic and diluted basis based on the weighted average number of common and common equivalent shares outstanding, excluding common shares in treasury. Basic earnings per share excludes dilution and is computed by dividing income available to stockholders by the weighted average number of common shares outstanding for the period. The Company has no outstanding unvested share-based payment awards that contain rights to nonforfeitable dividends that would be considered participating securities for the basic calculation. Diluted earnings per share reflects the potential dilution that could occur if securities or other contracts to issue common stock were exercised or converted into common stock or resulted from the issuance of common stock that then would share in earnings.
Comprehensive Income	Comprehensive Income— Comprehensive income is reported in addition to net income for all periods presented. Comprehensive income is a more inclusive financial reporting methodology that includes disclosure of other comprehensive income (loss) that historically has not been recognized in the calculation of net income. Unrealized gains and losses on the Company's available-for-sale investment securities are required to be included in other comprehensive income or loss. Total comprehensive income (loss) and the components of accumulated other comprehensive income or loss are presented in the Consolidated Statement of Stockholders’ Equity and Consolidated Statements of Comprehensive Income.
Loss Contingencies	Loss Contingencies— Loss contingencies, including claims and legal action arising in the ordinary course of business, are recorded as liabilities when the likelihood of loss is probable and an amount or range of loss can be reasonably estimated. Management does not believe there now are such matters that will have a material effect on the financial statements.
Fair Value of Financial Instruments	Fair Value of Financial Instruments— Fair values of financial instruments are estimated using relevant market information and other assumptions, as more fully disclosed in a separate note. Fair value estimates involve uncertainties and matters of significant judgment regarding interest rates, credit risk, prepayments, and other factors, especially in the absence of broad markets for particular items. Changes in assumptions or in market conditions could significantly affect these estimates. The fair value of an asset or liability is the price that would be received to sell that asset or paid to transfer that liability in an orderly transaction occurring in the principal market (or most advantageous market in the absence of a principal market) for such asset or liability. In estimating fair value, the Company utilizes valuation techniques that are consistent with the market approach, the income approach, and/or the cost approach. Such valuation techniques are consistently applied. Inputs to valuation techniques include the assumptions that market participants would use in pricing an asset or liability. ASC Topic 825 requires disclosure of the fair value of financial assets and financial liabilities, including both those financial assets and financial liabilities that are not measured and reported at fair value on a recurring basis and a non-recurring basis. The methodologies for estimating the fair value of financial assets and financial liabilities that are measured at fair value, and for estimating the fair value of financial assets and financial liabilities not recorded at fair value, are discussed below. In accordance with accounting guidance, the Company groups its financial assets and financial liabilities measured at fair value in three levels, based on the markets in which the assets and liabilities are traded and the reliability of the assumptions used to determine fair value. The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1 measurements) and the lowest priority to unobservable inputs (Level 3 measurements). The three levels of the fair value hierarchy are described as follows: Level 1 - Unadjusted quoted prices in active markets that are accessible at the measurement date for identical, unrestricted assets or liabilities. Level 2 - Inputs other than quoted prices included in Level 1 that are observable for the asset or liability, either directly or indirectly. These might include quoted prices for similar instruments in active markets, quoted prices for identical or similar instruments in markets that are not active, inputs other than quoted prices that are observable for the asset or liability (such as interest rates, prepayment speeds, volatilities, etc.) or model-based valuation techniques where all significant assumptions are observable, either directly or indirectly, in the market. Level 3 - Valuation is generated from model-based techniques where one or more significant inputs are not observable, either directly or indirectly, in the market. These unobservable assumptions reflect the Company’s own estimates of assumptions that market participants would use in pricing the asset or liability. Valuation techniques may include use of matrix pricing, discounted cash flow models, and similar techniques. Because no market exists for a significant portion of the Company’s financial instruments, fair value estimates are based on judgments regarding current economic conditions, risk characteristics of various financial instruments, and other factors. These estimates are subjective in nature and involve uncertainties and matters of significant judgment and, therefore, cannot be determined with precision. Changes in assumptions could significantly affect the fair values presented. Management uses its best judgment in estimating the fair value of the Company’s financial instruments; however, there are inherent limitations in any estimation technique. Therefore, for substantially all financial instruments, the fair value estimates presented herein are not necessarily indicative of the amounts the Company could have realized in a sales transaction at December 31, 2017 and December 31, 2016 . A financial instrument’s level within the fair value hierarchy is based on the lowest level of input that is significant to the fair value measurement. Management maximizes the use of observable inputs and attempts to minimize the use of unobservable inputs when determining fair value measurements. The following is a description of both the general and specific valuation methodologies used for certain instruments measured at fair value, as well as the general classification of these instruments pursuant to the valuation hierarchy. Cash and due from banks —The carrying amounts of cash and short-term instruments approximate fair value due to the liquidity of these instruments. Investment securities —Investment securities are generally valued based upon quotes obtained from an independent third-party pricing service, which uses evaluated pricing applications and model processes. Observable market inputs, such as, benchmark yields, reported trades, broker/dealer quotes, issuer spreads, two-sided markets, benchmark securities, bids, offers and reference data are considered as part of the evaluation. The inputs are related directly to the security being evaluated, or indirectly to a similarly situated security. Market assumptions and market data are utilized in the valuation models. The Company reviews the market prices provided by the third-party pricing service for reasonableness based on the Company’s understanding of the market place and credit issues related to the securities. The Company has not made any adjustments to the market quotes provided by them and, accordingly, the Company categorized its investment portfolio within Level 2 of the fair value hierarchy. FHLB, FRB, Other Stock —Due to restrictions placed on its transferability, it is not practical to determine the fair value of the stock. Loans Held for Sale —The fair value of loans held for sale is estimated based upon binding contracts and quotes from third party investors resulting in a Level 2 classification. Loans Held for Investment —The fair value of loans, other than loans on nonaccrual status, was estimated by discounting the remaining contractual cash flows using the estimated current rate at which similar loans would be made to borrowers with similar credit risk characteristics and for the same remaining maturities, reduced by deferred net loan origination fees and the allocable portion of the allowance for loan losses. Accordingly, in determining the estimated current rate for discounting purposes, no adjustment has been made for any change in borrowers’ credit risks since the origination of such loans. Rather, the allocable portion of the allowance for loan losses is considered to provide for such changes in estimating fair value. As a result, this fair value is not necessarily the value, which would be derived using an exit price. These loans are included within Level 3 of the fair value hierarchy. Impaired loans and OREO —Impaired loans and OREO assets are recorded at the fair value less estimated costs to sell at the time of foreclosure. The fair value of impaired loans and OREO assets are generally based on recent real estate appraisals adjusted for estimated selling costs. These appraisals may utilize a single valuation approach or a combination of approaches including comparable sales and the income approach. Adjustments are routinely made in the appraisal process by the appraisers to adjust for differences between the comparable sales and income data available. Such adjustments are typically significant and result in a Level 3 classification of the inputs for determining fair value. Deposit Accounts and Short-term Borrowings— The amounts payable to depositors for demand, savings, and money market accounts, and short-term borrowings are considered to approximate fair value. The fair value of fixed-maturity certificates of deposit is estimated using the rates currently offered for deposits of similar remaining maturities using a discounted cash flow calculation. Interest-bearing deposits and borrowings are included within Level 2 of the fair value hierarchy. Term FHLB Advances and Other Long-term Borrowings— The fair value of long term borrowings is determined using rates currently available for similar borrowings with similar credit risk and for the remaining maturities and are classified as Level 2. Subordinated Debentures —The fair value of subordinated debentures is estimated by discounting the balance by the current three-month LIBOR rate plus the current market spread. The fair value is determined based on the maturity date as the Company does not currently have intentions to call the debenture and is classified as Level 2. Accrued Interest Receivable/Payable— The carrying amounts of accrued interest receivable and accrued interest payable are deemed to approximate fair value. Estimated fair values are disclosed for financial instruments for which it is practicable to estimate fair value. These estimates are made at a specific point in time based on relevant market data and information about the financial instruments. These estimates do not reflect any premium or discount that could result from offering the Company’s entire holdings of a particular financial instrument for sale at one time, nor do they attempt to estimate the value of anticipated future business related to the instruments. In addition, the tax ramifications related to the realization of unrealized gains and losses can have a significant effect on fair value estimates and have not been considered in any of these estimates.
Recent Accounting Pronouncements	Accounting Standards Adopted in 2017 In March 2016, the FASB issued Accounting Standards Update ("ASU") 2016-09 , Compensation-Stock Compensation (Topic 718): Improvements to Employee Share-Based Accounting . The amendments simplify several aspects of the accounting for share-based payment award transactions, including accounting for excess tax benefits and tax deficiencies, classifying excess tax benefits on the statement of cash flows, accounting for forfeitures, classifying awards that permit share repurchases to satisfy statutory tax-withholding requirements and classifying tax payments on behalf of employees on the statement of cash flows. For public business entities, the amendment is effective for annual periods beginning after December 15, 2016 and interim periods within those annual periods. Early adoption is permitted for any organization in any interim or annual period. As a result of the adoption of ASU 2016-09, the Company began recognizing the tax effects of exercised or vested awards as discrete items in the reporting period in which they occur, resulting in a $2.0 million tax benefit to the Company for the year ended December 31, 2017. In March 2016, the FASB issued ASU 2016-07, Investments-Equity Method and Joint Ventures (Topic 323): Simplifying the Transition to the Equity Method of Accounting . The amendments eliminate the requirement to retrospectively apply the equity method to an investment that subsequently qualifies for such accounting as a result of an increase in the level of ownership interest or degree of influence. As result, when an investment qualifies for the equity method, the equity method investor will add the cost of acquiring the additional interest in the investee to the current basis of the investor’s previously held interest and adopt the equity method of account as of the date the investment becomes qualified for equity method accounting. The amendments further require unrealized holding gains or losses in accumulated other comprehensive income related to an available-for-sale security that becomes eligible for the equity method to be recognized in earnings as of the date on which the investment qualifies for the equity method. The amendments are effective for all entities for fiscal years and interim periods within those fiscal years, beginning after December 15, 2016. The adoption of this standard did not have a material effect on the Company's operating results or financial condition. In March 2016, the FASB issued ASU 2016-06, Derivatives and Hedging (Topic 815): Contingent Put and Call Options in Debt Instruments . The amendments clarify the required steps to be taken when assessing whether the economic characteristics and risks of call/put options are clearly and closely related to those of their debt hosts - which is one of the criteria for bifurcating an embedded derivative. The Update is effective for public business entities for fiscal years beginning after December 31, 2016, including interim periods within those years. The adoption of this standard did not have a material effect on the Company's operating results or financial condition. In March 2016, the FASB issued ASU 2016-05, Derivatives and Hedging (Topic 815): Effect of Derivative Contract Novations on Existing Hedge Accounting Relationships . The amendments clarify that a change in the counterparty to a derivative instrument designated as a hedging instrument does not, in and of itself, require designation of that hedging relationship provided that all other hedge accounting criteria remain the same. The Update is effective for public business entities for fiscal years beginning after December 31, 2016, including interim periods within those years. The adoption of this standard did not have a material effect on the Company's operating results or financial condition. Recent Accounting Guidance Not Yet Effective In February 2018, the FASB issued ASU 2018-02, Income Statement-Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income. On December 22, 2017, the Tax Cuts and Jobs Act of 2017 was signed into law, which among other things reduced the maximum federal corporate tax rate from 35% to 21%. This Update addresses concerns about the guidance in current GAAP that requires deferred tax liabilities and assets to be adjusted for the effect of a change in tax laws or rates with the effect included in income from continuing operations in the reporting period that includes the enactment date. That guidance is applicable even in situations in which the related income tax effects of items in accumulated other comprehensive income were originally recognized in other comprehensive income (rather than in income from continuing operations). As a result of the adjustment of deferred taxes being required to be included in income from continuing operations, the tax effects of items within accumulated other comprehensive income (referred to as stranded tax effects for purposes of this Update) do not reflect the appropriate tax rate. This Update allows for an election to reclass between retained earnings and AOCI the impact of the federal income tax rate change. The amendments in this Update are effective for fiscal years beginning after December 15, 2018 and interim periods within those fiscal years. Early adoption of the amendments of this Update is permitted. The Company has analyzed the effects of this Update and has elected to early adopt in the first quarter of 2018. Accordingly, the Company will record a reclass of approximately $81,000 from retained earnings to AOCI in the first quarter of 2018. In January 2017, the FASB issued ASU 2017-01, Business Combinations (Topic 805): Clarifying the Definition of a Business . Under the current implementation guidance in Topic 805, there are three elements of a business-inputs, processes, and outputs. While an integrated set of assets and activities (collectively referred to as a “set”) that is a business usually has outputs, outputs are not required to be present. In addition, all the inputs and processes that a seller uses in operating a set are not required if market participants can acquire the set and continue to produce outputs. The amendments in this Update provide a screen to determine when a set is not a business. The screen requires that when substantially all of the fair value of the gross assets acquired (or disposed of) is concentrated in a single identifiable asset or a group of similar identifiable assets, the set is not a business. This screen reduces the number of transactions that need to be further evaluated. If the screen is not met, the amendments in this Update (1) require that to be considered a business, a set must include, at a minimum, an input and a substantive process that together significantly contribute to the ability to create output and (2) remove the evaluation of whether a market participant could replace missing elements. The amendments provide a framework to assist entities in evaluating whether both an input and a substantive process are present. The framework includes two sets of criteria to consider that depend on whether a set has outputs. Although outputs are not required for a set to be a business, outputs generally are a key element of a business; therefore, the Board has developed more stringent criteria for sets without outputs. Lastly, the amendments in this Update narrow the definition of the term output so that the term is consistent with how outputs are described in Topic 606. Public business entities should apply the amendments in this Update to annual periods beginning after December 15, 2017, including interim periods within those periods. The adoption of this standard will not have a material effect on the Company's operating results or financial condition. In November 2016, the FASB issued ASU 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash . The Update requires that a statement of cash flows explain the change during the period in the total of cash, cash equivalents, and amounts generally described as restricted cash or restricted cash equivalents. Therefore, amounts generally described as restricted cash and restricted cash equivalents should be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. The amendments in this Update are effective for public business entities for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years. The adoption of this standard will not have a material effect on the Company's operating results or financial condition. In August 2016, the FASB issued ASU 2016-15, Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments . The Update provides guidance on eight specific cash flow classification issues, which include: 1) debt prepayment or debt extinguishment costs; 2) settlement of zero-coupon debt instruments or debt with coupon interest rates that are insignificant in relation to the effective interest rate; 3) contingent consideration payments made soon after a business combination; 4) proceeds from the settlement of insurance claims; 5) proceeds from the settlement of corporate-owned life insurance policies, including bank-owned life insurance policies; 6) distributions received from equity method investments; 7) beneficial interest in securitization transactions; and 8) separately identifiable cash flows and the application of the predominance principle. The amendments in this Update are effective for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years. Early adoption is permitted, including adoption in an interim period; however, an entity is required to adopt all of the amendments in the same period. The amendments in this Update should be applied using a retrospective transition method to each period presented. The adoption of this standard will not have a material effect on the Company's operating results or financial condition. In June 2016, the FASB issued ASU 2016-13, Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments. The amendments replace the incurred loss impairment methodology in current GAAP with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to inform credit loss estimates. For public business entities, the amendment is effective for annual periods beginning after December 15, 2019 and interim period within those annual periods. The Company is currently evaluating the effects of ASU 2016-13 on its financial statements and disclosures. The Company is in the process of compiling key data elements and is in the process of purchasing a software model in an effort to meet the requirements of the new guidance. I n February 2016, the FASB issued ASU 2016-02, Leases (Topic 842). The new standard is being issued to increase the transparency and comparability around lease obligations. Previously unrecorded off-balance sheet obligations will now be brought more prominently to light by presenting lease liabilities on the face of the balance sheet, accompanied by enhanced qualitative and quantitative disclosures in the notes to the financial statements. The Update is generally effective for public business entities in fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. The Company is in the early stages of its implementation assessment, which includes identifying the population of the Company's leases that are within the scope of the new guidance and gathering all key lease data that will facilitate application of the new accounting requirements. In January 2016, the FASB issued ASU 2016-01, Financial Instruments-Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities . Changes made to the current measurement model primarily affect the accounting for equity securities with readily determinable fair values, where changes in fair value will impact earnings instead of other comprehensive income. The accounting for other financial instruments, such as loans, investments in debt securities, and financial liabilities is largely unchanged. The Update also changes the presentation and disclosure requirements for financial instruments including a requirement that public business entities use exit price when measuring the fair value of financial instruments measured at amortized cost for disclosure purposes. This Update is generally effective for public business entities in fiscal years beginning after December 15, 2017, including interim periods within those fiscal years. The adoption of this standard will not have a material effect on the Company's operating results or financial condition. However, the Company will be required to expand its disclosures concerning its valuation techniques. ASU 2014-09, Revenue From Contracts With Customers (Topic 606) , ASU 2015-14 Revenue from Contracts with Customers (Topic 606): Deferral of Effective Date , ASU 2016-08 Revenue from Contracts with Customers (Topic 606): Principal versus Agent Considerations (Reporting Revenue Gross versus Net) , ASU 2016-10 Revenue from Contracts with Customers (Topic 606): Identifying Performance Obligations and Licensing , ASU 2016-11 Revenue Recognition (Topic 605) and Derivatives ad Hedging (Topic 815): Rescission of SEC Guidance Because of Accounting Standards Updates 2014-09 and 2014-16 Pursuant to Staff Announcements at the March 3, 2016 EITF Meeting , ASU 2016-12 Revenue from Contracts with Customers (Topic 606): Narrow-Scope Improvements and Practical Expedients , and ASU 2016-20 Revenue from Contracts with Customers (Topic 606): Technical Corrections and Improvements to Topic 606 . The FASB amended existing guidance related to revenue from contracts with customers, superseding and replacing nearly all existing revenue recognition guidance, including industry-specific guidance, establishing a new control-based revenue recognition model, changing the basis for deciding when revenue is recognized over time or at a point in time, providing new and more detailed guidance on specific topics and expanding and improving disclosures about revenue. In addition, this guidance specifies the accounting for some costs to obtain or fulfill a contract with a customer. The amendments are effective for public entities for annual reporting periods beginning after December 15, 2017. The Company has completed its review of its various revenue streams and has determined that approximately 98% of the Company’s revenue is out of the scope of ASU 2014-09, including all of the Company’s net interest income and a significant portion of non-interest income. For those revenue streams that are within the scope of ASU 2014-09, the Company has reviewed the associated customer contracts and agreements to determine the appropriate accounting for revenues under those contracts. The Company’s review did not identify any significant changes in the timing of revenue recognition under those contracts within the scope of ASU 2014-09. Revenue streams that are within scope primarily relate to service charges and fees associated customer deposit accounts, as well as fees for various other services the Company provides customers. The Company also evaluated the need for changes to internal controls as a result of the implementation of ASU 2014-09 and, as a result, has made some enhancements. The Company plans to adopt the provisions of ASU 2014-09 using the modified retrospective transition method, and believes the impact of the adoption of ASU 2014-09 will be insignificant to the financial statements. However, the Company will be required to expand its disclosures concerning revenue recognition.

Regulatory Capital Requiremen36

Regulatory Capital Requirements and Other Regulatory Matters (Tables)	12 Months Ended
	Dec. 31, 2017
Banking and Thrift [Abstract]
Schedule of Company's and Bank's actual capital amounts and ratios	As defined in applicable regulations and set forth in the table below, which excludes the capital conservation buffer, at December 31, 2017 and 2016 , the Company and the Bank continue to exceed the “well capitalized” standards: Actual Minimum Required for Capital Adequacy Purposes Required to be Well Capitalized Under Prompt Corrective Action Regulations Amount Ratio Amount Ratio Amount Ratio (dollars in thousands) At December 31, 2017 Pacific Premier Bancorp, Inc. Consolidated Tier 1 Leverage Ratio $ 744,233 10.70 % $ 278,183 4.00 % N/A N/A Common Equity Tier 1 to Risk-Weighted Assets 724,205 10.59 % 307,778 4.50 % N/A N/A Tier 1 Capital to Risk-Weighted Assets 744,233 10.88 % 410,371 6.00 % N/A N/A Total Capital to Risk-Weighted Assets 859,442 12.57 % 547,161 8.00 % N/A N/A Pacific Premier Bank Tier 1 Leverage Ratio $ 812,170 11.68 % $ 278,152 4.00 % $ 347,690 5.00 % Common Equity Tier 1 to Risk-Weighted Assets 812,170 11.88 % 307,702 4.50 % 444,458 6.50 % Tier 1 Capital to Risk-Weighted Assets 812,170 11.88 % 410,269 6.00 % 547,025 8.00 % Total Capital to Risk-Weighted Assets 843,005 12.33 % 547,025 8.00 % 683,781 10.00 % At December 31, 2016 Pacific Premier Bancorp, Inc. Consolidated Tier 1 Leverage Ratio $ 366,658 9.78 % $ 150,027 4.00 % N/A N/A Common Equity Tier 1 to Risk-Weighted Assets 356,658 10.12 % 158,574 4.50 % N/A N/A Tier 1 Capital to Risk-Weighted Assets 366,658 10.41 % 211,432 6.00 % N/A N/A Total Capital to Risk-Weighted Assets 448,150 12.72 % 281,909 8.00 % N/A N/A Pacific Premier Bank Tier 1 Leverage Ratio $ 410,524 10.94 % $ 150,107 4.00 % $ 187,634 5.00 % Common Equity Tier 1 to Risk-Weighted Assets 410,524 11.65 % 158,536 4.50 % 228,997 6.50 % Tier 1 Capital to Risk-Weighted Assets 410,524 11.65 % 211,382 6.00 % 281,842 8.00 % Total Capital to Risk-Weighted Assets 432,943 12.29 % 281,842 8.00 % 352,303 10.00 %

Investment Securities (Tables)

Investment Securities (Tables)	12 Months Ended
	Dec. 31, 2017
Investments, Debt and Equity Securities [Abstract]
Schedule of amortized cost and estimated fair value of securities	The amortized cost and estimated fair value of securities were as follows: December 31, 2017 Amortized Cost Unrealized Gain Unrealized Loss Estimated Fair Value (dollars in thousands) Investment securities available-for-sale Agency $ 47,051 $ 236 $ (78 ) $ 47,209 Corporate 78,155 1,585 (194 ) 79,546 Municipal bonds 228,929 3,942 (743 ) 232,128 Collateralized mortgage obligation: residential 33,984 132 (335 ) 33,781 Mortgage-backed securities: residential 398,664 266 (4,165 ) 394,765 Total investment securities available-for-sale 786,783 6,161 (5,515 ) 787,429 Investment securities held-to-maturity Mortgage-backed securities: residential 17,153 — (209 ) 16,944 Other 1,138 — — 1,138 Total investment securities held-to-maturity 18,291 — (209 ) 18,082 Total investment securities $ 805,074 $ 6,161 $ (5,724 ) $ 805,511 December 31, 2016 Amortized Unrealized Unrealized Estimated Cost Gain Loss Fair Value (dollars in thousands) Investment securities available-for-sale Corporate $ 37,475 $ 372 $ (205 ) $ 37,642 Municipal bonds 120,155 338 (1,690 ) 118,803 Collateralized mortgage obligation: residential 31,536 25 (173 ) 31,388 Mortgage-backed securities: residential 196,496 69 (3,435 ) 193,130 Total investment securities available-for-sale 385,662 804 (5,503 ) 380,963 Investment securities held-to-maturity Mortgage-backed securities: residential 7,375 — (104 ) 7,271 Other 1,190 — — 1,190 Total investment securities held-to-maturity 8,565 — (104 ) 8,461 Total investment securities $ 394,227 $ 804 $ (5,607 ) $ 389,424
Schedule of number, fair value and gross unrealized holding losses of the Company's investment securities by investment category and length of time that the securities have been in a continuous loss position	The table below shows the number, fair value and gross unrealized holding losses of the Company’s investment securities by investment category and length of time that the securities have been in a continuous loss position. December 31, 2017 Less than 12 months 12 months or Longer Total Number Fair Value Gross Unrealized Holding Losses Number Fair Value Gross Unrealized Holding Losses Number Fair Value Gross Unrealized Holding Losses (dollars in thousands) Investment securities available-for-sale Agency 6 $ 13,754 $ (78 ) — $ — $ — 6 $ 13,754 $ (78 ) Corporate 4 10,079 (64 ) 2 6,076 (130 ) 6 16,155 (194 ) Municipal bonds 103 61,313 (268 ) 30 15,658 (475 ) 133 76,971 (743 ) Collateralized mortgage obligation: residential 5 13,971 (149 ) 3 8,943 (186 ) 8 22,914 (335 ) Mortgage-backed securities: residential 66 220,951 (1,600 ) 41 110,062 (2,565 ) 107 331,013 (4,165 ) Total investment securities available-for-sale 184 320,068 (2,159 ) 76 140,739 (3,356 ) 260 460,807 (5,515 ) Investment securities held-to-maturity Mortgage-backed securities: residential 2 10,745 (133 ) 1 6,198 (76 ) 3 16,943 (209 ) Total investment securities held-to-maturity 2 10,745 (133 ) 1 6,198 (76 ) 3 16,943 (209 ) Total investment securities 186 $ 330,813 $ (2,292 ) 77 $ 146,937 $ (3,432 ) 263 $ 477,750 $ (5,724 ) December 31, 2016 Less than 12 months 12 months or Longer Total Number Fair Gross Number Fair Gross Number Fair Gross (dollars in thousands) Investment securities available-for-sale Corporate 3 $ 7,609 $ (205 ) — $ — $ — 3 $ 7,609 $ (205 ) Municipal bonds 152 85,750 (1,690 ) — — — 152 85,750 (1,690 ) Collateralized mortgage obligation: residential 5 19,092 (173 ) — — — 5 19,092 (173 ) Mortgage-backed securities: residential 55 149,740 (2,916 ) 4 16,039 (519 ) 59 165,779 (3,435 ) Total available-for-sale 215 262,191 (4,984 ) 4 16,039 (519 ) 219 278,230 (5,503 ) Investment securities held-to-maturity Mortgage-backed securities: residential 1 7,271 (104 ) — — — 1 7,271 (104 ) Total held-to-maturity 1 7,271 (104 ) — — — 1 7,271 (104 ) Total securities 216 $ 269,462 $ (5,088 ) 4 $ 16,039 $ (519 ) 220 $ 285,501 $ (5,607 )
Schedule of amortized cost and estimated fair value of investment securities available for sale by contractual maturity	The amortized cost and estimated fair value of investment securities available for sale at December 31, 2017 , by contractual maturity are shown in the table below. One Year or Less More than One Year to Five Years More than Five Years to Ten Years More than Ten Years Total Amortized Cost Fair Value Amortized Cost Fair Value Amortized Cost Fair Value Amortized Cost Fair Value Amortized Cost Fair Value (dollars in thousands) Investment securities available-for-sale Agency $ — $ — $ — $ — $ 15,156 $ 15,164 $ 31,895 $ 32,045 $ 47,051 $ 47,209 Corporate — — — — 78,155 79,546 — — 78,155 79,546 Municipal bonds 4,124 4,121 32,390 32,424 72,845 73,312 119,570 122,271 228,929 232,128 Collateralized mortgage obligation: residential — — — — 1,069 1,071 32,915 32,710 33,984 33,781 Mortgage-backed securities: residential 2,591 2,583 2,647 2,611 65,541 65,014 327,885 324,557 398,664 394,765 Total investment securities available-for-sale 6,715 6,704 35,037 35,035 232,766 234,107 512,265 511,583 786,783 787,429 Investment securities held-to-maturity Mortgage-backed securities: residential — — — — — — 17,153 16,944 17,153 16,944 Other — — — — — — 1,138 1,138 1,138 1,138 Total investment securities held-to-maturity — — — — — — 18,291 18,082 18,291 18,082 Total investment securities $ 6,715 $ 6,704 $ 35,037 $ 35,035 $ 232,766 $ 234,107 $ 530,556 $ 529,665 $ 805,074 $ 805,511

Loans (Tables)

Loans (Tables)	12 Months Ended
	Dec. 31, 2017
Receivables [Abstract]
Schedule of components of loans held for investment	The following table presents the composition of the loan portfolio as of the dates indicated: For the Years Ended December 31, 2017 2016 (dollars in thousands) Business Loans Commercial and industrial $ 1,086,659 $ 563,169 Franchise 660,414 459,421 Commercial owner occupied 1,289,213 454,918 SBA 185,514 88,994 Agribusiness 116,066 — Total business loans 3,337,866 1,566,502 Real Estate Loans Commercial non-owner occupied 1,243,115 586,975 Multi-family 794,384 690,955 One-to-four family 270,894 100,451 Construction 282,811 269,159 Farmland 145,393 — Land 31,233 19,829 Total real estate loans 2,767,830 1,667,369 Consumer Loans Consumer loans 92,931 4,112 Gross loans held for investment 6,198,627 3,237,983 Plus: Deferred loan origination costs/(fees) and premiums/(discounts), net (2,159 ) 3,630 Loans held for investment 6,196,468 3,241,613 Allowance for loan losses (28,936 ) (21,296 ) Loans held for investment, net $ 6,167,532 $ 3,220,317 Loans held for sale, at lower of cost or fair value $ 23,426 $ 7,711
Summary of Company's investment in purchased credit impaired loans	The carrying amount of those loans at December 31, 2017 , and 2016 was as follows: For the Years Ended December 31, 2017 2016 (dollars in thousands) Business Loans Commercial and industrial $ 3,310 $ 2,586 Commercial owner occupied 1,262 491 SBA 1,802 — Total business loans 6,374 3,077 Real Estate Loans Commercial non-owner occupied 1,650 1,088 One-to-four family 255 1 Construction 517 — Land 83 — Total real estate loans 2,505 1,089 Consumer Loans Consumer loans 10 393 Total purchase credit impaired $ 8,889 $ 4,559
Summary of accretable yield on purchased credit impaired	The following table summarizes the accretable yield on the purchased credit impaired for the years ended December 31, 2017 , 2016 and 2015 : For the Years Ended December 31, 2017 2016 2015 (dollars in thousands) Balance at the beginning of period $ 3,747 $ 2,726 $ 1,403 Additions 3,102 788 602 Accretion (2,037 ) (1,354 ) (385 ) Payoffs (2,125 ) 165 (249 ) Reclassification from nonaccretable difference 332 1,422 1,355 Balance at the end of period $ 3,019 $ 3,747 $ 2,726
Summary of Company's investment in impaired loans	The following tables provide a summary of the Company’s investment in impaired loans as of and for the periods indicated: Impaired Loans Recorded Investment Unpaid Principal Balance With Specific Allowance Without Specific Allowance Specific Allowance for Impaired Loans Average Recorded Investment Interest Income Recognized (dollars in thousands) December 31, 2017 Business Loans Commercial and industrial $ 1,160 $ 1,585 $ — $ 1,160 $ — $ 441 $ — Commercial owner occupied 97 98 97 — 55 153 — SBA 1,201 4,329 — 1,201 — 434 — Real Estate Loans Commercial non-owner occupied — — — — — 86 — One-to-four family 817 849 — 817 — 166 — Construction — — — — — 1,017 — Land 9 35 — 9 — 12 — Totals $ 3,284 $ 6,896 $ 97 $ 3,187 $ 55 $ 2,309 $ — December 31, 2016 Business Loans Commercial and industrial $ 250 $ 1,990 $ 250 $ — $ 250 $ 864 $ 76 Franchise — — — — — 1,016 68 Commercial owner occupied 436 847 — 436 — 505 37 SBA 316 3,865 — 316 — 331 23 Real Estate Loans Commercial non-owner occupied — — — — — 1,072 93 One-to-four family 124 291 — 124 — 226 18 Land 15 36 — 15 — 18 2 Totals $ 1,141 $ 7,029 $ 250 $ 891 $ 250 $ 4,032 $ 317 December 31, 2015 Business Loans Commercial and industrial $ 313 $ 578 $ — $ 313 $ — $ 90 $ 29 Franchise 1,630 2,394 1,461 169 731 1,386 3 Commercial owner occupied 536 883 — 536 — 415 67 Real Estate Loans Commercial non-owner occupied 214 329 — 214 — 430 19 One-to-four family 70 98 — 70 — 204 5 Land 21 37 — 21 — 13 — Totals $ 2,784 $ 4,319 $ 1,461 $ 1,323 $ 731 $ 2,538 $ 123
Summary of loan portfolio by the Company's internal risk grading system	The following tables stratify the loan portfolio by the Company’s internal risk grading system as well as certain other information concerning the credit quality of the loan portfolio as of the periods indicated: Credit Risk Grades Pass Special Mention Substandard Doubtful Total Gross Loans December 31, 2017 (dollars in thousands) Business Loans Commercial and industrial $ 1,063,452 $ 8,163 $ 15,044 $ — $ 1,086,659 Franchise 660,415 — — — 660,415 Commercial owner occupied 1,273,380 654 21,180 — 1,295,214 SBA 199,468 1 3,469 — 202,938 Agribusiness 108,143 4,079 3,844 — 116,066 Real Estate Loans Commercial non-owner occupied 1,242,045 — 1,070 — 1,243,115 Multi-family 794,156 — 228 — 794,384 One-to-four family 268,776 154 1,964 — 270,894 Construction 282,294 517 — — 282,811 Farmland 144,234 44 1,115 — 145,393 Land 30,979 — 254 — 31,233 Consumer Loans Consumer loans 92,794 — 137 — 92,931 Totals $ 6,160,136 $ 13,612 $ 48,305 $ — $ 6,222,053 Credit Risk Grades Pass Special Mention Substandard Doubtful Total Gross Loans December 31, 2016 (dollars in thousands) Business Loans Commercial and industrial $ 550,919 $ 8,216 $ 3,784 $ 250 $ 563,169 Franchise 459,421 — — — 459,421 Commercial owner occupied 450,416 281 4,221 — 454,918 SBA 96,190 53 462 — 96,705 Real Estate Loans Commercial non-owner occupied 585,093 810 1,072 — 586,975 Multi-family 681,942 6,610 2,403 — 690,955 One-to-four family 100,010 — 441 — 100,451 Construction 269,159 — — — 269,159 Land 19,814 — 15 — 19,829 Consumer Loans Consumer loans 3,719 — 393 — 4,112 Totals $ 3,216,683 $ 15,970 $ 12,791 $ 250 $ 3,245,694
Schedule of credit quality of the loan portfolio	Days Past Due Current 30-59 60-89 90+ Total Gross Loans Non-accruing December 31, 2017 (dollars in thousands) Business Loans Commercial and industrial $ 1,085,770 $ 84 $ 570 $ 235 $ 1,086,659 $ 1,160 Franchise 660,415 — — — 660,415 — Commercial owner occupied 1,291,254 3,474 486 — 1,295,214 97 SBA 200,821 177 — 1,940 202,938 1,201 Agribusiness 116,066 — — — 116,066 — Real Estate Loans Commercial non-owner occupied 1,243,115 — — — 1,243,115 — Multi-family 792,603 1,781 — — 794,384 — One-to-four family 269,725 354 — 815 270,894 817 Construction 282,811 — — — 282,811 — Farmland 145,393 — — — 145,393 — Land 31,141 83 — 9 31,233 9 Consumer Loans Consumer loans 92,880 11 — 40 92,931 — Totals $ 6,211,994 $ 5,964 $ 1,056 $ 3,039 $ 6,222,053 $ 3,284 Days Past Due Current 30-59 60-89 90+ Total Gross Loans Non-accruing December 31, 2016 (dollars in thousands) Business Loans Commercial and industrial $ 562,805 $ 104 $ — $ 260 $ 563,169 $ 250 Franchise 459,421 — — — 459,421 — Commercial owner occupied 454,918 — — — 454,918 436 SBA 96,389 — — 316 96,705 316 Real Estate Loans Commercial non-owner occupied 586,975 — — — 586,975 — Multi-family 690,955 — — — 690,955 — One-to-four family 100,314 18 71 48 100,451 124 Construction 269,159 — — — 269,159 — Land 19,814 — — 15 19,829 15 Consumer Loans Consumer loans 4,112 — — — 4,112 — Totals $ 3,244,862 $ 122 $ 71 $ 639 $ 3,245,694 $ 1,141

Allowance for Loan Losses (Tabl

Allowance for Loan Losses (Tables)	12 Months Ended
	Dec. 31, 2017
Provision for Loan and Lease Losses [Abstract]
Summary of allocation of the allowance as well as the activity in the allowance attributed to various segments in the loan portfolio	The following tables summarize the allocation of the allowance as well as the activity in the allowance attributed to various segments in the loan portfolio as of and for the periods indicated: Commercial and Industrial Franchise Commercial Owner Occupied SBA Agribusiness Warehouse Facilities Commercial Non-owner Occupied Multi-family One-to-four Family Construction Farmland Land Consumer Loans Total (dollars in thousands) Balance, December 31, 2016 $ 6,362 $ 3,845 $ 1,193 $ 1,039 $ — $ — $ 1,715 $ 2,927 $ 365 $ 3,632 $ — $ 198 $ 20 $ 21,296 Charge-offs (1,344 ) — — (8 ) — — — — (10 ) — — — — (1,362 ) Recoveries 94 — 105 127 — — — — 35 — — — 1 362 Provisions for (reduction in) loan losses 4,609 1,952 (531 ) 1,732 1,291 — (449 ) (2,320 ) 413 937 137 795 74 8,640 Balance, December 31, 2017 $ 9,721 $ 5,797 $ 767 $ 2,890 $ 1,291 $ — $ 1,266 $ 607 $ 803 $ 4,569 $ 137 $ 993 $ 95 $ 28,936 Amount of allowance attributed to: Specifically evaluated impaired loans $ — $ — $ 55 $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — $ 55 General portfolio allocation 9,721 5,797 712 2,890 1,291 — 1,266 607 803 4,569 137 993 95 28,881 Loans individually evaluated for impairment 1,160 — 97 1,201 — — — — 817 — — 9 — 3,284 Specific reserves to total loans individually evaluated for impairment — % — % 56.70 % — % — % — % — % — % — % — % — % — % — % 1.67 % Loans collectively evaluated for impairment $ 1,085,499 $ 660,414 $ 1,289,116 $ 184,313 $ 116,066 $ — $ 1,243,115 $ 794,384 $ 270,077 $ 282,811 $ 145,393 $ 31,224 $ 92,931 $ 6,195,343 General reserves to total loans collectively evaluated for impairment 0.90 % 0.88 % 0.06 % 1.57 % 1.11 % — % 0.10 % 0.08 % 0.30 % 1.62 % 0.09 % 3.18 % 0.10 % 0.47 % Total gross loans $ 1,086,659 $ 660,414 $ 1,289,213 $ 185,514 $ 116,066 $ — $ 1,243,115 $ 794,384 $ 270,894 $ 282,811 $ 145,393 $ 31,233 $ 92,931 $ 6,198,627 Total allowance to gross loans 0.89 % 0.88 % 0.06 % 1.56 % 1.11 % — % 0.10 % 0.08 % 0.30 % 1.62 % 0.09 % 3.18 % 0.10 % 0.47 % Commercial and Industrial Franchise Commercial Owner Occupied SBA Agribusiness Warehouse Facilities Commercial Non-owner Occupied Multi-family One-to-four Family Construction Farmland Land Consumer Loans Total (dollars in thousands) Balance, December 31, 2015 $ 3,449 $ 3,124 $ 1,870 $ 1,500 $ — $ 759 $ 2,048 $ 1,583 $ 698 $ 2,030 $ — $ 233 $ 23 $ 17,317 Charge-offs (2,802 ) (980 ) (329 ) (980 ) — — — — (151 ) — — — — (5,242 ) Recoveries 177 — 25 193 — — 21 — 25 — — — 4 445 Provisions for (reduction in) loan losses 5,538 1,701 (373 ) 326 — (759 ) (354 ) 1,344 (207 ) 1,602 — (35 ) (7 ) 8,776 Balance, December 31, 2016 $ 6,362 $ 3,845 $ 1,193 $ 1,039 $ — $ — $ 1,715 $ 2,927 $ 365 $ 3,632 $ — $ 198 $ 20 $ 21,296 Amount of allowance attributed to: Specifically evaluated impaired loans $ 250 $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — $ 250 General portfolio allocation 6,112 3,845 1,193 1,039 — — 1,715 2,927 365 3,632 — 198 20 21,046 Loans individually evaluated for impairment 250 — 436 316 — — — — 124 — — 15 — 1,141 Specific reserves to total loans individually evaluated for impairment 100.00 % — % — % — % — % — % — % — % — % — % — % — % — % 21.91 % Loans collectively evaluated for impairment $ 562,919 $ 459,421 $ 454,482 $ 88,678 $ — $ — $ 586,975 $ 690,955 $ 100,327 $ 269,159 $ — $ 19,814 $ 4,112 $ 3,236,842 General reserves to total loans collectively evaluated for impairment 1.09 % 0.84 % 0.26 % 1.17 % — % — % 0.29 % 0.42 % 0.36 % 1.35 % — % 1.00 % 0.49 % 0.65 % Total gross loans $ 563,169 $ 459,421 $ 454,918 $ 88,994 $ — $ — $ 586,975 $ 690,955 $ 100,451 $ 269,159 $ — $ 19,829 $ 4,112 $ 3,237,983 Total allowance to gross loans 1.13 % 0.84 % 0.26 % 1.17 % — % — % 0.29 % 0.42 % 0.36 % 1.35 % — % 1.00 % 0.49 % 0.66 % Commercial and Industrial Franchise Commercial Owner Occupied SBA Agribusiness Warehouse Facilities Commercial Non-owner Occupied Multi-family One-to-four Family Construction Farmland Land Consumer Loans Total (dollars in thousands) Balance, December 31, 2014 $ 2,646 $ 1,554 $ 1,757 $ 568 $ — $ 546 $ 2,007 $ 1,060 $ 842 $ 1,088 $ — $ 108 $ 24 $ 12,200 Charge-offs (484 ) (764 ) — — — — (116 ) — (16 ) — — — — (1,380 ) Recoveries 47 — — 8 — — 3 — 13 — — — 1 72 Provisions for (reduction in) loan losses 1,240 2,334 113 924 — 213 154 523 (141 ) 942 — 125 (2 ) 6,425 Balance, December 31, 2015 $ 3,449 $ 3,124 $ 1,870 $ 1,500 $ — $ 759 $ 2,048 $ 1,583 $ 698 $ 2,030 $ — $ 233 $ 23 $ 17,317 Amount of allowance attributed to: Specifically evaluated impaired loans $ — $ 731 $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — $ 731 General portfolio allocation 3,449 2,393 1,870 1,500 — 759 2,048 1,583 698 2,030 — 233 23 16,586 Loans individually evaluated for impairment 313 1,630 536 — — — 214 — 70 — — 21 — 2,784 Specific reserves to total loans individually evaluated for impairment — % 44.85 % — % — % — % — % — % — % — % — % — % — % — % 26.26 % Loans collectively evaluated for impairment $ 309,428 $ 327,295 $ 294,190 $ 62,256 $ — $ 143,200 $ 421,369 $ 429,003 $ 79,980 $ 169,748 $ — $ 18,319 $ 5,111 $ 2,259,899 General reserves to total loans collectively evaluated for impairment 1.11 % 0.73 % 0.64 % 2.41 % — % 0.53 % 0.49 % 0.37 % 0.87 % 1.20 % — % 1.27 % 0.45 % 0.73 % Total gross loans $ 309,741 $ 328,925 $ 294,726 $ 53,691 $ — $ 143,200 $ 421,583 $ 429,003 $ 80,050 $ 169,748 $ — $ 18,340 $ 5,111 $ 2,254,118 Total allowance to gross loans 1.11 % 0.95 % 0.63 % 2.79 % — % 0.53 % 0.49 % 0.37 % 0.87 % 1.20 % — % 1.27 % 0.45 % 0.77 %

Other Real Estate Owned (Tables

Other Real Estate Owned (Tables)	12 Months Ended
	Dec. 31, 2017
Other Real Estate [Abstract]
Summary of the activity in the other real estate owned	The following summarizes the activity in the other real estate owned for the years ended December 31: 2017 2016 2015 (dollars in thousands) Balance, beginning of year $ 460 $ 1,161 $ 1,037 Additions / foreclosures 326 197 450 Sales (507 ) (577 ) (233 ) Gain (loss) on sale 47 18 (52 ) Write downs — (339 ) (41 ) Balance, end of year $ 326 $ 460 $ 1,161

Premises and Equipment (Tables)

Premises and Equipment (Tables)	12 Months Ended
	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
Schedule of components of premises and equipment	The Company's premises and equipment consisted of the following at December 31: 2017 2016 (dollars in thousands) Land $ 16,920 $ 200 Premises 19,868 1,707 Leasehold improvements 14,025 8,982 Furniture, fixtures and equipment 20,480 14,565 Automobiles 187 187 Subtotal 71,480 25,641 Less: accumulated depreciation 18,325 13,627 Total $ 53,155 $ 12,014

Goodwill and Core Deposit Int42

Goodwill and Core Deposit Intangibles (Tables)	12 Months Ended
	Dec. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Goodwill	The following table presents changes in the carrying value of goodwill for the periods indicated: 2017 2016 (dollars in thousands) Balance, beginning of year $ 102,490 $ 50,832 Goodwill acquired during the year 390,839 51,658 Impairment losses — — Balance, end of year $ 493,329 $ 102,490 Accumulated impairment losses at end of year — —
Schedule of Finite-Lived Intangible Assets	he Company's change in the gross amount of core deposit intangibles and the related accumulated amortization consisted of the following at December 31: 2017 2016 2015 (dollars in thousands) Gross amount of CDI: Balance, beginning of year $ 15,102 $ 10,782 $ 7,876 Additions due to acquisitions 39,707 4,320 2,906 Balance, end of year 54,809 15,102 10,782 Accumulated amortization: Balance, beginning of year (5,651 ) (3,612 ) (2,262 ) Amortization (6,144 ) (2,039 ) (1,350 ) Balance, end of year (11,795 ) (5,651 ) (3,612 ) Net CDI, end of year $ 43,014 $ 9,451 $ 7,170

Qualified Affordable Housing 43

Qualified Affordable Housing Project Investments (Tables)	12 Months Ended
	Dec. 31, 2017
Equity Method Investments and Joint Ventures [Abstract]
Investment in LIHTC Projects	The following table presents the Company's original investment in the LIHTC funds, the current recorded investment balance, and the unfunded liability balance of each investment at December 31, 2017 and 2016 . In addition, the table reflects the tax credits and tax benefits recorded by the Company during 2017 and 2016 , the amortization of the investment and the net impact to the Company's income tax provision for 2017 and 2016 . Qualified Affordable Housing Funds at Original Investment Value Current Recorded Investment Unfunded Liability Obligation Tax Credits and Tax Deductions (1) Amortization of Investments (2) Net Income Tax Benefit WNC Institutional Tax Credit $ 5,000 $ 2,750 $ 85 $ 455 $ 500 $ (663 ) WNC Institutional Tax Credit 5,000 3,250 288 482 500 (690 ) Sycamore Court 6,181 5,582 927 1,577 599 (782 ) Total - Investments in $ 16,181 $ 11,582 $ 1,300 $ 2,514 $ 1,599 $ (2,135 ) Qualified Affordable Housing Funds at Original Investment Value Current Recorded Investment Unfunded Liability Obligation Tax Credits and Tax Deductions (1) Amortization of Investments (2) Net Income Tax Benefit WNC Institutional Tax Credit $ 5,000 $ 3,250 $ 223 $ 488 $ 542 $ (596 ) WNC Institutional Tax Credit 5,000 3,750 526 473 782 (637 ) Total - Investments in $ 10,000 $ 7,000 $ 749 $ 961 $ 1,324 $ (1,233 ) (1) The amounts reflected in this column represent both the tax credits, as well as the tax benefits generated by the Qualified Affordable Housing Projects operating loss for the year, which are included in the calculation of income tax expense. (2) This amount represents the amortization of the investment cost of the LIHTC.

Deposit Accounts (Tables)

Deposit Accounts (Tables)	12 Months Ended
	Dec. 31, 2017
Deposits [Abstract]
Schedule of components of deposit accounts and weighted average interest rates	Deposit accounts and weighted average interest rates consisted of the following at December 31: 2017 Weighted 2016 Weighted (dollars in thousands) Transaction accounts Noninterest-bearing checking $ 2,226,848 — % $ 1,185,768 — % Interest-bearing checking 365,193 0.13 % 182,893 0.11 % Money market 2,181,571 0.48 % 1,100,787 0.34 % Savings 227,436 0.13 % 101,574 0.14 % Total transaction accounts 5,001,048 0.21 % 2,571,022 0.16 % Certificates of deposit accounts Less than 100,000 192,409 0.85 % 121,148 0.74 % $100,000 through $250,000 369,748 1.01 % 153,103 0.82 % Greater than $250,000 522,663 1.26 % 300,308 0.74 % Total certificates of deposit accounts 1,084,820 1.10 % 574,559 0.76 % Total deposits $ 6,085,868 0.33 % $ 3,145,581 0.27 %
Schedule of aggregate annual maturities of certificates of deposit accounts	The aggregate annual maturities of certificates of deposit accounts at December 31, 2017 are as follows: 2017 Balance Weighted Average Interest Rate (dollars in thousands) Within 3 months $ 318,794 0.93 % 4 to 6 months 250,026 1.07 % 7 to 12 months 279,192 1.18 % 13 to 24 months 175,005 1.24 % 25 to 36 months 29,270 1.33 % 37 to 60 months 22,936 1.44 % Over 60 months 9,597 1.13 % Total $ 1,084,820 1.10 %
Schedule of interest expense on deposit accounts	Interest expense on deposit accounts for the years ended December 31 is summarized as follows: 2017 2016 2015 (dollars in thousands) Checking accounts $ 365 $ 200 $ 165 Money market accounts 6,720 3,641 2,426 Savings 251 151 141 Certificates of deposit accounts 6,035 4,399 3,898 Total $ 13,371 $ 8,391 $ 6,630

Federal Home Loan Bank Advanc45

Federal Home Loan Bank Advances and Other Borrowings (Tables)	12 Months Ended
	Dec. 31, 2017
Long-term Federal Home Loan Bank Advances [Abstract]
Summary of activities in advances from the FHLB	The following table summarizes activities in advances from the FHLB for the periods indicated: Year Ended December 31, 2017 2016 (dollars in thousands) Average balance outstanding $ 290,839 $ 58,814 Maximum amount outstanding at any month-end during the year 490,148 278,000 Balance outstanding at end of year 490,148 278,000 Weighted average interest rate during the year 1.19 % 0.59 %
Summary of activities in other borrowings	The following table summarizes activities in other borrowings for the periods indicated: Year Ended December 31, 2017 2016 (dollars in thousands) Average balance outstanding $ 50,866 $ 48,732 Maximum amount outstanding at any month-end during the year 52,996 53,586 Balance outstanding at end of year 46,139 49,971 Weighted average interest rate during the year 1.86 % 1.94 %

Subordinated Debentures (Tables

Subordinated Debentures (Tables)	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Schedule of summarizes activities for our subordinated debentures	The following table summarizes activities for our subordinated debentures for the periods indicated: Year Ended December 31, 2017 2016 (dollars in thousands) Average balance outstanding $ 81,466 $ 69,347 Maximum amount outstanding at any month-end during the year 105,123 69,383 Balance outstanding at end of year 105,123 69,383 Weighted average interest rate during the year 5.80 % 5.54 %

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Schedule of components of income taxes	Income taxes for the years ended December 31 consisted of the following: 2017 2016 2015 (dollars in thousands) Current income tax provision: Federal $ 18,644 $ 16,928 $ 12,460 State 7,062 4,655 4,144 Total current income tax provision 25,706 21,583 16,604 Deferred income tax provision (benefit): Federal 8,294 2,379 (887 ) Effect of Tax Act 5,633 — — State 2,493 1,253 (508 ) Total deferred income tax provision (benefit) 16,420 3,632 (1,395 ) Total income tax provision $ 42,126 $ 25,215 $ 15,209
Schedule of reconciliation from statutory federal income taxes to the Company's effective income taxes	A reconciliation from statutory federal income taxes, that are based on a statutory rate of 35% , to the Company's effective income taxes for the years ended December 31 is as follows: 2017 2016 2015 (dollars in thousands) Statutory federal income tax provision $ 35,778 $ 22,863 $ 14,253 State taxes, net of federal income tax effect 6,720 4,135 2,886 Cash surrender life insurance (645 ) (407 ) (483 ) Tax exempt interest (1,660 ) (764 ) (742 ) Merger costs 824 533 447 LIHTC investments (1,031 ) (909 ) (871 ) Effect of the Tax Act 5,633 — — Excess tax benefit of stock-based compensation (1,995 ) — — Prior year true-up (1,108 ) — — Other (390 ) (236 ) (281 ) Total income tax provision $ 42,126 $ 25,215 $ 15,209
Schedule of deferred tax assets (liabilities) comprised of the temporary differences between the financial statement carrying amounts and the tax basis of assets	Deferred tax assets (liabilities) were comprised of the following temporary differences between the financial statement carrying amounts and the tax basis of assets at December 31: 2017 2016 2015 (dollars in thousands) Deferred tax assets: Accrued expenses $ 2,463 $ 2,839 $ 1,717 Net operating loss 4,834 3,977 5,192 Allowance for loan losses, net of bad debt charge-offs 8,400 8,061 6,252 Deferred compensation 3,074 2,348 2,547 State taxes 1,500 1,879 1,451 Depreciation — 1,090 651 Loan discount 8,642 3,477 — Stock-based compensation 1,914 1,108 639 Unrealized loss on available for sale securities — 1,939 — Capital loss carryover 380 — — AMT credit 107 — — Total deferred tax assets 31,314 26,718 18,449 Deferred tax liabilities: Deferred FDIC gain (524 ) (1,675 ) (1,656 ) Core deposit intangibles (11,691 ) (3,331 ) (2,266 ) Loan origination costs (3,368 ) (4,208 ) — Depreciation (699 ) — — Unrealized loss on available for sale securities (188 ) — (231 ) Other (1,199 ) (697 ) (2,785 ) Total deferred tax liabilities (17,669 ) (9,911 ) (6,938 ) Valuation allowance (380 ) — — Net deferred tax asset $ 13,265 $ 16,807 $ 11,511
Reconciliation of unrecognized tax benefits	A reconciliation of the beginning and ending amount of unrecognized tax benefits for the years ended December 31, 2017 and 2016 is as follows: 2017 2016 (dollars in thousands) Balance at January 1, $ — $ — Additions based on tax positions related to prior years 2,906 — Balance at December 31, $ 2,906 $ —

Commitments, Contingencies an48

Commitments, Contingencies and Concentrations of Risk (Tables)	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Schedule of minimum annual lease payments, excluding any renewals and extensions, property taxes, and other operating expenses, due under the agreements	The following schedule shows the minimum annual lease payments, excluding any renewals and extensions, property taxes, and other operating expenses, due under these agreements: Year ending December 31, Amount (dollars in thousands) 2018 $ 7,170 2019 5,476 2020 2,675 2021 1,887 2022 1,421 Thereafter 2,312 Total $ 20,941

Benefit Plans (Tables)

Benefit Plans (Tables)	12 Months Ended
	Dec. 31, 2017
Retirement Benefits [Abstract]
Summary of the activity in the Option Plan	Below is a summary of the stock option activity in the Plans for the year ended December 31, 2017 : 2017 Number of Stock Options Outstanding Weighted Average Exercise Price Per Share Weighted Average Remaining Contractual Term Aggregate Intrinsic value (in years) (dollars in thousands) Outstanding at January 1, 2017 1,083,667 $ 12.61 Granted 210,977 20.40 Exercised (333,959 ) 13.49 Forfeited and Expired (6,162 ) 34.68 Outstanding at December 31, 2017 954,523 $ 13.89 5.8 $ 24,926 Vested and Exercisable at December 31, 2017 749,281 $ 12.47 5.3 $ 20,627
Schedule of assumptions used for valuing options granted with the Black-Scholes model	Options granted under the Option Plans during 2017 , 2016 and 2015 were valued using the Black-Scholes model with the following average assumptions: Year Ended December 31, 2017 2016 2015 Expected volatility 22.43% - 28.77% 21.98% - 26.88% 29.47% Expected term .33 - 6 Years 6.00 Years 6.00 Years Expected dividends None None None Risk free rate 1.03% - 2.02% 1.32% - 1.83% 1.39% Weighted-average grant date fair value $19.66 $5.55 $4.73
Schedule of Other Share-based Compensation, Activity	Below is a summary of the restricted stock activity in the Plans for the years ended December 31, 2017 : 2017 Shares Weighted Average Grant-Date Fair Value per share Unvested at the beginning of the year 370,334 $ 23.53 Granted 201,544 38.70 Vested (125,035 ) 26.26 Forfeited — — Unvested at the end of the year 446,843 $ 29.61

Fair Value of Financial Instr50

Fair Value of Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Schedule of carrying amount and estimated fair value of financial instruments	The fair value estimates presented herein are based on pertinent information available to management as of December 31, 2017 and 2016 . At December 31, 2017 Carrying Amount Level 1 Level 2 Level 3 Estimated Fair Value (dollars in thousands) Assets: Cash and cash equivalents $ 200,064 $ 200,064 $ — $ — $ 200,064 Interest-bearing time deposits with financial institutions 3,693 3,693 — — 3,693 Investments held to maturity 18,291 — 18,082 — 18,082 Investment securities available-for-sale 787,429 — 787,429 — 787,429 FHLB, FRB and other stock 65,881 N/A N/A N/A N/A Loans held for sale 23,426 — 23,524 — 23,524 Loans held for investment, net 6,167,532 — — 6,269,366 6,269,366 Accrued interest receivable 27,053 27,053 — — 27,053 Liabilities: Deposit accounts 6,085,868 5,001,053 1,074,564 — 6,075,617 FHLB advances 490,148 — 489,823 — 489,823 Other borrowings 46,139 — 46,373 — 46,373 Subordinated debentures 105,123 — 115,159 — 115,159 Accrued interest payable 2,131 2,131 — — 2,131 At December 31, 2016 Carrying Amount Level 1 Level 2 Level 3 Estimated Fair Value (dollars in thousands) Assets: Cash and cash equivalents $ 156,857 $ 156,857 $ — $ — $ 156,857 Interest-bearing time deposits with financial institutions 3,944 3,944 — — 3,944 Investments held to maturity 8,565 — 8,461 — 8,461 Investment securities available for sale 380,963 — 380,963 — 380,963 FHLB, FRB and other stock 37,304 N/A N/A N/A N/A Loans held for sale 7,711 — 8,405 — 8,405 Loans held for investment, net 3,220,317 — — 3,211,154 3,211,154 Accrued interest receivable 13,145 13,145 — — 13,145 Liabilities: Deposit accounts 3,145,581 2,330,579 573,467 — 2,904,046 FHLB advances 278,000 — 277,935 — 277,935 Other borrowings 49,971 — 50,905 — 50,905 Subordinated debentures 69,383 — 69,982 — 69,982 Accrued interest payable 1,481 1,481 — — 1,481
Schedule of Off-balance sheet commitments and standby letters of credit	The fair value estimates presented herein are based on pertinent information available to management as of December 31, 2017 and 2016 . At December 31, 2017 Carrying Amount Level 1 Level 2 Level 3 Estimated Fair Value (dollars in thousands) Assets: Cash and cash equivalents $ 200,064 $ 200,064 $ — $ — $ 200,064 Interest-bearing time deposits with financial institutions 3,693 3,693 — — 3,693 Investments held to maturity 18,291 — 18,082 — 18,082 Investment securities available-for-sale 787,429 — 787,429 — 787,429 FHLB, FRB and other stock 65,881 N/A N/A N/A N/A Loans held for sale 23,426 — 23,524 — 23,524 Loans held for investment, net 6,167,532 — — 6,269,366 6,269,366 Accrued interest receivable 27,053 27,053 — — 27,053 Liabilities: Deposit accounts 6,085,868 5,001,053 1,074,564 — 6,075,617 FHLB advances 490,148 — 489,823 — 489,823 Other borrowings 46,139 — 46,373 — 46,373 Subordinated debentures 105,123 — 115,159 — 115,159 Accrued interest payable 2,131 2,131 — — 2,131 At December 31, 2016 Carrying Amount Level 1 Level 2 Level 3 Estimated Fair Value (dollars in thousands) Assets: Cash and cash equivalents $ 156,857 $ 156,857 $ — $ — $ 156,857 Interest-bearing time deposits with financial institutions 3,944 3,944 — — 3,944 Investments held to maturity 8,565 — 8,461 — 8,461 Investment securities available for sale 380,963 — 380,963 — 380,963 FHLB, FRB and other stock 37,304 N/A N/A N/A N/A Loans held for sale 7,711 — 8,405 — 8,405 Loans held for investment, net 3,220,317 — — 3,211,154 3,211,154 Accrued interest receivable 13,145 13,145 — — 13,145 Liabilities: Deposit accounts 3,145,581 2,330,579 573,467 — 2,904,046 FHLB advances 278,000 — 277,935 — 277,935 Other borrowings 49,971 — 50,905 — 50,905 Subordinated debentures 69,383 — 69,982 — 69,982 Accrued interest payable 1,481 1,481 — — 1,481
Schedule of Company's assets measured at fair value on a recurring basis	The following fair value hierarchy tables present information about the Company’s assets measured at fair value on a recurring basis at the dates indicated: At December 31, 2017 Fair Value Measurement Using Level 1 Level 2 Level 3 Securities at Fair Value (dollars in thousands) Investment securities available for sale: Agency $ — $ 47,209 $ — $ 47,209 Corporate — 79,546 — 79,546 Municipal bonds — 232,128 — 232,128 Collateralized mortgage obligation: residential — 33,781 — 33,781 Mortgage-backed securities: residential — 394,765 — 394,765 Total securities available for sale: $ — $ 787,429 $ — $ 787,429 At December 31, 2016 Fair Value Measurement Using Level 1 Level 2 Level 3 Securities at Fair Value (dollars in thousands) Investment securities available for sale: Corporate $ — $ 37,642 $ — $ 37,642 Municipal bonds — 118,803 — 118,803 Collateralized mortgage obligation: residential — 31,388 — 31,388 Mortgage-backed securities: residential — 193,130 — 193,130 Total securities available for sale: $ — $ 380,963 $ — $ 380,963

Earnings Per Share (Tables)

Earnings Per Share (Tables)	12 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
Schedule of Company's unaudited earnings per share calculations	A reconciliation of the numerators and denominators used in basic and diluted earnings per share computations is presented in the table below. Income/(Loss) (numerator) Shares (denominator) Per Share Amount (dollars in thousands, except share data) For the year ended December 31, 2017: Net income applicable to earnings per share $ 60,100 Basic earnings per share: Income available to common stockholders 60,100 37,705,556 $ 1.59 Effect of dilutive securities: Warrants and stock option plans — 805,705 Diluted earnings per share: Income available to common stockholders $ 60,100 38,511,261 $ 1.56 For the year ended December 31, 2016: Net income applicable to earnings per share $ 40,103 Basic earnings per share: Income available to common stockholders 40,103 26,931,634 $ 1.49 Effect of dilutive securities: Warrants and stock option plans — 507,525 Diluted earnings per share: Income available to common stockholders $ 40,103 27,439,159 $ 1.46 For the year ended December 31, 2015: Net income applicable to earnings per share $ 25,515 Basic earnings per share: Income available to common stockholders 25,515 21,156,668 $ 1.21 Effect of dilutive securities: Warrants and stock option plans — 332,030 Diluted earnings per share: Income available to common stockholders $ 25,515 21,488,698 $ 1.19

Derivative Instruments (Tables)

Derivative Instruments (Tables)	12 Months Ended
	Dec. 31, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Derivative Instruments	The Company's derivative instruments were acquired as part of the HEOP acquisition, and the Company did not have any at December 31, 2016: December 31, 2017 Derivative Assets Derivative Liabilities Notional Fair Value Notional Fair Value (dollars in thousands) Derivative instruments not designated as hedging instruments: Interest rate swap contracts $ 58,599 $ 1,135 $ 58,599 $ 1,135 Total derivative instruments $ 58,599 $ 1,135 $ 58,599 $ 1,135

Balance Sheet Offsetting (Table

Balance Sheet Offsetting (Tables)	12 Months Ended
	Dec. 31, 2017
Offsetting [Abstract]
Offsetting Assets and Liabilities	Financial instruments that are eligible for offset in the consolidated statements of financial condition as of December 31, 2017 are presented in the table below: December 31, 2017 Gross Amounts Not Offset in the Consolidated Gross Amounts Recognized in the Consolidated Balance Sheets Gross Amounts Offset in the Consolidated Balance Sheets Net Amounts Presented in the Consolidated Balance Sheets Financial Instruments Cash Collateral (1) Net Amount (dollars in thousands) Financial assets: Derivatives not designated as $ 1,833 $ (698 ) $ 1,135 $ — $ — $ 1,135 Total $ 1,833 $ (698 ) $ 1,135 $ — $ — $ 1,135 Financial liabilities: Derivatives not designated as $ 1,135 $ — $ 1,135 $ — $ — $ 1,135 Total $ 1,135 $ — $ 1,135 $ — $ — $ 1,135 (1) Represents cash collateral held with counterparty bank.

Quarterly Results of Operatio54

Quarterly Results of Operations (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Summary of selected financial data by quarter	The following is a summary of selected financial data presented below by quarter for the periods indicated: First Quarter Second Quarter Third Quarter Fourth Quarter (dollars in thousands, except per share data) For the year ended December 31, 2017: Interest income $ 45,427 $ 68,733 $ 70,161 $ 85,684 Interest expense 3,724 5,395 5,870 7,514 Provision for loan losses 2,502 1,904 2,049 2,185 Noninterest income 4,683 8,759 8,221 9,451 Noninterest expense 29,747 48,496 39,612 49,895 Income tax provision 4,616 7,521 10,619 19,370 Net income $ 9,521 $ 14,176 $ 20,232 $ 16,171 Earnings per share: Basic $ 0.35 $ 0.36 $ 0.51 $ 0.37 Diluted 0.34 0.35 0.50 0.36 For the year ended December 31, 2016: Interest income $ 37,505 $ 40,874 $ 42,429 $ 45,797 Interest expense 3,304 3,313 3,420 3,493 Provision for loan losses 1,120 1,589 4,013 2,054 Noninterest income 4,848 4,468 5,968 4,318 Noninterest expense 23,633 23,713 25,860 25,377 Income tax provision 5,742 6,358 5,877 7,238 Net income $ 8,554 $ 10,369 $ 9,227 $ 11,953 Earnings per share: Basic $ 0.33 $ 0.38 $ 0.34 $ 0.44 Diluted 0.33 0.37 0.33 0.43

Parent Company Financial Info55

Parent Company Financial Information (Tables) - Corporation	12 Months Ended
	Dec. 31, 2017
Parent Company Financial Information
Schedule of condensed balance sheets	PACIFIC PREMIER BANCORP, INC. STATEMENTS OF FINANCIAL CONDITION (Parent company only) At December 31, 2017 2016 (dollars in thousands) Assets Cash and cash equivalents $ 17,097 $ 15,124 Investment in subsidiaries 1,329,961 513,606 Other assets 2,599 2,400 Total Assets $ 1,349,657 $ 531,130 Liabilities Subordinated debentures $ 105,123 $ 69,383 Accrued expenses and other liabilities 2,538 2,007 Total Liabilities 107,661 71,390 Total Stockholders’ Equity 1,241,996 459,740 Total Liabilities and Stockholders’ Equity $ 1,349,657 $ 531,130
Schedule of condensed statements of operations	PACIFIC PREMIER BANCORP, INC. STATEMENTS OF OPERATIONS (Parent company only) For the Years Ended December 31, 2017 2016 2015 (dollars in thousands) Income Interest income $ 36 $ 31 $ 27 Noninterest income — — — Total income 36 31 27 Expense Interest expense 4,720 3,844 3,937 Noninterest expense 8,956 3,769 2,831 Total expense 13,676 7,613 6,768 Loss before income tax provision (13,640 ) (7,582 ) (6,741 ) Income tax benefit (5,417 ) (2,785 ) (2,783 ) Net loss (parent only) (8,223 ) (4,797 ) (3,958 ) Equity in net earnings of subsidiaries 68,323 44,900 29,473 Net income $ 60,100 $ 40,103 $ 25,515
Schedule of condensed statements of cash flows	PACIFIC PREMIER BANCORP, INC. SUMMARY STATEMENTS OF CASH FLOWS (Parent company only) For the Years Ended December 31, 2017 2016 2015 CASH FLOWS FROM OPERATING ACTIVITIES (dollars in thousands) Net income $ 60,100 $ 40,103 $ 25,515 Adjustments to reconcile net income to cash used in operating activities: Share-based compensation expense 5,809 2,729 1,165 Equity in undistributed earnings of subsidiaries and dividends from the bank (68,323 ) (44,901 ) (29,473 ) Increase (decrease) in accrued expenses and other liabilities (365 ) 240 166 (Decrease) increase in current and deferred taxes (896 ) — 3,566 Decrease (increase) in other assets 1,714 4,794 (6,893 ) Net cash (used in) provided by operating activities (1,961 ) 2,965 (5,954 ) CASH FLOWS FROM FINANCING ACTIVITIES: Proceeds from issuance of common stock, net of issuance cost — — — Repurchase of common stock (1,258 ) (125 ) (116 ) Proceeds from exercise of options and warrants 4,592 1,107 758 Capital contribution to Bank 600 7,765 (10,000 ) Proceeds from issuance of subordinated debentures — — — Net cash provided by (used in) financing activities 3,934 8,747 (9,358 ) Net increase (decrease) in cash and cash equivalents 1,973 11,712 (15,312 ) Cash and cash equivalents, beginning of year 15,124 3,412 18,724 Cash and cash equivalents, end of year $ 17,097 $ 15,124 $ 3,412

Acquisitions (Tables)

Acquisitions (Tables)	12 Months Ended
	Dec. 31, 2017
Business Combinations [Abstract]
Schedule of assets acquired and liabilities assumed and the provisional fair value adjustments and amounts recorded	The following table represents the assets acquired and liabilities assumed of PLZZ as of November 1, 2017 and the fair value adjustments and amounts recorded by the Company in 2017 under the acquisition method of accounting, which are subject to adjustment for up to one year after the merger date: PLZZ Fair Value Fair Book Value Adjustment Value (dollars in thousands) ASSETS ACQUIRED Cash and cash equivalents $ 150,459 $ — $ 150,459 Loans, gross 1,069,359 (6,418 ) 1,062,941 Allowance for loan losses (13,009 ) 13,009 — Fixed assets 7,389 (194 ) 7,195 Core deposit intangible 198 11,382 11,580 Deferred tax assets 11,849 (6,876 ) 4,973 Other assets 19,495 (330 ) 19,165 Total assets acquired $ 1,245,740 $ 10,573 $ 1,256,313 LIABILITIES ASSUMED Deposits $ 1,081,727 $ 1,224 $ 1,082,951 Borrowings 40,755 397 41,152 Other Liabilities 8,956 (622 ) 8,334 Total liabilities assumed 1,131,438 999 1,132,437 Excess of assets acquired over liabilities assumed $ 114,302 $ 9,574 123,876 Consideration paid 250,939 Paid by PLZZ prior to close 6,544 Capitalized merger-related expense 1,366 Goodwill recognized $ 121,885 The following table represents the assets acquired and liabilities assumed of HEOP as of April 1, 2017 and the fair value adjustments and amounts recorded by the Company in 2017 under the acquisition method of accounting: HEOP Book Value Fair Value Adjustments Fair Value ASSETS ACQUIRED (dollars in thousands) Cash and cash equivalents $ 78,728 $ — $ 78,728 Investment securities 447,520 (4,597 ) 442,923 Loans, gross 1,387,949 (23,300 ) 1,364,649 Allowance for loan losses (17,200 ) 17,200 — Fixed assets 35,567 (665 ) 34,902 Core deposit intangible — 28,123 28,123 Deferred tax assets 17,850 (6,567 ) 11,283 Other assets 55,223 (9 ) 55,214 Total assets acquired $ 2,005,637 $ 10,185 $ 2,015,822 LIABILITIES ASSUMED Deposits $ 1,668,079 $ 1,471 $ 1,669,550 Borrowings 141,996 (2,962 ) 139,034 Other Liabilities 7,290 771 8,061 Total liabilities assumed 1,817,365 (720 ) 1,816,645 Excess of assets acquired over liabilities assumed $ 188,272 $ 10,905 199,177 Consideration paid 465,482 Capitalized merger-related expense 2,649 Goodwill recognized $ 268,954 The following table represents the assets acquired and liabilities assumed of SCAF as of January 31, 2016 and the fair value adjustments and amounts recorded by the Company in 2016 under the acquisition method of accounting: SCAF Book Value Fair Value Adjustments Fair Value (dollars in thousands) ASSETS ACQUIRED Cash and cash equivalents $ 40,947 $ — $ 40,947 Interest-bearing deposits with financial institutions 1,972 — 1,972 Investment securities 191,881 (1,627 ) 190,254 Loans, gross 467,197 (11,039 ) 456,158 Allowance for loan losses (7,399 ) 7,399 — Fixed assets 5,335 (1,145 ) 4,190 Core deposit intangible 493 3,826 4,319 Deferred tax assets 5,618 1,130 6,748 Other assets 10,589 (1,227 ) 9,362 Total assets acquired $ 716,633 $ (2,683 ) $ 713,950 LIABILITIES ASSUMED Deposits $ 636,450 $ 141 $ 636,591 Borrowings — — — Deferred tax liability — — — Other Liabilities 9,063 (220 ) 8,843 Total liabilities assumed 645,513 (79 ) 645,434 Excess of assets acquired over liabilities assumed $ 71,120 $ (2,604 ) 68,516 Consideration paid 120,174 Goodwill recognized $ 51,658
Schedule of contractual amounts due, expected cash flows to be collected, interest component and fair value as of the respective acquisition dates	For loans acquired from SCAF, HEOP and PLZZ, the contractual amounts due, expected cash flows to be collected, interest component and fair value as of the respective acquisition dates were as follows: Acquired Loans SCAF HEOP PLZZ (dollars in thousands) Contractual amounts due $ 539,806 $ 1,717,230 $ 1,703,246 Cash flows not expected to be collected 2,765 4,442 20,152 Expected cash flows 537,041 1,712,788 1,683,094 Interest component of expected cash flows 80,883 348,100 625,592 Fair value of acquired loans $ 456,158 $ 1,364,688 $ 1,057,502
Summary of pro forma net interest and other income, net income and earnings per share	Unaudited pro forma net interest and other income, net income and earnings per share presented below: Year Ended December 31, 2017 2016 2015 Net interest and other income $ 342,159 $ 258,970 $ 246,622 Net income 72,316 71,722 58,257 Basic earnings per share 1.58 1.58 1.30 Diluted earnings per share 1.55 1.56 1.29

Description of Business and S57

Description of Business and Summary of Significant Accounting Policies (Details)	3 Months Ended	12 Months Ended
	Mar. 31, 2018USD ($)	Dec. 31, 2017USD ($)depository_branch	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Accounting Policies [Abstract]
Percentage of capital stock of the Bank held		100.00%
Number of depository branches | depository_branch		33
Cash and Cash Equivalents
Cash reserves required by the Board of Governors of the Federal Reserve for depository institutions (in dollars)		$ 0
Premises, furniture and equipment
Valuation allowance		380,000	$ 0	$ 0
Adjustments to Additional Paid in Capital, Income Tax Benefit from Share-based Compensation		$ 1,995,000	$ 0	$ 0
Subsequent Event
Premises, furniture and equipment
Reclassification from retained earnings to AOCI	$ 81,000
Core Deposits | Minimum
Premises, furniture and equipment
Weighted average useful life (in years)		6 years
Core Deposits | Maximum
Premises, furniture and equipment
Weighted average useful life (in years)		10 years
Premises
Premises, furniture and equipment
Estimated useful life (in years)		40 years
Furniture, fixtures and equipment
Premises, furniture and equipment
Estimated useful life (in years)		7 years
Computer and telecommunication
Premises, furniture and equipment
Estimated useful life (in years)		3 years

Regulatory Capital Requiremen58

Regulatory Capital Requirements and Other Regulatory Matters (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Tier 1 Leverage Ratio
Actual, Amount (in dollars)	$ 744,233	$ 366,658
Actual, Ratio (as a percent)	10.70%	9.78%
Minimum Required for Capital Adequacy Purposes Amount (in dollars)	$ 278,183	$ 150,027
Minimum Required for Capital Adequacy Purposes Ratio (as a percent)	4.00%	4.00%
Common Equity Tier 1 to Risk-Weighted Assets
Actual, Amount (in dollars)	$ 724,205	$ 356,658
Actual, Ratio (as a percent)	10.59%	10.12%
Minimum Required for Capital Adequacy Purposes (in dollars)	$ 307,778	$ 158,574
Minimum Required for Capital Adequacy Purposes (as a percent)	4.50%	4.50%
Tier 1 Capital to Risk-Weighted Assets
Actual, Amount (in dollars)	$ 744,233	$ 366,658
Actual, Ratio (as a percent)	10.88%	10.41%
Minimum Required for Capital Adequacy Purposes Amount (in dollars)	$ 410,371	$ 211,432
Minimum Required for Capital Adequacy Purposes Ratio (as a percent)	6.00%	6.00%
Total Capital to Risk-Weighted Assets
Actual, Amount (in dollars)	$ 859,442	$ 448,150
Actual, Ratio (as a percent)	12.57%	12.72%
Minimum Required for Capital Adequacy Purposes Amount (in dollars)	$ 547,161	$ 281,909
Minimum Required for Capital Adequacy Purposes Ratio (as a percent)	8.00%	8.00%
Pacific Premier Bank
Tier 1 Leverage Ratio
Actual, Amount (in dollars)	$ 812,170	$ 410,524
Actual, Ratio (as a percent)	11.68%	10.94%
Minimum Required for Capital Adequacy Purposes Amount (in dollars)	$ 278,152	$ 150,107
Minimum Required for Capital Adequacy Purposes Ratio (as a percent)	4.00%	4.00%
Required to be Well Capitalized Under Prompt Corrective Action Regulations, Amount (in dollars)	$ 347,690	$ 187,634
Required to be Well Capitalized Under Prompt Corrective Action Regulations, Ratio (as a percent)	5.00%	5.00%
Common Equity Tier 1 to Risk-Weighted Assets
Actual, Amount (in dollars)	$ 812,170	$ 410,524
Actual, Ratio (as a percent)	11.88%	11.65%
Minimum Required for Capital Adequacy Purposes (in dollars)	$ 307,702	$ 158,536
Minimum Required for Capital Adequacy Purposes (as a percent)	4.50%	4.50%
Required to be Well Capitalized Under Prompt Corrective Action Regulations (in dollars)	$ 444,458	$ 228,997
Required to be Well Capitalized Under Prompt Corrective Action Regulations (as a percent)	6.50%	6.50%
Tier 1 Capital to Risk-Weighted Assets
Actual, Amount (in dollars)	$ 812,170	$ 410,524
Actual, Ratio (as a percent)	11.88%	11.65%
Minimum Required for Capital Adequacy Purposes Amount (in dollars)	$ 410,269	$ 211,382
Minimum Required for Capital Adequacy Purposes Ratio (as a percent)	6.00%	6.00%
Required to be Well Capitalized Under Prompt Corrective Action Regulations, Amount (in dollars)	$ 547,025	$ 281,842
Required to be Well Capitalized Under Prompt Corrective Action Regulations, Ratio (as a percent)	8.00%	8.00%
Total Capital to Risk-Weighted Assets
Actual, Amount (in dollars)	$ 843,005	$ 432,943
Actual, Ratio (as a percent)	12.33%	12.29%
Minimum Required for Capital Adequacy Purposes Amount (in dollars)	$ 547,025	$ 281,842
Minimum Required for Capital Adequacy Purposes Ratio (as a percent)	8.00%	8.00%
Required to be Well Capitalized Under Prompt Corrective Action Regulations, Amount (in dollars)	$ 683,781	$ 352,303
Required to be Well Capitalized Under Prompt Corrective Action Regulations, Ratio (as a percent)	10.00%	10.00%

Investment Securities - The amo

Investment Securities - The amortized cost and estimated fair value of securities (Details)	3 Months Ended	12 Months Ended
	Mar. 31, 2017USD ($)	Dec. 31, 2017USD ($)purchase_agreement	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Mar. 31, 2016USD ($)
Investment securities available-for-sale
Amortized Cost		$ 786,783,000	$ 385,662,000
Unrealized Gain		6,161,000	804,000
Unrealized Loss		(5,515,000)	(5,503,000)
Estimated Fair Value		787,429,000	380,963,000
Investment securities held-to-maturity
Amortized Cost		18,291,000	8,565,000
Unrealized Gain		0	0
Unrealized Loss		(209,000)	(104,000)
Estimated Fair Value		18,082,000	8,461,000
Total investment securities
Amortized Cost		805,074,000	394,227,000
Unrealized Gain		6,161,000	804,000
Unrealized Loss		(5,724,000)	(5,607,000)
Estimated Fair Value		805,511,000	389,424,000
Additional disclosures
Accumulated other comprehensive income (loss)		646,000	(4,700,000)
Accumulated other comprehensive income (loss), net of tax		$ 415,000	(2,721,000)
Number of inverse putable reverse repurchase of the Bank's secured by collateral | purchase_agreement		3
Value of inverse putable reverse repurchases secured by collateral		$ 28,500,000
OTTI realized		2,000	205,000
Gross gains		3,100,000	1,800,000	$ 317,000
Gross losses		(386,000)	(9,000)	(27,000)
Net proceeds from the sale of available-for-sale securities		268,596,000	230,945,000	$ 27,642,000
CRA
Investment securities available-for-sale
Estimated Fair Value					$ 500,000
Additional disclosures
OTTI realized	$ 207,000
CRA investment purchased, par value					$ 50
Mortgage-backed securities: residential
Additional disclosures
Estimated par value of securities pledged as collateral for the Bank's inverse putable reverse repurchases		55,600,000
Fair value of securities pledged as collateral for the Bank's inverse putable reverse repurchases		57,000,000
Home Owners Association Loans
Additional disclosures
Value of inverse putable reverse repurchases secured by collateral		17,600,000
Agency
Investment securities available-for-sale
Amortized Cost		47,051,000
Unrealized Gain		236,000
Unrealized Loss		(78,000)
Estimated Fair Value		47,209,000
Corporate
Investment securities available-for-sale
Amortized Cost		78,155,000	37,475,000
Unrealized Gain		1,585,000	372,000
Unrealized Loss		(194,000)	(205,000)
Estimated Fair Value		79,546,000	37,642,000
Municipal bonds
Investment securities available-for-sale
Amortized Cost		228,929,000	120,155,000
Unrealized Gain		3,942,000	338,000
Unrealized Loss		(743,000)	(1,690,000)
Estimated Fair Value		232,128,000	118,803,000
Collateralized mortgage obligation: residential
Investment securities available-for-sale
Amortized Cost		33,984,000	31,536,000
Unrealized Gain		132,000	25,000
Unrealized Loss		(335,000)	(173,000)
Estimated Fair Value		33,781,000	31,388,000
Mortgage-backed securities: residential
Investment securities available-for-sale
Amortized Cost		398,664,000	196,496,000
Unrealized Gain		266,000	69,000
Unrealized Loss		(4,165,000)	(3,435,000)
Estimated Fair Value		394,765,000	193,130,000
Investment securities held-to-maturity
Amortized Cost		17,153,000	7,375,000
Unrealized Gain		0	0
Unrealized Loss		(209,000)	(104,000)
Estimated Fair Value		16,944,000	7,271,000
Other
Investment securities held-to-maturity
Amortized Cost		1,138,000	1,190,000
Unrealized Gain		0	0
Unrealized Loss		0	0
Estimated Fair Value		$ 1,138,000	$ 1,190,000

Investment Securities - Number,

Investment Securities - Number, fair value and gross unrealized holding losses (Details) $ in Thousands	Dec. 31, 2017USD ($)investment_security	Dec. 31, 2016USD ($)investment_security
Number
Less than 12 months | investment_security	184	215
12 months or Longer | investment_security	76	4
Total | investment_security	260	219
Fair Value
Less than 12 months	$ 320,068	$ 262,191
12 months or Longer	140,739	16,039
Total	460,807	278,230
Gross Unrealized Holding Losses
Less than 12 months	(2,159)	(4,984)
12 months or Longer	(3,356)	(519)
Total	$ (5,515)	$ (5,503)
Number
Less than 12 months | investment_security	2	1
12 months or Longer | investment_security	1	0
Total | investment_security	3	1
Fair Value
Less than 12 months	$ 10,745	$ 7,271
12 months or Longer	6,198	0
Total	16,943	7,271
Gross Unrealized Holding Losses
Less than 12 months	(133)	(104)
12 months or Longer	(76)	0
Total	$ (209)	$ (104)
Total investment securities
Number, Less than 12 months (in investments) | investment_security	186	216
Number, 12 months or Longer (in investments) | investment_security	77	4
Number, Total (in investments) | investment_security	263	220
Fair Value, Less than 12 months	$ 330,813	$ 269,462
Fair Value, 12 months or Longer	146,937	16,039
Fair Value, Total	477,750	285,501
Gross Unrealized Holding Losses, Less than 12 months	(2,292)	(5,088)
Gross Unrealized Holding Losses, 12 months or longer	(3,432)	(519)
Gross Unrealized Holding Losses, Total	$ (5,724)	$ (5,607)
Agency
Number
Less than 12 months | investment_security	6
12 months or Longer | investment_security	0
Total | investment_security	6
Fair Value
Less than 12 months	$ 13,754
12 months or Longer	0
Total	13,754
Gross Unrealized Holding Losses
Less than 12 months	(78)
12 months or Longer	0
Total	$ (78)
Corporate
Number
Less than 12 months | investment_security	4	3
12 months or Longer | investment_security	2	0
Total | investment_security	6	3
Fair Value
Less than 12 months	$ 10,079	$ 7,609
12 months or Longer	6,076	0
Total	16,155	7,609
Gross Unrealized Holding Losses
Less than 12 months	(64)	(205)
12 months or Longer	(130)	0
Total	$ (194)	$ (205)
Municipal bonds
Number
Less than 12 months | investment_security	103	152
12 months or Longer | investment_security	30	0
Total | investment_security	133	152
Fair Value
Less than 12 months	$ 61,313	$ 85,750
12 months or Longer	15,658	0
Total	76,971	85,750
Gross Unrealized Holding Losses
Less than 12 months	(268)	(1,690)
12 months or Longer	(475)	0
Total	$ (743)	$ (1,690)
Collateralized mortgage obligation: residential
Number
Less than 12 months | investment_security	5	5
12 months or Longer | investment_security	3	0
Total | investment_security	8	5
Fair Value
Less than 12 months	$ 13,971	$ 19,092
12 months or Longer	8,943	0
Total	22,914	19,092
Gross Unrealized Holding Losses
Less than 12 months	(149)	(173)
12 months or Longer	(186)	0
Total	$ (335)	$ (173)
Mortgage-backed securities: residential
Number
Less than 12 months | investment_security	66	55
12 months or Longer | investment_security	41	4
Total | investment_security	107	59
Fair Value
Less than 12 months	$ 220,951	$ 149,740
12 months or Longer	110,062	16,039
Total	331,013	165,779
Gross Unrealized Holding Losses
Less than 12 months	(1,600)	(2,916)
12 months or Longer	(2,565)	(519)
Total	$ (4,165)	$ (3,435)
Number
Less than 12 months | investment_security	2	1
12 months or Longer | investment_security	1	0
Total | investment_security	3	1
Fair Value
Less than 12 months	$ 10,745	$ 7,271
12 months or Longer	6,198	0
Total	16,943	7,271
Gross Unrealized Holding Losses
Less than 12 months	(133)	(104)
12 months or Longer	(76)	0
Total	$ (209)	$ (104)

Investment Securities - Contrac

Investment Securities - Contractual maturity (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Amortized Cost
One Year or Less	$ 6,715
More than One Year to Five Years	35,037
More than Five Years to Ten Years	232,766
More than Ten Years	512,265
Amortized Cost	786,783	$ 385,662
Fair Value
One Year or Less	6,704
More than One Year to Five Years	35,035
More than Five Years to Ten Years	234,107
More than Ten Years	511,583
Total	787,429	380,963
Amortized Cost
One Year or Less	0
More than One Year to Five Years	0
More than Five Years to Ten Years	0
More than Ten Years	18,291
Amortized Cost	18,291	8,565
Fair Value
One Year or Less	0
More than One Year to Five Years	0
More than Five Years to Ten Years	0
More than Ten Years	18,082
Total	18,082	8,461
Amortized Cost
One Year or Less	6,715
More than One Year to Five Years	35,037
More than Five Years to Ten Years	232,766
More than Ten Years	530,556
Total	805,074
Fair Value
One Year or Less	6,704
More than One Year to Five Years	35,035
More than Five Years to Ten Years	234,107
More than Ten Years	529,665
Total	805,511
Agency
Amortized Cost
One Year or Less	0
More than One Year to Five Years	0
More than Five Years to Ten Years	15,156
More than Ten Years	31,895
Amortized Cost	47,051
Fair Value
One Year or Less	0
More than One Year to Five Years	0
More than Five Years to Ten Years	15,164
More than Ten Years	32,045
Total	47,209
Corporate
Amortized Cost
One Year or Less	0
More than One Year to Five Years	0
More than Five Years to Ten Years	78,155
More than Ten Years	0
Amortized Cost	78,155	37,475
Fair Value
One Year or Less	0
More than One Year to Five Years	0
More than Five Years to Ten Years	79,546
More than Ten Years	0
Total	79,546	37,642
Municipal bonds
Amortized Cost
One Year or Less	4,124
More than One Year to Five Years	32,390
More than Five Years to Ten Years	72,845
More than Ten Years	119,570
Amortized Cost	228,929	120,155
Fair Value
One Year or Less	4,121
More than One Year to Five Years	32,424
More than Five Years to Ten Years	73,312
More than Ten Years	122,271
Total	232,128	118,803
Collateralized mortgage obligation: residential
Amortized Cost
One Year or Less	0
More than One Year to Five Years	0
More than Five Years to Ten Years	1,069
More than Ten Years	32,915
Amortized Cost	33,984	31,536
Fair Value
One Year or Less	0
More than One Year to Five Years	0
More than Five Years to Ten Years	1,071
More than Ten Years	32,710
Total	33,781	31,388
Mortgage-backed securities: residential
Amortized Cost
One Year or Less	2,591
More than One Year to Five Years	2,647
More than Five Years to Ten Years	65,541
More than Ten Years	327,885
Amortized Cost	398,664	196,496
Fair Value
One Year or Less	2,583
More than One Year to Five Years	2,611
More than Five Years to Ten Years	65,014
More than Ten Years	324,557
Total	394,765	193,130
Amortized Cost
One Year or Less	0
More than One Year to Five Years	0
More than Five Years to Ten Years	0
More than Ten Years	17,153
Amortized Cost	17,153	7,375
Fair Value
One Year or Less	0
More than One Year to Five Years	0
More than Five Years to Ten Years	0
More than Ten Years	16,944
Total	16,944	$ 7,271
Other
Amortized Cost
One Year or Less	0
More than One Year to Five Years	0
More than Five Years to Ten Years	0
More than Ten Years	1,138
Amortized Cost	1,138
Fair Value
One Year or Less	0
More than One Year to Five Years	0
More than Five Years to Ten Years	0
More than Ten Years	1,138
Total	$ 1,138

Investment Securities - FHLB, F

Investment Securities - FHLB, FRB, and other stock (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Investments, Debt and Equity Securities [Abstract]
Federal Home Loan Bank Stock	$ 17,300,000
Federal Reserve Bank Stock	25,300,000
Other stock	23,300,000
Excess Federal Home Loan Bank Stock with Entity Repurchased by Federal Home Loan Bank	$ 10,300,000	$ 0	$ 16,400,000

Loans - Composition of Loan Por

Loans - Composition of Loan Portfolio (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Loans Held for Investment
Gross loans held for investment	$ 6,198,627	$ 3,237,983
Plus: Deferred loan origination costs/(fees) and premiums/(discounts), net	(2,159)	3,630
Loans held for investment	6,196,468	3,241,613
Allowance for loan losses	(28,936)	(21,296)	$ (17,317)	$ (12,200)
Loans held for investment, net	6,167,532	3,220,317
Less loans held for sale, net	23,426	7,711
Servicing rights retained from guaranteed portion of SBA loans sold	8,800	5,300
Unpaid principal balance for loans and participations serviced for others	635,000	303,000
Business Loans
Loans Held for Investment
Gross loans held for investment	3,337,866	1,566,502
Business Loans | Commercial and industrial
Loans Held for Investment
Gross loans held for investment	1,086,659	563,169
Allowance for loan losses	(9,721)	(6,362)	(3,449)	(2,646)
Business Loans | Franchise
Loans Held for Investment
Gross loans held for investment	660,414	459,421
Allowance for loan losses	(5,797)	(3,845)	(3,124)	(1,554)
Business Loans | Commercial owner occupied
Loans Held for Investment
Gross loans held for investment	1,289,213	454,918
Allowance for loan losses	(767)	(1,193)	(1,870)	(1,757)
Business Loans | SBA
Loans Held for Investment
Gross loans held for investment	185,514	88,994
Allowance for loan losses	(2,890)	(1,039)	(1,500)	(568)
Business Loans | Agribusiness
Loans Held for Investment
Gross loans held for investment	116,066	0
Allowance for loan losses	(1,291)	0	0	0
Real Estate Loans
Loans Held for Investment
Gross loans held for investment	2,767,830	1,667,369
Real Estate Loans | Commercial non-owner occupied
Loans Held for Investment
Gross loans held for investment	1,243,115	586,975
Allowance for loan losses	(1,266)	(1,715)	(2,048)	(2,007)
Real Estate Loans | Multi-family
Loans Held for Investment
Gross loans held for investment	794,384	690,955
Allowance for loan losses	(607)	(2,927)	(1,583)	(1,060)
Real Estate Loans | One-to-four family
Loans Held for Investment
Gross loans held for investment	270,894	100,451
Allowance for loan losses	(803)	(365)	(698)	(842)
Real Estate Loans | Construction
Loans Held for Investment
Gross loans held for investment	282,811	269,159
Allowance for loan losses	(4,569)	(3,632)	(2,030)	(1,088)
Real Estate Loans | Farmland
Loans Held for Investment
Gross loans held for investment	145,393	0
Allowance for loan losses	(137)	0	0	0
Real Estate Loans | Land
Loans Held for Investment
Gross loans held for investment	31,233	19,829
Allowance for loan losses	(993)	(198)	(233)	(108)
Consumer Loans | Consumer loans
Loans Held for Investment
Gross loans held for investment	92,931	4,112
Allowance for loan losses	$ (95)	$ (20)	$ (23)	$ (24)

Loans - Purchased Credit Impair

Loans - Purchased Credit Impaired Loans (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Business Loans | Commercial and industrial
Loans Held for Investment
Total purchase credit impaired	$ 1,585	$ 1,990	$ 578
Business Loans | Commercial owner occupied
Loans Held for Investment
Total purchase credit impaired	98	847	883
Business Loans | SBA
Loans Held for Investment
Total purchase credit impaired	4,329	3,865
Real Estate Loans
Loans Held for Investment
Total purchase credit impaired	6,896	7,029	4,319
Real Estate Loans | Commercial non-owner occupied
Loans Held for Investment
Total purchase credit impaired	0	0	329
Real Estate Loans | One-to-four family
Loans Held for Investment
Total purchase credit impaired	849	291	98
Real Estate Loans | Construction
Loans Held for Investment
Total purchase credit impaired	0
Real Estate Loans | Land
Loans Held for Investment
Total purchase credit impaired	35	36	$ 37
Acquired Banks
Loans Held for Investment
Total purchase credit impaired	8,889	4,559
Acquired Banks | Business Loans
Loans Held for Investment
Total purchase credit impaired	6,374	3,077
Acquired Banks | Business Loans | Commercial and industrial
Loans Held for Investment
Total purchase credit impaired	3,310	2,586
Acquired Banks | Business Loans | Commercial owner occupied
Loans Held for Investment
Total purchase credit impaired	1,262	491
Acquired Banks | Business Loans | SBA
Loans Held for Investment
Total purchase credit impaired	1,802	0
Acquired Banks | Real Estate Loans
Loans Held for Investment
Total purchase credit impaired	2,505	1,089
Acquired Banks | Real Estate Loans | Commercial non-owner occupied
Loans Held for Investment
Total purchase credit impaired	1,650	1,088
Acquired Banks | Real Estate Loans | One-to-four family
Loans Held for Investment
Total purchase credit impaired	255	1
Acquired Banks | Real Estate Loans | Construction
Loans Held for Investment
Total purchase credit impaired	517	0
Acquired Banks | Real Estate Loans | Land
Loans Held for Investment
Total purchase credit impaired	83	0
Acquired Banks | Consumer Loans | Consumer loans
Loans Held for Investment
Total purchase credit impaired	$ 10	$ 393

Loans - Accretable yield on the

Loans - Accretable yield on the purchased credit impaired (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accretable yield on purchased credit impaired
Balance at the beginning of period	$ 3,747	$ 2,726	$ 1,403
Additions	3,102	788	602
Accretion	(2,037)	(1,354)	(385)
Payoffs	(2,125)	165	(249)
Reclassification from nonaccretable difference	332	1,422	1,355
Balance at the end of period	$ 3,019	$ 3,747	$ 2,726

Loans - Investment in impaired

Loans - Investment in impaired loans (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Impaired Loans
Investment in TDR	$ 97,000	$ 0
Nonaccruing loans	3,300,000	1,100,000	$ 4,000,000
Additional loan interest income, had such loans been performing	155,000	360,000	279,000
Loans 90 days or more past due and still accruing	$ 1,800,000	0
Second Relationship [Member] | Extended Maturity [Member]
Impaired Loans
Extension of maturity	3 years
Business Loans | Commercial and industrial
Impaired Loans
Recorded Investment	$ 1,160,000	250,000	313,000
Unpaid Principal Balance	1,585,000	1,990,000	578,000
With Specific Allowance	0	250,000	0
Without Specific Allowance	1,160,000	0	313,000
Specific Allowance for Impaired Loans	0	250,000	0
Average Recorded Investment	441,000	864,000	90,000
Interest Income Recognized	0	76,000	29,000
Business Loans | Franchise
Impaired Loans
Recorded Investment		0	1,630,000
Unpaid Principal Balance		0	2,394,000
With Specific Allowance		0	1,461,000
Without Specific Allowance		0	169,000
Specific Allowance for Impaired Loans		0	731,000
Average Recorded Investment		1,016,000	1,386,000
Interest Income Recognized		68,000	3,000
Business Loans | Commercial owner occupied
Impaired Loans
Recorded Investment	97,000	436,000	536,000
Unpaid Principal Balance	98,000	847,000	883,000
With Specific Allowance	97,000	0	0
Without Specific Allowance	0	436,000	536,000
Specific Allowance for Impaired Loans	55,000	0	0
Average Recorded Investment	153,000	505,000	415,000
Interest Income Recognized	0	37,000	67,000
Business Loans | SBA
Impaired Loans
Recorded Investment	1,201,000	316,000
Unpaid Principal Balance	4,329,000	3,865,000
With Specific Allowance	0	0
Without Specific Allowance	1,201,000	316,000
Specific Allowance for Impaired Loans	0	0
Average Recorded Investment	434,000	331,000
Interest Income Recognized	0	23,000
Real Estate Loans
Impaired Loans
Recorded Investment	3,284,000	1,141,000	2,784,000
Unpaid Principal Balance	6,896,000	7,029,000	4,319,000
With Specific Allowance	97,000	250,000	1,461,000
Without Specific Allowance	3,187,000	891,000	1,323,000
Specific Allowance for Impaired Loans	55,000	250,000	731,000
Average Recorded Investment	2,309,000	4,032,000	2,538,000
Interest Income Recognized	0	317,000	123,000
Real Estate Loans | Commercial non-owner occupied
Impaired Loans
Recorded Investment	0	0	214,000
Unpaid Principal Balance	0	0	329,000
With Specific Allowance	0	0	0
Without Specific Allowance	0	0	214,000
Specific Allowance for Impaired Loans	0	0	0
Average Recorded Investment	86,000	1,072,000	430,000
Interest Income Recognized	0	93,000	19,000
Real Estate Loans | One-to-four family
Impaired Loans
Recorded Investment	817,000	124,000	70,000
Unpaid Principal Balance	849,000	291,000	98,000
With Specific Allowance	0	0	0
Without Specific Allowance	817,000	124,000	70,000
Specific Allowance for Impaired Loans	0	0	0
Average Recorded Investment	166,000	226,000	204,000
Interest Income Recognized	0	18,000	5,000
Real Estate Loans | Construction
Impaired Loans
Recorded Investment	0
Unpaid Principal Balance	0
With Specific Allowance	0
Without Specific Allowance	0
Specific Allowance for Impaired Loans	0
Average Recorded Investment	1,017,000
Interest Income Recognized	0
Real Estate Loans | Land
Impaired Loans
Recorded Investment	9,000	15,000	21,000
Unpaid Principal Balance	35,000	36,000	37,000
With Specific Allowance	0	0	0
Without Specific Allowance	9,000	15,000	21,000
Specific Allowance for Impaired Loans	0	0	0
Average Recorded Investment	12,000	18,000	13,000
Interest Income Recognized	$ 0	$ 2,000	$ 0

Loans - Internal risk grading s

Loans - Internal risk grading system (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)areagrade	Dec. 31, 2016USD ($)
Receivables [Abstract]
Number of areas where the entity's credit quality is maintained and credit risk managed | area	2
Number of Pass scale grades | grade	6
Credit Risk Grades
Gross loans	$ 6,222,053	$ 3,245,694
Pass
Credit Risk Grades
Gross loans	6,160,136	3,216,683
Special Mention
Credit Risk Grades
Gross loans	13,612	15,970
Substandard
Credit Risk Grades
Gross loans	48,305	12,791
Doubtful
Credit Risk Grades
Gross loans	0	250
Business Loans | Commercial and industrial
Credit Risk Grades
Gross loans	1,086,659	563,169
Business Loans | Franchise
Credit Risk Grades
Gross loans	660,415	459,421
Business Loans | Commercial owner occupied
Credit Risk Grades
Gross loans	1,295,214	454,918
Business Loans | SBA
Credit Risk Grades
Gross loans	202,938	96,705
Business Loans | Agribusiness
Credit Risk Grades
Gross loans	116,066
Business Loans | Pass | Commercial and industrial
Credit Risk Grades
Gross loans	1,063,452	550,919
Business Loans | Pass | Franchise
Credit Risk Grades
Gross loans	660,415	459,421
Business Loans | Pass | Commercial owner occupied
Credit Risk Grades
Gross loans	1,273,380	450,416
Business Loans | Pass | SBA
Credit Risk Grades
Gross loans	199,468	96,190
Business Loans | Pass | Agribusiness
Credit Risk Grades
Gross loans	108,143
Business Loans | Special Mention | Commercial and industrial
Credit Risk Grades
Gross loans	8,163	8,216
Business Loans | Special Mention | Franchise
Credit Risk Grades
Gross loans	0	0
Business Loans | Special Mention | Commercial owner occupied
Credit Risk Grades
Gross loans	654	281
Business Loans | Special Mention | SBA
Credit Risk Grades
Gross loans	1	53
Business Loans | Special Mention | Agribusiness
Credit Risk Grades
Gross loans	4,079
Business Loans | Substandard | Commercial and industrial
Credit Risk Grades
Gross loans	15,044	3,784
Business Loans | Substandard | Franchise
Credit Risk Grades
Gross loans	0	0
Business Loans | Substandard | Commercial owner occupied
Credit Risk Grades
Gross loans	21,180	4,221
Business Loans | Substandard | SBA
Credit Risk Grades
Gross loans	3,469	462
Business Loans | Substandard | Agribusiness
Credit Risk Grades
Gross loans	3,844
Business Loans | Doubtful | Commercial and industrial
Credit Risk Grades
Gross loans	0	250
Business Loans | Doubtful | Franchise
Credit Risk Grades
Gross loans	0	0
Business Loans | Doubtful | Commercial owner occupied
Credit Risk Grades
Gross loans	0	0
Business Loans | Doubtful | SBA
Credit Risk Grades
Gross loans	0	0
Business Loans | Doubtful | Agribusiness
Credit Risk Grades
Gross loans	0
Real Estate Loans | Commercial non-owner occupied
Credit Risk Grades
Gross loans	1,243,115	586,975
Real Estate Loans | Multi-family
Credit Risk Grades
Gross loans	794,384	690,955
Real Estate Loans | One-to-four family
Credit Risk Grades
Gross loans	270,894	100,451
Real Estate Loans | Construction
Credit Risk Grades
Gross loans	282,811	269,159
Real Estate Loans | Farmland
Credit Risk Grades
Gross loans	145,393
Real Estate Loans | Land
Credit Risk Grades
Gross loans	31,233	19,829
Real Estate Loans | Pass | Commercial non-owner occupied
Credit Risk Grades
Gross loans	1,242,045	585,093
Real Estate Loans | Pass | Multi-family
Credit Risk Grades
Gross loans	794,156	681,942
Real Estate Loans | Pass | One-to-four family
Credit Risk Grades
Gross loans	268,776	100,010
Real Estate Loans | Pass | Construction
Credit Risk Grades
Gross loans	282,294	269,159
Real Estate Loans | Pass | Farmland
Credit Risk Grades
Gross loans	144,234
Real Estate Loans | Pass | Land
Credit Risk Grades
Gross loans	30,979	19,814
Real Estate Loans | Special Mention | Commercial non-owner occupied
Credit Risk Grades
Gross loans	0	810
Real Estate Loans | Special Mention | Multi-family
Credit Risk Grades
Gross loans	0	6,610
Real Estate Loans | Special Mention | One-to-four family
Credit Risk Grades
Gross loans	154	0
Real Estate Loans | Special Mention | Construction
Credit Risk Grades
Gross loans	517	0
Real Estate Loans | Special Mention | Farmland
Credit Risk Grades
Gross loans	44
Real Estate Loans | Special Mention | Land
Credit Risk Grades
Gross loans	0	0
Real Estate Loans | Substandard | Commercial non-owner occupied
Credit Risk Grades
Gross loans	1,070	1,072
Real Estate Loans | Substandard | Multi-family
Credit Risk Grades
Gross loans	228	2,403
Real Estate Loans | Substandard | One-to-four family
Credit Risk Grades
Gross loans	1,964	441
Real Estate Loans | Substandard | Construction
Credit Risk Grades
Gross loans	0	0
Real Estate Loans | Substandard | Farmland
Credit Risk Grades
Gross loans	1,115
Real Estate Loans | Substandard | Land
Credit Risk Grades
Gross loans	254	15
Real Estate Loans | Doubtful | Commercial non-owner occupied
Credit Risk Grades
Gross loans	0	0
Real Estate Loans | Doubtful | Multi-family
Credit Risk Grades
Gross loans	0	0
Real Estate Loans | Doubtful | One-to-four family
Credit Risk Grades
Gross loans	0	0
Real Estate Loans | Doubtful | Construction
Credit Risk Grades
Gross loans	0	0
Real Estate Loans | Doubtful | Farmland
Credit Risk Grades
Gross loans	0
Real Estate Loans | Doubtful | Land
Credit Risk Grades
Gross loans	0	0
Consumer Loans | Consumer loans
Credit Risk Grades
Gross loans	92,931	4,112
Consumer Loans | Pass | Consumer loans
Credit Risk Grades
Gross loans	92,794	3,719
Consumer Loans | Special Mention | Consumer loans
Credit Risk Grades
Gross loans	0	0
Consumer Loans | Substandard | Consumer loans
Credit Risk Grades
Gross loans	137	393
Consumer Loans | Doubtful | Consumer loans
Credit Risk Grades
Gross loans	$ 0	$ 0

Loans - Days past due and Non-a

Loans - Days past due and Non-accruing (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Other information concerning the credit quality
Total Gross Loans	$ 6,222,053	$ 3,245,694
Non-accruing	3,284	1,141
Current
Other information concerning the credit quality
Current	6,211,994	3,244,862
30-59
Other information concerning the credit quality
Days Past Due	5,964	122
60-89
Other information concerning the credit quality
Days Past Due	1,056	71
90
Other information concerning the credit quality
Days Past Due	3,039	639
Business Loans | Commercial and industrial
Other information concerning the credit quality
Total Gross Loans	1,086,659	563,169
Non-accruing	1,160	250
Business Loans | Franchise
Other information concerning the credit quality
Total Gross Loans	660,415	459,421
Non-accruing	0	0
Business Loans | Commercial owner occupied
Other information concerning the credit quality
Total Gross Loans	1,295,214	454,918
Non-accruing	97	436
Business Loans | SBA
Other information concerning the credit quality
Total Gross Loans	202,938	96,705
Non-accruing	1,201	316
Business Loans | Agribusiness
Other information concerning the credit quality
Total Gross Loans	116,066
Non-accruing	0
Business Loans | Current | Commercial and industrial
Other information concerning the credit quality
Current	1,085,770	562,805
Business Loans | Current | Franchise
Other information concerning the credit quality
Current	660,415	459,421
Business Loans | Current | Commercial owner occupied
Other information concerning the credit quality
Current	1,291,254	454,918
Business Loans | Current | SBA
Other information concerning the credit quality
Current	200,821	96,389
Business Loans | Current | Agribusiness
Other information concerning the credit quality
Current	116,066
Business Loans | 30-59 | Commercial and industrial
Other information concerning the credit quality
Days Past Due	84	104
Business Loans | 30-59 | Franchise
Other information concerning the credit quality
Days Past Due	0	0
Business Loans | 30-59 | Commercial owner occupied
Other information concerning the credit quality
Days Past Due	3,474	0
Business Loans | 30-59 | SBA
Other information concerning the credit quality
Days Past Due	177	0
Business Loans | 30-59 | Agribusiness
Other information concerning the credit quality
Days Past Due	0
Business Loans | 60-89 | Commercial and industrial
Other information concerning the credit quality
Days Past Due	570	0
Business Loans | 60-89 | Franchise
Other information concerning the credit quality
Days Past Due	0	0
Business Loans | 60-89 | Commercial owner occupied
Other information concerning the credit quality
Days Past Due	486	0
Business Loans | 60-89 | SBA
Other information concerning the credit quality
Days Past Due	0	0
Business Loans | 60-89 | Agribusiness
Other information concerning the credit quality
Days Past Due	0
Business Loans | 90 | Commercial and industrial
Other information concerning the credit quality
Days Past Due	235	260
Business Loans | 90 | Franchise
Other information concerning the credit quality
Days Past Due	0	0
Business Loans | 90 | Commercial owner occupied
Other information concerning the credit quality
Days Past Due	0	0
Business Loans | 90 | SBA
Other information concerning the credit quality
Days Past Due	1,940	316
Business Loans | 90 | Agribusiness
Other information concerning the credit quality
Days Past Due	0
Real Estate Loans | Commercial non-owner occupied
Other information concerning the credit quality
Total Gross Loans	1,243,115	586,975
Non-accruing	0	0
Real Estate Loans | Multi-family
Other information concerning the credit quality
Total Gross Loans	794,384	690,955
Non-accruing	0	0
Real Estate Loans | One-to-four family
Other information concerning the credit quality
Total Gross Loans	270,894	100,451
Non-accruing	817	124
Real Estate Loans | Construction
Other information concerning the credit quality
Total Gross Loans	282,811	269,159
Non-accruing	0	0
Real Estate Loans | Farmland
Other information concerning the credit quality
Total Gross Loans	145,393
Non-accruing	0
Real Estate Loans | Land
Other information concerning the credit quality
Total Gross Loans	31,233	19,829
Non-accruing	9	15
Real Estate Loans | Current | Commercial non-owner occupied
Other information concerning the credit quality
Current	1,243,115	586,975
Real Estate Loans | Current | Multi-family
Other information concerning the credit quality
Current	792,603	690,955
Real Estate Loans | Current | One-to-four family
Other information concerning the credit quality
Current	269,725	100,314
Real Estate Loans | Current | Construction
Other information concerning the credit quality
Current	282,811	269,159
Real Estate Loans | Current | Farmland
Other information concerning the credit quality
Current	145,393
Real Estate Loans | Current | Land
Other information concerning the credit quality
Current	31,141	19,814
Real Estate Loans | 30-59 | Commercial non-owner occupied
Other information concerning the credit quality
Days Past Due	0	0
Real Estate Loans | 30-59 | Multi-family
Other information concerning the credit quality
Days Past Due	1,781	0
Real Estate Loans | 30-59 | One-to-four family
Other information concerning the credit quality
Days Past Due	354	18
Real Estate Loans | 30-59 | Construction
Other information concerning the credit quality
Days Past Due	0	0
Real Estate Loans | 30-59 | Farmland
Other information concerning the credit quality
Days Past Due	0
Real Estate Loans | 30-59 | Land
Other information concerning the credit quality
Days Past Due	83	0
Real Estate Loans | 60-89 | Commercial non-owner occupied
Other information concerning the credit quality
Days Past Due	0	0
Real Estate Loans | 60-89 | Multi-family
Other information concerning the credit quality
Days Past Due	0	0
Real Estate Loans | 60-89 | One-to-four family
Other information concerning the credit quality
Days Past Due	0	71
Real Estate Loans | 60-89 | Construction
Other information concerning the credit quality
Days Past Due	0	0
Real Estate Loans | 60-89 | Farmland
Other information concerning the credit quality
Days Past Due	0
Real Estate Loans | 60-89 | Land
Other information concerning the credit quality
Days Past Due	0	0
Real Estate Loans | 90 | Commercial non-owner occupied
Other information concerning the credit quality
Days Past Due	0	0
Real Estate Loans | 90 | Multi-family
Other information concerning the credit quality
Days Past Due	0	0
Real Estate Loans | 90 | One-to-four family
Other information concerning the credit quality
Days Past Due	815	48
Real Estate Loans | 90 | Construction
Other information concerning the credit quality
Days Past Due	0	0
Real Estate Loans | 90 | Farmland
Other information concerning the credit quality
Days Past Due	0
Real Estate Loans | 90 | Land
Other information concerning the credit quality
Days Past Due	9	15
Consumer Loans | Consumer loans
Other information concerning the credit quality
Total Gross Loans	92,931	4,112
Non-accruing	0	0
Consumer Loans | Current | Consumer loans
Other information concerning the credit quality
Current	92,880	4,112
Consumer Loans | 30-59 | Consumer loans
Other information concerning the credit quality
Days Past Due	11	0
Consumer Loans | 60-89 | Consumer loans
Other information concerning the credit quality
Days Past Due	0	0
Consumer Loans | 90 | Consumer loans
Other information concerning the credit quality
Days Past Due	$ 40	$ 0

Allowance for Loan Losses (Deta

Allowance for Loan Losses (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Allocation of allowance as well as the activity in allowance
Balance, at the beginning of the period				$ 21,296				$ 17,317	$ 21,296	$ 17,317	$ 12,200
Charge-offs									(1,362)	(5,242)	(1,380)
Recoveries									362	445	72
Provisions for (reduction in) loan losses	$ 2,185	$ 2,049	$ 1,904	2,502	$ 2,054	$ 4,013	$ 1,589	1,120	8,640	8,776	6,425
Balance, at the end of the period	28,936				21,296				28,936	21,296	17,317
Amount of allowance attributed to:
Specifically evaluated impaired loans	55				250				55	250	731
General portfolio allocation	28,881				21,046				28,881	21,046	16,586
Loans individually evaluated for impairment	3,284				1,141				$ 3,284	$ 1,141	$ 2,784
Specific reserves to total loans individually evaluated for impairment									1.67%	21.91%	26.26%
Loans collectively evaluated for impairment	6,195,343				3,236,842				$ 6,195,343	$ 3,236,842	$ 2,259,899
General reserves to total loans collectively evaluated for impairment									0.47%	0.65%	0.73%
Total gross loans	6,198,627				3,237,983				$ 6,198,627	$ 3,237,983	$ 2,254,118
Total allowance to gross loans									0.47%	0.66%	0.77%
Owner Occupied Commercial Real Estate Loans Commercial and Industrial Loans and Small Business Administration Loans
Allowance for Loan Losses
Period One Considered for Comparison of Allowance for Loan Losses Factor									1 year
Period Two Considered for Comparison of Allowance for Loan Losses Factor									1 year 4 months 24 days
Business Loans | Commercial and industrial
Allocation of allowance as well as the activity in allowance
Balance, at the beginning of the period				6,362				3,449	$ 6,362	$ 3,449	$ 2,646
Charge-offs									(1,344)	(2,802)	(484)
Recoveries									94	177	47
Provisions for (reduction in) loan losses									4,609	5,538	1,240
Balance, at the end of the period	9,721				6,362				9,721	6,362	3,449
Amount of allowance attributed to:
Specifically evaluated impaired loans	0				250				0	250	0
General portfolio allocation	9,721				6,112				9,721	6,112	3,449
Loans individually evaluated for impairment	1,160				250				$ 1,160	$ 250	$ 313
Specific reserves to total loans individually evaluated for impairment									0.00%	100.00%	0.00%
Loans collectively evaluated for impairment	1,085,499				562,919				$ 1,085,499	$ 562,919	$ 309,428
General reserves to total loans collectively evaluated for impairment									0.90%	1.09%	1.11%
Total gross loans	1,086,659				563,169				$ 1,086,659	$ 563,169	$ 309,741
Total allowance to gross loans									0.89%	1.13%	1.11%
Business Loans | Franchise
Allocation of allowance as well as the activity in allowance
Balance, at the beginning of the period				3,845				3,124	$ 3,845	$ 3,124	$ 1,554
Charge-offs									0	(980)	(764)
Recoveries									0	0	0
Provisions for (reduction in) loan losses									1,952	1,701	2,334
Balance, at the end of the period	5,797				3,845				5,797	3,845	3,124
Amount of allowance attributed to:
Specifically evaluated impaired loans	0				0				0	0	731
General portfolio allocation	5,797				3,845				5,797	3,845	2,393
Loans individually evaluated for impairment	0				0				$ 0	$ 0	$ 1,630
Specific reserves to total loans individually evaluated for impairment									0.00%	0.00%	44.85%
Loans collectively evaluated for impairment	660,414				459,421				$ 660,414	$ 459,421	$ 327,295
General reserves to total loans collectively evaluated for impairment									0.88%	0.84%	0.73%
Total gross loans	660,414				459,421				$ 660,414	$ 459,421	$ 328,925
Total allowance to gross loans									0.88%	0.84%	0.95%
Business Loans | Commercial owner occupied
Allocation of allowance as well as the activity in allowance
Balance, at the beginning of the period				1,193				1,870	$ 1,193	$ 1,870	$ 1,757
Charge-offs									0	(329)	0
Recoveries									105	25	0
Provisions for (reduction in) loan losses									(531)	(373)	113
Balance, at the end of the period	767				1,193				767	1,193	1,870
Amount of allowance attributed to:
Specifically evaluated impaired loans	55				0				55	0	0
General portfolio allocation	712				1,193				712	1,193	1,870
Loans individually evaluated for impairment	97				436				$ 97	$ 436	$ 536
Specific reserves to total loans individually evaluated for impairment									56.70%	0.00%	0.00%
Loans collectively evaluated for impairment	1,289,116				454,482				$ 1,289,116	$ 454,482	$ 294,190
General reserves to total loans collectively evaluated for impairment									0.06%	0.26%	0.64%
Total gross loans	1,289,213				454,918				$ 1,289,213	$ 454,918	$ 294,726
Total allowance to gross loans									0.06%	0.26%	0.63%
Business Loans | SBA
Allocation of allowance as well as the activity in allowance
Balance, at the beginning of the period				1,039				1,500	$ 1,039	$ 1,500	$ 568
Charge-offs									(8)	(980)	0
Recoveries									127	193	8
Provisions for (reduction in) loan losses									1,732	326	924
Balance, at the end of the period	2,890				1,039				2,890	1,039	1,500
Amount of allowance attributed to:
Specifically evaluated impaired loans	0				0				0	0	0
General portfolio allocation	2,890				1,039				2,890	1,039	1,500
Loans individually evaluated for impairment	1,201				316				$ 1,201	$ 316	$ 0
Specific reserves to total loans individually evaluated for impairment									0.00%	0.00%	0.00%
Loans collectively evaluated for impairment	184,313				88,678				$ 184,313	$ 88,678	$ 62,256
General reserves to total loans collectively evaluated for impairment									1.57%	1.17%	2.41%
Total gross loans	185,514				88,994				$ 185,514	$ 88,994	$ 53,691
Total allowance to gross loans									1.56%	1.17%	2.79%
Business Loans | Agribusiness
Allocation of allowance as well as the activity in allowance
Balance, at the beginning of the period				0				0	$ 0	$ 0	$ 0
Charge-offs									0	0	0
Recoveries									0	0	0
Provisions for (reduction in) loan losses									1,291	0	0
Balance, at the end of the period	1,291				0				1,291	0	0
Amount of allowance attributed to:
Specifically evaluated impaired loans	0				0				0	0	0
General portfolio allocation	1,291				0				1,291	0	0
Loans individually evaluated for impairment	0				0				$ 0	$ 0	$ 0
Specific reserves to total loans individually evaluated for impairment									0.00%	0.00%	0.00%
Loans collectively evaluated for impairment	116,066				0				$ 116,066	$ 0	$ 0
General reserves to total loans collectively evaluated for impairment									1.11%	0.00%	0.00%
Total gross loans	116,066				0				$ 116,066	$ 0	$ 0
Total allowance to gross loans									1.11%	0.00%	0.00%
Business Loans | Warehouse Facilities
Allocation of allowance as well as the activity in allowance
Balance, at the beginning of the period				0				759	$ 0	$ 759	$ 546
Charge-offs									0	0	0
Recoveries									0	0	0
Provisions for (reduction in) loan losses									0	(759)	213
Balance, at the end of the period	0				0				0	0	759
Amount of allowance attributed to:
Specifically evaluated impaired loans	0				0				0	0	0
General portfolio allocation	0				0				0	0	759
Loans individually evaluated for impairment	0				0				$ 0	$ 0	$ 0
Specific reserves to total loans individually evaluated for impairment									0.00%	0.00%	0.00%
Loans collectively evaluated for impairment	0				0				$ 0	$ 0	$ 143,200
General reserves to total loans collectively evaluated for impairment									0.00%	0.00%	0.53%
Total gross loans	0				0				$ 0	$ 0	$ 143,200
Total allowance to gross loans									0.00%	0.00%	0.53%
Real Estate Loans | Commercial non-owner occupied
Allocation of allowance as well as the activity in allowance
Balance, at the beginning of the period				1,715				2,048	$ 1,715	$ 2,048	$ 2,007
Charge-offs									0	0	(116)
Recoveries									0	21	3
Provisions for (reduction in) loan losses									(449)	(354)	154
Balance, at the end of the period	1,266				1,715				1,266	1,715	2,048
Amount of allowance attributed to:
Specifically evaluated impaired loans	0				0				0	0	0
General portfolio allocation	1,266				1,715				1,266	1,715	2,048
Loans individually evaluated for impairment	0				0				$ 0	$ 0	$ 214
Specific reserves to total loans individually evaluated for impairment									0.00%	0.00%	0.00%
Loans collectively evaluated for impairment	1,243,115				586,975				$ 1,243,115	$ 586,975	$ 421,369
General reserves to total loans collectively evaluated for impairment									0.10%	0.29%	0.49%
Total gross loans	1,243,115				586,975				$ 1,243,115	$ 586,975	$ 421,583
Total allowance to gross loans									0.10%	0.29%	0.49%
Real Estate Loans | Multi-family
Allocation of allowance as well as the activity in allowance
Balance, at the beginning of the period				2,927				1,583	$ 2,927	$ 1,583	$ 1,060
Charge-offs									0	0	0
Recoveries									0	0	0
Provisions for (reduction in) loan losses									(2,320)	1,344	523
Balance, at the end of the period	607				2,927				607	2,927	1,583
Amount of allowance attributed to:
Specifically evaluated impaired loans	0				0				0	0	0
General portfolio allocation	607				2,927				607	2,927	1,583
Loans individually evaluated for impairment	0				0				$ 0	$ 0	$ 0
Specific reserves to total loans individually evaluated for impairment									0.00%	0.00%	0.00%
Loans collectively evaluated for impairment	794,384				690,955				$ 794,384	$ 690,955	$ 429,003
General reserves to total loans collectively evaluated for impairment									0.08%	0.42%	0.37%
Total gross loans	794,384				690,955				$ 794,384	$ 690,955	$ 429,003
Total allowance to gross loans									0.08%	0.42%	0.37%
Real Estate Loans | One-to-four family
Allocation of allowance as well as the activity in allowance
Balance, at the beginning of the period				365				698	$ 365	$ 698	$ 842
Charge-offs									(10)	(151)	(16)
Recoveries									35	25	13
Provisions for (reduction in) loan losses									413	(207)	(141)
Balance, at the end of the period	803				365				803	365	698
Amount of allowance attributed to:
Specifically evaluated impaired loans	0				0				0	0	0
General portfolio allocation	803				365				803	365	698
Loans individually evaluated for impairment	817				124				$ 817	$ 124	$ 70
Specific reserves to total loans individually evaluated for impairment									0.00%	0.00%	0.00%
Loans collectively evaluated for impairment	270,077				100,327				$ 270,077	$ 100,327	$ 79,980
General reserves to total loans collectively evaluated for impairment									0.30%	0.36%	0.87%
Total gross loans	270,894				100,451				$ 270,894	$ 100,451	$ 80,050
Total allowance to gross loans									0.30%	0.36%	0.87%
Real Estate Loans | Construction
Allocation of allowance as well as the activity in allowance
Balance, at the beginning of the period				3,632				2,030	$ 3,632	$ 2,030	$ 1,088
Charge-offs									0	0	0
Recoveries									0	0	0
Provisions for (reduction in) loan losses									937	1,602	942
Balance, at the end of the period	4,569				3,632				4,569	3,632	2,030
Amount of allowance attributed to:
Specifically evaluated impaired loans	0				0				0	0	0
General portfolio allocation	4,569				3,632				4,569	3,632	2,030
Loans individually evaluated for impairment	0				0				$ 0	$ 0	$ 0
Specific reserves to total loans individually evaluated for impairment									0.00%	0.00%	0.00%
Loans collectively evaluated for impairment	282,811				269,159				$ 282,811	$ 269,159	$ 169,748
General reserves to total loans collectively evaluated for impairment									1.62%	1.35%	1.20%
Total gross loans	282,811				269,159				$ 282,811	$ 269,159	$ 169,748
Total allowance to gross loans									1.62%	1.35%	1.20%
Real Estate Loans | Farmland
Allocation of allowance as well as the activity in allowance
Balance, at the beginning of the period				0				0	$ 0	$ 0	$ 0
Charge-offs									0	0	0
Recoveries									0	0	0
Provisions for (reduction in) loan losses									137	0	0
Balance, at the end of the period	137				0				137	0	0
Amount of allowance attributed to:
Specifically evaluated impaired loans	0				0				0	0	0
General portfolio allocation	137				0				137	0	0
Loans individually evaluated for impairment	0				0				$ 0	$ 0	$ 0
Specific reserves to total loans individually evaluated for impairment									0.00%	0.00%	0.00%
Loans collectively evaluated for impairment	145,393				0				$ 145,393	$ 0	$ 0
General reserves to total loans collectively evaluated for impairment									0.09%	0.00%	0.00%
Total gross loans	145,393				0				$ 145,393	$ 0	$ 0
Total allowance to gross loans									0.09%	0.00%	0.00%
Real Estate Loans | Land
Allocation of allowance as well as the activity in allowance
Balance, at the beginning of the period				198				233	$ 198	$ 233	$ 108
Charge-offs									0	0	0
Recoveries									0	0	0
Provisions for (reduction in) loan losses									795	(35)	125
Balance, at the end of the period	993				198				993	198	233
Amount of allowance attributed to:
Specifically evaluated impaired loans	0				0				0	0	0
General portfolio allocation	993				198				993	198	233
Loans individually evaluated for impairment	9				15				$ 9	$ 15	$ 21
Specific reserves to total loans individually evaluated for impairment									0.00%	0.00%	0.00%
Loans collectively evaluated for impairment	31,224				19,814				$ 31,224	$ 19,814	$ 18,319
General reserves to total loans collectively evaluated for impairment									3.18%	1.00%	1.27%
Total gross loans	31,233				19,829				$ 31,233	$ 19,829	$ 18,340
Total allowance to gross loans									3.18%	1.00%	1.27%
Consumer Loans | Consumer loans
Allocation of allowance as well as the activity in allowance
Balance, at the beginning of the period				$ 20				$ 23	$ 20	$ 23	$ 24
Charge-offs									0	0	0
Recoveries									1	4	1
Provisions for (reduction in) loan losses									74	(7)	(2)
Balance, at the end of the period	95				20				95	20	23
Amount of allowance attributed to:
Specifically evaluated impaired loans	0				0				0	0	0
General portfolio allocation	95				20				95	20	23
Loans individually evaluated for impairment	0				0				$ 0	$ 0	$ 0
Specific reserves to total loans individually evaluated for impairment									0.00%	0.00%	0.00%
Loans collectively evaluated for impairment	92,931				4,112				$ 92,931	$ 4,112	$ 5,111
General reserves to total loans collectively evaluated for impairment									0.10%	0.49%	0.45%
Total gross loans	$ 92,931				$ 4,112				$ 92,931	$ 4,112	$ 5,111
Total allowance to gross loans									0.10%	0.49%	0.45%

Other Real Estate Owned (Detail

Other Real Estate Owned (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Other Real Estate Owned
Balance, beginning of year	$ 460	$ 1,161	$ 1,037
Additions / foreclosures	326	197	450
Sales	(507)	(577)	(233)
Gain (loss) on sale	47	18	(52)
Write downs	0	(339)	(41)
Balance, end of year	326	460	$ 1,161
Consumer mortgage loans collaterlized by residential real estate, foreclosure proceedings in process	$ 73	$ 41

Premises and Equipment (Details

Premises and Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Premises and Equipment
Subtotal	$ 71,480	$ 25,641
Less: accumulated depreciation	18,325	13,627
Total	53,155	12,014
Depreciation and amortization expense	4,888	2,854	$ 2,432
Land
Premises and Equipment
Subtotal	16,920	200
Premises
Premises and Equipment
Subtotal	19,868	1,707
Leasehold improvements
Premises and Equipment
Subtotal	14,025	8,982
Furniture, fixtures and equipment
Premises and Equipment
Subtotal	20,480	14,565
Automobiles
Premises and Equipment
Subtotal	$ 187	$ 187

Goodwill and Core Deposit Int72

Goodwill and Core Deposit Intangibles - Narrative (Details) - USD ($)	3 Months Ended	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Nov. 01, 2017	Apr. 01, 2017
Goodwill [Line Items]
Goodwill	$ 493,329,000	$ 493,329,000	$ 102,490,000	$ 50,832,000
Goodwill acquired during the year		390,839,000	51,658,000
Impairment losses	0	0	0
Net CDI	43,014,000	43,014,000	9,451,000	7,170,000
Additions due to acquisitions		39,707,000	$ 4,320,000	$ 2,906,000
Estimated aggregate amortization expense
2,018	8,400,000	8,400,000
2,019	7,300,000	7,300,000
2,020	6,500,000	6,500,000
2,021	5,400,000	5,400,000
2,022	4,500,000	4,500,000
Plaza Bancorp
Goodwill [Line Items]
Goodwill	121,885,000	121,885,000			$ 122,000,000
Additions due to acquisitions		11,600,000
Heritage Oaks Bank
Goodwill [Line Items]
Goodwill	$ 268,954,000	268,954,000				$ 269,000,000
Additions due to acquisitions		$ 28,100,000

Goodwill and Core Deposit Int73

Goodwill and Core Deposit Intangibles - Goodwill Roll Forward (Details) - USD ($)	3 Months Ended	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2017	Dec. 31, 2016
Goodwill [Roll Forward]
Balance, beginning of year		$ 102,490,000	$ 50,832,000
Goodwill acquired during the year		390,839,000	51,658,000
Impairment losses	$ 0	0	0
Balance, end of year	493,329,000	493,329,000	102,490,000
Accumulated impairment losses at end of year	$ 0	$ 0	$ 0

Goodwill and Core Deposit Int74

Goodwill and Core Deposit Intangibles - CDI Roll Forward (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Gross amount of CDI:
Balance, beginning of year	$ 15,102	$ 10,782	$ 7,876
Additions due to acquisitions	39,707	4,320	2,906
Balance, end of year	54,809	15,102	10,782
Accumulated amortization:
Balance, beginning of year	(5,651)	(3,612)	(2,262)
Amortization	(6,144)	(2,039)	(1,350)
Balance, end of year	(11,795)	(5,651)	(3,612)
Net CDI, end of year	$ 43,014	$ 9,451	$ 7,170

Bank Owned Life Insurance (Deta

Bank Owned Life Insurance (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Investments, All Other Investments [Abstract]
Bank owned life insurance	$ 75,976	$ 40,409
Income from bank owned life insurance, non-interest income	$ 2,300	$ 1,400	$ 1,300

Qualified Affordable Housing 76

Qualified Affordable Housing Project Investments (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)project	Dec. 31, 2016USD ($)
Schedule of Equity Method Investments [Line Items]
Original Investment Value	$ 16,181	$ 10,000
Current Recorded Investment	11,582	7,000
Unfunded Liability Obligation	1,300	749
Tax Credits and Tax Deductions	2,514	961
Amortization of Investments	1,599	1,324
Net Income Tax Benefit	$ (2,135)	(1,233)
Number of projects | project	3
Period of tax credits	10 years
WNC Institutional Tax Credit Fund X, CA Series 11 L.P.
Schedule of Equity Method Investments [Line Items]
Original Investment Value	$ 5,000	5,000
Current Recorded Investment	2,750	3,250
Unfunded Liability Obligation	85	223
Tax Credits and Tax Deductions	455	488
Amortization of Investments	500	542
Net Income Tax Benefit	(663)	(596)
WNC Institutional Tax Credit Fund X, CA Series 12, L.P.
Schedule of Equity Method Investments [Line Items]
Original Investment Value	5,000	5,000
Current Recorded Investment	3,250	3,750
Unfunded Liability Obligation	288	526
Tax Credits and Tax Deductions	482	473
Amortization of Investments	500	782
Net Income Tax Benefit	(690)	$ (637)
Sycamore Court
Schedule of Equity Method Investments [Line Items]
Original Investment Value	6,181
Current Recorded Investment	5,582
Unfunded Liability Obligation	927
Tax Credits and Tax Deductions	1,577
Amortization of Investments	599
Net Income Tax Benefit	$ (782)

Deposit Accounts - Deposit acco

Deposit Accounts - Deposit accounts and weighted average interest rates (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Transaction accounts
Noninterest-bearing checking	$ 2,226,848	$ 1,185,768
Interest-bearing checking	365,193	182,893
Money market	2,181,571	1,100,787
Savings	227,436	101,574
Total transaction accounts	5,001,048	2,571,022
Certificates of deposit accounts
Less than 100,000	192,409	121,148
$100,000 through $250,000	369,748	153,103
Greater than $250,000	522,663	300,308
Total certificates of deposit accounts	1,084,820	574,559
Total deposits	$ 6,085,868	$ 3,145,581
Transaction accounts
Noninterest-bearing checking (as a percent)	0.00%	0.00%
Interest-bearing checking (as a percent)	0.13%	0.11%
Money market (as a percent)	0.48%	0.34%
Savings (as a percent)	0.13%	0.14%
Total transaction accounts (as a percent)	0.21%	0.16%
Certificates of deposit accounts
Less than $100,000 (as a percent)	0.85%	0.74%
$100,000 through $250,000 (as a percent)	1.01%	0.82%
Greater than $250,000 (as a percent)	1.26%	0.74%
Total certificates of deposit accounts (as a percent)	1.10%	0.76%
Total deposits (as a percent)	0.33%	0.27%

Deposit Accounts - The aggregat

Deposit Accounts - The aggregate annual maturities of certificates of deposit accounts (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Balance
Within 3 months	$ 318,794
4 to 6 months	250,026
7 to 12 months	279,192
13 to 24 months	175,005
25 to 36 months	29,270
37 to 60 months	22,936
Over 60 months	9,597
Total certificates of deposit accounts	$ 1,084,820	$ 574,559
Weighted Average Interest Rate
Within 3 months (as a percent)	0.93%
4 to 6 months (as a percent)	1.07%
7 to 12 months (as a percent)	1.18%
13 to 24 months (as a percent)	1.24%
25 to 36 months (as a percent)	1.33%
37 to 60 months (as a percent)	1.44%
Over 60 months (as a percent)	1.13%
Total certificates of deposit accounts (as a percent)	1.10%	0.76%

Deposit Accounts - Interest exp

Deposit Accounts - Interest expense on deposit accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Interest expense on deposit accounts
Checking accounts	$ 365	$ 200	$ 165
Money market accounts	6,720	3,641	2,426
Savings	251	151	141
Certificates of deposit accounts	6,035	4,399	3,898
Total	13,371	8,391	$ 6,630
Accrued interest on deposits	$ 526	$ 178

Federal Home Loan Bank Advanc80

Federal Home Loan Bank Advances and Other Borrowings (Details)	12 Months Ended
	Dec. 31, 2017USD ($)bank	Dec. 31, 2016USD ($)	Jan. 31, 2017USD ($)
Federal Home Loan Bank Advances and Other Borrowings
Maximum percentage of assets up to which advances will be provided by FHLB	45.00%
Maximum credit line available from FHLB	$ 2,900,000,000
Additional available advances	677,000,000
Aggregate principal balance of real estate loans used to collateralize FHLB advances	1,400,000,000
Federal Home Loan Bank Stock	17,300,000
Overnight FHLB advances	310,000,000	$ 278,000,000
Maximum amount outstanding in respect of term advances	180,000,000	0
Estimated fair value of MBS used to secure outstanding borrowings	$ 27,300,000	$ 50,000,000
Weighted average interest rate during the year	1.19%	0.59%
Securities Sold under Agreements to Repurchase	$ 28,500,000
Reverse repurchase facility
Federal Home Loan Bank Advances and Other Borrowings
Estimated fair value of MBS used to secure outstanding borrowings	$ 17,600,000
Weighted average interest rate during the year	0.01%
Securities Sold under Agreements to Repurchase	$ 29,700,000
Unsecured lines of credit
Federal Home Loan Bank Advances and Other Borrowings
Unused facility	$ 168,000,000
Number of correspondent banks | bank	8
Amount outstanding	$ 0	$ 0
Federal Reserve discount window
Federal Home Loan Bank Advances and Other Borrowings
Unused facility	3,300,000
Citigroup | Line of Credit
Federal Home Loan Bank Advances and Other Borrowings
Balance outstanding at end of year	18,500,000	18,500,000
Barclays Bank | Line of Credit
Federal Home Loan Bank Advances and Other Borrowings
Balance outstanding at end of year	10,000,000	$ 10,000,000
Union Bank | Reverse repurchase facility
Federal Home Loan Bank Advances and Other Borrowings
Unused facility	50,000,000
Wells Fargo Bank | Line of Credit
Federal Home Loan Bank Advances and Other Borrowings
Unused facility			$ 15,000,000
Amount outstanding	$ 0
Minimum
Federal Home Loan Bank Advances and Other Borrowings
Term advances, rate	0.90%
Maximum
Federal Home Loan Bank Advances and Other Borrowings
Term advances, rate	2.73%

Federal Home Loan Bank Advanc81

Federal Home Loan Bank Advances and Other Borrowings - Activities in advances from the FHLB (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Activities in advances from the FHLB
Average balance outstanding	$ 290,839	$ 58,814
Maximum amount outstanding at any month-end during the year	490,148	278,000
Balance outstanding at end of year	$ 490,148	$ 278,000
Weighted average interest rate during the year	1.19%	0.59%

Federal Home Loan Bank Advanc82

Federal Home Loan Bank Advances and Other Borrowings - Activities in other borrowings (Details) - Other Borrowings - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Average balance outstanding	$ 50,866	$ 48,732
Maximum amount outstanding at any month-end during the year	52,996	53,586
Balance outstanding at end of year	$ 46,139	$ 49,971
Weighted average interest rate during the year	1.86%	1.94%

Subordinated Debentures (Detail

Subordinated Debentures (Details)	Nov. 01, 2017USD ($)notes	Mar. 25, 2004USD ($)	Aug. 31, 2014USD ($)	Dec. 31, 2017USD ($)	Apr. 01, 2017USD ($)	Dec. 31, 2016
PPBI Trust I
Debt Instrument [Line Items]
Floating Rate Trust Preferred Securities issue amount		$ 10,000,000
Subordinated Notes Due 2024
Debt Instrument [Line Items]
Debt issued			$ 60,000,000
Fixed interest rate (as a percent)			5.75%
Contribution of net proceeds from the Private Placement to the Bank to support general corporate purposes			$ 50,000,000
Subordinated Debentures
Debt Instrument [Line Items]
Floating interest rate, base rate				3-month LIBOR
Floating interest rate, basis points added to base rate (as a percent)				2.75%
Effective rate (as a percent)				4.11%		3.63%
Subordinated Debentures | Mission Community Capital Trust I
Debt Instrument [Line Items]
Effective rate (as a percent)				4.31%
Purchase accounting fair value adjustments				$ 327,000
Debt assumed in acquisition				$ 2,800,000	$ 3,100,000
Subordinated Debentures | Santa Lucia Bancorp (CA) Capital Trust
Debt Instrument [Line Items]
Effective rate (as a percent)				2.84%
Purchase accounting fair value adjustments				$ 1,400,000
Debt assumed in acquisition				$ 3,800,000	5,200,000
Subordinated Debentures | LIBOR | Mission Community Capital Trust I
Debt Instrument [Line Items]
Floating interest rate, basis points added to base rate (as a percent)				2.95%
Subordinated Debentures | LIBOR | Santa Lucia Bancorp (CA) Capital Trust
Debt Instrument [Line Items]
Floating interest rate, basis points added to base rate (as a percent)				1.48%
Subordinated Debentures | Heritage Oaks Bank
Debt Instrument [Line Items]
Effective rate (as a percent)				3.06%
Purchase accounting fair value adjustments				$ 1,300,000
Debt assumed in acquisition				$ 3,900,000	$ 5,200,000
Subordinated Debentures | Heritage Oaks Bank | LIBOR
Debt Instrument [Line Items]
Floating interest rate, basis points added to base rate (as a percent)				1.72%
Subordinated Debentures | PPBI Trust I
Debt Instrument [Line Items]
Debt issued		$ 10,310,000
Minority interest purchased (as a percent)		3.00%
Amount of minority interest purchased		$ 310,000
Subordinated Notes 7.125% | Plaza Bancorp
Debt Instrument [Line Items]
Fixed interest rate (as a percent)	7.125%
Number of subordinated notes assumed | notes	3
Debt assumed in acquisition	$ 25,000,000
Redemption price (as a percent)	103.00%
Redemption price, subsequent reduction (as a percent)	50.00%

Subordinated Debentures - Activ

Subordinated Debentures - Activities for our subordinated debentures (Details) - Subordinated Debentures - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Average balance outstanding	$ 81,466	$ 69,347
Maximum amount outstanding at any month-end during the year	105,123	69,383
Balance outstanding at end of year	$ 105,123	$ 69,383
Weighted average interest rate during the year	5.80%	5.54%

Income Taxes - Total income tax

Income Taxes - Total income tax provision (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Current income tax provision:
Federal									$ 18,644	$ 16,928	$ 12,460
State									7,062	4,655	4,144
Total current income tax provision									25,706	21,583	16,604
Deferred income tax provision (benefit):
Federal									8,294	2,379	(887)
Effect of Tax Act									5,633	0	0
State									2,493	1,253	(508)
Total deferred income tax provision (benefit)									16,420	3,632	(1,395)
Total income tax provision	$ 19,370	$ 10,619	$ 7,521	$ 4,616	$ 7,238	$ 5,877	$ 6,358	$ 5,742	$ 42,126	$ 25,215	$ 15,209

Income Taxes - Reconciliation f

Income Taxes - Reconciliation from statutory federal income taxes (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Federal statutory rate (percent)									35.00%
Reconciliation from statutory federal income taxes to the company's effective income taxes
Statutory federal income tax provision									$ 35,778	$ 22,863	$ 14,253
State taxes, net of federal income tax effect									6,720	4,135	2,886
Cash surrender life insurance									(645)	(407)	(483)
Tax exempt interest									(1,660)	(764)	(742)
Merger costs									824	533	447
LIHTC investments									(1,031)	(909)	(871)
Effect of the Tax Act									5,633	0	0
Excess tax benefit of stock-based compensation									(1,995)	0	0
Prior year true-up									(1,108)	0	0
Other									(390)	(236)	(281)
Total income tax provision	$ 19,370	$ 10,619	$ 7,521	$ 4,616	$ 7,238	$ 5,877	$ 6,358	$ 5,742	$ 42,126	$ 25,215	$ 15,209

Income Taxes - Deferred tax ass

Income Taxes - Deferred tax assets (liabilities) (Details) - USD ($)	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Deferred tax assets:
Accrued expenses	$ 2,463,000	$ 2,839,000	$ 1,717,000
Net operating loss	4,834,000	3,977,000	5,192,000
Allowance for loan losses, net of bad debt charge-offs	8,400,000	8,061,000	6,252,000
Deferred compensation	3,074,000	2,348,000	2,547,000
State taxes	1,500,000	1,879,000	1,451,000
Depreciation	0	1,090,000	651,000
Loan discount	8,642,000	3,477,000	0
Stock-based compensation	1,914,000	1,108,000	639,000
Unrealized loss on available for sale securities	0	1,939,000	0
Capital loss carryover	380,000	0	0
AMT credit	107,000	0	0
Total deferred tax assets	31,314,000	26,718,000	18,449,000
Deferred tax liabilities:
Deferred FDIC gain	(524,000)	(1,675,000)	(1,656,000)
Core deposit intangibles	(11,691,000)	(3,331,000)	(2,266,000)
Loan origination costs	(3,368,000)	(4,208,000)	0
Depreciation	(699,000)	0	0
Unrealized loss on available for sale securities	(188,000)	0	(231,000)
Other	(1,199,000)	(697,000)	(2,785,000)
Total deferred tax liabilities	(17,669,000)	(9,911,000)	(6,938,000)
Valuation allowance	(380,000)	0	0
Net deferred tax asset	$ 13,265,000	$ 16,807,000	$ 11,511,000

Income Taxes - Income Taxes (De

Income Taxes - Income Taxes (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Taxes
Effect of Tax Act	$ 5,633,000	$ 0	$ 0
Valuation allowance	$ 380,000	0	0
Minimum cumulative change in ownership that could result in a Section 382 ownership change (as a percent)	50.00%
Amount of unrecognized tax benefits	$ 2,906,000	0	$ 0
Tax benefits that would impact the effective tax rate	0
Interest and penalties accrued related to unrecognized tax benefits	104,000,000	$ 0
Federal income tax purpose
Income Taxes
Net operating loss carryforward	17,400,000
California franchise tax purpose
Income Taxes
Net operating loss carryforward	$ 14,700,000

Income Taxes - Unrecognized Tax

Income Taxes - Unrecognized Tax Benefits (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at January 1	$ 0	$ 0
Additions based on tax positions related to prior years	2,906,000	0
Balance at December 31	$ 2,906,000	$ 0

Commitments, Contingencies an90

Commitments, Contingencies and Concentrations of Risk (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Employment Agreements
Rental expense	$ 4.8	$ 4.4	$ 3.8
CEO | Employment Agreements
Employment Agreements
Term of agreements (in years)	3 years
Chief Banking Officer | Employment Agreements
Employment Agreements
Term of agreements (in years)	3 years
Chief Financial Officer | Employment Agreements
Employment Agreements
Term of agreements (in years)	3 years
Chief Credit Officer | Employment Agreements
Employment Agreements
Term of agreements (in years)	3 years

Commitments, Contingencies an91

Commitments, Contingencies and Concentrations of Risk - Minimum annual lease payments (Details) $ in Thousands	Dec. 31, 2017USD ($)
Lease Commitments
2,018	$ 7,170
2,019	5,476
2,020	2,675
2,021	1,887
2,022	1,421
Thereafter	2,312
Total	$ 20,941

Benefit Plans - 401(k) Plan (De

Benefit Plans - 401(k) Plan (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plan Disclosure [Line Items]
Employer's match of employees' contributions of the first 3% of eligible compensation (as a percent)	100.00%	100.00%	100.00%
Percentage of eligible compensation, matched 100% by employer	3.00%	3.00%	3.00%
Employer's match of employees' contributions of the next 2% of eligible compensation (as a percent)	50.00%	50.00%	50.00%
Percentage of eligible compensation, matched 50% by employer	2.00%	2.00%	2.00%
Contributions made	$ 1,449	$ 959	$ 769
Minimum
Defined Benefit Plan Disclosure [Line Items]
Employee contribution, as a percentage of compensation	1.00%
Maximum
Defined Benefit Plan Disclosure [Line Items]
Employee contribution, as a percentage of compensation	100.00%

Benefit Plans - Long-Term Incen

Benefit Plans - Long-Term Incentive Plan (Details)	12 Months Ended
	Dec. 31, 2017shares	May 31, 2017shares	May 31, 2015shares	May 31, 2014shares	May 31, 2004shares
2004 Long-Term Incentive Plan
Share based plans
Shares authorized					525,500
Term of plan (in years)	10 years
Vesting percentage per year	33.30%
Number of options outstanding (in shares)	114,454
Granted (in shares)	0
2012 Plan
Share based plans
Shares authorized		3,580,000	620,000	800,000
Term of plan (in years)	10 years
Number of options outstanding (in shares)	755,362
Granted (in shares)	3,594,149
2012 Plan | Minimum
Share based plans
Award vesting period (in years)	1 year
2012 Plan | Maximum
Share based plans
Award vesting period (in years)	3 years
2014 Plan
Share based plans
Shares authorized				1,420,000
2017 Plan
Share based plans
Shares authorized		5,000,000
2015 Equity Based Compensation Plan
Share based plans
Shares authorized	250,000		2,500,000
Number of options outstanding (in shares)	36,175
Shares issued ratio, actual number of shares	2
Shares issued ratio	1
Granted (in shares)	0
2005 Long-Term Incentive Plan
Share based plans
Number of options outstanding (in shares)	48,532
Granted (in shares)	0

Benefit Plans - Option Plans (D

Benefit Plans - Option Plans (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Additional disclosure
Intrinsic value	$ 7,700	$ 2,000	$ 60
Compensation expense	$ 927	$ 883	$ 514
Stock option
Number of Stock Options Outstanding
Options outstanding at the beginning of the year (in shares)	1,083,667
Granted (in shares)	210,977
Exercised (in shares)	(333,959)
Forfeited and expired (in shares)	(6,162)
Options outstanding at the end of the year (in shares)	954,523	1,083,667
Vested at the end of the year (in shares)	749,281
Weighted Average Exercise Price Per Share
Options outstanding at the beginning of the year (in dollars per share)	$ 12.61
Granted (in dollars per share)	20.40
Exercised (in dollars per share)	13.49
Forfeited and expired (in dollars per share)	34.68
Options outstanding at the end of the year (in dollars per share)	13.89	$ 12.61
Vested at the end of the year (in dollars per shares)	$ 12.47
Weighted average remaining contractual life
Outstanding at the end of the year	5 years 9 months 18 days
Vested at the end of the year	5 years 3 months 15 days
Additional disclosure
Aggregate intrinsic value, outstanding	$ 24,926
Aggregate Intrinsic value, vested and expected to vest	20,627
Unrecognized compensation expense	$ 814

Benefit Plans - Black-Scholes m

Benefit Plans - Black-Scholes model (Details) - Stock option - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share based plans
Expected volatility (as a percent)			29.47%
Expected term (in years)		6 years	6 years
Risk free rate (as a percent)			1.39%
Weighted-average grant date fair value (in dollars per share)	$ 19.66	$ 5.55	$ 4.73
Minimum
Share based plans
Expected volatility (as a percent)	22.43%	21.98%
Expected term (in years)	3 months 29 days
Risk free rate (as a percent)	1.03%	1.32%
Maximum
Share based plans
Expected volatility (as a percent)	28.77%	26.88%
Expected term (in years)	6 years
Risk free rate (as a percent)	2.02%	1.83%

Benefit Plans - Restricted Stoc

Benefit Plans - Restricted Stock (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Weighted Average Grant-Date Fair Value per share
Compensation expense	$ 927	$ 883	$ 514
Restricted Stock
Shares
Unvested at the beginning of the year (in shares)	370,334
Granted (in shares)	201,544
Vested (in shares)	(125,035)
Forfeited (in shares)	0
Unvested at the end of the year (in shares)	446,843	370,334
Weighted Average Grant-Date Fair Value per share
Unvested at the beginning of the year (in dollars per share)	$ 23.53
Granted (in dollars per share)	38.70
Vested (in dollars per share)	26.26
Forfeited (in dollars per share)	0
Unvested at the end of the year (in dollars per share)	$ 29.61	$ 23.53
Compensation expense	$ 5,000	$ 2,000	$ 260
Grant date fair value	7,800
Unrecognized compensation expense	$ 8,200

Benefit Plans - Other Benefits

Benefit Plans - Other Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Deferred compensation plan | Executive Officer
Benefit Plans
Amounts expensed	$ 721	$ 573	$ 555
Amounts recorded as liability	8,400	5,700	5,400
SERP
Benefit Plans
Expense incurred for SERP	721	573	$ 307
Deferred compensation liability	8,300	$ 5,100
SERP | Plaza Bancorp
Benefit Plans
Deferred compensation liability	$ 2,000

Financial Instruments with Of98

Financial Instruments with Off-Balance Sheet Risk (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Undisbursed loans and unused lines of credit
Financial Instruments with Off-Balance Sheet Risk
Allowance for credit losses	$ 1.9	$ 1.1
Commitments to extend credit
Financial Instruments with Off-Balance Sheet Risk
Financial instruments with off-balance sheet risk	1,200	$ 581
Undisbursed Commitments For C&I Loans
Financial Instruments with Off-Balance Sheet Risk
Financial instruments with off-balance sheet risk	$ 707

Fair Value of Financial Instr99

Fair Value of Financial Instruments - Fair value estimates (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Assets:
Investments held to maturity	$ 18,082	$ 8,461
Investment securities available-for-sale	787,429	380,963
Accrued interest receivable	27,053	13,145
Liabilities:
FHLB advances	490,148	278,000
Level 1
Assets:
Cash and cash equivalents	200,064	156,857
Investments held to maturity	0	0
Investment securities available-for-sale	0	0
Loans held for sale	0	0
Loans held for investment, net	0	0
Accrued interest receivable	27,053	13,145
Liabilities:
Deposit accounts	5,001,053	2,330,579
FHLB advances	0	0
Other borrowings	0	0
Subordinated debentures	0	0
Accrued interest payable	2,131	1,481
Level 2
Assets:
Cash and cash equivalents	0	0
Investments held to maturity	18,082	8,461
Investment securities available-for-sale	787,429	380,963
Loans held for sale	23,524	8,405
Loans held for investment, net	0	0
Accrued interest receivable	0	0
Liabilities:
Deposit accounts	1,074,564	573,467
FHLB advances	489,823	277,935
Other borrowings	46,373	50,905
Subordinated debentures	115,159	69,982
Accrued interest payable	0	0
Level 3
Assets:
Cash and cash equivalents	0	0
Investments held to maturity	0	0
Investment securities available-for-sale	0	0
Loans held for sale	0	0
Loans held for investment, net	6,269,366	3,211,154
Accrued interest receivable	0	0
Liabilities:
Deposit accounts	0	0
FHLB advances	0	0
Other borrowings	0	0
Subordinated debentures	0	0
Accrued interest payable	0	0
Carrying Amount
Assets:
Cash and cash equivalents	200,064	156,857
Investments held to maturity	18,291	8,565
Investment securities available-for-sale	787,429	380,963
FHLB, FRB and other stock	65,881	37,304
Loans held for sale	23,426	7,711
Loans held for investment, net	6,167,532	3,220,317
Accrued interest receivable	27,053	13,145
Liabilities:
Deposit accounts	6,085,868	3,145,581
FHLB advances	490,148	278,000
Other borrowings	46,139	49,971
Subordinated debentures	105,123	69,383
Accrued interest payable	2,131	1,481
Estimated Fair Value
Assets:
Cash and cash equivalents	200,064	156,857
Investments held to maturity	18,082	8,461
Investment securities available-for-sale	787,429	380,963
Loans held for sale	23,524	8,405
Loans held for investment, net	6,269,366	3,211,154
Accrued interest receivable	27,053	13,145
Liabilities:
Deposit accounts	6,075,617	2,904,046
FHLB advances	489,823	277,935
Other borrowings	46,373	50,905
Subordinated debentures	115,159	69,982
Accrued interest payable	2,131	1,481
Bank Time Deposits | Level 1
Assets:
Cash and cash equivalents	3,693	3,944
Bank Time Deposits | Level 2
Assets:
Cash and cash equivalents	0	0
Bank Time Deposits | Level 3
Assets:
Cash and cash equivalents	0	0
Bank Time Deposits | Carrying Amount
Assets:
Cash and cash equivalents	3,693	3,944
Bank Time Deposits | Estimated Fair Value
Assets:
Cash and cash equivalents	$ 3,693	$ 3,944

Fair Value of Financial Inst100

Fair Value of Financial Instruments - Assets measured at fair value on a recurring basis (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Fair Value Disclosures
Total securities available for sale:	$ 805,511	$ 389,424
Recurring basis | Level 1
Fair Value Disclosures
Total securities available for sale:	0	0
Recurring basis | Level 2
Fair Value Disclosures
Total securities available for sale:	787,429	380,963
Recurring basis | Level 3
Fair Value Disclosures
Total securities available for sale:	0	0
Recurring basis | Agency | Level 1
Fair Value Disclosures
Total securities available for sale:	0
Recurring basis | Agency | Level 2
Fair Value Disclosures
Total securities available for sale:	47,209
Recurring basis | Agency | Level 3
Fair Value Disclosures
Total securities available for sale:	0
Recurring basis | Corporate | Level 1
Fair Value Disclosures
Total securities available for sale:	0	0
Recurring basis | Corporate | Level 2
Fair Value Disclosures
Total securities available for sale:	79,546	37,642
Recurring basis | Corporate | Level 3
Fair Value Disclosures
Total securities available for sale:	0	0
Recurring basis | Municipal bonds | Level 1
Fair Value Disclosures
Total securities available for sale:	0	0
Recurring basis | Municipal bonds | Level 2
Fair Value Disclosures
Total securities available for sale:	232,128	118,803
Recurring basis | Municipal bonds | Level 3
Fair Value Disclosures
Total securities available for sale:	0	0
Recurring basis | Collateralized mortgage obligation: residential | Level 1
Fair Value Disclosures
Total securities available for sale:	0	0
Recurring basis | Collateralized mortgage obligation: residential | Level 2
Fair Value Disclosures
Total securities available for sale:	33,781	31,388
Recurring basis | Collateralized mortgage obligation: residential | Level 3
Fair Value Disclosures
Total securities available for sale:	0	0
Recurring basis | Mortgage-backed securities: residential | Level 1
Fair Value Disclosures
Total securities available for sale:	0	0
Recurring basis | Mortgage-backed securities: residential | Level 2
Fair Value Disclosures
Total securities available for sale:	394,765	193,130
Recurring basis | Mortgage-backed securities: residential | Level 3
Fair Value Disclosures
Total securities available for sale:	0	0
Recurring basis | Estimated Fair Value
Fair Value Disclosures
Total securities available for sale:	787,429	380,963
Recurring basis | Estimated Fair Value | Agency
Fair Value Disclosures
Total securities available for sale:	47,209
Recurring basis | Estimated Fair Value | Corporate
Fair Value Disclosures
Total securities available for sale:	79,546	37,642
Recurring basis | Estimated Fair Value | Municipal bonds
Fair Value Disclosures
Total securities available for sale:	232,128	118,803
Recurring basis | Estimated Fair Value | Collateralized mortgage obligation: residential
Fair Value Disclosures
Total securities available for sale:	33,781	31,388
Recurring basis | Estimated Fair Value | Mortgage-backed securities: residential
Fair Value Disclosures
Total securities available for sale:	$ 394,765	$ 193,130

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Earnings Per Share [Abstract]
Weighted average number of stock options excluded (in shares)									17,524	82,760	222,858
Income/(Loss) (numerator)
Net income applicable to earnings per share									$ 60,100	$ 40,103	$ 25,515
Basic earnings per share: Income available to common stockholders	$ 16,171	$ 20,232	$ 14,176	$ 9,521	$ 11,953	$ 9,227	$ 10,369	$ 8,554	60,100	40,103	25,515
Diluted earnings per share: Income available to common stockholders									$ 60,100	$ 40,103	$ 25,515
Shares (denominator)
Basic earnings per share: Income available to common stockholders (in shares)									37,705,556	26,931,634	21,156,668
Effect of dilutive securities: Warrants and stock option plans (in shares)									805,705	507,525	332,030
Diluted earnings per share: Income available to common stockholders (in shares)									38,511,261	27,439,159	21,488,698
Per Share Amount
Basic earnings per share: Income available to common stockholders (in dollars per share)	$ 0.37	$ 0.51	$ 0.36	$ 0.35	$ 0.44	$ 0.34	$ 0.38	$ 0.33	$ 1.59	$ 1.49	$ 1.21
Diluted earnings per share: Income available to common stockholders plus assumed conversions (in dollars per share)	$ 0.36	$ 0.50	$ 0.35	$ 0.34	$ 0.43	$ 0.33	$ 0.37	$ 0.33	$ 1.56	$ 1.46	$ 1.19

Derivative Instruments (Details

Derivative Instruments (Details) $ in Thousands	Dec. 31, 2017USD ($)
Derivative [Line Items]
Derivative assets, fair value	$ 1,135
Derivative liabilities, fair value	1,135
Not Designated as Hedging Instrument
Derivative [Line Items]
Notional	58,599
Derivative assets, fair value	1,135
Derivative liabilities, fair value	1,135
Not Designated as Hedging Instrument | Interest rate swap contracts
Derivative [Line Items]
Notional	58,599
Derivative assets, fair value	1,135
Derivative liabilities, fair value	$ 1,135

Balance Sheet Offsetting (Detai

Balance Sheet Offsetting (Details) $ in Thousands	Dec. 31, 2017USD ($)
Financial assets:
Gross Amounts Recognized in the Consolidated Balance Sheets	$ 1,833
Gross Amounts Offset in the Consolidated Balance Sheets	(698)
Net Amounts Presented in the Consolidated Balance Sheets	1,135
Financial Instruments	0
Cash Collateral	0
Net Amount	1,135
Financial liabilities:
Gross Amounts Recognized in the Consolidated Balance Sheets	1,135
Gross Amounts Offset in the Consolidated Balance Sheets	0
Net Amounts Presented in the Consolidated Balance Sheets	1,135
Financial Instruments	0
Cash Collateral	0
Net Amount	1,135
Not Designated as Hedging Instrument
Financial assets:
Gross Amounts Recognized in the Consolidated Balance Sheets	1,833
Gross Amounts Offset in the Consolidated Balance Sheets	(698)
Net Amounts Presented in the Consolidated Balance Sheets	1,135
Financial Instruments	0
Cash Collateral	0
Net Amount	1,135
Financial liabilities:
Gross Amounts Recognized in the Consolidated Balance Sheets	1,135
Gross Amounts Offset in the Consolidated Balance Sheets	0
Net Amounts Presented in the Consolidated Balance Sheets	1,135
Financial Instruments	0
Cash Collateral	0
Net Amount	$ 1,135

Related Parties (Details)

Related Parties (Details) - USD ($) $ in Thousands	Jan. 08, 2018	Dec. 31, 2017	Dec. 31, 2016
Related Party Transaction [Line Items]
Related party deposits		$ 746,000	$ 354,000
Associa
Related Party Transaction [Line Items]
Related party deposits		736,000	352,000
Executive Officers And Directors
Related Party Transaction [Line Items]
Loan receivable		$ 6,120	$ 2,380
Executive Officers And Directors | Subsequent Event
Related Party Transaction [Line Items]
Loan receivable	$ 4,000

Quarterly Results of Operati105

Quarterly Results of Operations (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Interest income	$ 85,684	$ 70,161	$ 68,733	$ 45,427	$ 45,797	$ 42,429	$ 40,874	$ 37,505	$ 270,005	$ 166,605	$ 118,356
Interest expense	7,514	5,870	5,395	3,724	3,493	3,420	3,313	3,304	22,503	13,530	12,057
Provision for loan losses	2,185	2,049	1,904	2,502	2,054	4,013	1,589	1,120	8,640	8,776	6,425
Noninterest income	9,451	8,221	8,759	4,683	4,318	5,968	4,468	4,848	31,114	19,602	14,388
Noninterest expense	49,895	39,612	48,496	29,747	25,377	25,860	23,713	23,633	167,750	98,583	73,538
Income tax provision	19,370	10,619	7,521	4,616	7,238	5,877	6,358	5,742	42,126	25,215	15,209
Net income	$ 16,171	$ 20,232	$ 14,176	$ 9,521	$ 11,953	$ 9,227	$ 10,369	$ 8,554	$ 60,100	$ 40,103	$ 25,515
Earnings per share:
Basic (in dollars per share)	$ 0.37	$ 0.51	$ 0.36	$ 0.35	$ 0.44	$ 0.34	$ 0.38	$ 0.33	$ 1.59	$ 1.49	$ 1.21
Diluted (in dollars per share)	$ 0.36	$ 0.50	$ 0.35	$ 0.34	$ 0.43	$ 0.33	$ 0.37	$ 0.33	$ 1.56	$ 1.46	$ 1.19

Parent Company Financial Inf106

Parent Company Financial Information - STATEMENTS OF FINANCIAL CONDITION (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Percentage of capital stock of the Bank held	100.00%
Assets
Cash and cash equivalents	$ 200,064	$ 156,857	$ 78,417	$ 110,925
Other assets	52,067	25,874
Total assets	8,024,501	4,036,311
Liabilities
Subordinated debentures	105,123	69,383
Accrued expenses and other liabilities	55,227	33,636
Total liabilities	6,782,505	3,576,571
Total Stockholders’ Equity	1,241,996	459,740	298,980	199,592
Total liabilities and stockholders' equity	8,024,501	4,036,311
Corporation
Assets
Cash and cash equivalents	17,097	15,124	$ 3,412	$ 18,724
Investment in subsidiaries	1,329,961	513,606
Other assets	2,599	2,400
Total assets	1,349,657	531,130
Liabilities
Subordinated debentures	105,123	69,383
Accrued expenses and other liabilities	2,538	2,007
Total liabilities	107,661	71,390
Total Stockholders’ Equity	1,241,996	459,740
Total liabilities and stockholders' equity	$ 1,349,657	$ 531,130

Parent Company Financial Inf107

Parent Company Financial Information - STATEMENTS OF OPERATIONS (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income
Interest income	$ 85,684	$ 70,161	$ 68,733	$ 45,427	$ 45,797	$ 42,429	$ 40,874	$ 37,505	$ 270,005	$ 166,605	$ 118,356
Noninterest income	9,451	8,221	8,759	4,683	4,318	5,968	4,468	4,848	31,114	19,602	14,388
Expense
Interest expense	7,514	5,870	5,395	3,724	3,493	3,420	3,313	3,304	22,503	13,530	12,057
Noninterest expense	49,895	39,612	48,496	29,747	25,377	25,860	23,713	23,633	167,750	98,583	73,538
Net income before income taxes									102,226	65,318	40,724
Income tax	19,370	10,619	7,521	4,616	7,238	5,877	6,358	5,742	42,126	25,215	15,209
Net income	$ 16,171	$ 20,232	$ 14,176	$ 9,521	$ 11,953	$ 9,227	$ 10,369	$ 8,554	60,100	40,103	25,515
Corporation
Income
Interest income									36	31	27
Noninterest income									0	0	0
Total income									36	31	27
Expense
Interest expense									4,720	3,844	3,937
Noninterest expense									8,956	3,769	2,831
Total expense									13,676	7,613	6,768
Net income before income taxes									(13,640)	(7,582)	(6,741)
Income tax									(5,417)	(2,785)	(2,783)
Net loss (parent only)									(8,223)	(4,797)	(3,958)
Equity in net earnings of subsidiaries									68,323	44,900	29,473
Net income									$ 60,100	$ 40,103	$ 25,515

Parent Company Financial Inf108

Parent Company Financial Information - SUMMARY STATEMENTS OF CASH FLOWS (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Parent Company Financial Information
Net income	$ 16,171	$ 20,232	$ 14,176	$ 9,521	$ 11,953	$ 9,227	$ 10,369	$ 8,554	$ 60,100	$ 40,103	$ 25,515
Adjustments to reconcile net income to cash used in operating activities:
Share-based compensation expense									5,809	2,729	1,165
Increase (decrease) in accrued expenses and other liabilities									5,003	(4,428)	6,786
Net cash (used in) provided by operating activities									83,999	63,447	23,669
Cash flows from financing activities:
Repurchase of common stock									(1,258)	(126)	(116)
Proceeds from issuance of subordinated debentures									12,012	0	0
Net cash provided by financing activities									255,087	445,908	275,103
Net increase (decrease) in cash and cash equivalents									43,207	78,440	(32,508)
Cash and cash equivalents, beginning of year				156,857				78,417	156,857	78,417	110,925
Cash and cash equivalents, end of year	200,064				156,857				200,064	156,857	78,417
Corporation
Parent Company Financial Information
Net income									60,100	40,103	25,515
Adjustments to reconcile net income to cash used in operating activities:
Share-based compensation expense									5,809	2,729	1,165
Equity in undistributed earnings of subsidiaries and dividends from the bank									(68,323)	(44,901)	(29,473)
Increase (decrease) in accrued expenses and other liabilities									(365)	240	166
(Decrease) increase in current and deferred taxes									(896)	0	3,566
Decrease (increase) in other assets									1,714	4,794	(6,893)
Net cash (used in) provided by operating activities									(1,961)	2,965	(5,954)
Cash flows from financing activities:
Proceeds from issuance of common stock, net of issuance cost									0	0	0
Repurchase of common stock									(1,258)	(125)	(116)
Proceeds from exercise of options and warrants									4,592	1,107	758
Capital contribution to Bank									600	7,765	(10,000)
Proceeds from issuance of subordinated debentures									0	0	0
Net cash provided by financing activities									3,934	8,747	(9,358)
Net increase (decrease) in cash and cash equivalents									1,973	11,712	(15,312)
Cash and cash equivalents, beginning of year				$ 15,124				$ 3,412	15,124	3,412	18,724
Cash and cash equivalents, end of year	$ 17,097				$ 15,124				$ 17,097	$ 15,124	$ 3,412

Acquisitions - Narrative (Detai

Acquisitions - Narrative (Details) $ / shares in Units, $ in Thousands	Nov. 01, 2017USD ($)$ / sharesshares	Apr. 01, 2017USD ($)shares	Jan. 31, 2016USD ($)bankshares	Dec. 31, 2017USD ($)	Sep. 30, 2017USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2017USD ($)	Mar. 31, 2017$ / shares	Dec. 31, 2016USD ($)	Jan. 29, 2016USD ($)$ / shares	Dec. 31, 2015USD ($)
Business Acquisition [Line Items]
Goodwill				$ 493,329		$ 493,329	$ 493,329		$ 102,490		$ 50,832
Plaza Bancorp
Business Acquisition [Line Items]
Total assets acquired	$ 1,245,740			1,256,313		1,256,313	1,256,313
Gross loans acquired	1,100,000
Deposits	$ 1,081,727			1,082,951		1,082,951	1,082,951
Equity issued (shares)	0.2
Consideration paid	$ 251,000			250,939
Paid by PLZZ prior to close	$ 6,500			6,544		6,544	6,544
Number of shares of common stock issued as consideration | shares	6,049,373
Closing stock price of common stock (in dollars per share) | $ / shares	$ 40.4
Goodwill	$ 122,000			121,885		121,885	121,885
Deferred tax assets				(6,876)
Heritage Oaks Bank
Business Acquisition [Line Items]
Total assets acquired		$ 2,005,637		2,015,822		2,015,822	2,015,822
Gross loans acquired		1,400,000
Deposits		$ 1,668,079		1,669,550		1,669,550	1,669,550
Equity issued (shares)		0.3471
Consideration paid		$ 465,000				465,482
Paid by PLZZ prior to close		3,900
Closing stock price of common stock (in dollars per share) | $ / shares								$ 38.55
Goodwill		$ 269,000		268,954		268,954	268,954
Deferred tax assets					$ 1,100	(6,567)
Security California Bancorp
Business Acquisition [Line Items]
Total assets acquired			$ 716,633	713,950		713,950	713,950
Gross loans acquired			456,000
Deposits			$ 636,450	636,591		636,591	636,591
Equity issued (shares)			0.9629
Consideration paid			$ 120,000				120,174
Paid by PLZZ prior to close			$ 788
Closing stock price of common stock (in dollars per share) | $ / shares										$ 20.53
Number of branches | bank			6
Goodwill			$ 51,700	$ 51,658		$ 51,658	51,658
Deferred tax assets							$ 1,130
Common Stock | Heritage Oaks Bank
Business Acquisition [Line Items]
Number of shares of common stock issued as consideration | shares		11,959,022
Common Stock | Security California Bancorp
Business Acquisition [Line Items]
Number of shares of common stock issued as consideration | shares			5,815,051
Value of shares of common stock to be issued										$ 119,400

Acquisitions - Assets Acquired

Acquisitions - Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	Nov. 01, 2017	Apr. 01, 2017	Jan. 31, 2016	Dec. 31, 2017	Sep. 30, 2017	Dec. 31, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
LIABILITIES ASSUMED
Goodwill recognized				$ 493,329		$ 493,329	$ 493,329	$ 102,490	$ 50,832
Plaza Bancorp
ASSETS ACQUIRED
Cash and cash equivalents	$ 150,459			150,459		150,459	150,459
Loans, gross	1,069,359			1,062,941		1,062,941	1,062,941
Allowance for loan losses	(13,009)			0		0	0
Fixed assets	7,389			7,195		7,195	7,195
Core deposit intangible	198			11,580		11,580	11,580
Deferred tax assets	11,849			4,973		4,973	4,973
Other assets	19,495			19,165		19,165	19,165
Total assets acquired	1,245,740			1,256,313		1,256,313	1,256,313
LIABILITIES ASSUMED
Deposits	1,081,727			1,082,951		1,082,951	1,082,951
Borrowings	40,755			41,152		41,152	41,152
Other Liabilities	8,956			8,334		8,334	8,334
Total liabilities assumed	1,131,438			1,132,437		1,132,437	1,132,437
Excess of assets acquired over liabilities assumed	114,302			123,876		123,876	123,876
Consideration paid	251,000			250,939
Paid by PLZZ prior to close	6,500			6,544		6,544	6,544
Capitalized merger-related expense				1,366		1,366	1,366
Goodwill recognized	$ 122,000			121,885		121,885	121,885
Fair Value Adjustment
Cash and cash equivalents				0
Loans, gross				(6,418)
Allowance for loan losses				13,009
Fixed assets				(194)
Core deposit intangible				11,382
Deferred tax assets				(6,876)
Other assets				(330)
Total assets acquired				10,573
Deposits				1,224
Borrowings				397
Other Liabilities				(622)
Total liabilities assumed				999
Excess of assets acquired over liabilities assumed				9,574
Heritage Oaks Bank
ASSETS ACQUIRED
Cash and cash equivalents		$ 78,728		78,728		78,728	78,728
Investment securities		447,520		442,923		442,923	442,923
Loans, gross		1,387,949		1,364,649		1,364,649	1,364,649
Allowance for loan losses		(17,200)		0		0	0
Fixed assets		35,567		34,902		34,902	34,902
Core deposit intangible		0		28,123		28,123	28,123
Deferred tax assets		17,850		11,283		11,283	11,283
Other assets		55,223		55,214		55,214	55,214
Total assets acquired		2,005,637		2,015,822		2,015,822	2,015,822
LIABILITIES ASSUMED
Deposits		1,668,079		1,669,550		1,669,550	1,669,550
Borrowings		141,996		139,034		139,034	139,034
Other Liabilities		7,290		8,061		8,061	8,061
Total liabilities assumed		1,817,365		1,816,645		1,816,645	1,816,645
Excess of assets acquired over liabilities assumed		188,272		199,177		199,177	199,177
Consideration paid		465,000				465,482
Paid by PLZZ prior to close		3,900
Capitalized merger-related expense				2,649		2,649	2,649
Goodwill recognized		$ 269,000		268,954		268,954	268,954
Fair Value Adjustment
Cash and cash equivalents						0
Investment securities						(4,597)
Loans, gross						(23,300)
Allowance for loan losses						17,200
Fixed assets						(665)
Core deposit intangible						28,123
Deferred tax assets					$ 1,100	(6,567)
Other assets						(9)
Total assets acquired						10,185
Deposits						1,471
Borrowings						(2,962)
Other Liabilities						771
Total liabilities assumed						(720)
Excess of assets acquired over liabilities assumed						10,905
Security California Bancorp
ASSETS ACQUIRED
Cash and cash equivalents			$ 40,947	40,947		40,947	40,947
Investment securities			191,881	190,254		190,254	190,254
Loans, gross			467,197	456,158		456,158	456,158
Allowance for loan losses			(7,399)	0		0	0
Fixed assets			5,335	4,190		4,190	4,190
Core deposit intangible			493	4,319		4,319	4,319
Deferred tax assets			5,618	6,748		6,748	6,748
Other assets			10,589	9,362		9,362	9,362
Total assets acquired			716,633	713,950		713,950	713,950
LIABILITIES ASSUMED
Deposits			636,450	636,591		636,591	636,591
Borrowings			0	0		0	0
Deferred tax liability			0	0		0	0
Other Liabilities			9,063	8,843		8,843	8,843
Total liabilities assumed			645,513	645,434		645,434	645,434
Excess of assets acquired over liabilities assumed			71,120	68,516		68,516	68,516
Consideration paid			120,000				120,174
Paid by PLZZ prior to close			788
Goodwill recognized			51,700	51,658		51,658	51,658
Fair Value Adjustment
Cash and cash equivalents							0
Investment securities							(1,627)
Loans, gross							(11,039)
Allowance for loan losses							7,399
Fixed assets							(1,145)
Core deposit intangible							3,826
Deferred tax assets							1,130
Other assets							(1,227)
Total assets acquired							(2,683)
Deposits							141
Borrowings							0
Deferred tax liability							0
Other Liabilities							(220)
Total liabilities assumed							(79)
Excess of assets acquired over liabilities assumed							(2,604)
Security California Bancorp | Bank Time Deposits
ASSETS ACQUIRED
Cash and cash equivalents			$ 1,972	$ 1,972		$ 1,972	1,972
Fair Value Adjustment
Cash and cash equivalents							$ 0

Acquisitions - Additional infor

Acquisitions - Additional information (Details) - Acquired Loans $ in Thousands	Dec. 31, 2017USD ($)
Security California Bancorp
Business Acquisition [Line Items]
Contractual amounts due	$ 539,806
Cash flows not expected to be collected	2,765
Expected cash flows	537,041
Interest component of expected cash flows	80,883
Fair value of acquired loans	456,158
Heritage Oaks Bank
Business Acquisition [Line Items]
Contractual amounts due	1,717,230
Cash flows not expected to be collected	4,442
Expected cash flows	1,712,788
Interest component of expected cash flows	348,100
Fair value of acquired loans	1,364,688
Plaza Bancorp
Business Acquisition [Line Items]
Contractual amounts due	1,703,246
Cash flows not expected to be collected	20,152
Expected cash flows	1,683,094
Interest component of expected cash flows	625,592
Fair value of acquired loans	$ 1,057,502

Acquisitions - Pro Forma Inform

Acquisitions - Pro Forma Information (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Business Combinations [Abstract]
Net interest and other income	$ 342,159	$ 258,970	$ 246,622
Net income	$ 72,316	$ 71,722	$ 58,257
Basic earnings per share (in dollars per share)	$ 1.58	$ 1.58	$ 1.30
Diluted earnings per share (in dollars per share)	$ 1.55	$ 1.56	$ 1.29

Subsequent Events (Details)

Subsequent Events (Details) $ in Thousands	Feb. 09, 2018USD ($)bank	Jan. 08, 2018USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Executive Officers And Directors
Subsequent Events
Loan receivable			$ 6,120	$ 2,380
Subsequent Event | Executive Officers And Directors
Subsequent Events
Loan receivable		$ 4,000
Subsequent Event | Grandpoint Capital, Inc.
Subsequent Events
Total assets acquired	$ 3,200,000
Gross loans acquired	2,400,000
Deposits	$ 2,400,000
Number of regional offices | bank	14
Equity issued (shares)	0.4750