Byline Bancorp (BY) 10-K 30 Mar 18 2017 FY Annual report Financial data

Document And Entity Information

Document And Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2017	Mar. 29, 2018	Jun. 30, 2017
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	FY
Trading Symbol	BY
Entity Registrant Name	Byline Bancorp, Inc.
Entity Central Index Key	1,702,750
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Public Float			$ 332,611,295
Entity Common Stock, Shares Outstanding		29,404,048

CONSOLIDATED STATEMENTS OF FINA

CONSOLIDATED STATEMENTS OF FINANCIAL CONDITION - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
ASSETS
Cash and due from banks	$ 19,404	$ 17,735
Interest bearing deposits with other banks	38,945	28,798
Cash and cash equivalents	58,349	46,533
Securities available-for-sale, at fair value	583,236	608,560
Securities held-to-maturity, at amortized cost ($117,277 and $138,082 fair value at December 31, 2017 and 2016, respectively)	117,163	138,846
Restricted stock, at cost	16,343	14,993
Loans held for sale	5,212	23,976
Loans and leases:
Loans and leases	2,277,492	2,148,011
Allowance for loan and lease losses	(16,706)	(10,923)
Net loans and leases	2,260,786	2,137,088
Servicing assets, at fair value	21,400	21,091
Accrued interest receivable	7,670	6,866
Premises and equipment, net	95,224	102,074
Assets held for sale	9,779	14,748
Other real estate owned, net	10,626	16,570
Goodwill	51,975	51,975
Other intangible assets, net	16,756	19,826
Bank-owned life insurance	5,718	6,557
Deferred tax assets, net	49,963	67,760
Due from counterparty	39,824
Other assets	16,106	18,367
Total assets	3,366,130	3,295,830
LIABILITIES
Non-interest bearing demand deposits	760,887	724,457
Interest bearing deposits:
NOW, savings accounts, and money market accounts	973,685	989,421
Time deposits	708,757	776,516
Total deposits	2,443,329	2,490,394
Accrued interest payable	1,306	2,427
Line of credit		20,650
Federal Home Loan Bank advances	361,506	313,715
Securities sold under agreements to repurchase	31,187	17,249
Junior subordinated debentures issued to capital trusts, net	27,647	26,926
Accrued expenses and other liabilities	42,577	41,811
Total liabilities	2,907,552	2,913,172
COMMITMENTS AND CONTINGENT LIABILITIES (Note 17)
STOCKHOLDERS’ EQUITY (Note 25)
Preferred stock	10,438	25,441
Common stock, voting $0.01 par value at December 31, 2017 and no par value at December 31, 2016; 150,000,000 shares authorized at December 31, 2017 and 2016; 29,317,298 shares issued and outstanding at December 31, 2017 and 24,616,706 issued and outstanding at December 31, 2016	292
Additional paid-in capital	391,586	313,552
Retained earnings	61,349	50,933
Accumulated other comprehensive loss, net of tax	(5,087)	(7,268)
Total stockholders’ equity	458,578	382,658
Total liabilities and stockholders’ equity	$ 3,366,130	$ 3,295,830

CONSOLIDATED STATEMENTS OF FIN3

CONSOLIDATED STATEMENTS OF FINANCIAL CONDITION (Parenthetical) $ in Thousands	Dec. 31, 2016USD ($)$ / sharesshares
Statement Of Financial Position [Abstract]
Securities held-to-maturity, fair value | $	$ 138,082
Common stock, voting no par value | $ / shares	$ 0
Common stock, voting shares authorized	150,000,000
Common stock, voting shares issued	24,616,706
Common stock, voting shares outstanding	24,616,706

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
INTEREST AND DIVIDEND INCOME
Interest and fees on loans and leases	$ 120,406,000	$ 83,150,000	$ 69,621,000
Interest on taxable securities	14,892,000	14,169,000	12,799,000
Interest on tax-exempt securities	634,000	653,000	651,000
Other interest and dividend income	871,000	393,000	192,000
Total interest and dividend income	136,803,000	98,365,000	83,263,000
INTEREST EXPENSE
Deposits	7,736,000	4,580,000	4,313,000
Federal Home Loan Bank advances	3,291,000	706,000	23,000
Subordinated debentures and other borrowings	2,864,000	2,461,000	2,295,000
Total interest expense	13,891,000	7,747,000	6,631,000
Net interest income	122,912,000	90,618,000	76,632,000
PROVISION FOR LOAN AND LEASE LOSSES	12,653,000	10,352,000	6,966,000
Net interest income after provision for loan and lease losses	110,259,000	80,266,000	69,666,000
NON-INTEREST INCOME
Fees and service charges on deposits	5,289,000	5,665,000	5,803,000
Servicing fees	3,658,000	1,906,000	0
ATM and interchange fees	5,840,000	5,856,000	6,101,000
Net gains on sales of securities available-for-sale	8,000	3,227,000	3,064,000
Net gains on sales of loans	33,062,000	4,323,000	3,151,000
Other non-interest income	2,201,000	4,927,000	2,720,000
Total non-interest income	50,058,000	25,904,000	20,839,000
NON-INTEREST EXPENSE
Salaries and employee benefits	67,269,000	50,585,000	45,960,000
Occupancy expense, net	14,078,000	14,330,000	15,995,000
Equipment expense	2,472,000	2,032,000	2,359,000
Loan and lease related expenses	3,685,000	2,004,000	(21,000)
Legal, audit and other professional fees	7,027,000	5,862,000	7,089,000
Data processing	9,539,000	8,157,000	7,033,000
Net (gain) loss recognized on other real estate owned and other related expenses	(294,000)	1,719,000	7,792,000
Regulatory assessments	1,193,000	2,553,000	3,316,000
Other intangible assets amortization expense	3,074,000	3,003,000	2,980,000
Advertising and promotions	1,035,000	623,000	1,570,000
Telecommunications	1,593,000	1,698,000	1,643,000
Other non-interest expense	8,852,000	8,120,000	9,456,000
Total non-interest expense	119,523,000	100,686,000	105,172,000
INCOME (LOSS) BEFORE PROVISION FOR INCOME TAXES	40,794,000	5,484,000	(14,667,000)
PROVISION (BENEFIT) FOR INCOME TAXES	19,099,000	(61,245,000)	307,000
NET INCOME (LOSS)	21,695,000	66,729,000	(14,974,000)
Dividends on preferred shares	11,277,000
INCOME AVAILABLE (LOSS ATTRIBUTABLE) TO COMMON STOCKHOLDERS	$ 10,418,000	$ 66,729,000	$ (14,974,000)
EARNINGS (LOSS) PER COMMON SHARE
Basic	$ 0.39	$ 3.31	$ (0.86)
Diluted	$ 0.38	$ 3.27	$ (0.86)

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) AND CONSOLIDATED STATEMENTS OF CHANGES IN ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) - USD ($)	3 Months Ended				12 Months Ended
	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Net income (loss)	$ (766,000)	$ 6,560,000	$ 63,915,000	$ (1,352,000)	$ 21,695,000	$ 66,729,000	$ (14,974,000)
Securities available-for-sale
Unrealized holding losses (gains) arising during the period					2,111,000	(3,100,000)	(3,804,000)
Reclassification adjustments for net gains included in net income (loss)					(8,000)	(3,227,000)	(3,064,000)
Tax effect					(602,000)	2,533,000
Net of tax					1,501,000	(3,794,000)	(6,868,000)
Cash flow hedges
Unrealized holding gains arising during the period					688,000	3,684,000
Reclassification adjustments for losses included in net income (loss)					579,000	40,000
Tax effect					(587,000)	(1,491,000)
Net of tax					680,000	2,233,000
Beginning balance		382,658,000		188,274,000	382,658,000	188,274,000	209,071,000
Total other comprehensive income (loss)					2,181,000	(1,561,000)	(6,868,000)
Ending balance	458,578,000		382,658,000		458,578,000	382,658,000	188,274,000
Comprehensive income (loss)					23,876,000	65,168,000	(21,842,000)
Gains (Losses) on Cash Flow Hedges
Cash flow hedges
Beginning balance		2,233,000			2,233,000
Total other comprehensive income (loss)					680,000	2,233,000
Ending balance	2,913,000		2,233,000		2,913,000	2,233,000
Unrealized Gains (Losses) on Available-for-Sale Securities
Cash flow hedges
Beginning balance		(9,501,000)		(5,707,000)	(9,501,000)	(5,707,000)	1,161,000
Total other comprehensive income (loss)					1,501,000	(3,794,000)	(6,868,000)
Ending balance	(8,000,000)		(9,501,000)		(8,000,000)	(9,501,000)	(5,707,000)
Total Accumulated Other Comprehensive Income (Loss)
Cash flow hedges
Beginning balance		$ (7,268,000)		$ (5,707,000)	(7,268,000)	(5,707,000)	1,161,000
Total other comprehensive income (loss)					2,181,000	(1,561,000)	(6,868,000)
Ending balance	$ (5,087,000)		$ (7,268,000)		$ (5,087,000)	$ (7,268,000)	$ (5,707,000)

CONSOLIDATED STATEMENTS OF CHAN

CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS EQUITY - USD ($) $ in Thousands	Total	Preferred Stock	Common Stock	Additional Paid-In Capital	Retained Earnings (Accumulated Deficit)	Accumulated Other Comprehensive Income (Loss)
Beginning balance at Dec. 31, 2014	$ 209,071	$ 15,003		$ 193,729	$ (822)	$ 1,161
Beginning balance, shares at Dec. 31, 2014		15,003	17,332,775
Net income (loss)	(14,974)				(14,974)
Other comprehensive income (loss), net of tax	(6,868)					(6,868)
Share-based compensation expense	1,045			1,045
Ending balance at Dec. 31, 2015	188,274	$ 15,003		194,774	(15,796)	(5,707)
Ending balance, shares at Dec. 31, 2015		15,003	17,332,775
Net income (loss)	66,729				66,729
Other comprehensive income (loss), net of tax	(1,561)					(1,561)
Issuance of common stock, net of issuance cost	49,592			49,592
Issuance of common stock, net of issuance cost, shares			3,078,075
Issuance of common stock due to business combination	68,247			68,247
Issuance of common stock due to business combination, shares			4,199,791
Issuance of preferred stock	9,388	$ 9,388
Issuance of preferred stock, shares		9,388
Subscription of preferred stock	1,050	$ 1,050
Subscription of preferred stock, shares		1,050
Share-based compensation expense	899			899
Exercise of stock options, net of tax	40			40
Exercise of stock options, net of tax, shares			6,065
Ending balance at Dec. 31, 2016	382,658	$ 25,441		313,552	50,933	(7,268)
Ending balance, shares at Dec. 31, 2016		25,441	24,616,706
Net income (loss)	21,695				21,695
Other comprehensive income (loss), net of tax	2,181					2,181
Issuance of common stock in connection with reincorporation merger			$ 246	(246)
Repurchase of preferred stock	(15,003)	$ (15,003)
Repurchase of preferred stock, shares		(15,003)
Issuance of common stock, net of issuance cost	76,829		$ 46	76,783
Issuance of common stock, net of issuance cost, shares			4,630,194
Issuance of common stock in connection with restricted stock awards, shares			70,798
Forfeiture of restricted stock awards, shares			(400)
Cash dividends declared on preferred stock	(11,277)				(11,277)
Cash paid in lieu of fractional shares	(2)				(2)
Share-based compensation expense	1,497			1,497
Ending balance at Dec. 31, 2017	$ 458,578	$ 10,438	$ 292	$ 391,586	$ 61,349	$ (5,087)
Ending balance, shares at Dec. 31, 2017		10,438	29,317,298

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
CASH FLOWS FROM OPERATING ACTIVITIES
Net income (loss)	$ 21,695,000	$ 66,729,000	$ (14,974,000)
Adjustments to reconcile net income to net cash from operating activities:
PROVISION FOR LOAN AND LEASE LOSSES	12,653,000	10,352,000	6,966,000
Impairment loss on premises and equipment		327,000	687,000
Impairment loss on assets held for sale	951,000	408,000
Depreciation and amortization of premises and equipment	5,193,000	5,060,000	5,800,000
Net amortization of securities	4,670,000	7,090,000	7,969,000
Net gains on sales of securities available-for-sale	(8,000)	(3,227,000)	(3,064,000)
Net losses on sales or disposals of premises and equipment	110,000	20,000	197,000
Net losses (gains) on sales of assets held for sale	217,000	(967,000)
Net gains on sales of loans	(33,062,000)	(4,323,000)	(3,151,000)
Originations of mortgage loans held for sale	(4,000)	(5,687,000)	(3,805,000)
Proceeds from mortgage loans sold	155,000	6,003,000	3,888,000
Originations of government guaranteed loans	(293,615,000)	(35,949,000)
Proceeds from government guaranteed loans sold	309,164,000	30,624,000
Accretion of premiums and discounts on acquired loans, net	(32,992,000)	(33,179,000)	(42,998,000)
Net change in servicing assets	(309,000)	(796,000)
Net valuation adjustments on other real estate owned	460,000	953,000	9,265,000
Net gains on sales of other real estate owned	(2,147,000)	(1,364,000)	(5,828,000)
Amortization of intangible assets	3,074,000	3,003,000	2,980,000
Amortization of time deposit premium	(778,000)	(590,000)	(143,000)
Amortization of Federal Home Loan Bank advances premium	(209,000)	(44,000)
Accretion of junior subordinated debentures discount	721,000	876,000	944,000
Share-based compensation expense	1,497,000	899,000	1,045,000
Exercise of share-based awards		40,000
Deferred tax provision (benefit), net of valuation	16,604,000	(61,503,000)
Increase in cash surrender value of bank owned life insurance	(247,000)	(223,000)	(209,000)
Gain on death benefit of bank owned life insurance	(313,000)
Changes in assets and liabilities:
Accrued interest receivable	(799,000)	(503,000)	(978,000)
Other assets	(350,000)	(3,950,000)	(843,000)
Accrued interest payable	(1,121,000)	1,355,000	(4,521,000)
Accrued expenses and other liabilities	(9,095,000)	(7,655,000)	(2,700,000)
Net cash provided by (used in) operating activities	2,115,000	(26,221,000)	(43,473,000)
CASH FLOWS FROM INVESTING ACTIVITIES
Purchases of securities available-for-sale	(53,480,000)	(557,527,000)	(856,768,000)
Proceeds from maturities and calls of securities available-for-sale	7,917,000	95,412,000	103,274,000
Proceeds from paydowns of securities available-for-sale	69,320,000	105,837,000	144,158,000
Proceeds from sales of securities available-for-sale	8,000	534,418,000	511,028,000
Purchases of securities held-to-maturity		(59,436,000)	(120,498,000)
Proceeds from maturities and calls of securities held-to-maturity	655,000	30,469,000	15,155,000
Proceeds from paydowns of securities held-to-maturity	19,747,000
Purchases of Federal Home Loan Bank stock	(19,485,000)	(6,454,000)	(124,000)
Federal Home Loan Bank stock repurchases	18,135,000
Proceeds from other loans sold	9,984,000	2,213,000	27,606,000
Net change in loans and leases	(107,830,000)	(420,065,000)	(48,662,000)
Purchases of premises and equipment	(2,538,000)	(5,948,000)	(4,019,000)
Proceeds from sales of premises and equipment		1,156,000	1,354,000
Proceeds from sales of assets held for sale	5,373,000	2,566,000
Proceeds from sales of other real estate owned	13,898,000	17,306,000	38,563,000
Proceeds from bank owned life insurance death benefit	1,399,000
Net cash paid in acquisition of business		(11,273,000)
Net cash (used in) investing activities	(36,897,000)	(271,326,000)	(188,933,000)
CASH FLOWS FROM FINANCING ACTIVITIES
Net increase (decrease) in deposits	(46,287,000)	(51,010,000)	80,710,000
Proceeds from Federal Home Loan Bank advances	3,037,000,000	6,512,100,000	1,943,500,000
Repayments of Federal Home Loan Bank advances	(2,989,000,000)	(6,246,114,000)	(1,905,500,000)
Proceeds from line of credit		30,000,000
Repayments of line of credit	(20,650,000)	(9,350,000)
Net increase in securities sold under agreements to repurchase	13,938,000	4,590,000	1,927,000
Dividends paid on preferred stock	(11,277,000)
Cash paid in lieu of fractional shares	(2,000)
Proceeds from issuance of common stock	76,829,000	49,592,000
Proceeds from issuance of preferred stock	1,050,000	9,388,000
Repurchase of preferred stock	(15,003,000)
Net cash provided by financing activities	46,598,000	299,196,000	120,637,000
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	11,816,000	1,649,000	(111,769,000)
CASH AND CASH EQUIVALENTS, beginning of period	46,533,000	44,884,000	156,653,000
CASH AND CASH EQUIVALENTS, end of period	58,349,000	46,533,000	44,884,000
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION:
Cash paid during the period for interest	15,279,000	6,150,000	10,351,000
Cash payments (refunds) during the period for taxes	2,849,000	(250,000)
SUPPLEMENTAL DISCLOSURES OF NON-CASH INVESTING AND FINANCING ACTIVITIES:
Change in fair value of available-for-sale securities, net of tax	1,501,000	(3,794,000)	(6,868,000)
Change in fair value of cash flow hedges, net of tax	680,000	2,233,000
Delayed payments of mortgage-backed securities	311,000	121,000	2,228,000
Due to broker	9,838,000	9,978,000	10,000,000
Due from counterparties	39,824,000
Transfers of loans to loans held for sale	10,061,000	1,477,000	65,074,000
Transfers of loans to other real estate owned	6,266,000	6,672,000	13,792,000
Internally financed loan sale			40,252,000
Internally financed sale of other real estate owned		1,447,000	1,259,000
Internally financed sale of assets held for sale	1,800,000
Transfers of land and premises to assets held for sale	3,372,000	14,496,000	$ 2,259,000
Subscription receivable of preferred stock		1,050,000
Total assets acquired from acquisition		456,153,000
Total liabilities assumed from acquisition		377,440,000
Common stock issued due to acquisition of business		$ 68,247,000
Transfers of premises and equipment to other assets	$ 713,000

Business and Summary of Signifi

Business and Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2017
Business Description And Accounting Policies [Abstract]
Business and Summary of Significant Accounting Policies	Note 1—Business and Summary of Significant Accounting Policies Nature of business —Byline Bancorp, Inc. (the “Company,” “we,” “us,” “our”) is a bank holding company whose principal activity is the ownership and management of its subsidiary bank, Byline Bank (the “Bank”). The Bank originates commercial, mortgage and consumer loans and leases, government guaranteed loans, and receives deposits from customers located primarily in the Chicago, Illinois metropolitan area. The Bank operates 55 Chicago metropolitan area and one Brookfield, Wisconsin, banking offices. The Bank operates under an Illinois state bank charter, provides a full range of banking services, and has full trust powers. As an Illinois state‑chartered financial institution that is not a member of the Federal Reserve System, the Bank is subject to regulation by the Illinois Department of Financial and Professional Regulation and the Federal Deposit Insurance Corporation. The Company is regulated by the Board of Governors of the Federal Reserve System. On June 28, 2013, the Company completed an external recapitalization involving a series of transactions that included the merging of the Company’s multiple subsidiary banks into the Bank. In connection with the merger of the subsidiary banks at the time of recapitalization, the Company entered into certain Conditions and Commitments to the merger and integration of the banks, which contained on‑going requirements related to payment of dividends, execution of an integration plan, director and senior officer appointments, changes in responsibilities, and reporting requirements. The Company accounted for the external recapitalization as a business combination in accordance with Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) Topic 805, Business Combinations. The transaction qualified as a recapitalization under Section 368(a)(1)(E) of the Internal Revenue Code and resulted in carryover treatment of the existing tax bases and tax loss carryforwards. As a result of its acquisition of Ridgestone Financial Services, Inc. (“Ridgestone”) on October 14, 2016, the Bank is a participant in the Small Business Administration (“SBA”) and the United States Department of Agriculture (“USDA”) (collectively referred to as “government guaranteed loans”) lending programs and originates government guaranteed loans. See Note 3—Acquisition of a Business for additional information regarding the transaction. The Bank also engages in short‑term direct financing lease contracts through BFG Corporation, doing business as Byline Financial Group (“BFG”), a wholly‑owned subsidiary of the Bank. BFG is located in Bannockburn, Illinois with sales offices in Texas, North Carolina and New York, and sales representatives in Florida, New Jersey, Michigan and Arizona. On June 14, 2017, stockholders of record as of May 22, 2017 voted to approve an Agreement and Plan of Merger between Byline Bancorp, Inc., an Illinois corporation (“Byline Illinois”), and Byline Bancorp, Inc., a wholly owned Delaware subsidiary of the Company, including the amended and restated certificate of incorporation and by‑laws of the Company. Each share of Byline Illinois common stock issued and outstanding immediately prior to the effective time of the Merger was converted automatically into the right to receive one fifth (0.20) of a share of common stock of the Company. Stockholders were paid a total of $2,000 in cash for remaining fractional shares based on the offering price of $19.00 per share. On November 27, 2017, Byline Bancorp, Inc., First Evanston Bancorp, Inc. (which we refer to as “First Evanston”), and Wildcat Acquisition Corporation, a wholly owned subsidiary of Byline (which we refer to as “Merger Sub”), entered into an Agreement and Plan of Merger (which we refer to as the “merger agreement”), that provides for the merger of Merger Sub with and into First Evanston, with First Evanston as the surviving corporation (which we refer to as the “merger”). Immediately following the merger, First Evanston will merge with and into Byline, with Byline as the surviving corporation (which we refer to as the “parent merger”) and immediately following the parent merger, First Bank & Trust, First Evanston’s wholly owned bank subsidiary (which we refer to as “First Bank & Trust”), will merge with and into the Bank, with the Bank as the surviving bank (which we refer to as the “bank merger”). At such time, First Bank & Trust’s banking offices will become banking offices of the Bank. The above described mergers are anticipated to be completed during the first half of 2018, subject to the satisfaction or waiver of the conditions included in the merger agreement. Basis of financial statement presentation and consolidation —The consolidated financial statements include the accounts of the Company and its subsidiaries. Significant intercompany items and transactions have been eliminated in consolidation. The accounting and reporting policies of the Company conform to accounting principles generally accepted in the United States of America (“GAAP”) as contained within the FASB’s ASC and rules and regulations of the Securities and Exchange Commission (“SEC”), including the instructions to Regulation S‑X. In accordance with applicable accounting standards, the Company does not consolidate statutory trusts established for the sole purposes of issuing trust preferred securities and related trust common securities. See Note 15, Junior Subordinated Debentures, for additional discussion. Dollars within footnote tables disclosed within the consolidated financial statements are presented in thousands, except share and per share data. Operating results include the years ended December 31, 2017, 2016 and 2015. Note 1—Business and Summary of Significant Accounting Policies (continued) Use of estimates —In preparing the consolidated financial statements, management is required to make estimates and assumptions that affect the reported amounts of certain assets and liabilities and the disclosure of contingent assets and liabilities as of the date of the Consolidated Statements of Financial Condition and certain revenues and expenses for the periods included in the Consolidated Statements of Operations and the accompanying notes. Actual results could differ from those estimates. Estimates that are particularly susceptible to significant changes in the near term relate to the determination of expected cash flows of acquired impaired loans, the allowance for loan and lease losses, valuation of servicing assets, fair value measurements for assets and liabilities, goodwill, other intangible assets, the valuation or recognition of deferred tax assets and liabilities, and the valuation of assets and liabilities acquired in business combinations. Business combinations —The Company accounts for business combinations under the acquisition method of accounting in accordance with ASC Topic 805, Business Combinations (“ASC 805”). The Company recognizes the fair value of the assets acquired and liabilities assumed as of the date of acquisition, with any excess of the fair value of consideration provided over the fair value of the identifiable net tangible and intangible assets acquired recorded as goodwill. Transaction costs are immediately expensed. The results of operations of the acquired business are included in the Consolidated Statements of Operations from the effective date of the acquisition, which is the date control is obtained. In accordance with ASC 805, the acquiring company retains the right to make appropriate adjustments to the assets and liabilities of the acquired entity for information obtained during the measurement period about facts and circumstances that existed as of the acquisition date. The measurement period ends as of the earlier of (a) one year from the acquisition date or (b) the date when the acquirer receives the information necessary to complete the business combination accounting. Cash and cash equivalents —Cash and cash equivalents have original maturities of three months or less. The Company holds cash and cash equivalents on deposit with other banks and financial institutions in amounts that periodically exceed the federal deposit insurance limit. The Company evaluates the credit quality of these banks and financial institutions to mitigate its credit risk and has not experienced any losses in such accounts. Cash on hand or on deposit with the Federal Reserve Bank of Chicago was required to meet regulatory reserve and clearing requirements. The reserve requirement was $15.8 million and $14.1 million as of December 31, 2017 and 2016, respectively, and the Bank met the requirement at each balance sheet date. Securities —Securities that are held principally for resale in the near term are classified as trading and recorded at fair value with changes in fair value included in earnings. The Company did not invest in securities classified as trading during 2017 and 2016. Securities are classified as available‑for‑sale if the instrument may be sold in response to such factors including changes in market interest rates and related changes in prepayment risk, needs for liquidity, changes in the availability of and the yield on alternative instruments, and changes in funding sources and terms. Gains or losses on the sales of available‑for‑sale securities are recorded on the trade date and determined using the specific‑identification method. Unrealized holding gains or losses, net of tax, on available‑for‑sale securities are carried as accumulated other comprehensive income (loss) within stockholders’ equity until realized. Securities are classified as held‑to‑maturity and carried at amortized cost when management has the positive intent and ability to hold them to maturity. Fair values of securities are generally based on quoted market prices for the same or similar instruments. See Note 18—Fair Value Measurement for additional discussion on the determination of fair values. Interest income includes the amortization of purchase premiums and discounts, which are recognized using the effective interest method over the terms of the securities. Management evaluates securities for other‑than‑temporary impairment (“OTTI”) on a quarterly basis, and more frequently when economic or market conditions warrant such evaluation. The evaluation is based upon factors such as the creditworthiness of the issuers or guarantors, the underlying collateral, if applicable, and the continuing performance of the securities. Management also evaluates other facts and circumstances that may be indicative of an OTTI condition. This includes, but is not limited to, an evaluation of the type of security, length of time and extent to which the fair value has been less than cost, and near‑term prospects of the issuer. The Company’s assessment of OTTI considers whether it intends to sell a security or if it is likely that it would be required to sell the security before recovery of the amortized cost basis of the investment, which may be at maturity. For debt securities, if the Company intends to sell the security or it is more likely than not that it will be required to sell the security before recovering its cost basis, the entire impairment loss is recognized in earnings as an OTTI. If the Company does not intend to sell the security and it is more likely Note 1—Business and Summary of Significant Accounting Policies (continued) than not that it will not be required to sell the security, and the Company does not expect to recover the entire amortized cost basis of the security, only the portion of the impairment loss representing credit losses would be recognized in earnings. The credit loss on a security is measured as the difference between the amortized cost basis and the present value of the cash flows expected to be collected. Projected cash flows are discounted by the original or current effective interest rate depending on the nature of the security being measured for potential OTTI. The remaining impairment related to all other factors, the difference between the present value of the cash flows expected to be collected and fair value, is recognized as a charge to other comprehensive income (loss). Restricted stock —The Company owns stock of the Federal Home Loan Bank of Chicago (“FHLB”). No ready market exists for this stock, and it has no quoted market value. As a member of the FHLB system, the Bank is required to maintain an investment in FHLB stock. The stock is redeemable at par by the FHLB and is, therefore, carried at cost. In addition, the Company owns stock of Bankers Bank that was acquired as part of the Ridgestone transaction. The stock is redeemable at par and carried at cost. Restricted stock is generally viewed as a long‑term investment. Accordingly, when evaluating for impairment, its value is determined based on the ultimate recoverability of the par value rather than by recognizing temporary declines in value. The Company did not recognize impairment of its restricted stock as a result of its impairment analyses for the years ended December 31, 2017 and 2016. Loans held for sale —Loans that management has the intent and ability to sell are designated as held for sale. Government guaranteed loans and mortgage loans originated are carried at either amortized cost or estimated fair value. The Company determines whether to account for loans at fair value or amortized cost at origination. The loans accounted for at fair value remain at fair value after the determination. The loans accounted for at amortized cost are carried at the lower of cost or fair value, valued on a loan by loan basis. Net unrealized losses, if any, are recorded as a valuation allowance and charged to earnings. Gains or losses on sales of government guaranteed loans are recognized based on the difference between the net sales proceeds, carrying value of the sold loan, fair value of the servicing asset recognized, and fair value of the retained loan (if any), and are reflected as operating activities in the Consolidated Statements of Cash Flows. The difference between the initial carrying balance of the retained loan and the relative fair value is recorded as a discount to the retained loan, establishing a new carrying balance. The recorded discount is accreted to earnings on a level yield basis. Government guaranteed loans are generally sold with servicing retained. Loans transferred to loans held for sale are carried at the lower of cost or fair value, less estimated costs to sell. At the time of transfer, write‑downs are recorded as charge‑offs, establishing a new cost basis. Any subsequent adjustments are determined on an individual loan basis and are recognized as a charge to non‑interest income. Sales proceeds received that are in excess of the new cost basis within 90 days are recorded to the allowance for loan and lease losses, up to the amount previously charged off. Any remaining proceeds are recorded as a gain on sale and included in non‑interest income. Sales proceeds that are less than the new cost basis upon transfer and are received within 90 days of classifying the loans as held for sale are recorded as a charge‑off to the allowance for loan and lease losses. Any proceeds received after 90 days of classifying the loans as held for sale are recorded as a gain or loss on sale and included in other non‑interest income. Loans held for sale that have not yet settled as of year-end are classified as due-from counterparty on the consolidated statement of financial condition. Originated loans —Originated loans are stated at the amount of unpaid principal outstanding, net of purchase premiums and discounts, and any deferred fees or costs. Net deferred fees, costs, discounts and premiums are recognized as yield adjustments over the contractual life of the loan. Interest on loans is calculated daily based on the principal amount outstanding. Originated loans are classified as impaired when, based on current information and events, it is probable that the Company will be unable to collect the scheduled payments of principal and interest when due, in accordance with the terms of the original loan agreement. The carrying value of impaired loans is based on the present value of expected future cash flows (discounted at each loan’s effective interest rate) or, for collateral dependent loans, at the fair value of the collateral less estimated selling costs. If the measurement of each impaired loan’s value is less than the recorded investment in the loan, impairment is recognized and the carrying value of the loan is adjusted in the allowance for loan and lease losses as a specific component provided or through a charge‑off of the impaired portion of the loan. Accrual of interest on impaired loans is discontinued when the loan is 90 days past due or when, in management’s opinion, the borrower may be unable to make payments as they become due. When the accrual of interest is discontinued, all unpaid accrued interest is reversed through interest income. Payments received during the time a loan is on non‑accrual status are applied to principal. Interest income is not recognized until the loan is returned to accrual status or after the principal balance is paid in full. Loans are Note 1—Business and Summary of Significant Accounting Policies (continued) returned to accrual status when all the principal and interest amounts contractually due are brought current and future payments are reasonably assured as evidenced by agreed upon performance for a period of not less than six months. Troubled debt restructuring —A troubled debt restructuring (“TDR”) is a formal restructuring of a loan in which the Company, for economic or legal reasons related to the borrower’s financial difficulties, grants a concession to the borrower. The concessions may be granted in various forms, including providing a below‑market interest rate, reduction in the loan balance or accrued interest, extension of the maturity date, or a combination of these. Troubled debt restructurings are considered to be impaired loans and are subject to the Company’s impaired loan accounting policy. Acquired impaired loans are not subject to TDR accounting. The Company does not accrue interest on a TDR unless it believes collection of all principal and interest under the modified terms is reasonably assured. For a TDR to begin accruing interest, the borrower must demonstrate some level of past performance and the future capacity to perform under the modified terms. Generally, six months of consecutive payment performance under the restructured terms is required before a TDR is returned to accrual status. Direct finance leases —The Company engages in leasing for small‑ticket equipment, software, machinery and ancillary supplies and services to customers under leases that qualify as direct financing leases for financial reporting. Certain leases qualify as operating leases for income tax purposes. Under the direct financing method of accounting, the minimum lease payments to be received under the lease contract, together with the estimated unguaranteed residual values of up to 15% of the cost of the related equipment, are recorded as lease receivables when the lease is signed and funded and the lease property is delivered to the customer. The excess of the minimum lease payments and residual values over the amount financed is recorded as unearned lease income. Unearned lease income is recognized over the term of the lease based on the effective yield interest method. Residual value is the estimated fair market value of the equipment on lease at lease termination. In estimating the equipment’s fair value at lease termination, the Company relies on historical experience by equipment type and manufacturer and, where available, valuations by independent appraisers, adjusted for known trends. The Company’s estimates are for reasonableness; however, the amounts the Company will ultimately realize could differ from the estimated amounts. If the review results in other‑than‑temporary impairment, the impairment is recognized in current period earnings. An upward adjustment of the estimated residual value is not recorded. The policies for delinquency and non‑accrual for direct finance leases are materially consistent with those described for all classes of loan receivables. The Company defers and amortizes certain initial direct costs over the contractual term of the lease as an adjustment to the yield. The unamortized direct costs are recorded as a reduction of unearned lease income. Acquired impaired loans —Loans initially acquired with evidence of credit quality deterioration are accounted for under ASC Topic 310‑30, Accounting for Purchased Loans with Deteriorated Credit Quality (“ASC 310‑30”). These loans are recorded either on a pool or a loan‑by‑loan basis at their estimated fair value where applicable. The Company may aggregate loans into pools based on similar credit risks and predominant risk characteristics such as delinquency status and loan type. Management estimated the fair values of acquired impaired loans at both the Recapitalization date and the Ridgestone acquisition date based on estimated future cash flows. The excess of cash flows expected to be collected over a loan’s carrying value is considered to be the accretable yield and is recognized as interest income over the estimated life of the loan or pool using the effective yield method. The acquisition date estimates of accretable yield may subsequently change due to changes in management’s estimates of timing and amounts of expected cash flows. The excess of the contractual amounts due over the cash flows expected to be collected is considered to be the non‑accretable difference. The non‑accretable difference represents the Company’s estimate of the credit losses expected to occur and is considered in determining the fair value of the loans. Reclassifications between accretable yield and non‑accretable difference represent changes in expected cash flows over the remaining estimated life of the loan or pool. Subsequent increases in expected cash flows over those expected at inception are adjusted through an increase to the accretable yield on a prospective basis. Any subsequent decreases in expected cash flows attributable to credit deterioration are recognized by recording an additional provision for loan losses. Once a pool of loans is assembled, the integrity of the pool is maintained. A loan can only be removed from a pool if either of the following conditions is met: (1) the Company sells, forecloses, or otherwise receives assets in satisfaction of the loan, or (2) the loan is written off. A refinancing or restructuring of a loan does not result in a removal of a loan from a pool. Loan sales are accounted for under ASC Topic 860, Transfers and Servicing (“ASC 860”), when control over the assets have been relinquished. See transfers of financial assets accounting policy. Note 1—Business and Summary of Significant Accounting Policies (continued) Acquired non‑impaired loans and leases —Acquired non‑impaired loans and leases are accounted for under ASC Subtopic 310‑20, Receivables Nonrefundable Fees and Other Costs (“ASC 310‑20”). These loans and leases were individually recorded at fair value at the time of acquisition. The component of fair value representing an adjustment to an asset’s outstanding principal balance is accreted or amortized over the life of the related asset as a yield adjustment. Any previously recognized allowance for loan and lease losses and unearned fees or discounts are not carried over and recognized at the date of acquisition. The balance of the asset is then evaluated periodically pursuant to the Company’s allowance for loan and lease loss accounting policy and any adjustment required for credit risk is recorded within the allowance for loan and lease losses. Allowance for loan and lease losses and reserve for unfunded commitments —The allowance for loan and lease losses is maintained at a level management believes is appropriate to provide for probable loan and lease losses as of the date of the Consolidated Statements of Financial Condition. The allowance for loan and lease losses is increased by a provision for loans and lease losses and decreased by charge‑offs, net of recoveries. Loan and lease losses are charged against the allowance for loan and lease losses when management believes the uncollectibility of a loan or lease balance is confirmed. Subsequent recoveries, if any, are credited to the allowance for loan and lease losses. The allowance for loan and lease losses is based on management’s evaluation of the loan and lease portfolio giving consideration to the nature and volume of the portfolio, the value of the underlying collateral, overall portfolio quality, review of specific problem loans or leases, and prevailing economic conditions that may affect the borrower’s ability to pay. While management uses the best information available to make its evaluation, future adjustments to the allowance for loan and lease losses may be necessary if there are significant changes in economic condition. The allowance for loan and lease losses consists of general and specific components. Allocations of the allowance for loan and lease losses not attributable to acquired impaired loans may be made for specific loans and leases, but the entire allowance is available for any loan and lease that, in management’s judgement, should be charged off. The general component covers loans and leases that are collectively evaluated for impairment. Larger groups of smaller balance homogeneous loans, such as consumer and residential real estate loans, and leases are collectively evaluated for impairment, and accordingly, they are not included in the separately identified impairment disclosures. The general component is based on a trailing 12‑quarter weighted average loss rate for each loan category based on the Company’s historical losses and its peer group and adjusted for qualitative and other economic factors. These factors include (1) changes in lending policies and procedures, including changes in underwriting standards and collections, charge‑off and recovery practices; (2) changes in international, national, regional and local conditions; (3) changes in the nature and volume of the portfolio and terms of the loans and leases; (4) changes in experience, depth and ability of lending management and other relevant staff; (5) changes in the volume and severity of past due loans and leases; (6) changes in the quality of the Company’s loan review system; (7) changes in the value of the underlying collateral for collateral dependent loans and leases; (8) existence and effect of any concentrations of credit and changes in the levels of such concentrations; and (9) the effect of other external factors (i.e., competition, legal and regulatory requirements) on the level of estimated credit losses. Based upon management’s judgement of other factors that fall outside of the predefined qualitative or historical loss rates, the allowance for loan and lease losses may include an unallocated component not included in these predefined factors. The specific component relates to loans that are risk‑rated substandard or worse, and based on current information and events, it is likely that the Company will be unable to collect all amounts due according to the contractual terms of the loan agreement. Factors considered by management in determining the impairment include payment status, collateral value, strength of guarantor, and the probability of collecting scheduled principal and interest payments when due. Loans that experience insignificant payment delays and payment shortfalls generally are not classified as impaired and are reviewed on a case‑by‑case basis. TDRs are individually evaluated for impairment and are measured at the present value of estimated future cash flows using the loan’s effective rate at origination. If a TDR is considered to be a collateral dependent loan, the loan is reported at the fair value of the collateral, less estimated costs to sell. The allowance for loan losses also includes amounts representing decreases in expected cash flows attributable to credit deterioration of acquired impaired loans. The evaluation is inherently subjective, as it requires estimates that are susceptible to significant revision as more information becomes available. A reserve for unfunded commitments is maintained at a level that, in the opinion of management, is sufficient to absorb probable losses associated with the Company’s commitment to lend funds under existing agreements, such as letters or lines of credit. Management determines the appropriate reserve for unfunded commitments based upon reviews of individual credit facilities, current economic conditions, the risk characteristics of the various categories of commitments, and other relevant factors. The reserve for unfunded commitments is based on estimates, and ultimate losses may vary from the current estimates. These estimates are evaluated Note 1—Business and Summary of Significant Accounting Policies (continued) on a quarterly basis and, as adjustments become necessary, they are recognized in earnings in the periods in which they become known. Advances that are considered uncollectible are charged to the reserve for unfunded commitments. Provisions and recoveries of advances previously charged‑off are recognized within the reserve for unfunded commitments, which is included in other liabilities within the Consolidated Statements of Financial Condition. The factors supporting the allowance for loan and lease losses and the reserve for unfunded commitments do not diminish the fact that the entire allowance for loan and lease losses and reserve for unfunded commitments not attributable to acquired impaired loans are each available to absorb losses in the loan and lease portfolios and related commitment portfolio, respectively. The allowance for loan and lease losses and reserve for unfunded commitments are both subject to review by regulatory agencies during examinations and may require us to recognize adjustments to the allowance for loan and lease losses or the reserve for unfunded commitments. Servicing assets —Servicing assets are recognized separately when they are acquired through sales of loans. When loans are sold with servicing rights retained, servicing assets are recorded at fair value in accordance with ASC 860. Fair value is based on market prices for comparable servicing contracts, when available, or alternatively, is based on a valuation model that calculates the present value of estimated future net servicing income. Sales of government guaranteed loans are executed on a servicing retained basis. The standard SBA loan sale agreement is structured to provide the Company with a servicing spread paid from a portion of the interest cash flow of the loan. SBA regulations require the Company to retain a portion of the cash flow from the interest payments received for a sold loan. The USDA loan sale agreements are not standardized with respect to servicing. Servicing fee income, which is reported on the Consolidated Statements of Operations as servicing fees, is recorded for fees earned for servicing loans. The fees are based on a contractual percentage of the outstanding principal. Late fees and ancillary fees related to loan servicing are not material. The Company has elected the fair value measurement method and measures servicing rights at fair value at each reporting date and reports changes in fair value of servicing assets in earnings in the period in which the changes occur, and are included with servicing fees on the Consolidated Statements of Operations. The fair values of servicing rights are subject to significant fluctuations as a result of changes in estimated and actual prepayment speeds, default rates, and losses. Concentrations of credit risk —Most of the Company’s business activity is concentrated with customers located within its principal market areas, with the exception of government guaranteed loans and leasing activities. The Company originates commercial real estate, construction, land development and other land, commercial and industrial, residential real estate, installment and other loans, and leases. Generally, loans are secured by accounts receivable, inventory, deposit accounts, personal property or real estate. Rights to collateral vary and are legally documented to the extent practicable. The Company has a concentration in commercial real estate loans and the ability of borrowers to hon

Recently Issued Accounting Pron

Recently Issued Accounting Pronouncements	12 Months Ended
	Dec. 31, 2017
Accounting Changes And Error Corrections [Abstract]
Recently Issued Accounting Pronouncements	Note 2—Recently Issued Accounting Pronouncements The following reflect recent accounting pronouncements that have been adopted or are pending adoption by the Company. As the Company qualifies as an emerging growth company and has elected the extended transition period for complying with new or revised accounting pronouncements, it is not subject to new or revised accounting standards applicable to public companies during the extended transition period. The accounting pronouncements pending adoption below reflect effective dates for the Company as an emerging growth company with the extended transition period. Revenue from Contracts with Customers —In May 2014, FASB issued Accounting Standards Update (“ASU”) No. 2014‑09, deferred by ASU No. 2015‑14 and clarifying standards, Revenue from Contracts with Customers, which creates Topic 606 and supersedes Topic 605, Revenue Recognition. The core principle of Topic 606 is that an entity recognizes revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. In general, the new guidance requires companies to use more judgment and make more estimates than under current guidance, including identifying performance obligations in the contract, estimating the amount of variable consideration to include in the transaction price and allocating the transaction price to each separate performance obligation. Under the terms of ASU No. 2015‑14 the standard is effective for interim and annual periods beginning after December 15, 2017. For financial reporting purposes, the standard allows for either full retrospective adoption, meaning the standard is applied to all of the periods presented, or modified retrospective adoption, meaning the standard is applied only to the most current period presented in the financial statements with the cumulative effect of initially applying the standard recognized at the date of initial application. The Company is currently evaluating the provisions of ASU No. 2014‑09 to determine the potential impact the standard will have on the Company’s Consolidated Financial Statements. As a financial institution, the Company’s largest component of revenue, interest income, is excluded from the scope of this ASU. The Company is currently evaluating which, if any, of its sources of non‑interest income will be impacted by this ASU. Assuming the Company remains an emerging growth company, the Company expects to adopt this new guidance on January 1, 2019, with a cumulative effect adjustment to opening retained earnings, if such adjustment is deemed to be significant. In April 2016, FASB issued ASU No. 2016‑10, . The amendments in this ASU do not change the core principle of the guidance in Topic 606. Rather, the amendments in this ASU clarify the following two aspects of Topic 606: (1) identifying performance obligations and (2) licensing implementation guidance, while retaining the related principles for those areas. The amendments in this ASU affect the guidance in ASU 2014‑09, discussed above, which is not yet effective. The effective date and transition requirements for the amendments in this ASU are the same as the effective date and transition requirements in Topic 606, . The Company is evaluating the provisions of this ASU in conjunction with ASU No. 2014‑09 to determine the potential impact Topic 606 and its amendments will have on the Company’s Consolidated Financial Statements. In May 2016, FASB issued ASU No. 2016‑12, Narrow‑Scope Improvements and Practical Expedients Revenue from Contracts with Customers In November 2017, FASB issued ASU No. 2017-14, amending ASC Topic 606, Revenue from Contracts with Customers Revenue from Contracts with Customers Customer’s Accounting for Fees Paid in a Cloud Computing Arrangement —In April 2015, FASB issued ASU No. 2015‑05, . The amendments in this ASU provide guidance to customers in cloud computing arrangements about whether a cloud computing arrangement includes a software license. If a cloud computing arrangement includes a software license, the customer should account for the software license element of the arrangement consistent with the acquisition of other software licenses. If a cloud computing arrangement does not include a software license, the customer should account for the arrangement as a service contract. The amendments were effective for annual periods, including interim periods within those annual periods, beginning after December 15, 2015 and were adopted by the Company as of January 1, 2016. This ASU did not have a material effect on the Company’s Consolidated Financial Statements. Note 2—Recently Issued Accounting Pronouncements (continued) Business Combinations—Simplifying the Accounting for Measurement‑Period Adjustments —In September 2015, FASB issued ASU No. 2015‑16, . The amendments in this ASU require that an acquirer recognize adjustments to provisional amounts that are identified during the measurement period in the reporting period when the adjustment amounts are determined. The acquirer is required to record in the same period’s financial statements the effect on earnings from changes in depreciation, amortization, or other income effects resulting from the change to provisional amounts, calculated as if the accounting had been completed at the acquisition date. The acquirer must present separately on the income statement, or disclose in the notes, the amount recorded in current‑period earnings that would have been recorded in previous reporting periods if the provisional amount had been recognized at the acquisition date. The amendments in this ASU were effective for fiscal years beginning after December 15, 2015. The Company adopted this new authoritative guidance on January 1, 2016, and it did not have an impact on the Company’s Consolidated Financial Statements, but may in the future. Recognition and Measurement of Financial Assets and Financial Liabilities —In January 2016, FASB issued ASU No. 2016‑01, . The amendments in this ASU require equity securities to be measured at fair value with changes in the fair value recognized through net income. The amendments allow equity investments that do not have readily determinable fair values to be remeasured at fair value under certain circumstances and require enhanced disclosures about those investments. The amendments simplify the impairment assessment of equity investments without readily determinable fair values. The amendments also eliminate the requirement to disclose the method(s) and significant assumptions used to estimate the fair value that is required to be disclosed for financial instruments measured at amortized cost on the balance sheet. The amendments in this ASU require separate presentation in other comprehensive income of the portion of the total change in the fair value of a liability resulting from a change in the instrument‑specific credit risk when the entity has elected to measure the liability at fair value in accordance with the fair value option for financial instruments. This amendment excludes from net income gains or losses that the entity may not realize because those financial liabilities are not usually transferred or settled at their fair values before maturity. The amendments in this ASU require separate presentation of financial assets and financial liabilities by measurement category and form of financial asset (that is, securities or loans and receivables) on the balance sheet or in the accompanying notes to the financial statements. The amendments in this ASU are effective for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years. The Company is currently evaluating the provisions of ASU No. 2016‑01 to determine the potential impact the new standard will have on the Company’s Consolidated Financial Statements. Assuming the Company remains an emerging growth company, the new authoritative guidance will be effective for reporting periods beginning January 1, 2019 and is not expected to have a significant impact on the Company’s Consolidated Financial Statements. Leases (Topic 842) —In February 2016, FASB issued ASU No. 2016‑02, . The amendments in this ASU require lessees to recognize the following for all leases (with the exception of short‑term) at the commencement date; a lease liability, which is a lessee’s obligation to make lease payments arising from a lease, measured on a discounted basis; and a right‑of‑use asset, which is an asset that represents the lessee’s right to use, or control the use of, a specified asset for the lease term. The amendments in this ASU leave lessor accounting largely unchanged, although certain targeted improvements were made to align lessor accounting with the lessee accounting model. This ASU simplifies the accounting for sale and leaseback transactions primarily because lessees must recognize lease assets and lease liabilities. Lessees will no longer be provided with a source of off‑balance sheet financing. The amendments in this ASU are effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. Early application is permitted upon issuance. Lessees (for capital and operating leases) and lessors (for sales‑type, direct financing, and operating leases) must apply a modified retrospective transition approach for leases existing at, or entered into after, the beginning of the earliest comparative period presented in the financial statements. The modified retrospective approach would not require any transition accounting for leases that expired before the earliest comparative period presented. Lessees and lessors may not apply a full retrospective transition approach. The Company is evaluating the new guidance and its impact on the Company’s Consolidated Statements of Operations and Consolidated Statements of Financial Condition. Assuming the Company remains an emerging growth company, the new authoritative guidance will be effective for reporting periods after January 1, 2020. The Company expects an increase in assets and liabilities as a result of recognizing additional lease contracts where the Company is lessee. Derivatives and Hedging (Topic 815) —In March 2016, FASB issued ASU No. 2016‑05, . The amendments in this ASU clarify that a change in the counterparty to a derivative instrument that has been designated as the hedging instrument under Topic 815 (Derivatives and Hedging) does not, in and of itself, require dedesignation of that hedging relationship provided that all other hedge accounting criteria continue to be met. The amendments in this ASU are effective for financial statements issued for fiscal years beginning after December 15, 2016, and interim periods within those fiscal years. An entity has an option to apply the amendments in this ASU on either a prospective basis or a modified retrospective basis. Early adoption is permitted, including adoption in an interim period. This ASU became effective for the Company on January 1, 2017 and did not have a material impact on the Company’s Consolidated Financial Statements. Note 2—Recently Issued Accounting Pronouncements (continued) In March 2016, FASB issued ASU No. 2016‑06, Contingent Put and Call Options in Debt Instruments In August 2017, FASB issued ASU No. 2017‑12, Targeted Improvements to Accounting for Hedging Activities Compensation—Stock Compensation (Topic 718) —In March 2016, FASB issued ASU No. 2016‑09, . FASB issued this ASU as part of its Simplification Initiative. The areas for simplification in this ASU involve several aspects of the accounting for share‑based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities, and classification on the statement of cash flows. Amendments in this ASU relate to the timing of when excess tax benefits are recognized, minimum statutory withholding requirements, forfeitures, and intrinsic value should be applied using a modified retrospective transition method by means of a cumulative‑effect adjustment to equity as of the beginning of the period in which the guidance is adopted. Amendments related to the presentation of employee taxes paid on the statement of cash flows when an employer withholds shares to meet the minimum statutory withholding requirement should be applied retrospectively. Amendments in this ASU require recognition of excess tax benefits and tax deficiencies in the income statement and the practical expedient for estimating expected term should be applied prospectively. An entity may elect to apply the amendments in this ASU related to the presentation of excess tax benefits on the statement of cash flows using either a prospective transition method or a retrospective transition method. The amendments in this ASU are effective for annual periods beginning after December 15, 2016, and interim periods within those annual periods. This ASU became effective for the Company on January 1, 2017 and did not have a material impact on the Company’s Consolidated Financial Statements. In May 2017, FASB issued ASU No. 2017-09, Scope of Modification Accounting Note 2—Recently Issued Accounting Pronouncements (continued) company, the new authoritative guidance will be effective for reporting periods after January 1, 2019. The Company is evaluating the new guidance and its impact on the Company’s Consolidated Statements of Operations and Consolidated Statements of Financial Condition. . Financial Instruments—Credit Losses (Topic 326) —In June 2016, FASB issued ASU No. 2016‑13, . Current GAAP requires an “incurred loss” methodology for recognizing credit losses that delays recognition until it is probable a loss has been incurred. The main objective of this ASU is to provide financial statement users with more decision‑useful information about the expected credit losses on financial instruments and other commitments to extend credit held by a reporting entity at each reporting date. The amendments in this ASU 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. The amendments in this ASU require a financial asset (or group of financial assets) measured at amortized cost basis to be presented at the net amount expected to be collected. The allowance for credit losses is a valuation account that is deducted from the amortized cost basis of the financial asset(s) to present the net carrying value at the amount expected to be collected on the financial asset. The measurement of expected credit losses will be based on relevant information about past events, including historical experience, current conditions, and reasonable and supportable forecasts that affect the collectability of the reported amount. The amendments in this ASU broaden the information that an entity must consider in developing its expected credit loss estimate for assets measured either collectively or individually. The use of forecasted information incorporates more timely information in the estimate of expected credit loss, which will be more decision useful to users of the financial statements. The amendments in this ASU will be effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. Assuming the Company remains an emerging growth company, the new authoritative guidance will be effective for reporting periods after January 1, 2021. The Company is still evaluating the effects this ASU will have on the Company’s Consolidated Financial Statements. While the Company has not quantified the impact of this ASU, it does expect changing from the current incurred loss model to an expected loss model will result in an earlier recognition of losses. Statement of Cash Flows (Topic 230) —In August 2016, FASB issued ASU No. 2016‑15, . There is diversity in practice in how certain cash receipts and cash payments are presented and classified in the statement of cash flows under Topic 230 and other Topics. This ASU addresses eight specific cash flow issues with the objective of reducing the existing diversity in practice. Those eight issues are (1) debt prepayment or debt extinguishment costs, (2) settlement of zero‑coupon debt instruments or other debt instruments with coupon interest rates that are insignificant in relation to the effective interest rate of the borrowing, (3) contingent consideration payments made 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 investees, (7) beneficial interests in securitization transactions, and (8) separately identifiable cash flows and application of the predominance principle. Current GAAP either is unclear or does not include specific guidance on these eight cash flow classification issues. These amendments provide guidance for each of the eight issues, thereby reducing current and potential future diversity in practice. The amendments in this ASU 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. Assuming the Company remains an emerging growth company, the new authoritative guidance will be effective for reporting periods after January 1, 2019. The Company is currently evaluating the provisions of ASU No. 2016‑15 to determine the potential impact the new standard will have on the Company’s Consolidated Financial Statements. In November 2016, the FASB issued ASU No. 2016‑18, Statement of Cash Flows (230), Restricted Cash Income Taxes (Topic 740) —In October 2016, the FASB issued ASU No. 2016‑16, . The ASU was issued to improve the accounting for income tax consequences of intra‑entity transfers of assets other than inventory. Current GAAP prohibits the recognition of current and deferred income taxes for an intra‑entity asset transfer until the asset has been sold to an outside party; this update clarifies that an entity should recognize the income tax consequences of an intra‑entity transfer of assets other than inventory when the transfer occurs. The amendment is effective for annual Note 2—Recently Issued Accounting Pronouncements (continued) reporting periods beginning after December 15, 2017, and interim periods within those fiscal years. Early adoption of the update is permitted. Assuming the Company remains an emerging growth company, the new authoritative guidance will be effective for reporting periods after January 1, 2019. The Company does not expect this ASU to have a material impact on the Company’s Consolidated Financial Statements. Consolidation (Topic 810)— In October 2016, the FASB issued ASU No. 2016‑17, . The ASU was issued to amend the consolidation guidance on how a reporting entity that is the single decision maker of a variable interest entity (“VIE”) should treat indirect interests in the entity held through related parties that are under common control with the reporting entity when determining whether it is the primary beneficiary of that VIE. The primary beneficiary of a VIE is the reporting entity that has a controlling financial interest in a VIE and, therefore, consolidates the VIE. A reporting entity has an indirect interest in a VIE if it has a direct interest in a related party that, in turn, has a direct interest in the VIE. The amendment is effective for annual reporting periods beginning after December 15, 2016, and interim periods within those fiscal years. Early adoption of the update is permitted. The Company adopted this new authoritative guidance on January 1, 2017 and it did not have an impact on the Company’s Consolidated Financial Statements. Business Combinations (Topic 805) —In January 2017, the FASB issued ASU No. 2017‑01, . The guidance clarifies the definition of a business to assist entities with evaluating whether transactions should be accounted for as acquisitions or disposals of assets or businesses. This guidance is effective for annual and interim periods beginning after December 15, 2017. Early adoption is permitted. Assuming the Company remains an emerging growth company, the new authoritative guidance will be effective for reporting periods after January 1, 2019. The Company does not expect a material impact of this ASU on the Company’s Consolidated Financial Statements. Intangibles—Goodwill and Other (Topic 350) —In January 2017, FASB issued ASU No. 2017‑04, . The amendments in this ASU are intended to reduce the cost and complexity of the goodwill impairment test by eliminating step two from the impairment test. The amendments modify the concept of impairment from the condition that exists when the carrying amount of goodwill exceeds its implied fair value to the condition that exists when the carrying amount of a reporting unit exceeds its fair value. Under the amendments in this ASU, if an entity performs a quantitative annual, or interim, goodwill impairment test by comparing the fair value of the reporting unit with its carrying amount. An impairment charge should be recognized for the amount which the carrying amount exceeds the reporting unit’s fair value; however, the loss recognized should not exceed the total amount of goodwill allocated to that reporting unit. The amendments in this ASU are effective for the Company’s annual or any interim goodwill impairment test in fiscal years beginning after December 15, 2019. Early adoption is permitted for interim or annual goodwill impairment tests performed on testing dates after January 1, 2017. The Company is early adopting these amendments in 2017 and does not expect a material impact on the Company’s Consolidated Financial Statements. Other Income (Subtopic 610‑20) —In February 2017, the FASB issued ASU No. 2017‑05, . This ASU will clarify the scope of Subtopic 610‑20 and add guidance for partial sales of nonfinancial assets. The amendments should be applied either on retrospectively to each period presented or with a modified retrospective approach. The amendment is effective for annual periods beginning after December 15, 2018, and interim periods within annual periods beginning after December 15, 2019. The Company is currently evaluating the provisions of ASU No. 2017‑05 to determine the potential impact the new standard will have on the Company’s Consolidated Financial Statements. Nonrefundable Fees and Other Costs (Subtopic 310‑20) —In March 2017, FASB issued ASU No. 2017‑08, . The amendments in the ASU shorten the amortization period for certain callable debt securities held at a premium at the earliest call date. Under current GAAP, the Company amortizes the premium as an adjustment of yield over the contractual life of the instrument. As a result, upon exercise of a call on a callable debt security held at a premium, the unamortized premium is charged to earnings. The ASU shortens the amortization period for certain callable debt securities held at a premium and requires the premium to be amortized to the earliest call date. However, the amendments do not require an accounting change for securities held at a discount; the discount continues to be amortized to maturity. The amendments are effective for annual periods beginning after December 15, 2019, and interim periods within annual periods beginning after December 15, 2020. Early adoption is permitted. The Company is required to apply the amendments on a modified retrospective basis through a cumulative‑effect adjustment directly to retained earnings as of the beginning of the period of adoption. Assuming the Company remains an emerging growth company, the new authoritative guidance will be effective for reporting periods after January 1, 2020. The Company is currently evaluating the provisions of ASU No. 2017‑08 to determine the potential impact the new standard will have on the Company’s Consolidated Financial Statements. Note 2—Recently Issued Accounting Pronouncements (continued) Earnings Per share (Topic 260), Distinguishing Liabilities from Equity (Topic 480), Derivatives and Hedging (Topic 815 )—In July 2017, FASB issued ASU No. 2017-11, . The ASU simplifies the accounting for certain financial instruments with down round features, a provision in an equity-linked financial instrument (or embedded feature) that provides a downward adjustment of the current exercise price based on the price of future equity offerings. Down round features are common in warrants, convertible preferred shares, and convertible debt instruments. The ASU requires companies to disregard the down round feature when assessing whether the instrument is indexed to its own stock, for purposes of determining liability or equity classification. Companies that provide earnings per share (EPS) data will adjust their basic EPS calculation for the effect of the feature when triggered (i.e., when the exercise price of the related equity-linked financial instrument is adjusted downward because of the down round feature) and will also recognize the effect of the trigger within equity. The amendments are effective for annual periods beginning after December 15, 2019, and interim periods within annual periods beginning after December 15, 2020. Early adoption is permitted. Assuming the Company remains an emerging growth company, the new authoritative guidance will be effective for reporting periods after January 1, 2020. The Company is currently evaluating the provisions of ASU No. 2017‑11 to determine the potential impact the new standard will have on the Company’s Consolidated Financial Statements. Income Statement—Reporting Comprehensive Income (Topic 220) )—In February 2018, FASB issued ASU No.2018-02, . The ASU helps organizations address certain stranded income tax effects in accumulated other comprehensive income (AOCI) resulting from the Tax Cuts and Jobs Act. The ASU provides reporting entities with an option to reclassify stranded tax effects within AOCI to retained earnings in each period in which the effect of the change in the U.S. federal corporate income tax rate in the Tax Cuts and Jobs Act (or portion thereof) is recorded. The ASU requires reporting entities to disclose: a description of the accounting policy for releasing income tax effects from AOCI; whether they elect to reclassify the stranded income tax effects from the Tax Cuts and Jobs Act; and information about the other income tax effects that are reclassified. The amendments affect any organization that is required to apply the provisions of Topic 220, , and has items of other comprehensive income for which the related tax effects are presented in other comprehensive income as required by GAAP. The amendments are effective for annual periods beginning after December 15, 2018, and interim periods within those fiscal years. The Company early adopted the new guidance on January 1, 2018, and determined it will not have a significant impact on the Company’s statements of operations or financial condition.

Acquisition of a Business

Acquisition of a Business	12 Months Ended
	Dec. 31, 2017
Business Combinations [Abstract]
Acquisition of a Business	Note 3—Acquisition of a Business On October 14, 2016, the Company acquired stock of Ridgestone Financial Services, Inc. (“Ridgestone”) and its subsidiaries under the terms of a definitive merger agreement (“Agreement”) dated June 9, 2016. Ridgestone operated two wholly-owned subsidiaries, Ridgestone Bank and RidgeStone Capital Trust I, and specialized in government guaranteed lending as a participant in the SBA and USDA lending programs. Ridgestone provided financial services through its two full-service banking offices in Brookfield, Wisconsin and Schaumburg, Illinois. In addition, Ridgestone had loan production offices located in Wisconsin (Green Bay and Wausau), Indiana (Indianapolis) and California (Newport Beach). Under the terms of the Agreement, each Ridgestone common share was converted into the right to receive, at the election of the shareholder (subject to proration as outlined in the Agreement), either cash or Company common stock, or the combination of both. Total consideration included aggregate cash in the amount of $36.8 million and the issuance of 4,199,791 shares of the Company’s common stock valued at $16.25 per common share. The transaction resulted in goodwill of $26.3 million, which is nondeductible for tax purposes, as this acquisition was a nontaxable transaction. Goodwill represents the premium paid over the fair value of the net tangible and intangible assets acquired and reflects related synergies expected from the combined operations. Acquisition advisory expenses related to the Ridgestone acquisition of $1.6 million are reflected in non‑interest expense on the Consolidated Statements of Operations. Stock issuance costs were not material. There were no contingent assets or liabilities arising from the acquisition. The acquisition of Ridgestone was accounted for using the acquisition method of accounting in accordance with ASC Topic 805. Assets acquired, liabilities assumed and consideration exchanged were recorded at their respective acquisition date fair values. Determining the fair value of assets and liabilities involves significant judgment regarding methods and assumptions used to calculate estimated fair values. The fair value adjustments associated with this transaction were finalized during the fourth quarter of 2017 and required no measurement period adjustments during 2017. Note 3—Acquisition of a Business (continued) The following table presents a summary of the estimates of fair values of assets acquired and liabilities assumed as of the acquisition date: Assets Cash and cash equivalents $ 25,480 Securities available-for-sale 27,662 Restricted stock 931 Loans held for sale 15,363 Loans 351,820 Servicing assets 20,295 Premises and equipment 2,011 Other real estate owned 1,525 Other intangible assets 486 Bank-owned life insurance 2,352 Other assets 8,228 Total assets acquired $ 456,153 Liabilities Deposits $ 361,370 Federal Home Loan Bank advances 9,773 Junior subordinated debentures 1,339 Accrued expenses and other liabilities 4,958 Total liabilities assumed 377,440 Net assets acquired $ 78,713 Consideration paid Common stock (4,199,791 shares issued at $16.25 per share) $ 68,247 Cash paid 36,753 Total consideration paid 105,000 Goodwill $ 26,287 The following table presents the acquired non-impaired loans as of the acquisition date: Fair value $ 312,166 Gross contractual amounts receivable 450,292 Estimate of contractual cash flows not expected to be collected ( 1) 19,661 Estimate of contractual cash flows expected to be collected 430,631 (1) Includes interest payments not expected to be collected due to loan prepayments as well as principal and interest payments not expected to be collected due to customer default. The discount on the acquired non-impaired loans is being accreted into income over the life of the loans on an effective yield basis. Note 3—Acquisition of a Business (continued) The following table provides the pro forma information for the results of operations for the years ended December 31, 2016 and 2015, as if the acquisition had occurred on January 1, 2015. The pro forma results combine the historical results of Ridgestone into the Company’s Consolidated Statements of Operations, including the impact of certain acquisition accounting adjustments, which includes loan discount accretion, intangible assets amortization, deposit premium accretion and borrowing net discount amortization. The pro forma results have been prepared for comparative purposes only and are not necessarily indicative of the results that would have been obtained had the acquisition actually occurred on January 1, 2015. No assumptions have been applied to the pro forma results of operations regarding possible revenue enhancements, provision for credit losses, expense efficiencies or asset dispositions. The acquisition-related expenses that have been recognized are included in net income (loss) in the following table. Years ended December 31, 2016 2015 Total revenues (net interest income and non-interest income) $ 171,059 $ 151,054 Net income (loss) $ 82,252 $ (1,437 ) Earnings per share—basic $ 3.54 $ (0.07 ) Earnings per share—diluted $ 3.50 $ (0.07 ) The operating results of the Company include the operating results produced by the acquired assets and assumed liabilities of Ridgestone for period from October 15, 2016 through December 31, 2017. Revenues and earnings of the acquired company since the acquisition date have not been disclosed as it is not practicable as Ridgestone was merged into the Company and separate financial information is not readily available.

Securities

Securities	12 Months Ended
	Dec. 31, 2017
Investments Debt And Equity Securities [Abstract]
Securities	Note 4—Securities The following tables summarize the amortized cost and fair values of securities available-for-sale and securities held-to-maturity at December 31, 2017 and 2016 and the corresponding amounts of gross unrealized gains and losses: 2017 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Available-for-sale U.S. Treasury Notes $ 14,999 $ — $ (136 ) $ 14,863 U.S. Government agencies 54,248 — (1,290 ) 52,958 Obligations of states, municipalities, and political subdivisions 33,405 100 (335 ) 33,170 Residential mortgage-backed securities Agency 315,103 — (7,646 ) 307,457 Non-agency 39,485 104 (75 ) 39,514 Commercial mortgage-backed securities Agency 70,964 45 (1,966 ) 69,043 Non-agency 31,763 — (792 ) 30,971 Corporate securities 29,573 507 (104 ) 29,976 Other securities 3,627 1,730 (73 ) 5,284 Total $ 593,167 $ 2,486 $ (12,417 ) $ 583,236 Note 4—Securities (continued) 2017 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Held-to-maturity Obligations of states, municipalities, and political subdivisions $ 24,030 $ 197 $ (82 ) $ 24,145 Residential mortgage-backed securities Agency 53,731 79 (203 ) 53,607 Non-agency 39,402 174 (51 ) 39,525 Total $ 117,163 $ 450 $ (336 ) $ 117,277 2016 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Available-for-sale U.S. Treasury Notes $ 14,995 $ 4 $ (79 ) $ 14,920 U.S. Government agencies 60,180 — (1,323 ) 58,857 Obligations of states, municipalities, and political subdivisions 16,271 60 (272 ) 16,059 Residential mortgage-backed securities Agency 376,800 — (8,640 ) 368,160 Non-agency 20,107 — (174 ) 19,933 Commercial mortgage-backed securities Agency 78,954 — (1,551 ) 77,403 Non-agency 32,061 — (1,009 ) 31,052 Corporate securities 17,065 350 (86 ) 17,329 Other securities 4,161 742 (56 ) 4,847 Total $ 620,594 $ 1,156 $ (13,190 ) $ 608,560 2016 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Held-to-maturity Obligations of states, municipalities, and political subdivisions $ 24,878 $ 105 $ (229 ) $ 24,754 Residential mortgage-backed securities Agency 67,692 35 (283 ) 67,444 Non-agency 46,276 50 (442 ) 45,884 Total $ 138,846 $ 190 $ (954 ) $ 138,082 The Company did not classify securities as trading during 2017 and 2016. Note 4—Securities (continued) Gross unrealized losses and fair values, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position as of December 31, 2017 and 2016 are summarized as follows: Less than 12 Months 12 Months or Longer Total 2017 # of Securities Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses Available-for-sale U.S. Treasury Notes 5 $ 4,998 $ (2 ) $ 9,865 $ (134 ) $ 14,863 $ (136 ) U.S. Government agencies 9 992 (7 ) 51,966 (1,283 ) 52,958 (1,290 ) Obligations of states, municipalities and political subdivisions 29 16,059 (137 ) 4,453 (198 ) 20,512 (335 ) Residential mortgage-backed securities Agency 41 15,441 (181 ) 292,016 (7,465 ) 307,457 (7,646 ) Non-agency 1 — — 4,565 (75 ) 4,565 (75 ) Commercial mortgage-backed securities Agency 7 — — 57,442 (1,966 ) 57,442 (1,966 ) Non-agency 5 — — 30,971 (792 ) 30,971 (792 ) Corporate securities 3 2,406 (80 ) 2,489 (24 ) 4,895 (104 ) Other securities 1 — — 1,921 (73 ) 1,921 (73 ) Total 101 $ 39,896 $ (407 ) $ 455,688 $ (12,010 ) $ 495,584 $ (12,417 ) Less than 12 Months 12 Months or Longer Total 2017 # of Securities Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses Held-to-maturity Obligations of states, municipalities, and political subdivisions 12 $ 7,409 $ (38 ) $ 1,548 $ (44 ) $ 8,957 $ (82 ) Residential mortgage-backed securities Agency 13 24,344 (107 ) 7,935 (96 ) 32,279 (203 ) Non-agency 3 10,458 (10 ) 4,382 (41 ) 14,840 (51 ) Total 28 $ 42,211 $ (155 ) $ 13,865 $ (181 ) $ 56,076 $ (336 ) Note 4—Securities (continued) Less than 12 Months 12 Months or Longer Total 2016 # of Securities Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses Available-for-sale U.S. Treasury Notes 3 $ 9,918 $ (79 ) $ — $ — $ 9,918 $ (79 ) U.S. Government agencies 10 58,857 (1,323 ) — — 58,857 (1,323 ) Obligations of states, municipalities and political subdivisions 14 7,799 (259 ) 115 (13 ) 7,914 (272 ) Residential mortgage-backed securities Agency 41 364,713 (8,483 ) 3,447 (157 ) 368,160 (8,640 ) Non-agency 2 19,933 (174 ) — — 19,933 (174 ) Commercial mortgage-backed securities Agency 8 70,762 (1,488 ) 6,641 (63 ) 77,403 (1,551 ) Non-agency 5 31,052 (1,009 ) — — 31,052 (1,009 ) Corporate securities 4 5,097 (78 ) 2,522 (8 ) 7,619 (86 ) Other securities 1 — — 1,994 (56 ) 1,994 (56 ) Total 88 $ 568,131 $ (12,893 ) $ 14,719 $ (297 ) $ 582,850 $ (13,190 ) Less than 12 Months 12 Months or Longer Total 2016 # of Securities Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses Held-to-maturity Obligations of states, municipalities, and political subdivisions 22 $ 16,235 $ (229 ) $ — $ — $ 16,235 $ (229 ) Residential mortgage-backed securities Agency 15 52,156 (283 ) — — 52,156 (283 ) Non-agency 5 29,245 (442 ) — — 29,245 (442 ) Total 42 $ 97,636 $ (954 ) $ — $ — $ 97,636 $ (954 ) Certain securities have fair values less than amortized cost and, therefore, contain unrealized losses. The Company evaluated the securities which had an unrealized loss for other than temporary impairment and determined all declines in value to be temporary. There were 101 securities available-for-sale with unrealized losses at December 31, 2017, compared to 88 at December 31, 2016. There were 28 securities held-to-maturity with unrealized losses at December 31, 2017, compared to 42 at December 31, 2016. The Company anticipates full recovery of amortized cost with respect to these securities by maturity, or sooner, in the event of a more favorable market interest rate environment. The Company does not intend to sell these securities and it is not more likely than not that the Company will be required to sell them before recovery of their amortized cost basis, which may be at maturity. The proceeds from all sales of securities were available-for-sale, and the associated gains and losses for the years ended December 31, 2017, 2016, and 2015 are listed below: 2017 2016 2015 Proceeds $ 8 $ 534,418 $ 511,028 Gross gains 8 3,358 3,124 Gross losses — 131 60 The amount of net gains reclassified from accumulated other comprehensive income (loss) into earnings for the years ended December 31, 2017, 2016, and 2015 were $8,000, $3.2 million, and $3.1 million, respectively. Note 4—Securities (continued) Securities pledged at December 31, 2017 and 2016 had carrying amounts of $262.5 million and $178.6 million, respectively. At December 31, 2017 and 2016, of those pledged, the carrying amounts of securities pledged as collateral for public fund deposits were $99.3 million and $93.2 million, respectively, and for customer repurchase agreements of $34.8 million and $19.9 million, respectively. At December 31, 2017 and 2016, securities pledged for advances from the Federal Home Loan Bank were $128.4 million and $58.7 million, respectively. Other securities were pledged for derivative positions, letters of credit and for purposes required or permitted by law. At December 31, 2017 and 2016, there were no holdings of securities of any one issuer, other than the U.S. Government and its agencies, in an amount greater than 10% of stockholders’ equity. At December 31, 2017, the amortized cost and fair value of debt securities are shown by contractual maturity. Expected maturities may differ from contractual maturities if borrowers have the right to call or prepay obligations with or without call or prepayment penalties. Securities not due at a single maturity date are shown separately. Amortized Cost Fair Value Available-for-sale Due in one year or less $ 8,285 $ 8,268 Due from one to five years 72,432 71,826 Due from five to ten years 40,439 39,812 Due after ten years 11,604 11,738 Mortgage-backed securities 457,315 446,985 Other securities with no defined maturity 3,092 4,607 Total $ 593,167 $ 583,236 Held-to-maturity Due from one to five years $ 1,719 $ 1,732 Due from five to ten years 13,532 13,546 Due after ten years 8,779 8,867 Mortgage-backed securities 93,133 93,132 Total $ 117,163 $ 117,277

Loan and Lease Receivables

Loan and Lease Receivables	12 Months Ended
	Dec. 31, 2018
Receivables [Abstract]
Loans and Lease Receivables	Note 5—Loans and Lease Receivables Outstanding loan and lease receivables as of December 31, 2017 and 2016 were categorized as follows: 2017 2016 Commercial real estate $ 891,971 $ 796,950 Residential real estate 577,123 610,699 Construction, land development, and other land 105,996 141,122 Commercial and industrial 522,254 439,476 Installment and other 4,182 2,917 Lease financing receivables 174,165 155,999 Total loans and leases 2,275,691 2,147,163 Net unamortized deferred fees and costs (1,720 ) (2,119 ) Initial direct costs 3,521 2,967 Allowance for loan and lease losses (16,706 ) (10,923 ) Net loans and leases $ 2,260,786 $ 2,137,088 2017 2016 Lease financing receivables Net minimum lease payments $ 188,986 $ 168,345 Unguaranteed residual values 1,644 1,787 Unearned income (16,465 ) (14,133 ) Total lease financing receivables 174,165 155,999 Initial direct costs 3,521 2,967 Lease financial receivables before allowance for lease losses $ 177,686 $ 158,966 At December 31, 2017 and 2016, total loans and leases included the guaranteed amount of U.S. Government guaranteed loans of $77.0 million and $34.8 million, respectively. At December 31, 2017 and 2016, installment and other loans included overdraft deposits of $617,000 and $1.0 million, respectively, which were reclassified as loans. At December 31, 2017 and 2016, loans and loans held for sale pledged as security for borrowings were $516.9 million and $507.2 million, respectively. Total loans and leases consist of originated loans and leases, acquired impaired loans and acquired non-impaired loans and leases. The minimum annual lease payments for lease financing receivables as of December 31, 2017 are summarized as follows: Minimum Lease Payments 2018 $ 65,770 2019 53,702 2020 37,914 2021 21,743 2022 8,922 Thereafter 935 Total $ 188,986 Note 5—Loans and Lease Receivables (continued) Originated loans and leases represent originations excluding loans acquired in a business combination. Acquired impaired loans are loans acquired from a business combination with evidence of credit quality deterioration and are accounted for under ASC Topic 310-30. Acquired non-impaired loans and leases represent loans and leases acquired from a business combination without evidence of credit quality deterioration and are accounted for under ASC Topic 310-20. Leases and revolving loans do not qualify to be accounted for as acquired impaired loans and are accounted for under ASC Topic 310-20. The following tables summarize the balances for each respective loan and lease category as of December 31, 2017 and 2016: 2017 Originated Acquired Impaired Acquired Non- Impaired Total Commercial real estate $ 513,622 $ 166,712 $ 211,359 $ 891,693 Residential real estate 400,571 144,562 32,085 577,218 Construction, land development, and other land 97,638 5,946 1,845 105,429 Commercial and industrial 416,499 10,008 94,731 521,238 Installment and other 3,724 462 42 4,228 Lease financing receivables 141,329 — 36,357 177,686 Total loans and leases $ 1,573,383 $ 327,690 $ 376,419 $ 2,277,492 2016 Originated Acquired Impaired Acquired Non- Impaired Total Commercial real estate $ 338,752 $ 207,303 $ 250,289 $ 796,344 Residential real estate 394,168 175,717 40,853 610,738 Construction, land development, and other land 119,357 6,979 14,430 140,766 Commercial and industrial 309,097 13,464 115,677 438,238 Installment and other 2,021 574 364 2,959 Lease financing receivables 118,493 — 40,473 158,966 Total loans and leases $ 1,281,888 $ 404,037 $ 462,086 $ 2,148,011 Acquired impaired loans —As part of the Ridgestone acquisition, the Bank acquired impaired loans that are accounted for under ASC 310‑30 in the amount of $39.7 million. Refer to Note 3—Acquisition of a Business for additional information regarding the transaction. There were no other acquired impaired loans purchased during 2017 or 2016. The following table presents a reconciliation of the undiscounted contractual cash flows, non‑accretable difference, accretable yield, and fair value of acquired impaired loans as of the acquisition date of October 14, 2016: Undiscounted contractual cash flows $ 66,488 Undiscounted cash flows not expected to be collected (non-accretable difference) (19,918 ) Undiscounted cash flows expected to be collected 46,570 Accretable yield at acquisition (6,916 ) Estimated fair value of impaired loans acquired at acquisition $ 39,654 Note 5—Loans and Lease Receivables (continued) The outstanding balance and carrying amount of all acquired impaired loans are summarized below. The balances do not include an allowance for loan and lease losses of $3.9 million and $1.6 million, respectively, at December 31, 2017 and 2016. 2017 2016 Outstanding Balance Carrying Value Outstanding Balance Carrying Value Commercial real estate $ 235,898 $ 166,712 $ 278,893 $ 207,303 Residential real estate 207,660 144,562 236,384 175,717 Construction, land development, and other land 13,270 5,946 15,292 6,979 Commercial and industrial 18,333 10,008 23,164 13,464 Installment and other 1,819 462 1,976 574 Total acquired impaired loans $ 476,980 $ 327,690 $ 555,709 $ 404,037 The following table summarizes the changes in accretable yield for acquired impaired loans for the years ended December 31, 2017, 2016, and 2015: 2017 2016 2015 Beginning balance $ 36,868 $ 43,915 $ 68,238 Additions — 6,916 — Accretion to interest income (24,597 ) (26,208 ) (35,547 ) Reclassification from nonaccretable difference 24,175 12,245 11,224 Ending balance $ 36,446 $ 36,868 $ 43,915 Acquired non‑impaired loans and leases —The Company acquired non‑impaired loans as part of the Ridgestone acquisition in the amount of $312.2 million. Refer to Note 3—Acquisition of a Business for additional information regarding the transaction. The unpaid principal balance and carrying value for acquired non‑impaired loans and leases at December 31, 2017 and 2016 were as follows: 2017 2016 Unpaid Principal Balance Carrying Value Unpaid Principal Balance Carrying Value Commercial real estate $ 221,710 $ 211,359 $ 259,055 $ 250,289 Residential real estate 32,605 32,085 41,282 40,853 Construction, land development, and other land 1,926 1,845 14,619 14,430 Commercial and industrial 105,529 94,731 125,806 115,677 Installment and other 355 42 402 364 Lease financing receivables 37,476 36,357 40,205 40,473 Total acquired non-impaired loans and leases $ 399,601 $ 376,419 $ 481,369 $ 462,086

Allowance for Loan and Lease Lo

Allowance for Loan and Lease Losses and Reserve for Unfunded Commitments	12 Months Ended
	Dec. 31, 2017
Receivables [Abstract]
Allowance for Loan and Lease Losses and Reserve for Unfunded Commitments	Note 6—Allowance for Loan and Lease Losses and Reserve for Unfunded Commitments Loans and leases considered for inclusion in the allowance for loan and lease losses include acquired non-impaired loans and leases, those acquired impaired loans with credit deterioration after acquisition, and originated loans and leases. Although all acquired loans and leases are included in the following table, only those with credit deterioration subsequent to acquisition date are actually included in the allowance for loan and lease losses. The following tables summarize the balance and activity within the allowance for loan and lease losses, the components of the allowance for loan and lease losses in terms of loans and leases individually and collectively evaluated for impairment, and corresponding loan and lease balances by type for the years ended December 31, 2017, 2016 and 2015 are as follows: 2017 Commercial Real Estate Residential Real Estate Construction, Land Development, and Other Land Commercial and Industrial Installment and Other Lease Financing Receivables Total Allowance for loan and lease losses Beginning balance $ 1,945 $ 2,483 $ 742 $ 4,196 $ 334 $ 1,223 $ 10,923 Provisions 4,343 (405 ) (520 ) 6,058 34 3,143 12,653 Charge-offs (1,494 ) (440 ) — (2,836 ) (327 ) (3,099 ) (8,196 ) Recoveries — — — — — 1,326 1,326 Ending balance $ 4,794 $ 1,638 $ 222 $ 7,418 $ 41 $ 2,593 $ 16,706 Ending balance: Individually evaluated for impairment $ 1,101 $ 158 $ — $ 2,692 $ 14 $ — $ 3,965 Collectively evaluated for impairment 1,765 1,047 145 3,308 9 2,593 8,867 Loans acquired with deteriorated credit quality 1,928 433 77 1,418 18 — 3,874 Total allowance for loan and lease losses $ 4,794 $ 1,638 $ 222 $ 7,418 $ 41 $ 2,593 $ 16,706 2017 Commercial Real Estate Residential Real Estate Construction, Land Development, and Other Land Commercial and Industrial Installment and Other Lease Financing Receivables Total Loans and leases ending balance: Individually evaluated for impairment $ 13,884 $ 2,429 $ — $ 14,784 $ 14 $ — $ 31,111 Collectively evaluated for impairment 711,097 430,227 99,483 496,446 3,752 177,686 1,918,691 Loans acquired with deteriorated credit quality 166,712 144,562 5,946 10,008 462 — 327,690 Total loans and leases $ 891,693 $ 577,218 $ 105,429 $ 521,238 $ 4,228 $ 177,686 $ 2,277,492 Note 6—Allowance for Loan and Lease Losses and Reserve for Unfunded Commitments (continued) 2016 Commercial Real Estate Residential Real Estate Construction, Land Development, and Other Land Commercial and Industrial Installment and Other Lease Financing Receivables Total Allowance for loan and lease losses Beginning balance $ 2,280 $ 2,981 $ 232 $ 1,403 $ 357 $ 379 $ 7,632 Provisions 4,032 135 605 2,869 (11 ) 2,722 10,352 Charge-offs (4,367 ) (633 ) (95 ) (76 ) (12 ) (2,634 ) (7,817 ) Recoveries — — — — — 756 756 Ending balance $ 1,945 $ 2,483 $ 742 $ 4,196 $ 334 $ 1,223 $ 10,923 Ending balance: Individually evaluated for impairment $ — $ 293 $ — $ 396 $ 328 $ — $ 1,017 Collectively evaluated for impairment 1,456 1,743 742 3,126 5 1,223 8,295 Loans acquired with deteriorated credit quality 489 447 — 674 1 — 1,611 Total allowance for loan and lease losses $ 1,945 $ 2,483 $ 742 $ 4,196 $ 334 $ 1,223 $ 10,923 2016 Commercial Real Estate Residential Real Estate Construction, Land Development, and Other Land Commercial and Industrial Installment and Other Lease Financing Receivables Total Loans and leases ending balance: Individually evaluated for impairment $ 8,916 $ 1,300 $ — $ 1,382 $ 328 $ — $ 11,926 Collectively evaluated for impairment 580,125 433,721 133,787 423,392 2,057 158,966 1,732,048 Loans acquired with deteriorated credit quality 207,303 175,717 6,979 13,464 574 — 404,037 Total loans and leases $ 796,344 $ 610,738 $ 140,766 $ 438,238 $ 2,959 $ 158,966 $ 2,148,011 2015 Commercial Real Estate Residential Real Estate Construction, Land Development, and Other Land Commercial and Industrial Installment and Other Lease Financing Receivables Total Allowance for loan and lease losses Beginning balance $ 1,112 $ 1,936 $ 834 $ 648 $ 121 $ 143 $ 4,794 Provisions 2,464 1,873 (585 ) 782 237 2,195 6,966 Charge-offs (1,296 ) (828 ) (17 ) (30 ) (1 ) (2,187 ) (4,359 ) Recoveries — — — 3 — 228 231 Ending balance $ 2,280 $ 2,981 $ 232 $ 1,403 $ 357 $ 379 $ 7,632 Ending balance: Individually evaluated for impairment $ 1,076 $ 615 $ 137 $ 171 $ 327 $ — $ 2,326 Collectively evaluated for impairment 470 476 95 596 — 379 2,016 Loans acquired with deteriorated credit quality 734 1,890 — 636 30 — 3,290 Total allowance for loan and lease losses $ 2,280 $ 2,981 $ 232 $ 1,403 $ 357 $ 379 $ 7,632 Note 6—Allowance for Loan and Lease Losses and Reserve for Unfunded Commitments (continued) 2015 Commercial Real Estate Residential Real Estate Construction, Land Development, and Other Land Commercial and Industrial Installment and Other Lease Financing Receivables Total Loans and leases ending balance: Individually evaluated for impairment $ 4,160 $ 4,042 $ 208 $ 171 $ 327 $ — $ 8,908 Collectively evaluated for impairment 285,571 256,555 31,390 155,955 594 119,553 849,618 Loans acquired with deteriorated credit quality 243,964 223,738 8,634 9,570 1,005 — 486,911 Total loans and leases $ 533,695 $ 484,335 $ 40,232 $ 165,696 $ 1,926 $ 119,553 $ 1,345,437 The Company increased the allowance for loan and lease losses by $5.8 million and $3.3 million for the years ended December 31, 2017 and 2016, respectively. For acquired impaired loans, the Company increased the allowance for loan and lease losses by $2.3 million for the year ended December 31, 2017. There was a net reversal of $1.7 million of the allowance for loan and lease losses during the year ended December 31, 2016. The following tables summarize the recorded investment, unpaid principal balance, related allowance, average recorded investment, and interest income recognized for loans and leases considered impaired as of December 31, 2017, 2016, and 2015, which excludes acquired impaired loans: 2017 Recorded Investment Unpaid Principal Balance Related Allowance Average Recorded Investment Interest Income Recognized With no related allowance recorded Commercial real estate $ 11,425 $ 12,936 $ — $ 10,482 $ 525 Residential real estate 2,075 2,046 — 1,781 72 Construction, land development and other land — — — 295 2 Commercial and industrial 5,470 6,774 — 2,875 265 With an allowance recorded Commercial real estate 2,459 2,634 1,101 1,988 187 Residential real estate 354 351 158 422 6 Construction, land development and other land — — — 14 — Commercial and industrial 9,314 9,724 2,692 3,460 486 Installment and other 14 14 14 162 12 Total impaired loans $ 31,111 $ 34,479 $ 3,965 $ 21,479 $ 1,555 2016 Recorded Investment Unpaid Principal Balance Related Allowance Average Recorded Investment Interest Income Recognized With no related allowance recorded Commercial real estate $ 8,916 $ 9,502 $ — $ 8,975 $ 305 Residential real estate 804 1,999 — 827 45 Commercial and Industrial 521 524 — 516 (2 ) With an allowance recorded Residential real estate 496 528 293 519 1 Commercial and industrial 861 869 396 914 — Installment and other 328 361 328 328 16 Total impaired loans $ 11,926 $ 13,783 $ 1,017 $ 12,079 $ 365 Note 6—Allowance for Loan and Lease Losses and Reserve for Unfunded Commitments (continued) 2015 Recorded Investment Unpaid Principal Balance Related Allowance Average Recorded Investment Interest Income Recognized With no related allowance recorded Commercial real estate $ 1,362 $ 1,922 $ — $ 1,394 $ 64 Residential real estate 2,821 4,222 — 2,865 63 With an allowance recorded Commercial real estate 2,798 2,797 1,076 2,826 46 Residential real estate 1,221 1,216 615 1,250 15 Construction, land development and other land 208 1,201 137 208 — Commercial and industrial 171 171 171 185 1 Installment and other 327 335 327 327 23 Total impaired loans $ 8,908 $ 11,864 $ 2,326 $ 9,055 $ 212 For purposes of these tables, the unpaid principal balance represents the outstanding contractual balance. Impaired loans include loans that are individually evaluated for impairment as well as troubled debt restructurings for all loan categories. The sum of non‑accrual loans and loans past due 90 days still on accrual will differ from the total impaired loan amount. The Bank’s credit risk rating methodology assigns risk ratings from 1 to 10, where a higher rating represents higher risk. The risk rating categories are described by the following groupings: Pass —Ratings 1‑4 define the risk levels of borrowers and guarantors that offer a minimal to an acceptable level of risk. Watch —A watch asset (rating of 5) has credit exposure that presents higher than average risk and warrants greater than routine attention by Bank personnel due to conditions affecting the borrower, the borrower’s industry or the economic environment. Special Mention —A special mention asset (rating of 6) has potential weaknesses that deserve management’s close attention. If left uncorrected, these potential weaknesses may result in deterioration of the repayment prospects for the asset or in the Company’s credit position at some future date. Substandard Accrual —A substandard accrual asset (rating of 7) has well‑defined weakness or weaknesses in cash flow and collateral coverage resulting in a distinct possibility that the Company will sustain some loss if the deficiencies are not corrected. This classification may be used in limited cases, where despite credit severity, the borrower is current on payments and there is an agreed plan for credit remediation. Substandard Non‑Accrual —A substandard asset (rating of 8) has well‑defined weakness or weaknesses in cash flow and collateral coverage resulting in the distinct possibility that the Company will sustain some loss if the deficiencies are not corrected. Doubtful —A doubtful asset (rating of 9) has all the weaknesses inherent in one classified substandard 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 —A loss asset (rating of 10) is considered uncollectible and of such little value that its continuance as a realizable asset is not warranted. Note 6—Allowance for Loan and Lease Losses and Reserve for Unfunded Commitments (continued) The following tables summarize the risk rating categories of the loans and leases considered for inclusion in the allowance for loan and lease losses calculation, excluding acquired impaired loans, as of December 31, 2017 and 2016: 2017 Commercial Real Estate Residential Real Estate Construction, Land Development, and Other Land Commercial and Industrial Installment and Other Lease Financing Receivables Total Pass $ 638,066 $ 398,743 $ 73,935 $ 415,163 $ 3,732 $ 174,672 $ 1,704,311 Watch 58,217 29,165 22,380 67,024 20 190 176,996 Special Mention 14,645 2,251 3,168 13,535 — 1,293 34,892 Substandard 14,053 2,497 — 15,508 14 1,259 33,331 Doubtful — — — — — 272 272 Loss — — — — — — — Total $ 724,981 $ 432,656 $ 99,483 $ 511,230 $ 3,766 $ 177,686 $ 1,949,802 2016 Commercial Real Estate Residential Real Estate Construction, Land Development, and Other Land Commercial and Industrial Installment and Other Lease Financing Receivables Total Pass $ 536,499 $ 419,880 $ 129,732 $ 369,136 $ 2,052 $ 157,296 $ 1,614,595 Watch 38,707 10,885 2,897 52,872 4 324 105,689 Special Mention 5,377 3,116 1,158 1,258 1 512 11,422 Substandard 8,458 1,140 — 1,508 328 739 12,173 Doubtful — — — — — 95 95 Loss — — — — — — — Total $ 589,041 $ 435,021 $ 133,787 $ 424,774 $ 2,385 $ 158,966 $ 1,743,974 The following tables summarize contractual delinquency information for acquired non-impaired and originated loans and leases by category as of December 31, 2017 and 2016: 2017 30-59 Days Past Due 60-89 Days Past Due Greater than 90 Days and Accruing Non- accrual Total Past Due Current Total Commercial real estate $ 4,783 $ 968 $ — $ 8,459 $ 14,210 $ 710,771 $ 724,981 Residential real estate 148 — — 2,092 2,240 430,416 432,656 Construction, land development, and other land — — — - - 99,483 99,483 Commercial and industrial 6,667 967 — 4,348 11,982 499,248 511,230 Installment and other 18 — — 14 32 3,734 3,766 Lease financing receivables 997 638 — 851 2,486 175,200 177,686 Total $ 12,613 $ 2,573 $ — $ 15,764 $ 30,950 $ 1,918,852 $ 1,949,802 Note 6—Allowance for Loan and Lease Losses and Reserve for Unfunded Commitments (continued) 2016 30-59 Days Past Due 60-89 Days Past Due Greater than 90 Days and Accruing Non- accrual Total Past Due Current Total Commercial real estate $ 2,944 $ 648 $ — $ 3,935 $ 7,527 $ 581,514 $ 589,041 Residential real estate 243 — — 1,118 1,361 433,660 435,021 Construction, land development, and other land 1,363 — — — 1,363 132,424 133,787 Commercial and industrial 6,066 374 — 958 7,398 417,376 424,774 Installment and other — — — 328 328 2,057 2,385 Lease financing receivables 2,070 390 — 445 2,905 156,061 158,966 Total $ 12,686 $ 1,412 $ — $ 6,784 $ 20,882 $ 1,723,092 $ 1,743,974 Trouble debt restructurings are granted due to borrower financial difficulty and provide for a modification of loan repayment terms. TDRs are treated in the same manner as impaired loans for purposes of calculating the allowance for loan and lease losses. The tables below present TDRs by loan category as of December 31, 2017, 2016, and 2015. Refer to Note 1—Summary of Significant Accounting Policies for the accounting policy for TDRs. December 31, 2017 Number of Loans Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment Charge-offs Specific Reserves Troubled Debt Restructurings: Commercial real estate 5 $ 1,655 $ 1,655 $ — $ 111 Commercial and industrial 3 1,246 759 487 246 Residential real estate 2 216 216 — — Total 10 $ 3,117 $ 2,630 $ 487 $ 357 December 31, 2016 Number of Loans Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment Charge-offs Specific Reserves Troubled Debt Restructurings: Commercial real estate 2 $ 898 $ 898 $ — $ — Residential real estate 3 256 256 — — Total 5 $ 1,154 $ 1,154 $ — $ — December 31, 2015 Number of Loans Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment Charge-offs Specific Reserves Troubled Debt Restructurings: Commercial real estate 2 $ 979 $ 979 $ — $ — Residential real estate 4 1,762 1,762 — — Total 6 $ 2,741 $ 2,741 $ — $ — At December 31, 2017 and 2016, there were no commitments outstanding on troubled debt restructurings. TDRs that subsequently defaulted within twelve months of the restructure date during the years ended December 31, 2017, 2016, and 2015 had a recorded investment of $144,000, $477,000, and $750,000, respectively. At December 31, 2017 and 2016, TDRs classified as non-accrual totaled $1.6 million and $552,000, respectively. Note 6—Allowance for Loan and Lease Losses and Reserve for Unfunded Commitments (continued) At December 31, 2017 and 2016, the reserve for unfunded commitments was $923,000 and $760,000, respectively. During the years ended December 31, 2017 and 2016, the provisions for unfunded commitments were $162,000 and $493,000, respectively. There were no charge‑offs or recoveries related to the reserve for unfunded commitments during both periods.

Servicing Assets

Servicing Assets	12 Months Ended
	Dec. 31, 2017
Transfers And Servicing [Abstract]
Servicing Assets	Note 7—Servicing Assets As part of the Ridgestone acquisition, the Company acquired loan servicing assets. The Company did not hold any servicing assets until the acquisition on October 14, 2016. Loans serviced for others are not included in the Consolidated Statements of Financial Condition. The unpaid principal balances of these loans serviced for others were as follows as December 31, 2017 and 2016: 2017 2016 Loan portfolios serviced for: SBA $ 1,021,143 $ 911,803 USDA 91,758 106,125 Total $ 1,112,901 $ 1,017,928 Activity for servicing assets and the related changes in fair value for the years ended December 31, 2017 and 2016 is as follows: 2017 2016 Beginning balance $ 21,091 $ — Acquired servicing assets at fair value — $ 20,295 Additions, net 6,250 539 Changes in fair value (5,941 ) 257 Ending balance $ 21,400 $ 21,091 Loan servicing income totaled $3.7 million and $1.9 million for the years ended December 31, 2017 and 2016, respectively. The Company had no servicing income for the year ended December 31, 2015. The fair value of servicing rights is highly sensitive to changes in underlying assumptions. Changes in prepayment speed assumptions have the most significant impact on the fair value of servicing rights. Generally, as interest rates rise on variable rate loans, loan prepayments increase due to an increase in refinance activity, which may result in a decrease in the fair value of servicing assets. Measurement of fair value is limited to the condition existing and the assumptions used as of a particular point in time, and those assumptions may change over time. Refer to Note 18—Fair Value Measurement for further details.

Other Real Estate Owned

Other Real Estate Owned	12 Months Ended
	Dec. 31, 2017
Banking And Thrift [Abstract]
Other Real Estate Owned	Note 8—Other Real Estate Owned The following table presents the change in other real estate owned (“OREO”) for the years ended December 31, 2017, 2016, and 2015: 2017 2016 2015 Beginning balance $ 16,570 $ 26,715 $ 56,181 Acquisition of OREO through business combination — 1,525 — Net additions to OREO 6,266 6,672 13,793 Dispositions of OREO (11,750 ) (17,389 ) (33,994 ) Valuation adjustments (460 ) (953 ) (9,265 ) Ending balance $ 10,626 $ 16,570 $ 26,715 Note 8—Other Real Estate Owned (continued) At December 31, 2017 and 2016, the balance of real estate owned included $3.6 million and $3.3 million, respectively, of foreclosed residential real estate properties recorded as a result of obtaining physical possession of the property. At December 31, 2017 and 2016, the recorded investment of consumer mortgage loans secured by residential real estate properties for which formal foreclosure proceedings were in process is $1.9 million and $2.7 million, respectively.

Premises and Equipment and Asse

Premises and Equipment and Assets Held for Sale	12 Months Ended
	Dec. 31, 2017
Property Plant And Equipment [Abstract]
Premises and Equipment and Assets Held for Sale	Note 9—Premises and Equipment and Assets Held for Sale Classifications of premises and equipment as of December 31, 2017 and 2016 and were as follows: 2017 2016 Premises $ 51,743 $ 53,495 Furniture, fixtures and equipment 10,295 7,214 Leasehold improvements 1,538 1,093 Total cost 63,576 61,802 Less accumulated depreciation and amortization (13,906 ) (9,780 ) Net book value of premises, furniture, fixtures, equipment, leasehold improvements 49,670 52,022 Construction in progress 899 3,869 Land 44,655 46,183 Premises and equipment, net $ 95,224 $ 102,074 Depreciation and amortization expense related to premises and equipment for the years ended December 31, 2017, 2016, and 2015 was $5.2 million, $5.1 million and $5.8 million, respectively. Refer to Note 17—Commitments and Contingent Liabilities for additional discussion related to operating lease commitments. During 2015, the Company approved the closure of sixteen retail branches based on a detailed assessment of the branch network and analysis of branch and market data. During 2016 and 2017, an additional twelve and two retail branches were also approved to be closed, respectively. Branches owned by the Company and actively marketed for sale are transferred to assets held for sale based on their carrying value or fair value, less estimated costs to sell. Assets are considered held for sale when management has approved the sale of the assets following a branch closure or other events. An assessment of the recoverability of other long‑lived assets associated with all branches is periodically performed, resulting in impairment losses which are reflected in non-interest expense. The following table presents the change in assets held for sale for the years ended December 31, 2017, 2016, and 2015: 2017 2016 2015 Beginning balance $ 14,748 $ 2,259 $ — Transfers in 3,372 14,496 2,259 Proceeds from sales (5,373 ) (2,566 ) — Internally financed sales (1,800 ) — — Net gains (losses) on sales (217 ) 967 — Impairment loss (951 ) (408 ) — Ending balance $ 9,779 $ 14,748 $ 2,259

Goodwill, Core Deposit Intangib

Goodwill, Core Deposit Intangible and Other Intangible Assets	12 Months Ended
	Dec. 31, 2017
Goodwill And Intangible Assets Disclosure [Abstract]
Goodwill, Core Deposit Intangible and Other Intangible Assets	Note 10—Goodwill, Core Deposit Intangible and Other Intangible Assets The Company’s annual goodwill test was performed as of November 30, 2017. The Company determined that no impairment existed as of that date. Refer to Note 1—Business and Summary of Significant Accounting Policies for discussion of goodwill. The following table summarizes the changes in the Company’s goodwill and core deposit intangible assets for the years ended December 31, 2017, 2016 and 2015: 2017 2016 2015 Goodwill Core Intangible Goodwill Core Deposit Intangible Goodwill Core Deposit Intangible Beginning balance $ 51,975 $ 19,776 $ 25,688 $ 22,275 $ 25,613 $ 25,245 Additions — — 26,287 486 75 — Amortization or accretion — (3,056 ) — (2,985 ) — (2,970 ) Ending balance $ 51,975 $ 16,720 $ 51,975 $ 19,776 $ 25,688 $ 22,275 Accumulated amortization or accretion N/A $ 13,466 N/A $ 10,410 N/A $ 7,425 Weighted average remaining amortization or accretion period N/A 5.6 Years N/A 6.6 Years N/A 7.5 Years The Company has other intangible assets of $36,000, $50,000 and $51,000 as of December 31, 2017, 2016 and 2015, respectively, related to trademark‑related transactions. The increases in goodwill and core deposit intangible for the year ended December 31, 2016 resulted from the Ridgestone acquisition. The increase in goodwill during the year ended December 31, 2015 resulted in a measurement period adjustment related to finalizing the fair values of certain assets acquired and certain liabilities assumed in a business combination that occurred during 2014. The following table presents the estimated amortization expense for core deposit intangible and other intangible assets recognized at December 31, 2017: Estimated Amortization 2018 $ 3,061 2019 3,050 2020 3,026 2021 3,017 2022 3,010 Thereafter 1,592 Total $ 16,756

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Income Taxes	Note 11—Income Taxes The following were the components of provision for income taxes for the years ended December 31, 2017, 2016, and 2015: 2017 2016 2015 Current tax expense: Federal $ 1,010 $ — $ 250 State and local 1,485 — 57 Total current tax expense 2,495 — 307 Deferred tax expense: Federal 13,554 478 4,929 State and local 686 136 656 Remeasurement of net deferred tax assets 2,364 — — Total deferred tax expense before reversal of valuation allowance 16,604 614 5,585 Deferred tax valuation allowance — (61,859 ) (5,585 ) Provision (benefit) for income taxes $ 19,099 $ (61,245 ) $ 307 Note 11—Income Taxes (continued) The following is a reconciliation between the statutory U.S. federal income tax rate of 35% and the effective tax rate: 2017 2016 2015 Calculated tax benefit at statutory rate 35.0 % 35.0 % 35.0 % Increase (decrease) in income taxes resulting from: Reversal of valuation allowance, net of change in estimated Section 382 impact — (1,167.6 ) 73.4 State taxes, net of federal income tax 6.5 6.1 5.0 Tax exempt income (0.7 ) (5.3 ) 24.2 Non-deductible expenses 0.2 14.8 (137.6 ) Remeasurement of net deferred tax assets 5.8 — — Total income tax expense (benefit) 46.8 % (1,117.0 ) % — % The Tax Cuts and Jobs Act (the “Tax Act”) was enacted on December 22, 2017, and ASC 740 requires us to reflect the changes associated with the Tax Act’s provisions in the fourth quarter of 2017. The Tax Act is complex and has extensive implications for the Company’s federal and state taxes. Among other things, the Tax Act reduces the corporate federal income tax rate from 35% to 21%, effective January 1, 2018. Also on December 22, 2017, the SEC issued Staff Accounting Bulletin 118 (SAB 118), which provides guidance on accounting for the Tax Act’s impact. SAB 118 provides a measurement period, not to extend beyond one year from the date of enactment during which a company, acting in good faith, may complete the accounting for the impacts of the Tax Act. At December 31, 2017, the Company’s accounting for the impact of the Tax Act on its net deferred tax assets is based upon reasonable estimates of the tax effects of the Tax Act; however, these estimates may change as additional information and interpretive guidance regarding the provisions of the Tax Act become available. As a result of the rate change, the Company’s net deferred tax assets were required to be revalued during the period in which the new legislation was enacted, and the Company recorded net income tax expense of $7.2 million during the fourth quarter as a result of this change. Included in the provisional tax expense recorded for the re-measurement of the Company’s net deferred tax assets were deferred items for which the tax effects were originally established through OCI. This results in a disproportionate tax effect for those items still recorded in AOCI. Under GAAP as of December 31, 2017, those items would continue to be reported in AOCI until such time as the underlying transactions were settled and would then be reclassified as a component of the provision for income taxes. However, in February 2018, the FASB issued an ASU that permits entities to reclassify the tax effects stranded in AOCI as a result of the Tax Act to retained earnings. The guidance is effective for fiscal years beginning after December 15, 2018, and interim periods within those fiscal years, with early adoption in any period permitted. The Company did not early adopt this guidance in 2017. The income tax benefit for the year ended December 31, 2016 was primarily attributable to the reversal of the Company’s previously established valuation allowance of $61.4 million. Management concluded that no valuation allowance was necessary on the Company’s net deferred tax assets as a result of the Ridgestone acquisition. This determination was based on Ridgestone’s actual pre‑tax income over the prior three years, and pro‑forma combined earnings for the Company and Ridgestone over the prior three years, as well as management’s expectations for sustainable profitability in the future. Management monitors deferred tax assets on a quarterly basis for changes affecting realizability. The valuation allowance could be subject to change in future periods. Note 11—Income Taxes (continued) The following were the significant components of the deferred tax assets and liabilities as of December 31, 2017 and 2016: 2017 2016 Deferred tax assets: Net operating losses and tax credits $ 42,062 $ 61,906 Interest on non-accrual loans 2,755 2,882 Allowance for loan losses and loan basis 13,839 22,017 Deposits 5 316 Alternative minimum tax ("AMT") credit carryforward 2,140 1,073 Other real estate owned — 214 Net unrealized holding losses on securities available-for-sale 2,766 4,818 Other 2,413 3,241 Total deferred tax assets 65,980 96,467 Deferred tax liabilities: Other real estate owned (24 ) — Premises and equipment (3,385 ) (6,907 ) Core deposit intangibles (4,656 ) (7,858 ) Servicing assets (3,505 ) (7,899 ) Trust preferred securities (2,465 ) (3,809 ) Unrealized holding gain on cash flow hedges (1,390 ) (1,491 ) Other (592 ) (743 ) Total deferred tax liabilities (16,017 ) (28,707 ) Less valuation allowance on net deferred tax asset — — Net deferred tax assets after valuation allowance $ 49,963 $ 67,760 2017 2016 NOL carryforwards available to offset future taxable income: Federal gross NOL carryforwards - begin to expire in 2027 $ 63,964 $ 116,315 Illinois gross NLD carryforwards - begin to expire in 2021 381,471 420,764 AMT credit carryforward - no expiration date 2,140 1,073 Pursuant to Sections 382 and 383 of the Internal Revenue Code, annual use of net operating loss and credit carryforwards may be limited in the event a cumulative change in ownership of more than 50 percent occurs within a three‑year period. The Company has determined that such an ownership change occurred as of June 28, 2013 as a result of the recapitalization. This ownership change resulted in estimated limitations on the utilization of tax attributes, including net operating loss carryforwards and tax credits. Pursuant to Sections 382 and 383, a portion of the limited net operating loss carryforwards and credits become available to use each year. The Company estimates that approximately $756,000 of the restricted Federal and Illinois net operating losses will become available each year. The Company and the Bank file consolidated income tax returns. The Company and the Bank are no longer subject to United States federal income tax examinations for years before 2014 and state income tax examinations for years before 2013.

Federal Home Loan Bank Advances

Federal Home Loan Bank Advances	12 Months Ended
	Dec. 31, 2017
Federal Home Loan Banks [Abstract]
Federal Home Loan Bank Advances	Note 12—Federal Home Loan Bank Advances The following table summarizes the FHLB advances as of December 31, 2017 and 2016, which include acquisition accounting adjustments of $19,000 and $228,000, respectively, along with weighted average costs and scheduled maturities: 2017 2016 Federal Home Loan Bank advances $ 361,506 $ 313,715 Weighted average cost 1.49 % 0.73 % Scheduled Maturities 2018 $ 361,506 Total $ 361,506 At December 31, 2017, all advances were at a fixed‑rate with interest rates ranging from 1.32% to 3.22% and maturities ranging from January 2018 to March 2018. The Company’s advances from the FHLB are collateralized by residential real estate loans and securities. The Company’s required investment in FHLB stock is $1 for every $20 in advances. Refer to Note 4—Securities for additional discussion. At December 31, 2017 and 2016, the Bank has additional borrowing capacity from the FHLB of $795.0 million and $647.9 million, respectively, subject to the availability of qualifying collateral. The Bank’s maximum borrowing capacity is limited to 35% of total assets. FHLB advances assumed from the Ridgestone acquisition of $1.5 million are putable quarterly and are required to be repaid upon the request of the FHLB. The Company hedges interest rates on borrowed funds using interest rate swaps through which the Company receives variable amounts and pays fixed amounts. Refer to Note 22—Derivative Instruments and Hedging Activities for additional information.

Other Borrowings

Other Borrowings	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Other Borrowings	Note 13—Other Borrowings The following is a summary of the Company’s other borrowings as of December 31, 2017 and 2016: 2017 2016 Securities sold under agreements to repurchase $ 31,187 $ 17,249 Line of credit — 20,650 Total $ 31,187 $ 37,899 Securities sold under agreements to repurchase represent a demand deposit product offered to customers that sweep balances in excess of the FDIC insurance limit into overnight repurchase agreements. The Company pledges securities as collateral for the repurchase agreements. Refer to Note 4—Securities for additional discussion. On October 13, 2016, in connection with the Ridgestone acquisition, the Company entered into a $30.0 million credit agreement with The PrivateBank and Trust and Company, now known as CIBC Bank USA (“CIBC”), with a $300,000 commitment fee payable at such time. Note 13—Other Borrowings (continued) The following table presents short-term credit lines available for use, for which the Company did not have an outstanding balance as of December 31, 2017 and 2016: 2017 2016 Federal Reserve Bank of Chicago discount window line $ 144,248 $ 110,600 Available federal funds lines 55,000 20,000

Deposits

Deposits	12 Months Ended
	Dec. 31, 2017
Deposits [Abstract]
Deposits	Note 14—Deposits The following is a summary of the Company’s deposits as of December 31, 2017 and 2016: 2017 2016 Non-interest bearing demand deposits $ 760,887 $ 724,457 Interest bearing checking accounts 186,611 173,929 Money market demand accounts 349,862 369,074 Other savings 437,212 446,418 Time deposits (below $250,000) 627,255 659,129 Time deposits ($250,000 and above) 81,502 117,387 Total deposits $ 2,443,329 $ 2,490,394 Time deposits of $250,000 or more included $30.8 million of brokered deposits at December 31, 2016 and none at December 31, 2017. At December 31, 2017, the scheduled maturities of time deposits were as follows: Scheduled Maturities 2018 $ 548,208 2019 139,748 2020 9,552 2021 6,703 2022 4,546 Total $ 708,757

Junior Subordinated Debentures

Junior Subordinated Debentures	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Junior Subordinated Debentures	Note 15— Junior Subordinated Debentures At December 31, 2017 and 2016, the Company’s junior subordinated debentures by issuance were as follows: Name of Trust Aggregate Principal Amount 2017 Aggregate Principal Amount 2016 Stated Maturity Contractual Rate at December 31, 2017 Interest Rate Spread Metropolitan $ 35,000 $ 35,000 March 4.39 % Three-month LIBOR + 2.79% RidgeStone Capital Trust I 1,500 1,500 June 30, 2033 5.09 % Five-year LIBOR + 3.50% Total liability, at par 36,500 36,500 Discount (8,853 ) (9,574 ) Total liability, at carrying value $ 27,647 $ 26,926 In 2004, the Company’s predecessor, Metropolitan Bank Group, Inc., issued $35.0 million floating rate junior subordinated debentures to Metropolitan Statutory Trust 1, which was formed for the issuance of trust preferred securities. The debentures bear Note 15— Junior Subordinated Debentures (continued) interest at three-month LIBOR plus 2.79% (4.39% and 3.78% at December 31, 2017 and 2016, respectively). Interest is payable quarterly. The Company has the right to redeem the debentures, in whole or in part, on any interest payment date on or after March 2009. Accrued interest payable was $62,000 and $50,000 as of December 31, 2017 and 2016, respectively. As part of the Ridgestone acquisition, the Company assumed the obligations to RidgeStone Capital Trust I of $1.5 million in principal amount, which was formed for the issuance of trust preferred securities. Refer to Note 3—Acquisition of a Business for additional information. Beginning on June 30, 2008, the interest rate reset to the five-year LIBOR plus 3.50% (5.09% at December 31, 2017 and 2016), which is in effect until September 30, 2018 and updated every five years. Interest is paid on a quarterly basis. The Company has the right to redeem the debentures, in whole or in part, on any interest payment date on or after June 30, 2008. There was no accrued interest payable as of December 31, 2017 or 2016. The Trusts are not consolidated with the Company. Accordingly, the Company reports the subordinated debentures held by the Trusts as liabilities. The Company owns all of the common securities of each trust. The junior subordinated debentures qualify, and are treated as, Tier 1 regulatory capital of the Company subject to regulatory limitations. The trust preferred securities issued by each trust rank equally with the common securities in right of payment, except that if an event of default under the indenture governing the notes has occurred and is continuing, the preferred securities will rank senior to the common securities in right of payment.

Employee Benefit Plans

Employee Benefit Plans	12 Months Ended
	Dec. 31, 2017
Defined Contribution Pension And Other Postretirement Plans Disclosure [Abstract]
Employee Benefit Plans	Note 16— Employee Benefit Plans The Company’s defined contribution 401(k) savings plan (the “Plan”) covers substantially all employees that have completed certain service requirements. The Board of Directors determines the amount of any discretionary profit sharing contribution made to the plan. There were no profit sharing contributions to the Plan for the years ended December 31, 2017 and 2016. The net assets of the plan are not included in the Consolidated Statements of Financial Condition. As of February 1, 2016, a 401(k) employer match contribution was adopted by the Company, pursuant to which the Company will make a contribution equal to 50% of the first 4% contributed by employees. Total expense for the employer contributions made to the Plan was $655,000 during the year ended December 31, 2016. Effective January 1, 2017, the employer match was increased to equal 100% of the first 3% and 50% for the next 2% contributed by employees. Total expense for the employer contributions made to the Plan was $1.5 million during the year ended December 31, 2017. The Company’s board of directors adopted the Byline Bancorp, Inc. Employee Stock Purchase Plan (the “ESPP”) in connection with the IPO. The ESPP will allow employees to purchase shares of common stock at a discount from the market price through automatic payroll deductions. A total of 200,000 shares of common stock are reserved and available for sale under the ESPP, subject to adjustment in accordance with the terms of the ESPP. The Company intends for the ESPP to be qualified under Section 423 of the Code. The plan offering was in the first quarter of 2018, and there was no compensation expense for the years ended December 31, 2017, 2016, or 2015.

Commitments and Contingent Liab

Commitments and Contingent Liabilities	12 Months Ended
	Dec. 31, 2017
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingent Liabilities	Note 17— Commitments and Contingent Liabilities Legal contingencies —In the ordinary course of business, the Company and Bank have various outstanding commitments and contingent liabilities that are not recognized in the accompanying consolidated financial statements. In addition, the Company may be a defendant in certain claims and legal actions arising in the ordinary course of business. In the opinion of management, after consultation with legal counsel, the ultimate disposition of these matters is currently not expected to have a material adverse effect on the Company’s Consolidated Statements of Financial Condition. Operating lease commitments —The Company has entered into various operating lease agreements primarily for facilities and land on which banking facilities are located. Certain lease agreements have renewal options at the end of the original lease term and certain lease agreements have escalation clauses in the rent payments. Note 17— Commitments and Contingent Liabilities (continued) The minimum annual rental commitments for operating leases subsequent to December 31, 2017, exclusive of taxes and other charges, are summarized as follows: Minimum Commitments 2018 $ 3,000 2019 2,522 2020 2,023 2021 1,776 2022 972 Thereafter 2,073 Total $ 12,366 The Company’s rental expenses for the years ended December 31, 2017, 2016, and 2015 were $4.6 million, $3.8 million, and $3.6 million, respectively. During the years ended December 31, 2017, 2016, and 2015 the Company received $702,000, $737,000, and $744,000, respectively, in sublease income which is included in the consolidated statements of operations as a reduction of occupancy expense. The total amount of minimum rentals to be received in the future on these subleases is approximately $1.8 million, and the leases have contractual lives extending through 2025. In addition to the above required lease payments, the Company has contractual obligations related primarily to information technology contracts and other maintenance contracts. The amounts are not material. Commitments to extend credit —The Company is party to financial instruments with off‑balance sheet risk in the normal course of business to meet the financing needs of its customers. These financial instruments include commitments to extend credit and standby letters of credit. Those instruments involve, to varying degrees, elements of credit and interest rate risk in excess of the amount recognized in the Consolidated Statements of Financial Condition. The contractual or notional amounts of those instruments reflect the extent of involvement the Company has in particular classes of financial instruments. The Company’s exposure to credit loss in the event of non‑performance by the other party to the financial instrument for commitments to extend credit and standby letters of credit is represented by the contractual or notional amount of those instruments. The Company uses the same credit policies in making commitments and conditional obligations as it does for funded instruments. The Company does not anticipate any material losses as a result of the commitments and standby letters of credit. The following table summarizes the contract or notional amount of outstanding loan and lease commitments at December 31, 2017 and 2016: 2017 2016 Fixed Rate Variable Fixed Variable Commitments to extend credit $ 55,924 $ 467,429 $ 37,731 $ 332,928 Standby letters of credit 1,226 3,337 1,060 4,135 Total $ 57,150 $ 470,766 $ 38,791 $ 337,063 Commitments to extend credit are agreements to lend to a customer as long as there is no violation of any condition established in the contract. Commitments generally have fixed expiration dates or other termination clauses and may require payment of a fee. Since many of the commitments are expected to expire without being drawn upon, the total commitment amount does not necessarily represent future cash requirements. The Company evaluates each customer’s creditworthiness on a case-by-case basis. The amount of collateral obtained, if deemed necessary by the Company upon extension of credit, is based on management’s credit evaluation of the counterparty. Collateral is primarily obtained in the form of commercial and residential real estate (including income producing commercial properties). Standby letters of credit are conditional commitments issued by the Company to guarantee to a third-party the performance of a customer. Those guarantees are primarily issued to support public and private borrowing arrangements, bond financing and similar transactions. The credit risk involved in issuing letters of credit is essentially the same as that involved in extending loan facilities to customers. Note 17— Commitments and Contingent Liabilities (continued) Commitments to make loans are generally made for periods of 90 days or less. The fixed rate loan commitments have interest rates ranging from 3.05% to 19.50% and maturities up to 2020. Variable rate loan commitments have interest rates ranging from 2.45% to 9.25% and maturities up to 2040.

Fair Value Measurement

Fair Value Measurement	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Fair Value Measurement	Note 18— Fair Value Measurement Fair value is the exchange price that would be received for an asset or paid to transfer a liability (exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. In addition, the Company has the ability to obtain fair values for markets that are not accessible. These types of inputs create the following fair value hierarchy: Level 1 —Quoted prices in active markets for identical assets or liabilities. Level 2 —Quoted prices for similar instruments in active markets, quoted prices for identical or similar instruments in markets that are not active and model-derived valuations whose inputs are observable or whose significant value drivers are observable. Level 3 —Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the asset or liability. Unobservable inputs are used to measure fair value to the extent that observable inputs are not available. The Company’s own data used to develop unobservable inputs may be adjusted for market considerations when reasonably available. A financial instrument’s categorization within the valuation hierarchy is based upon the lowest level of input that is significant to the fair value measurement. The Company’s assessment of the significance of a particular input to the fair value measurement in its entirety requires judgment, and considers factors specific to assets and liabilities. The Company used the following methods and significant assumptions to estimate fair value for certain assets measured and carried at fair value on a recurring basis: Securities available-for-sale —The Company obtains fair value measurements from an independent pricing service. Management reviews the procedures used by the third party, including significant inputs used in the fair value calculations. The fair value measurements consider observable data that may include dealer quotes, market spreads, cash flows, the U.S. Treasury yield curve, live trading levels, trade execution data, market consensus prepayment speeds, credit information and the bond’s terms and conditions, among other things. When market quotes are not readily accessible or available, alternative approaches are utilized, such as matrix or model pricing. The Company’s methodology for pricing non-rated bonds focuses on three distinct inputs: equivalent rating, yield and other pricing terms. To determine the rating for a given non-rated municipal bond, the Company references a publicly issued bond by the same issuer if available as well as other additional key metrics to support the credit worthiness. Typically, pricing for these types of bonds would require a higher yield than a similar rated bond from the same issuer. A reduction in price is applied to the rating obtained from the comparable bond, as the Company believes if liquidated; a non-rated bond would be valued less than a similar bond with a verifiable rating. The reduction applied by the Company is one notch lower (i.e. a “AA” rating for a comparable bond would be reduced to “AA-” for the Company’s valuation). In 2017 and 2016, all of the ratings derived by the Company were “BBB” or better with and without comparable bond proxies. The fair value measurement of municipal bonds is sensitive to the rating input, as a higher rating typically results in an increased valuation. The remaining pricing inputs used in the bond valuation are observable. Based on the rating determined, the Company obtains a corresponding current market yield curve available to market participants. Other terms including coupon, maturity date, redemption price, number of coupon payments per year, and accrual method are obtained from the individual bond term sheets. Servicing assets —Fair value is based on a loan-by-loan basis taking into consideration the original term to maturity, the current age of the loan and the remaining term to maturity. The valuation methodology utilized for the servicing assets begins with generating future cash flows for each servicing asset, based on their unique characteristics and market-based assumptions for prepayment speeds. The present value of the future cash flows are then calculated utilizing market-based discount rate assumptions. Derivative instruments —Interest rate swaps are valued by a third party, using models that primarily use market observable inputs, such as yield curves, and are validated by comparison with valuations provided by the respective counterparties. Derivative financial instruments are included in other assets and other liabilities in the Consolidated Statements of Financial Condition. Note 18— Fair Value Measurement (continued) The following tables summarize the Company’s financial assets and liabilities that were measured at fair value on a recurring basis at December 31, 2017 and 2016: Fair Value Measurements Using 2017 Fair Value Level 1 Level 2 Level 3 Financial assets Securities available-for-sale U.S. Treasury Notes $ 14,863 $ 14,863 $ — $ — U.S. Government agencies 52,958 — 52,958 — Obligations of states, municipalities, and political subdivisions 33,170 — 32,795 375 Mortgage-backed securities; residential Agency 307,457 — 307,457 — Non-Agency 39,514 — 39,514 — Mortgage-backed securities; commercial Agency 69,043 — 69,043 — Non-Agency 30,971 — 30,971 — Corporate securities 29,976 — 29,976 — Other securities 5,284 1,921 2,686 677 Servicing assets 21,400 — — 21,400 Derivative assets 5,981 — 5,981 — Financial liabilities Derivative liabilities 994 — 994 — Fair Value Measurements Using 2016 Fair Value Level 1 Level 2 Level 3 Financial assets Securities available-for-sale U.S. Treasury Notes $ 14,920 $ 14,920 $ — $ — U.S. Government agencies 58,857 — 58,857 — Obligations of states, municipalities, and political subdivisions 16,059 — 15,509 550 Mortgage-backed securities; residential Agency 368,160 — 368,160 — Non-Agency 19,933 — 19,933 — Mortgage-backed securities; commercial Agency 77,403 — 77,403 — Non-Agency 31,052 — 31,052 — Corporate securities 17,329 — 17,329 — Other securities 4,847 1,938 2,379 530 Servicing assets 21,091 — — 21,091 Derivative assets 4,317 — 4,317 — Financial liabilities Derivative liabilities 559 — 559 — During 2016, the Company acquired the servicing assets and single‑issuer trust preferred securities included in other securities categorized as Level 3 of the fair value hierarchy through a business combination. Note 18— Fair Value Measurement (continued) In addition, during 2016, the Company purchased privately-issued municipal securities that are categorized as Level 3. These municipal securities are bonds issued for one municipal government entity located in the Chicago metropolitan area and are privately placed, non-rated bonds without Committee on Uniform Security Identification Procedures numbers. The Company did not have any transfers between Level 1 and Level 2 of the fair value hierarchy during the years ended December 31, 2017 and 2016. The Company’s policy for determining transfers between levels occurs at the end of the reporting period when circumstances in the underlying valuation criteria change and result in transfer between levels. The following table presents additional information about financial assets measured at fair value on recurring basis for which the Company used significant unobservable inputs (Level 3): Twelve Months Ended December 31, 2017 2016 2017 2016 Investment Securities Servicing Assets Balance, beginning of period $ 1,080 $ — $ 21,091 $ — Acquired at fair value — 548 — 20,295 Additions, net — 550 6,250 539 Maturities (175 ) — — — Amortization 5 — — — Change in unrealized loss 142 (18 ) — — Change in fair value — — (5,941 ) 257 Balance, end of period $ 1,052 $ 1,080 $ 21,400 $ 21,091 The following table presents additional information about the unobservable inputs used in the fair value measurements on recurring basis that were categorized within Level 3 of the fair value hierarchy as of December 31, 2017: Financial Instruments Valuation Technique Unobservable Inputs Range of Inputs Weighted Average Range Impact to Valuation from an Increased or Higher Input Value Obligations of states, municipalities, and political obligations Discounted Probability of default 2.2%—2.4% 2.3 % Decrease Single issuer trust preferred Discounted cash flow Probability of default 7.5%—9.9% 8.9 % Decrease Servicing assets Discounted cash flow Prepayment speeds 1.6%—9.9% 8.6 % Decrease Discount rate 9.9%—18.4% 13.8 % Decrease Expected weighted average loan life 0.2—8.2 years 5.8 years Increase The Company used the following methods and significant assumptions to estimate fair value for certain assets measured and carried at fair value on a non-recurring basis: Loans held for sale —Mortgage loans originated and intended for sale in the secondary market are carried at the lower of aggregate cost or fair value based on contract price. Loans transferred to loans held for sale are carried at the lower of cost or fair value, less estimated costs to sell. Impaired loans (excluding acquired impaired loans) —Impaired loans, other than those existing on the date of a business acquisition, are primarily carried at the fair value of the underlying collateral, less estimated costs to sell, if the loan is collateral dependent. Valuations of impaired loans that are collateral dependent are generally supported by third party appraisals in accordance with the Bank’s credit policy. Other valuation methods include analysis of discounted cash flows, which measures the present value of expected future cash flows discounted at the loan’s effective interest rate. Note 18— Fair Value Measurement (continued) Assets held for sale —Assets held for sale consist of former branch locations, vacant land, and property previously purchased for expansion. Assets are considered held for sale when management has approved selling the assets following a branch closure or other events. The properties are being actively marketed and transferred to assets held for sale based on the lower of carrying value or its fair value, less estimated costs to sell. Other real estate owned —Certain assets held within other real estate owned represent real estate or other collateral that has been adjusted to its estimated fair value, less cost to sell, as a result of transferring from the loan portfolio at the time of foreclosure or repossession and based on management’s periodic impairment evaluation. From time to time, non-recurring fair value adjustments to other real estate owned are recorded to reflect partial write-downs based on an observable market price or current appraised value of property. Adjustments to fair value based on such non-recurring transactions generally result from the application of lower-of-cost-or-market accounting or write-downs of individual assets due to impairment. The following tables summarize the Company’s assets that were measured at fair value on a non-recurring basis, excluding acquired impaired loans, as of December 31, 2017 and 2016: Fair Value Measurements Using 2017 Fair Value Level 1 Level 2 Level 3 Non-recurring Impaired loans (excluding acquired impaired loans) Commercial real estate $ 12,783 $ — $ — $ 12,783 Residential real estate 2,271 — — 2,271 Construction, land development, and other land — — — — Commercial and industrial 12,092 — — 12,092 Installment and other — — — — Assets held for sale 9,779 — — 9,779 Other real estate owned 10,626 — — 10,626 Fair Value Measurements Using 2016 Fair Value Level 1 Level 2 Level 3 Non-recurring Impaired loans (excluding acquired impaired loans) Commercial real estate $ 8,916 $ — $ — $ 8,916 Residential real estate 1,007 — — 1,007 Construction, land development, and other land — — — — Commercial and industrial 986 — — 986 Installment and other — — — — Assets held for sale 14,748 — — 14,748 Other real estate owned 16,570 — — 16,570 Note 18— Fair Value Measurement (continued) The following table provides a description of the valuation technique, unobservable inputs and qualitative information about the Company’s assets and liabilities classified as Level 3 and measured at fair value on a non-recurring basis as of December 31, 2017 and 2016: Financial Instruments Valuation Technique Unobservable Inputs Range of Inputs Impact to Valuation from an Increased or Higher Input Value Impaired loans (excluding acquired impaired loans) Appraisals Appraisal adjustments, sales costs and other discount adjustments for market conditions 6% - 10% Decrease Assets held for sale List price, contract price Sales costs and other discount adjustments for market conditions 7% Decrease Other real estate owned Appraisals Appraisal adjustments, sales costs and other discount adjustments for market conditions 7% - 20% Decrease The following methods and assumptions were used by the Company in estimating fair values of other assets and liabilities for disclosure purposes: Cash and cash equivalents —For these short-term instruments, the carrying amount is a reasonable estimate of fair value. The fair value for time certificates with other banks is based on the market values for comparable investments. Securities held-to-maturity —The Company obtains fair value measurements from an independent pricing service. Management reviews the procedures used by the third party, including significant inputs used in the fair value calculations. The fair value measurements consider observable data that may include dealer quotes, market spreads, cash flows, the U.S. Treasury yield curve, live trading levels, trade execution data, market consensus prepayment speeds, credit information and the bond’s terms and conditions, among other things. When market quotes are not readily accessible or available, alternative approaches are utilized, such as matrix or model pricing. Restricted stock —The fair value has been determined to approximate cost. Loans held for sale —The fair value of loans held for sale are based on quoted market prices, where available, and determined by discounted estimated cash flows using interest rates approximating the Company’s current origination rates for similar loans adjusted to reflect the inherent credit risk. Loan and lease receivables, net —For certain variable rate loans that reprice frequently and with no significant changes in credit risk, fair value is estimated at carrying value. The fair value of other types of loans is estimated by discounting future cash flows, using current rates at which similar loans would be made to borrowers with similar credit ratings and for the same remaining maturities. Deposit liabilities —The fair value of demand deposits, savings accounts, and certain money market deposits is the amount payable on demand at the reporting date. The fair value of fixed-maturity certificates of deposit is estimated by discounting future cash flows, using rates currently offered for deposits of similar remaining maturities. Federal Home Loan Bank advances —The fair value of FHLB advances is estimated by discounting the agreements based on maturities using rates currently offered for FHLB advances of similar remaining maturities adjusted for prepayment penalties that would be incurred if the borrowings were paid off on the measurement date. Securities sold under agreements to repurchase —The carrying amount approximates fair value due to maturities of less than ninety days. Note 18— Fair Value Measurement (continued) Junior subordinated debentures —The fair value of junior subordinated debentures, in the form of trust preferred securities, is determined using rates currently available to the Company for debt with similar terms and remaining maturities. Accrued interest receivable and payable —The carrying amount approximates fair value. Commitments to extend credit and commercial and standby letters of credit —The fair values of these off-balance sheet commitments to extend credit and commercial and standby letters of credit are not considered practicable to estimate because of the lack of quoted market prices and the inability to estimate fair value without incurring excessive costs. The estimated fair values of financial instruments and levels within the fair value hierarchy are as follows: Fair Value 2017 2016 Hierarchy Level Carrying Amount Estimated Fair Value Carrying Amount Estimated Fair Value Financial assets Cash and due from banks 1 $ 19,404 $ 19,404 $ 17,735 $ 17,735 Interest bearing deposits with other banks 2 38,945 38,945 28,798 28,798 Securities held-to-maturity 2 117,163 117,277 138,846 138,082 Other restricted stock 2 16,343 16,343 14,993 14,993 Loans held for sale 3 5,212 5,851 23,976 26,487 Loans and lease receivables, net 3 2,260,786 2,240,235 2,137,088 2,068,157 Accrued interest receivable 3 7,670 7,670 6,866 6,866 Financial liabilities Non-interest bearing deposits 2 760,887 760,887 724,457 724,457 Interest bearing deposits 2 1,682,442 1,678,535 1,765,937 1,764,078 Accrued interest payable 2 1,306 1,306 2,427 2,427 Line of credit 2 — — 20,650 20,650 Federal Home Loan Bank advances 2 361,506 361,500 313,715 313,646 Securities sold under repurchase agreement 2 31,187 31,187 17,249 17,249 Junior subordinated debentures 3 27,647 33,907 26,926 26,943

Share-Based Compensation

Share-Based Compensation	12 Months Ended
	Dec. 31, 2017
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Share-Based Compensation	Note 19— Share-Based Compensation In June 2017, the Company adopted the 2017 Omnibus Incentive Compensation Plan (the “Omnibus Plan”) in connection with our IPO. The Omnibus Plan provides for the grant of stock options, stock appreciation rights, restricted stock, restricted stock units, dividend equivalent rights and other equity-based, equity-related or cash-based awards. A total of 1,550,000 shares of our common stock have been reserved and are available for issuance under the Omnibus Plan. On July 6, 2017, in conjunction with the completion of the IPO, the Company granted 58,900 restricted shares of the Company’s common stock Note 19— Share-Based Compensation (continued) The following table discloses the changes in restricted shares for the year ended December 31, 2017: Omnibus Plan Number of Shares Weighted Average Grant Date Fair Value Beginning balance — $ — Granted 70,798 20.31 Vested — — Forfeited (400 ) 20.18 Ending balance outstanding at December 31, 2017 70,398 $ 20.31 No restricted shares vested during the year ended December 31, 2017. The Company recognizes share-based compensation based on the estimated fair value of the restricted stock at the grant date. Share-based compensation expense is included in non-interest expense in the Consolidated Statements of Operations. No restricted shares were outstanding in 2016. The following table summarizes restricted stock compensation expense for the year ended December 31, 2017: Year Ended December 31 2017 Total share-based compensation - restricted stock $ 203 Income tax benefit 83 Unrecognized compensation expense 1,227 Weighted-average amortization period remaining 2.8 years The fair value of the unvested restricted stock awards at December 31, 2017 was $1.6 million. The Company maintained a nonqualified, share-based, stock option plan adopted prior to recapitalization (“MBG Plan”). There were no options granted or exercised under this plan during the year ended December 31, 2016 through the termination date (June 30, 2017). At the time of the Company’s reincorporation in Delaware, in June 2017, the Board of Directors cancelled the MBG Plan and all outstanding options were cancelled. In October 2014, the Company adopted the Byline Bancorp, Inc. Equity Incentive Plan (“BYB Plan”). The maximum number of shares available for grants under this Plan was 2,476,122 shares. During 2016 and 2015, the Company granted options to purchase 212,400 and 1,634,568 shares, respectively, under this plan. The Company did not grant any stock options during the year ended December 31, 2017. In June 2017, the Board of Directors terminated the BYB Plan and no future grants can be made under this plan. Options to purchase a total of 1,783,020 shares remain outstanding under the BYB Plan. The types of stock options granted under the BYB Plan were Time Options and Performance Options. The exercise price of each option is equal to the fair value of the stock as of the date of grant. These option awards have vesting periods ranging from 1 to 5 years and have 10-year contractual terms. Stock volatility was computed as the average of the volatilities of peer group companies. The vesting of Time Options is conditional based on completion of service. Performance Options have conditional vesting based on either performance targets or market performance. Certain Performance Options’ performance goals will be satisfied (in whole or in part) if the Bank achieves various performance targets such as profitability, asset quality, and conditional based on market performance, as outlined in the BYB Plan. Each of the performance goals identified are measured for achievement (or failure to achieve) independent of each other. In October 2017, the Board of Directors determined that the Performance Option goals were satisfied, in whole, and these Performance Options converted to Time Options. As a result of the previous completion of service, 414,894 performance options vested on October 3, 2017. Note 19— Share-Based Compensation (continued) The fair values of the stock options were determined using the Black-Scholes-Merton model for Time Options and a Monte Carlo simulation model for Performance Options. The fair values of options under the BYB Plan were determined using the following assumptions as of the grant dates: Time Options Grants 2016 2015 Risk-free interest rate 1.34% - 1.40% 1.68% - 1.85% Expected term (years) 5.2 - 5.6 5.7 - 6.3 Expected stock price volatility 20.39 % 16.18% - 16.55% Expected dividend yield 0.00 % 0.00 % Weighted average grant date fair value $ 3.55 $ 2.25 Performance Options Grants 2016 2015 Risk-free interest rate Implied forward rates Implied forward rates Expected term (years) Variable Variable Expected stock price volatility 20.34% - 20.39% 16.18% - 16.55% Expected dividend yield 0.00 % 0.00 % Weighted average grant date fair value $ 3.75 $ 1.65 The following table discloses the activity in shares subject to options and the weighted average exercise prices, in actual dollars, for the year ended December 31, 2017: BYB Plan Number of Shares Weighted Average Exercise Price Intrinsic Value Weighted Average Remaining Contractual Term (in Years) Beginning balance 1,798,220 $ 11.95 $ 15,788 8.6 Granted — Expired — Exercised — Forfeited (15,200 ) 16.25 Ending balance outstanding at December 31, 2017 1,783,020 $ 11.91 $ 19,718 7.6 Exercisable at December 31, 2017 1,304,257 $ 11.51 $ 14,953 7.5 There were no stock options exercised during the year ended December 31, 2017. The Company recognizes share-based compensation based on the estimated fair value of the option at the grant date. Forfeitures are estimated based upon industry standards. Share-based compensation expense is included in non-interest expense in the Consolidated Statements of Operations. The following table summarizes stock option compensation expense for the years ended December 31, 2017 and 2016: Years Ended December 31, 2017 2016 Total share-based compensation - stock options $ 1,294 $ 899 Income tax benefit 521 360 Unrecognized compensation expense 729 1,752 Weighted-average amortization period remaining 1.2 years 1.8 years

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2017
Related Party Transactions [Abstract]
Related Party Transactions	Note 20— Related Party Transactions Loans to related parties —Loans that may be made to the Bank’s executive officers, as defined in 12 CFR 215 (Regulation O), directors, principal stockholders and their affiliates would be on substantially the same terms, including interest rates and collateral, as those prevailing at the time for comparable transactions with unrelated persons and would not involve more than normal risk of collectability. As of December 31, 2017 and 2016, there were no loans made to the related parties described above. Deposits from related parties —Deposits from related parties were not material as of December 31, 2017 and 2016. Other —As of December 31, 2017, there were no receivables outstanding from related parties. At December 31, 2016, a short‑term receivable of $100,000 was outstanding from a related party for a subscription for the Series B preferred stock subscription and was repaid in January 2017. Refer to Note 25—Stockholders’ Equity for additional information regarding the transaction.

Regulatory Capital Requirements

Regulatory Capital Requirements	12 Months Ended
	Dec. 31, 2017
Regulatory Capital Requirements [Abstract]
Regulatory Capital Requirements	Note 21—Regulatory Capital Requirements The Company and the Bank are subject to various regulatory capital requirements administered by their respective 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 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 their assets, liabilities and certain off‑balance sheet items as calculated under regulatory accounting practices. The 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 Company and the Bank to maintain minimum amounts and ratios of Common Equity Tier 1 capital (“CET1”), Tier 1 capital and total capital to risk‑weighted assets and of Tier 1 capital to average consolidated assets, as defined in the regulations. As of December 31, 2017, the most recent notification from the FDIC categorized the Bank as well‑capitalized under the framework for prompt corrective action. There are no conditions or events since that notification that management believes have changed the Bank’s category. The required regulatory capital ratios are set forth in the following tables along with the minimum capital amounts required for the Company and the Bank and well capitalized with respect to the Bank. The Company’s and the Bank’s actual capital amounts and ratios as of December 31, 2017 and 2016 are also presented. Actual Minimum Capital Required Required to be Considered Well Capitalized 2017 Amount Ratio Amount Ratio Amount Ratio Total capital to risk weighted assets: Company $ 410,831 15.98 % $ 205,661 8.00 % N/A N/A Bank 367,972 14.28 % 206,083 8.00 % 257,604 10.00 % Tier 1 capital to risk weighted assets: Company $ 392,520 15.27 % $ 154,246 6.00 % N/A N/A Bank 349,662 13.57 % 154,562 6.00 % 206,083 8.00 % Common Equity Tier 1 (CET1) to risk weighted assets: Company $ 353,995 13.77 % $ 115,684 4.50 % N/A N/A Bank 349,662 13.57 % 115,922 4.50 % 167,442 6.50 % Tier 1 capital to average assets: . Company $ 392,520 12.25 % $ 128,178 4.00 % N/A N/A Bank 349,662 10.89 % 128,409 4.00 % 160,511 5.00 % Note 21—Regulatory Capital Requirements (continued) Actual Minimum Capital Required Required to be Considered Well Capitalized 2016 Amount Ratio Amount Ratio Amount Ratio Total capital to risk weighted assets: Company $ 316,314 13.28 % $ 190,257 8.00 % N/A N/A Bank 325,465 13.61 % 191,267 8.00 % 239,084 10.00 % Tier 1 capital to risk weighted assets: Company $ 304,324 12.78 % $ 142,895 6.00 % N/A N/A Bank 313,474 13.11 % 143,450 6.00 % 191,267 8.00 % Common Equity Tier 1 (CET1) to risk weighted assets: Company $ 266,760 11.20 % $ 107,171 4.50 % N/A N/A Bank 313,474 13.11 % 107,588 4.50 % 155,404 6.50 % Tier 1 capital to average assets: Company $ 304,324 10.07 % $ 120,850 4.00 % N/A N/A Bank 313,474 10.35 % 121,169 4.00 % 151,461 5.00 % The Company and Byline Bank must maintain a capital conservation buffer consisting of CET1 capital greater than 2.5% of risk-weighted assets above the required minimum risk-based capital levels in order to avoid limitations on paying dividends, repurchasing shares, and paying discretionary bonuses. The capital conservation buffer requirement began to be phased in on January 1, 2016 when a buffer greater than 0.625% of risk-weighted assets was required, which amount increases each year until the buffer requirement is fully implemented on January 1, 2019. As of January 1, 2017 the capital conservation buffer requirement was 1.25%. The conservation buffers for the Company and Byline Bank exceed the fully phased in minimum capital requirement as of December 31, 2017. Provisions of state and federal banking regulations may limit, by statute, the amount of dividends that may be paid to the Company by Byline Bank without prior approval of Byline Bank’s regulatory agencies. The Company is economically dependent on the cash dividends received from Byline Bank. These dividends represent the primary cash flow from operating activities used to service obligations. For the year ended December 31, 2017, the Company received $2.8 million in cash dividends from Byline Bank to pay the line of credit interest; the trust preferred securities interest and preferred dividends. There were no cash dividends received by the Company from Byline Bank for the year ended December 31, 2016.

Derivative Instruments and Hedg

Derivative Instruments and Hedge Activities	12 Months Ended
	Dec. 31, 2017
Derivative Instruments And Hedging Activities Disclosure [Abstract]
Derivative Instruments and Hedge Activities	Note 22—Derivative Instruments and Hedge Activities The Company recognizes derivative financial instruments at fair value regardless of the purpose or intent for holding the instrument. The Company records derivative assets and derivative liabilities on the Consolidated Statements of Financial Condition within accrued interest receivable and other assets and accrued interest payable and other liabilities, respectively. The following tables present the fair value of the Company’s derivative financial instruments and classification on the Consolidated Statements of Financial Condition as of December 31, 2017 and 2016: 2017 2016 Fair Value Fair Value Notional Amount Other Assets Other Liabilities Notional Amount Other Assets Other Liabilities Derivatives designated as hedging instruments Interest rate swaps designated as cash flow hedges $ 250,000 $ 5,030 $ 38 $ 100,000 $ 3,719 $ — Derivatives not designated as hedging instruments Other interest rate swaps 94,726 951 956 51,213 598 559 Total derivatives $ 344,726 $ 5,981 $ 994 $ 151,213 $ 4,317 $ 559 Interest rate swaps designated as cash flow hedges —Cash flow hedges of interest payments associated with certain FHLB advances had notional amounts totaling $250.0 million and $100.0 million as of December 31, 2017, and 2016, respectively. The aggregate fair value of the swaps is recorded in other assets or other liabilities with changes in fair value recorded in other Note 22—Derivative Instruments and Hedge Activities (continued) comprehensive income (loss), net of taxes, to the extent effective. The amount included in accumulated other comprehensive income (loss) would be reclassified to current earnings when the hedged FHLB advances affect earnings. The Company assesses the effectiveness of each hedging relationship by comparing the changes in fair value of the derivative hedging instrument with the changes in fair value of the designated hedged transactions. The Company expects the hedges to remain highly effective during the remaining terms of the swaps and did not recognize any hedge ineffectiveness in current earnings during the years ended December 31, 2017 and 2016. The following table reflects the cash flow hedges as of December 31, 2017: Notional amounts $ 250,000 Derivative assets fair value 5,030 Derivative liabilities fair value 38 Weighted average pay rates 1.67 % Weighted average receive rates 1.63 % Weighted average maturity 4.2 years Interest expense recorded on these swap transactions totaled $579,000 and $40,000 during the years ended December 31, 2017 and 2016, respectively, and is reported as a component of interest expense on FHLB advances. At December 31, 2017, the Company estimates $512,000 of the unrealized gain to be reclassified as an increase to interest expense during the next twelve months. The following table reflects the net gains (losses) recorded in accumulated other comprehensive income (loss) and the Consolidated Statements of Operations relating to the cash flow derivative instruments for the year ended December 31, 2017: Amount of Gain Recognized in OCI (Effective Portion) Amount of Loss Reclassified from OCI to Income as an Increase to Interest Expense Amount of Gain (Loss) Recognized in Other Non-Interest Income (Ineffective Portion) Interest rate swaps $ 688 $ (579 ) $ — Other interest rate swaps —The total combined notional amount was $94.7 million with maturities ranging from January 2020 to November 2027. The fair values of the interest rate swap agreements are reflected in other assets and other liabilities with corresponding gains or losses reflected in non-interest income. During the years ended December 31, 2017 and 2016, transaction fees related to these derivative instruments were $393,000 and $679,000, respectively. There was no transaction fees related to these derivative instruments for the year ended December 31, 2015. The following table reflects other interest rate swaps as of December 31, 2017: Notional amounts $ 94,726 Derivative assets fair value 951 Derivative liabilities fair value 956 Weighted average pay rates 4.38 % Weighted average receive rates 3.73 % Weighted average maturity 6.3 years Credit risk —Derivative instruments are inherently subject to market risk and credit risk. Market risk is associated with changes in interest rates and credit risk relates to the Company’s risk of loss when the counterparty to a derivative contract fails to perform according to the terms of the agreement. Market and credit risks are managed and monitored as part of the Company’s overall asset-liability management process. The credit risk related to derivatives entered into with certain qualified borrowers is managed through the Company’s loan underwriting process. The Company’s loan underwriting process also approves the Bank’s swap Note 22—Derivative Instruments and Hedge Activities (continued) counterparty used to mirror the borrowers’ swap. The Company has a bilateral agreement with each swap counterparty that provides that fluctuations in derivative values are to be fully collateralized with either cash or securities. The credit valuation adjustment (“CVA”) is a fair value adjustment to the derivative to account for this risk. During the years ended December 31, 2017 and 2016, the CVA resulted in a decrease to non-interest income of $44,000 and increase $39,000, respectively. There was no derivative activity for the year ended December 31, 2015. The Company has agreements with its derivative counterparties that contain a cross-default provision under which if the Company defaults on any of its indebtedness, including default where repayment of the indebtedness has not been accelerated by the lender, then the Company could also be declared in default on its derivative obligations. The Company also has agreements with certain derivative counterparties that contain a provision where if the Company fails to maintain its status as a well or adequately capitalized institution, then the counterparty could terminate the derivative positions and the Company would be required to settle its obligations resulted in a net asset position. The Company records interest rate derivatives subject to master netting agreements at their gross value and does not offset derivative asset and liabilities on the Consolidated Statements of Financial Condition. The table below summarizes the Company’s interest rate derivatives and offsetting positions as of December 31, 2017: Derivative Assets Fair Value Derivative Liabilities Fair Value Gross amounts recognized $ 5,981 $ 994 Less: Amounts offset in the Consolidated Statements of Financial Condition — — Net amount presented in the Consolidated Statements of Financial Condition $ 5,981 $ 994 Gross amounts not offset in the Consolidated Statements of Financial Condition Offsetting derivative positions (232 ) (232 ) Collateral posted (5,371 ) (745 ) Net credit exposure $ 378 $ 17

Parent Company Only Condensed F

Parent Company Only Condensed Financial Statements	12 Months Ended
	Dec. 31, 2017
Condensed Financial Information Of Parent Company Only Disclosure [Abstract]
Parent Company Only Condensed Financial Statements	Note 23—Parent Company Only Condensed Financial Statements The following represents the condensed financial statements of Byline Bancorp, Inc., the Parent Company: Statements of Financial Condition Parent Company Only As of December 31, 2017 2016 ASSETS Cash 39,626 9,965 Investment in banking subsidiary 445,786 419,801 Other assets 1,236 2,755 Total assets $ 486,648 $ 432,521 LIABILITIES AND STOCKHOLDERS’ EQUITY Line of credit — 20,650 Junior subordinated debentures issued to capital trusts, net 27,647 26,926 Accrued expenses and other liabilities 423 2,287 Stockholders' equity 458,578 382,658 Total liabilities and stockholders' equity $ 486,648 $ 432,521 Note 23—Parent Company Only Condensed Financial Statements (continued) Statements of Operations Parent Company Only Years ended December 31, 2017 2016 2015 INCOME Dividends from subsidiary $ 2,800 $ - $ - Other noninterest income 9 57 - Total Income 2,809 57 — EXPENSES Interest expense 2,782 2,460 2,295 Other noninterest expense 1,804 381 312 Total Expenses 4,586 2,841 2,607 Loss before provision for income taxes and equity in undistributed income (loss) of subsidiary (1,777 ) (2,784 ) (2,607 ) Provision (benefit) for income taxes (1,166 ) 204 8 Loss before equity in undistributed income (loss) of subsidiary (611 ) (2,988 ) (2,615 ) Equity in undistributed income (loss) of subsidiary 22,306 69,717 (12,359 ) Net income (loss) $ 21,695 $ 66,729 $ (14,974 ) Statements of Cash Flows Parent Company Only Years ended December 31, 2017 2016 2015 CASH FLOWS FROM OPERATING ACTIVITIES Net income (loss) $ 21,695 $ 66,729 $ (14,974 ) Adjustments to reconcile net income (loss) to net cash from operating activities: Equity in undistributed income (loss) of subsidiary (22,306 ) (69,717 ) 12,359 Stock-based compensation expense 1,497 899 1,045 Exercise of share-based awards — 40 — Accretion of junior subordinated debentures discount 721 876 944 Changes in other assets and other liabilities (2,893 ) 16 (5,546 ) Net cash used in operating activities (1,286 ) (1,157 ) (6,172 ) CASH FLOWS FROM INVESTING ACTIVITIES Investments in and advances from subsidiary — (32,019 ) — Net cash paid in acquisition of business — (36,586 ) — Net cash used in investing activities — (68,605 ) — CASH FLOWS FROM FINANCING ACTIVITIES Proceeds from revolving line of credit — 30,000 — Repayments of revolving line of credit (20,650 ) (9,350 ) — Dividends paid on preferred stock (11,277 ) — — Cash paid in lieu of fractional shares (2 ) — — Proceeds from issuance of common stock, net 76,829 49,592 — Proceeds from issuance of preferred stock 1,050 9,388 Repurchase of preferred stock (15,003 ) — — Net cash provided by financing activities 30,947 79,630 — NET CHANGE IN CASH AND CASH EQUIVALENTS 29,661 9,868 (6,172 ) CASH AND CASH EQUIVALENTS, beginning of period 9,965 97 6,269 CASH AND CASH EQUIVALENTS, end of period $ 39,626 $ 9,965 $ 97

Earnings per Share

Earnings per Share	12 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
Earnings per Share	Note 24—Earnings per Share A reconciliation of the numerators and denominators for earnings per common share computations is presented below. Incremental shares represent outstanding stock options for which the exercise price is less than the average market price of the Company’s common stock during the periods presented. Options to purchase 1,783,023 shares of common stock were outstanding as of December 31, 2017 and 2016. There were 70,798 restricted stock awards outstanding at December 31, 2017. There were no restricted stock awards outstanding at December 31, 2016 and 2015. Years ended December 31, 2017 2016 2015 Net income (loss) $ 21,695 $ 66,729 $ (14,974 ) Less: Dividends on preferred shares 11,277 — — Net income (loss) available to common stockholders $ 10,418 $ 66,729 $ (14,974 ) Weighted-average common stock outstanding: Weighted-average common stock outstanding (basic) 26,963,517 20,141,630 17,332,775 Incremental shares 583,797 289,153 — Weighted-average common stock outstanding (dilutive) 27,547,314 20,430,783 17,332,775 Basic earnings per common share $ 0.39 $ 3.31 $ (0.86 ) Diluted earnings per common share $ 0.38 $ 3.27 $ (0.86 )

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2017
Equity [Abstract]
Stockholders' Equity	Note 25—Stockholders’ Equity A summary of the Company’s preferred and common stock at December 31, 2017 and 2016 is as follows: 2017 2016 Series A non-cumulative perpetual preferred stock Par value $ — $ 0.01 Shares authorized — 15,003 Shares issued — 15,003 Shares outstanding — 15,003 Series B 7.5% fixed non-cumulative perpetual preferred stock Par value $ 0.01 $ 0.01 Shares authorized 50,000 50,000 Shares issued 10,438 9,388 Subscription receivable — 1,050 Shares outstanding 10,438 9,388 Common stock, voting Par value $ 0.01 $ — Shares authorized 150,000,000 150,000,000 Shares issued 29,317,298 24,616,706 Shares outstanding 29,317,298 24,616,706 During 2016, the Company authorized and issued Series B 7.50% fixed-to-floating non-voting, noncumulative perpetual preferred stock with a liquidation preference of $1,000 per share, plus the amount of unpaid dividends, if any, which is redeemable at the Company’s option on or after March 31, 2022. Holders of either Series A or Series B preferred stock do not have any rights to convert such stock into shares of any other class of capital stock of the Company. On January 30, 2017, the Company issued an additional 1,050 shares of Series B preferred stock, which is reflected as a subscription receivable as of December 31, 2016. For the year ended December 31, 2017, the Company declared and paid dividends on the Series B preferred stock of $776,000. Note 25—Stockholders’ Equity (continued) On May 31, 2017, the Company filed a registration statement on Form S-1with the SEC in connection with its initial public offering (the "Registration Statement”), which was subsequently amended on June 19, 2017. The Registration Statement was declared effective by the SEC on June 29, 2017. In connection with the IPO, the Company issued 4,630,194 shares of common stock, par value $0.01 per share, which included 855,000 shares sold pursuant to the underwriters’ exercise of their option to purchase additional shares. The securities were sold at a price to the public of $19.00 per share and began trading on the New York Stock Exchange on June 30, 2017. On July 6, 2017, the closing date of the IPO, the Company received net proceeds of $82.7 million. On June 14, 2017, the Company’s stockholders approved the reincorporation of the Company to a Delaware corporation. Under the terms of the merger agreement, the Company reincorporated from Illinois to Delaware by merging with and into Byline Bancorp, Inc. Delaware (“Byline Delaware”), with Byline Delaware surviving (such transaction, the “Merger”). Each share of Byline Illinois common stock issued and outstanding immediately prior to the effective time of the Merger, was converted automatically into the right to receive one fifth (0.20) of a share of common stock of Byline Delaware. There were no fractional shares issued in connection with the Merger. The reincorporation and share conversion are retrospectively reflected in the consolidated financial statements. On June 16, 2017, after obtaining the necessary approval from the Federal Reserve, the Board of Directors of Byline Delaware unanimously approved the repurchase of all of the Company’s outstanding Series A preferred stock at a purchase price per share representing a liquidation value of $1,000 per share, equal to the cash value of (i) 89.469 shares of the Company’s common stock, multiplied by (ii) the initial public offering price of the common stock of $19.00 per share. On July 14, 2017, the Company completed the repurchase of all of the Series A Preferred Stock for $25.5 million. The $10.5 million excess of the purchase price over the carrying value of the Series A was recorded as a dividend.

Selected Quarterly Financial Da

Selected Quarterly Financial Data (unaudited)	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Selected Quarterly Financial Data (unaudited)	Note 26—Selected Quarterly Financial Data (unaudited) For the year ended December 31, 2017 First Quarter Second Quarter Third Quarter Fourth Quarter Interest and Dividend Income $ 32,488 $ 33,315 $ 35,044 $ 35,956 Interest Expense 2,950 3,504 3,632 3,805 Net interest income 29,538 29,811 31,412 32,151 Provision for loan and lease losses 1,891 3,515 3,900 3,347 Net interest income after provision for loan and lease losses 27,647 26,296 27,512 28,804 Non-interest income 12,308 13,193 11,918 12,639 Non-interest expense 28,851 29,249 31,065 30,358 Income before provision for income taxes 11,104 10,240 8,365 11,085 Provision (benefit) for income taxes 4,544 4,094 (1,390 ) 11,851 Net income (loss) 6,560 6,146 9,755 (766 ) Dividends on preferred shares 189 10,697 195 196 Income (loss) available (attributable) to common stockholders $ 6,371 $ (4,551 ) $ 9,560 $ (962 ) Basic earnings (loss) per common share $ 0.26 $ (0.18 ) $ 0.33 $ (0.03 ) Diluted earnings (loss) per common share $ 0.25 $ (0.18 ) $ 0.32 $ (0.03 ) During the second quarter of 2017, in connection with the Company’s initial public offering, proceeds were used to repurchase Series A Preferred Stock, which included $10.5 million of dividends in arrears. During the third quarter of 2017, the Legislature of the state of Illinois passed an increase in the corporate tax rate from 5.25% to 7.00%. As a result of the increase, the Company recorded a benefit of $4.6 million resulting from an increase in the value of deferred tax assets related to Illinois net loss deductions. The Company recorded a net loss of $766,000, or $0.03 per common share, for the fourth quarter of 2017. The Company’s net interest income before provision for loan losses was $32.2 million. In December 2017, the “Tax Cuts and Jobs Act” reduced the federal corporate tax rate to 21% effective January 1, 2018. As a result of the decrease, the Company’s fourth quarter 2017 operating results included incremental tax expense of $7.2 million from enactment of Tax Cuts and Jobs Act of 2017. Note 26—Selected Quarterly Financial Data (unaudited) (continued) For the year ended December 31, 2016 First Quarter Second Quarter Third Quarter Fourth Quarter Interest and Dividend Income $ 22,877 $ 22,055 $ 22,657 $ 30,776 Interest Expense 1,757 1,674 1,792 2,524 Net interest income 21,120 20,381 20,865 28,252 Provision for loan and lease losses 2,513 1,152 1,683 5,004 Net interest income after provision for loan and lease losses 18,607 19,229 19,182 23,248 Non-interest income 4,288 6,198 4,776 10,642 Non-interest expense 24,487 22,817 22,384 30,998 Income before provision for income taxes (1,592 ) 2,610 1,574 2,892 Provision (benefit) for income taxes (240 ) 9 9 (61,023 ) Net income (loss) (1,352 ) 2,601 1,565 63,915 Dividends on preferred shares - - - - Income (loss) available (attributable) to common stockholders $ (1,352 ) $ 2,601 $ 1,565 $ 63,915 Basic earnings (loss) per common share $ (0.08 ) $ 0.13 $ 0.08 $ 2.66 Diluted earnings (loss) per common share $ (0.08 ) $ 0.13 $ 0.08 $ 2.62 The Company recorded net income of $63.9 million, or $2.66 per common share, for the fourth quarter of 2016. The Company’s net interest income before provision for loan losses was $28.3 million. On October 14, 2016, the Company acquired the assets and assumed the liabilities of Ridgestone. Revenues and expenses of the acquired company since the acquisition were included in the Company’s fourth quarter 2016 operating results. The increase in the fourth quarter provision was primarily the result of increases in loan growth and adjustments to certain qualitative factors impacting the Company’s historical loss rate. The increase in non-interest income was the result of gains on sale of government guaranteed loans and servicing income after the Ridgestone acquisition. The Company’s fourth quarter 2016 operating results included income tax benefit of $61.0 million primarily due to the reversal of the $61.9 million valuation allowance established against the net deferred tax assets. The determination was made based on the business forecasts indicating sustainable profitability to support recoverability of the tax assets.

Business and Summary of Signi34

Business and Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2017
Business Description And Accounting Policies [Abstract]
Nature of business	Nature of business —Byline Bancorp, Inc. (the “Company,” “we,” “us,” “our”) is a bank holding company whose principal activity is the ownership and management of its subsidiary bank, Byline Bank (the “Bank”). The Bank originates commercial, mortgage and consumer loans and leases, government guaranteed loans, and receives deposits from customers located primarily in the Chicago, Illinois metropolitan area. The Bank operates 55 Chicago metropolitan area and one Brookfield, Wisconsin, banking offices. The Bank operates under an Illinois state bank charter, provides a full range of banking services, and has full trust powers. As an Illinois state‑chartered financial institution that is not a member of the Federal Reserve System, the Bank is subject to regulation by the Illinois Department of Financial and Professional Regulation and the Federal Deposit Insurance Corporation. The Company is regulated by the Board of Governors of the Federal Reserve System. On June 28, 2013, the Company completed an external recapitalization involving a series of transactions that included the merging of the Company’s multiple subsidiary banks into the Bank. In connection with the merger of the subsidiary banks at the time of recapitalization, the Company entered into certain Conditions and Commitments to the merger and integration of the banks, which contained on‑going requirements related to payment of dividends, execution of an integration plan, director and senior officer appointments, changes in responsibilities, and reporting requirements. The Company accounted for the external recapitalization as a business combination in accordance with Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) Topic 805, Business Combinations. The transaction qualified as a recapitalization under Section 368(a)(1)(E) of the Internal Revenue Code and resulted in carryover treatment of the existing tax bases and tax loss carryforwards. As a result of its acquisition of Ridgestone Financial Services, Inc. (“Ridgestone”) on October 14, 2016, the Bank is a participant in the Small Business Administration (“SBA”) and the United States Department of Agriculture (“USDA”) (collectively referred to as “government guaranteed loans”) lending programs and originates government guaranteed loans. See Note 3—Acquisition of a Business for additional information regarding the transaction. The Bank also engages in short‑term direct financing lease contracts through BFG Corporation, doing business as Byline Financial Group (“BFG”), a wholly‑owned subsidiary of the Bank. BFG is located in Bannockburn, Illinois with sales offices in Texas, North Carolina and New York, and sales representatives in Florida, New Jersey, Michigan and Arizona. On June 14, 2017, stockholders of record as of May 22, 2017 voted to approve an Agreement and Plan of Merger between Byline Bancorp, Inc., an Illinois corporation (“Byline Illinois”), and Byline Bancorp, Inc., a wholly owned Delaware subsidiary of the Company, including the amended and restated certificate of incorporation and by‑laws of the Company. Each share of Byline Illinois common stock issued and outstanding immediately prior to the effective time of the Merger was converted automatically into the right to receive one fifth (0.20) of a share of common stock of the Company. Stockholders were paid a total of $2,000 in cash for remaining fractional shares based on the offering price of $19.00 per share. On November 27, 2017, Byline Bancorp, Inc., First Evanston Bancorp, Inc. (which we refer to as “First Evanston”), and Wildcat Acquisition Corporation, a wholly owned subsidiary of Byline (which we refer to as “Merger Sub”), entered into an Agreement and Plan of Merger (which we refer to as the “merger agreement”), that provides for the merger of Merger Sub with and into First Evanston, with First Evanston as the surviving corporation (which we refer to as the “merger”). Immediately following the merger, First Evanston will merge with and into Byline, with Byline as the surviving corporation (which we refer to as the “parent merger”) and immediately following the parent merger, First Bank & Trust, First Evanston’s wholly owned bank subsidiary (which we refer to as “First Bank & Trust”), will merge with and into the Bank, with the Bank as the surviving bank (which we refer to as the “bank merger”). At such time, First Bank & Trust’s banking offices will become banking offices of the Bank. The above described mergers are anticipated to be completed during the first half of 2018, subject to the satisfaction or waiver of the conditions included in the merger agreement.
Basis of financial statement presentation and consolidation	Basis of financial statement presentation and consolidation —The consolidated financial statements include the accounts of the Company and its subsidiaries. Significant intercompany items and transactions have been eliminated in consolidation. The accounting and reporting policies of the Company conform to accounting principles generally accepted in the United States of America (“GAAP”) as contained within the FASB’s ASC and rules and regulations of the Securities and Exchange Commission (“SEC”), including the instructions to Regulation S ‑X. In accordance with applicable accounting standards, the Company does not consolidate statutory trusts established for the sole purposes of issuing trust preferred securities and related trust common securities. See Note 15, Junior Subordinated Debentures, for additional discussion. Dollars within footnote tables disclosed within the consolidated financial statements are presented in thousands, except share and per share data. Operating results include the years ended December 31, 2017, 2016 and 2015.
Use of estimates	Use of estimates —In preparing the consolidated financial statements, management is required to make estimates and assumptions that affect the reported amounts of certain assets and liabilities and the disclosure of contingent assets and liabilities as of the date of the Consolidated Statements of Financial Condition and certain revenues and expenses for the periods included in the Consolidated Statements of Operations and the accompanying notes. Actual results could differ from those estimates. Estimates that are particularly susceptible to significant changes in the near term relate to the determination of expected cash flows of acquired impaired loans, the allowance for loan and lease losses, valuation of servicing assets, fair value measurements for assets and liabilities, goodwill, other intangible assets, the valuation or recognition of deferred tax assets and liabilities, and the valuation of assets and liabilities acquired in business combinations.
Business combinations	Business combinations —The Company accounts for business combinations under the acquisition method of accounting in accordance with ASC Topic 805, Business Combinations (“ASC 805”). The Company recognizes the fair value of the assets acquired and liabilities assumed as of the date of acquisition, with any excess of the fair value of consideration provided over the fair value of the identifiable net tangible and intangible assets acquired recorded as goodwill. Transaction costs are immediately expensed. The results of operations of the acquired business are included in the Consolidated Statements of Operations from the effective date of the acquisition, which is the date control is obtained. In accordance with ASC 805, the acquiring company retains the right to make appropriate adjustments to the assets and liabilities of the acquired entity for information obtained during the measurement period about facts and circumstances that existed as of the acquisition date. The measurement period ends as of the earlier of (a) one year from the acquisition date or (b) the date when the acquirer receives the information necessary to complete the business combination accounting.
Cash and cash equivalents	Cash and cash equivalents —Cash and cash equivalents have original maturities of three months or less. The Company holds cash and cash equivalents on deposit with other banks and financial institutions in amounts that periodically exceed the federal deposit insurance limit. The Company evaluates the credit quality of these banks and financial institutions to mitigate its credit risk and has not experienced any losses in such accounts. Cash on hand or on deposit with the Federal Reserve Bank of Chicago was required to meet regulatory reserve and clearing requirements. The reserve requirement was $15.8 million and $14.1 million as of December 31, 2017 and 2016, respectively, and the Bank met the requirement at each balance sheet date.
Securities	Securities —Securities that are held principally for resale in the near term are classified as trading and recorded at fair value with changes in fair value included in earnings. The Company did not invest in securities classified as trading during 2017 and 2016. Securities are classified as available‑for‑sale if the instrument may be sold in response to such factors including changes in market interest rates and related changes in prepayment risk, needs for liquidity, changes in the availability of and the yield on alternative instruments, and changes in funding sources and terms. Gains or losses on the sales of available‑for‑sale securities are recorded on the trade date and determined using the specific‑identification method. Unrealized holding gains or losses, net of tax, on available‑for‑sale securities are carried as accumulated other comprehensive income (loss) within stockholders’ equity until realized. Securities are classified as held‑to‑maturity and carried at amortized cost when management has the positive intent and ability to hold them to maturity. Fair values of securities are generally based on quoted market prices for the same or similar instruments. See Note 18—Fair Value Measurement for additional discussion on the determination of fair values. Interest income includes the amortization of purchase premiums and discounts, which are recognized using the effective interest method over the terms of the securities. Management evaluates securities for other‑than‑temporary impairment (“OTTI”) on a quarterly basis, and more frequently when economic or market conditions warrant such evaluation. The evaluation is based upon factors such as the creditworthiness of the issuers or guarantors, the underlying collateral, if applicable, and the continuing performance of the securities. Management also evaluates other facts and circumstances that may be indicative of an OTTI condition. This includes, but is not limited to, an evaluation of the type of security, length of time and extent to which the fair value has been less than cost, and near‑term prospects of the issuer. The Company’s assessment of OTTI considers whether it intends to sell a security or if it is likely that it would be required to sell the security before recovery of the amortized cost basis of the investment, which may be at maturity. For debt securities, if the Company intends to sell the security or it is more likely than not that it will be required to sell the security before recovering its cost basis, the entire impairment loss is recognized in earnings as an OTTI. If the Company does not intend to sell the security and it is more likely Note 1—Business and Summary of Significant Accounting Policies (continued) than not that it will not be required to sell the security, and the Company does not expect to recover the entire amortized cost basis of the security, only the portion of the impairment loss representing credit losses would be recognized in earnings. The credit loss on a security is measured as the difference between the amortized cost basis and the present value of the cash flows expected to be collected. Projected cash flows are discounted by the original or current effective interest rate depending on the nature of the security being measured for potential OTTI. The remaining impairment related to all other factors, the difference between the present value of the cash flows expected to be collected and fair value, is recognized as a charge to other comprehensive income (loss).
Restricted stock	Restricted stock —The Company owns stock of the Federal Home Loan Bank of Chicago (“FHLB”). No ready market exists for this stock, and it has no quoted market value. As a member of the FHLB system, the Bank is required to maintain an investment in FHLB stock. The stock is redeemable at par by the FHLB and is, therefore, carried at cost. In addition, the Company owns stock of Bankers Bank that was acquired as part of the Ridgestone transaction. The stock is redeemable at par and carried at cost. Restricted stock is generally viewed as a long‑term investment. Accordingly, when evaluating for impairment, its value is determined based on the ultimate recoverability of the par value rather than by recognizing temporary declines in value. The Company did not recognize impairment of its restricted stock as a result of its impairment analyses for the years ended December 31, 2017 and 2016.
Loans held for sale	Loans held for sale —Loans that management has the intent and ability to sell are designated as held for sale. Government guaranteed loans and mortgage loans originated are carried at either amortized cost or estimated fair value. The Company determines whether to account for loans at fair value or amortized cost at origination. The loans accounted for at fair value remain at fair value after the determination. The loans accounted for at amortized cost are carried at the lower of cost or fair value, valued on a loan by loan basis. Net unrealized losses, if any, are recorded as a valuation allowance and charged to earnings. Gains or losses on sales of government guaranteed loans are recognized based on the difference between the net sales proceeds, carrying value of the sold loan, fair value of the servicing asset recognized, and fair value of the retained loan (if any), and are reflected as operating activities in the Consolidated Statements of Cash Flows. The difference between the initial carrying balance of the retained loan and the relative fair value is recorded as a discount to the retained loan, establishing a new carrying balance. The recorded discount is accreted to earnings on a level yield basis. Government guaranteed loans are generally sold with servicing retained. Loans transferred to loans held for sale are carried at the lower of cost or fair value, less estimated costs to sell. At the time of transfer, write‑downs are recorded as charge‑offs, establishing a new cost basis. Any subsequent adjustments are determined on an individual loan basis and are recognized as a charge to non‑interest income. Sales proceeds received that are in excess of the new cost basis within 90 days are recorded to the allowance for loan and lease losses, up to the amount previously charged off. Any remaining proceeds are recorded as a gain on sale and included in non‑interest income. Sales proceeds that are less than the new cost basis upon transfer and are received within 90 days of classifying the loans as held for sale are recorded as a charge‑off to the allowance for loan and lease losses. Any proceeds received after 90 days of classifying the loans as held for sale are recorded as a gain or loss on sale and included in other non‑interest income. Loans held for sale that have not yet settled as of year-end are classified as due-from counterparty on the consolidated statement of financial condition.
Originated loans	Originated loans —Originated loans are stated at the amount of unpaid principal outstanding, net of purchase premiums and discounts, and any deferred fees or costs. Net deferred fees, costs, discounts and premiums are recognized as yield adjustments over the contractual life of the loan. Interest on loans is calculated daily based on the principal amount outstanding. Originated loans are classified as impaired when, based on current information and events, it is probable that the Company will be unable to collect the scheduled payments of principal and interest when due, in accordance with the terms of the original loan agreement. The carrying value of impaired loans is based on the present value of expected future cash flows (discounted at each loan’s effective interest rate) or, for collateral dependent loans, at the fair value of the collateral less estimated selling costs. If the measurement of each impaired loan’s value is less than the recorded investment in the loan, impairment is recognized and the carrying value of the loan is adjusted in the allowance for loan and lease losses as a specific component provided or through a charge‑off of the impaired portion of the loan. Accrual of interest on impaired loans is discontinued when the loan is 90 days past due or when, in management’s opinion, the borrower may be unable to make payments as they become due. When the accrual of interest is discontinued, all unpaid accrued interest is reversed through interest income. Payments received during the time a loan is on non‑accrual status are applied to principal. Interest income is not recognized until the loan is returned to accrual status or after the principal balance is paid in full. Loans are Note 1—Business and Summary of Significant Accounting Policies (continued) returned to accrual status when all the principal and interest amounts contractually due are brought current and future payments are reasonably assured as evidenced by agreed upon performance for a period of not less than six months.
Troubled debt restructuring	Troubled debt restructuring —A troubled debt restructuring (“TDR”) is a formal restructuring of a loan in which the Company, for economic or legal reasons related to the borrower’s financial difficulties, grants a concession to the borrower. The concessions may be granted in various forms, including providing a below ‑market interest rate, reduction in the loan balance or accrued interest, extension of the maturity date, or a combination of these. Troubled debt restructurings are considered to be impaired loans and are subject to the Company’s impaired loan accounting policy. Acquired impaired loans are not subject to TDR accounting. The Company does not accrue interest on a TDR unless it believes collection of all principal and interest under the modified terms is reasonably assured. For a TDR to begin accruing interest, the borrower must demonstrate some level of past performance and the future capacity to perform under the modified terms. Generally, six months of consecutive payment performance under the restructured terms is required before a TDR is returned to accrual status.
Direct finance leases	Direct finance leases —The Company engages in leasing for small ‑ticket equipment, software, machinery and ancillary supplies and services to customers under leases that qualify as direct financing leases for financial reporting. Certain leases qualify as operating leases for income tax purposes. Under the direct financing method of accounting, the minimum lease payments to be received under the lease contract, together with the estimated unguaranteed residual values of up to 15% of the cost of the related equipment, are recorded as lease receivables when the lease is signed and funded and the lease property is delivered to the customer. The excess of the minimum lease payments and residual values over the amount financed is recorded as unearned lease income. Unearned lease income is recognized over the term of the lease based on the effective yield interest method. Residual value is the estimated fair market value of the equipment on lease at lease termination. In estimating the equipment’s fair value at lease termination, the Company relies on historical experience by equipment type and manufacturer and, where available, valuations by independent appraisers, adjusted for known trends. The Company’s estimates are for reasonableness; however, the amounts the Company will ultimately realize could differ from the estimated amounts. If the review results in other‑than‑temporary impairment, the impairment is recognized in current period earnings. An upward adjustment of the estimated residual value is not recorded. The policies for delinquency and non‑accrual for direct finance leases are materially consistent with those described for all classes of loan receivables. The Company defers and amortizes certain initial direct costs over the contractual term of the lease as an adjustment to the yield. The unamortized direct costs are recorded as a reduction of unearned lease income.
Acquired impaired loans	Acquired impaired loans —Loans initially acquired with evidence of credit quality deterioration are accounted for under ASC Topic 310 ‑30, Accounting for Purchased Loans with Deteriorated Credit Quality (“ASC 310‑30”). These loans are recorded either on a pool or a loan‑by‑loan basis at their estimated fair value where applicable. The Company may aggregate loans into pools based on similar credit risks and predominant risk characteristics such as delinquency status and loan type. Management estimated the fair values of acquired impaired loans at both the Recapitalization date and the Ridgestone acquisition date based on estimated future cash flows. The excess of cash flows expected to be collected over a loan’s carrying value is considered to be the accretable yield and is recognized as interest income over the estimated life of the loan or pool using the effective yield method. The acquisition date estimates of accretable yield may subsequently change due to changes in management’s estimates of timing and amounts of expected cash flows. The excess of the contractual amounts due over the cash flows expected to be collected is considered to be the non‑accretable difference. The non‑accretable difference represents the Company’s estimate of the credit losses expected to occur and is considered in determining the fair value of the loans. Reclassifications between accretable yield and non‑accretable difference represent changes in expected cash flows over the remaining estimated life of the loan or pool. Subsequent increases in expected cash flows over those expected at inception are adjusted through an increase to the accretable yield on a prospective basis. Any subsequent decreases in expected cash flows attributable to credit deterioration are recognized by recording an additional provision for loan losses. Once a pool of loans is assembled, the integrity of the pool is maintained. A loan can only be removed from a pool if either of the following conditions is met: (1) the Company sells, forecloses, or otherwise receives assets in satisfaction of the loan, or (2) the loan is written off. A refinancing or restructuring of a loan does not result in a removal of a loan from a pool. Loan sales are accounted for under ASC Topic 860, Transfers and Servicing (“ASC 860”), when control over the assets have been relinquished. See transfers of financial assets accounting policy.
Acquired non-impaired loans and leases	Note 1—Business and Summary of Significant Accounting Policies (continued) Acquired non‑impaired loans and leases —Acquired non‑impaired loans and leases are accounted for under ASC Subtopic 310‑20, Receivables Nonrefundable Fees and Other Costs (“ASC 310‑20”). These loans and leases were individually recorded at fair value at the time of acquisition. The component of fair value representing an adjustment to an asset’s outstanding principal balance is accreted or amortized over the life of the related asset as a yield adjustment. Any previously recognized allowance for loan and lease losses and unearned fees or discounts are not carried over and recognized at the date of acquisition. The balance of the asset is then evaluated periodically pursuant to the Company’s allowance for loan and lease loss accounting policy and any adjustment required for credit risk is recorded within the allowance for loan and lease losses.
Allowance for loan and lease losses and reserve for unfunded commitments	Allowance for loan and lease losses and reserve for unfunded commitments —The allowance for loan and lease losses is maintained at a level management believes is appropriate to provide for probable loan and lease losses as of the date of the Consolidated Statements of Financial Condition. The allowance for loan and lease losses is increased by a provision for loans and lease losses and decreased by charge ‑offs, net of recoveries. Loan and lease losses are charged against the allowance for loan and lease losses when management believes the uncollectibility of a loan or lease balance is confirmed. Subsequent recoveries, if any, are credited to the allowance for loan and lease losses. The allowance for loan and lease losses is based on management’s evaluation of the loan and lease portfolio giving consideration to the nature and volume of the portfolio, the value of the underlying collateral, overall portfolio quality, review of specific problem loans or leases, and prevailing economic conditions that may affect the borrower’s ability to pay. While management uses the best information available to make its evaluation, future adjustments to the allowance for loan and lease losses may be necessary if there are significant changes in economic condition. The allowance for loan and lease losses consists of general and specific components. Allocations of the allowance for loan and lease losses not attributable to acquired impaired loans may be made for specific loans and leases, but the entire allowance is available for any loan and lease that, in management’s judgement, should be charged off. The general component covers loans and leases that are collectively evaluated for impairment. Larger groups of smaller balance homogeneous loans, such as consumer and residential real estate loans, and leases are collectively evaluated for impairment, and accordingly, they are not included in the separately identified impairment disclosures. The general component is based on a trailing 12‑quarter weighted average loss rate for each loan category based on the Company’s historical losses and its peer group and adjusted for qualitative and other economic factors. These factors include (1) changes in lending policies and procedures, including changes in underwriting standards and collections, charge‑off and recovery practices; (2) changes in international, national, regional and local conditions; (3) changes in the nature and volume of the portfolio and terms of the loans and leases; (4) changes in experience, depth and ability of lending management and other relevant staff; (5) changes in the volume and severity of past due loans and leases; (6) changes in the quality of the Company’s loan review system; (7) changes in the value of the underlying collateral for collateral dependent loans and leases; (8) existence and effect of any concentrations of credit and changes in the levels of such concentrations; and (9) the effect of other external factors (i.e., competition, legal and regulatory requirements) on the level of estimated credit losses. Based upon management’s judgement of other factors that fall outside of the predefined qualitative or historical loss rates, the allowance for loan and lease losses may include an unallocated component not included in these predefined factors. The specific component relates to loans that are risk‑rated substandard or worse, and based on current information and events, it is likely that the Company will be unable to collect all amounts due according to the contractual terms of the loan agreement. Factors considered by management in determining the impairment include payment status, collateral value, strength of guarantor, and the probability of collecting scheduled principal and interest payments when due. Loans that experience insignificant payment delays and payment shortfalls generally are not classified as impaired and are reviewed on a case‑by‑case basis. TDRs are individually evaluated for impairment and are measured at the present value of estimated future cash flows using the loan’s effective rate at origination. If a TDR is considered to be a collateral dependent loan, the loan is reported at the fair value of the collateral, less estimated costs to sell. The allowance for loan losses also includes amounts representing decreases in expected cash flows attributable to credit deterioration of acquired impaired loans. The evaluation is inherently subjective, as it requires estimates that are susceptible to significant revision as more information becomes available. A reserve for unfunded commitments is maintained at a level that, in the opinion of management, is sufficient to absorb probable losses associated with the Company’s commitment to lend funds under existing agreements, such as letters or lines of credit. Management determines the appropriate reserve for unfunded commitments based upon reviews of individual credit facilities, current economic conditions, the risk characteristics of the various categories of commitments, and other relevant factors. The reserve for unfunded commitments is based on estimates, and ultimate losses may vary from the current estimates. These estimates are evaluated Note 1—Business and Summary of Significant Accounting Policies (continued) on a quarterly basis and, as adjustments become necessary, they are recognized in earnings in the periods in which they become known. Advances that are considered uncollectible are charged to the reserve for unfunded commitments. Provisions and recoveries of advances previously charged‑off are recognized within the reserve for unfunded commitments, which is included in other liabilities within the Consolidated Statements of Financial Condition. The factors supporting the allowance for loan and lease losses and the reserve for unfunded commitments do not diminish the fact that the entire allowance for loan and lease losses and reserve for unfunded commitments not attributable to acquired impaired loans are each available to absorb losses in the loan and lease portfolios and related commitment portfolio, respectively. The allowance for loan and lease losses and reserve for unfunded commitments are both subject to review by regulatory agencies during examinations and may require us to recognize adjustments to the allowance for loan and lease losses or the reserve for unfunded commitments.
Servicing assets	Servicing assets —Servicing assets are recognized separately when they are acquired through sales of loans. When loans are sold with servicing rights retained, servicing assets are recorded at fair value in accordance with ASC 860. Fair value is based on market prices for comparable servicing contracts, when available, or alternatively, is based on a valuation model that calculates the present value of estimated future net servicing income. Sales of government guaranteed loans are executed on a servicing retained basis. The standard SBA loan sale agreement is structured to provide the Company with a servicing spread paid from a portion of the interest cash flow of the loan. SBA regulations require the Company to retain a portion of the cash flow from the interest payments received for a sold loan. The USDA loan sale agreements are not standardized with respect to servicing. Servicing fee income, which is reported on the Consolidated Statements of Operations as servicing fees, is recorded for fees earned for servicing loans. The fees are based on a contractual percentage of the outstanding principal. Late fees and ancillary fees related to loan servicing are not material. The Company has elected the fair value measurement method and measures servicing rights at fair value at each reporting date and reports changes in fair value of servicing assets in earnings in the period in which the changes occur, and are included with servicing fees on the Consolidated Statements of Operations. The fair values of servicing rights are subject to significant fluctuations as a result of changes in estimated and actual prepayment speeds, default rates, and losses.
Concentrations of credit risk	Concentrations of credit risk —Most of the Company’s business activity is concentrated with customers located within its principal market areas, with the exception of government guaranteed loans and leasing activities. The Company originates commercial real estate, construction, land development and other land, commercial and industrial, residential real estate, installment and other loans, and leases. Generally, loans are secured by accounts receivable, inventory, deposit accounts, personal property or real estate. Rights to collateral vary and are legally documented to the extent practicable. The Company has a concentration in commercial real estate loans and the ability of borrowers to honor these and other contracts is dependent upon the real estate and general economic conditions within their geographic market.
Transfers of financial assets	Transfers of financial assets —Transfers of financial assets are accounted for as sales when control over the assets has been relinquished. The Company has assessed that partial sales of financial assets meet the definition of participating interest. Control over transferred assets is deemed to be surrendered when the assets have been isolated from the Company and the transferee obtains the right (free of conditions that constrain it from taking advantage of that right) to pledge or exchange the transferred assets. Gains or losses are recognized in the period of sale upon derecognition of the asset.
Premises and equipment	Premises and equipment —Premises and equipment acquired through a business combination are initially stated at the acquisition date fair value less accumulated depreciation. All other premises and equipment are stated at cost less accumulated depreciation. Depreciation on premises and equipment is recognized on a straight ‑line basis over their estimated useful lives ranging from three to 39 years. Land is also carried at its fair value following a business combination and is not subject to depreciation. Leasehold improvements are amortized over the shorter of the life of the related asset or expected term of the underlying lease. Gains and losses on the dispositions of premises and equipment are included in non‑interest income. Expenditures for new premises, equipment and major betterments are capitalized. Normal costs of maintenance and repairs are expensed as incurred. Note 1—Business and Summary of Significant Accounting Policies (continued) Long‑lived depreciable assets are evaluated periodically for impairment when events or changes in circumstances indicate the carrying amounts may be not recoverable. Impairment exists when the undiscounted expected future cash flows of a long‑lived asset are less than its carrying value. In that event, the Company recognizes a loss for the difference between the carrying amount and the estimated fair value of the asset based on a quoted market price, if applicable, or a discounted cash flow analysis. Impairment losses are recorded in non‑interest expense.
Assets held for sale	Assets held for sale —Assets held for sale consist of former branch locations and real estate previously purchased for expansion. Assets are considered held for sale when management has approved to sell the assets following a branch closure or other events. The properties are being actively marketed and transferred to assets held for sale based at the lower of its carrying value or its fair value, less estimated costs to sell. Assets held for sale are evaluated periodically for impairment, with any impairment losses recorded in non-interest expense.
Other real estate owned	Other real estate owned —Other real estate owned (“OREO”) includes real estate assets that have been acquired through, or in lieu of, loan foreclosure or repossession and are to be sold. OREO assets are initially recorded at fair value, less estimated costs to sell, of the collateral of the loan, on the date of foreclosure or repossession, establishing a new cost basis. Adjustments that reduce loan balances to fair value at the time of foreclosure or repossession are recognized as charge ‑offs in the allowance for loan and lease losses. Positive adjustments, if any, at the time of foreclosure or repossession are recognized in non‑interest expense. After foreclosure or repossession, management periodically obtains new valuations, and real estate or other assets may be adjusted to a lower carrying amount, determined by the fair value of the asset, less estimated costs to sell. Any subsequent write‑downs are recorded as a decrease in the asset and charged against other real estate owned valuation adjustments. Operating expenses of such properties, net of related income, and gains and losses on their disposition are included in non‑interest expense. Gains on internally financed other real estate owned sales are accounted for in accordance with the methods stated in ASC Topic 360‑20, Real Estate Sales (“ASC 360‑20”). Any losses on the sales of other real estate owned properties are recognized immediately.
Goodwill	Goodwill —The excess of the cost of the recapitalization and acquisitions over the fair value of the net assets acquired, including core deposit intangible, consists of goodwill. Goodwill is not amortized but is periodically evaluated for impairment under the provisions of ASC Topic 350, Intangibles—Goodwill and Other (“ASC 350”). Impairment testing is performed using either a qualitative or quantitative approach at the reporting unit level. All of the Company’s goodwill is allocated to the Bank, which is the Company’s only applicable reporting unit for the purposes of testing goodwill for impairment. The Company has selected November 30 as the date it performs the annual goodwill impairment test. Additionally, the Company performs a goodwill impairment evaluation on an interim basis when events or circumstances indicate impairment potentially exists. The Company performs impairment testing using a qualitative approach to determine whether it is more likely than not that the fair value of a reporting unit is less than its carrying amount. A significant amount of judgment is involved in determining if an indicator of impairment has occurred. Such indicators may include, among others, a material change in the estimated value of the Company based on current market multiples common for community banks of similar size and operations; a significant change in our stock price or market capitalization; a significant adverse change in legal factors or in the business climate; adverse action or assessment by a regulator; and unanticipated competition. If the assessment of qualitative factors indicates that it is not more likely than not that impairment exists, no further testing is performed; otherwise, the Company would proceed with a quantitative two‑step goodwill impairment test. In the first step, the Company compares its estimate of the fair value of the reporting unit, which is based on a discounted cash flow analysis, with its carrying amount, including goodwill. If the fair value of the reporting unit exceeds its carrying amount, goodwill of the reporting unit is not impaired and the second step is not required. If necessary, the second step compares the implied fair value of the reporting unit goodwill with the carrying amount of that goodwill. The implied fair value of goodwill is determined by assigning the value of the reporting unit to all of the assets and liabilities of that unit, including any other identifiable intangible assets. An impairment loss is recognized if the carrying amount of the reporting unit goodwill exceeds the implied fair value of the goodwill. Based on an annual analysis completed as of November 30, 2017, the Company did not recognize impairment losses during the year ended December 31, 2017.
Other intangible assets	Other intangible assets —Other intangible assets primarily consist of core deposit intangible assets. Other intangible assets with definite useful lives are amortized to their estimated residual values over their respective estimated useful lives, and are also reviewed periodically for impairment. Amortization of other intangible assets is included in other non ‑interest expense. Core deposit intangibles were recognized apart from goodwill at the time of the recapitalization and the acquisition of Ridgestone based on market valuations. Core deposit intangibles are amortized over a ten‑year period. In valuing core deposit intangibles, the Company considered variables such as deposit servicing costs, attrition rates and market discount rates. If the estimated fair value is less than the carrying value, the core deposit intangible would be reduced to such value and the impairment recognized as non‑interest expense. The Company did not recognize impairment on its core deposit intangibles for the years ended December 31, 2017 and 2016.
Bank-owned life insurance	Note 1—Business and Summary of Significant Accounting Policies (continued) Bank‑owned life insurance —The Company holds life insurance policies that provide protection against the adverse financial effects that could result from the death of current and former employees, and provide tax deferred income. Although the lives of individual current or former management‑level employees are insured, the Company is the owner and is split beneficiary on certain policies. The Company is exposed to credit risk to the extent an insurance company is unable to fulfill its financial obligations under a policy. Split‑dollar life insurance is recorded as an asset at cash surrender value. Increases in the cash value of these policies, as well as insurance proceeds received, are recorded in other non‑interest income and are not subject to income tax.
Income taxes	Income taxes —The Company uses the asset and liability method to account for income taxes. The objective of the asset and liability method is to establish deferred tax assets and liabilities for the temporary differences between the financial reporting basis and the income tax basis of the Company’s assets and liabilities at enacted tax rates expected to be in effect when such amounts are realized or settled. The Company’s annual tax rate is based on its income, statutory tax rates and available tax planning opportunities. Deferred tax assets and liabilities are adjusted through the tax provision for the effects of changes in tax laws and rates on the date of enactment. Tax laws are complex and subject to different interpretations by the taxpayer and respective governmental taxing authorities. Significant judgment is required in determining tax expense and in evaluating tax positions, including evaluating uncertainties. Deferred income tax assets represent amounts available to reduce income taxes payable on taxable income in future years. Such assets arise because of temporary differences between the financial reporting and tax bases of assets and liabilities, as well as from net operating loss carryforwards. The Company reviews its deferred tax positions periodically and adjusts the balances as new information becomes available. The Company evaluates the recoverability of these future tax deductions by assessing the adequacy of future expected taxable income from all sources, including reversal of taxable temporary differences, forecasted operating earnings and available tax planning strategies. The Company uses short and long‑range business forecasts to provide additional information for its evaluation of the recoverability of deferred tax assets. As of December 31, 2017 and 2016, the Company had no material uncertain tax positions. The Company elects to treat interest and penalties recognized for the underpayment of income taxes as income tax expense. However, interest and penalties imposed by taxing authorities on issues specifically addressed in ASC Topic 740 will be taken out of the tax reserves up to the amount allocated to interest and penalties. The amount of interest and penalties exceeding the amount allocated in the tax reserves will be treated as income tax expense. A deferred tax valuation allowance is established to reduce the net carrying amount of deferred tax assets if it is determined to be more likely than not that all or some of the deferred tax asset will not be realized. At December 31, 2017 and 2016, the Company did not record a deferred tax valuation allowance. Deferred tax assets and liabilities are adjusted for the effects of changes in tax laws and rates on the date of enactment.
Derivative financial instruments and hedging activities	Derivative financial instruments and hedging activities —The Company enters into derivative transactions principally to protect against the risk of adverse price or interest rate movements on the future cash flows of certain assets. ASC Topic 815, Derivatives and Hedging (“ASC 815”), establishes accounting and reporting standards requiring that every derivative instrument be recorded in the statement of condition as either an asset or liability measured at its fair value. The accounting for changes in the fair value of a derivative instrument depends on whether it has been designated and qualifies as part of a hedging relationship and on the type of hedging relationship. On the date the derivative contract is entered into, the Company designates the derivative as a fair value hedge, a cash flow hedge, or a non‑designated derivative. Fair value hedges are accounted for by recording the changes in the fair value of the derivative instrument and the changes in the fair value related to the risk being hedged of the hedged asset or liability on the Consolidated Statements of Financial Condition with corresponding offsets recorded in the Consolidated Statements of Operations. The adjustment to the hedged asset or liability is included in the basis of the hedged item, while the fair value of the derivative is recorded as an asset or liability. Cash flow hedges are accounted for by recording the changes in the fair value of the effective portion of the derivative instrument in other comprehensive income (loss) and are recognized in the Consolidated Statements of Operations when the hedged item affects earnings. Derivative instruments that are not designated as hedges according to accounting guidance are reported in the Consolidated Statements of Financial Condition at fair value and the changes in fair value are recognized as non‑interest income during the period of the change. Note 1—Business and Summary of Significant Accounting Policies (continued) The Company formally documents the relationship between a derivative instrument and a hedged asset or liability, as well as its risk management objective and strategy for undertaking various hedge transactions. The Company also formally assesses, both at the hedge’s inception and on an ongoing basis, whether the derivatives that are used in the hedging transactions are highly effective in offsetting changes in fair values or cash flows of hedged items.
Comprehensive income (loss)	Comprehensive income (loss) —Recognized revenue, expenses, gains and losses are included in net income (loss). Certain changes in assets and liabilities, such as unrealized gains and losses on available ‑for‑sale securities and adjustments related to cash flow hedges, are reported on a cumulative basis, net of tax effects, as a separate component of equity on the Consolidated Statements of Financial Condition. Changes in such items, along with net income (loss), are components of comprehensive income (loss).
Advertising expense	Advertising expense —Advertising costs are expensed as incurred.
Off-balance sheet instruments	Off‑balance sheet instruments —In the ordinary course of business, the Company has entered into off‑balance sheet arrangements consisting of commitments to extend credit, commercial letters of credit, and standby letters of credit. The face amount for these items represents the exposure to loss, before considering customer collateral or ability to repay. Such financial instruments are recorded in the consolidated financial statements when they are funded or when the related fees are incurred or received.
Segment reporting	Segment reporting —The Company has one reportable segment. The Company’s chief operating decision maker evaluates the operations of the Company using consolidated information for purposes of allocating resources and assessing performance. Therefore, segments disclosures are not required.
Loss contingencies	Loss contingencies —Loss contingencies, including claims and legal actions 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 are any such matters that will have a material effect on the Consolidated Financial Statements for the years ended December 31, 2017 and 2016.
Share-based compensation	Share‑based compensation —The Company accounts for share‑based compensation in accordance with ASC Topic 718, Compensation—Stock Compensation (“ASC 718”), which requires compensation cost relating to share‑based compensation transactions be recognized in the Consolidated Statements of Operations, based generally upon the grant‑date fair value of the share‑based compensation granted by the Company. Share‑based awards may have service, market or performance conditions. Refer to Note 19—Share-Based Compensation for additional information.
Earnings per share	Earnings per share — Earnings per common share is computed under the two-class method. Pursuant to the two-class method, non-vested stock-based payment awards that contain non-forfeitable rights to dividends or dividend equivalents are participating securities and are included in the computation of EPS. The two-class method is an earnings allocation formula that determines earnings per share for each class of common stock and participating security according to dividends declared (or accumulated) and participation rights in undistributed earnings. Application of the two-class method resulted in the equivalent earnings per share to the treasury method. Basic earnings per common share is computed by dividing net earnings allocated to common shareholders by the weighted-average number of common shares outstanding during the applicable period, excluding outstanding participating securities. Diluted earnings per common share is computed using the weighted-average number of shares determined for the basic earnings per common share computation plus the dilutive effect of stock compensation and warrants for common stock using the treasury stock method.
Fair value of assets and liabilities	Fair value of assets and liabilities —Fair value is defined as the price that would be received to sell an asset, or paid to transfer a liability, including respective accrued interest balances, in an orderly transaction between market participants at the measurement date. The Company determines fair value based upon quoted prices when available or through the use of alternative approaches, such as matrix or model pricing, when market quotes are not readily accessible or available. The valuation techniques used are based on observable and unobservable inputs. Observable inputs reflect market data obtained from independent sources, while unobservable inputs reflect the Company’s market assumptions.
Reclassifications	Reclassifications —Some items in the prior year consolidated financial statements were reclassified to conform to the current presentation. Reclassifications had no effect on prior years net income (loss) or stockholders’ equity.
Recently Issued Accounting Pronouncements	The following reflect recent accounting pronouncements that have been adopted or are pending adoption by the Company. As the Company qualifies as an emerging growth company and has elected the extended transition period for complying with new or revised accounting pronouncements, it is not subject to new or revised accounting standards applicable to public companies during the extended transition period. The accounting pronouncements pending adoption below reflect effective dates for the Company as an emerging growth company with the extended transition period. Revenue from Contracts with Customers —In May 2014, FASB issued Accounting Standards Update (“ASU”) No. 2014‑09, deferred by ASU No. 2015‑14 and clarifying standards, Revenue from Contracts with Customers, which creates Topic 606 and supersedes Topic 605, Revenue Recognition. The core principle of Topic 606 is that an entity recognizes revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. In general, the new guidance requires companies to use more judgment and make more estimates than under current guidance, including identifying performance obligations in the contract, estimating the amount of variable consideration to include in the transaction price and allocating the transaction price to each separate performance obligation. Under the terms of ASU No. 2015‑14 the standard is effective for interim and annual periods beginning after December 15, 2017. For financial reporting purposes, the standard allows for either full retrospective adoption, meaning the standard is applied to all of the periods presented, or modified retrospective adoption, meaning the standard is applied only to the most current period presented in the financial statements with the cumulative effect of initially applying the standard recognized at the date of initial application. The Company is currently evaluating the provisions of ASU No. 2014‑09 to determine the potential impact the standard will have on the Company’s Consolidated Financial Statements. As a financial institution, the Company’s largest component of revenue, interest income, is excluded from the scope of this ASU. The Company is currently evaluating which, if any, of its sources of non‑interest income will be impacted by this ASU. Assuming the Company remains an emerging growth company, the Company expects to adopt this new guidance on January 1, 2019, with a cumulative effect adjustment to opening retained earnings, if such adjustment is deemed to be significant. In April 2016, FASB issued ASU No. 2016‑10, . The amendments in this ASU do not change the core principle of the guidance in Topic 606. Rather, the amendments in this ASU clarify the following two aspects of Topic 606: (1) identifying performance obligations and (2) licensing implementation guidance, while retaining the related principles for those areas. The amendments in this ASU affect the guidance in ASU 2014‑09, discussed above, which is not yet effective. The effective date and transition requirements for the amendments in this ASU are the same as the effective date and transition requirements in Topic 606, . The Company is evaluating the provisions of this ASU in conjunction with ASU No. 2014‑09 to determine the potential impact Topic 606 and its amendments will have on the Company’s Consolidated Financial Statements. In May 2016, FASB issued ASU No. 2016‑12, Narrow‑Scope Improvements and Practical Expedients Revenue from Contracts with Customers In November 2017, FASB issued ASU No. 2017-14, amending ASC Topic 606, Revenue from Contracts with Customers Revenue from Contracts with Customers Customer’s Accounting for Fees Paid in a Cloud Computing Arrangement —In April 2015, FASB issued ASU No. 2015‑05, . The amendments in this ASU provide guidance to customers in cloud computing arrangements about whether a cloud computing arrangement includes a software license. If a cloud computing arrangement includes a software license, the customer should account for the software license element of the arrangement consistent with the acquisition of other software licenses. If a cloud computing arrangement does not include a software license, the customer should account for the arrangement as a service contract. The amendments were effective for annual periods, including interim periods within those annual periods, beginning after December 15, 2015 and were adopted by the Company as of January 1, 2016. This ASU did not have a material effect on the Company’s Consolidated Financial Statements. Note 2—Recently Issued Accounting Pronouncements (continued) Business Combinations—Simplifying the Accounting for Measurement‑Period Adjustments —In September 2015, FASB issued ASU No. 2015‑16, . The amendments in this ASU require that an acquirer recognize adjustments to provisional amounts that are identified during the measurement period in the reporting period when the adjustment amounts are determined. The acquirer is required to record in the same period’s financial statements the effect on earnings from changes in depreciation, amortization, or other income effects resulting from the change to provisional amounts, calculated as if the accounting had been completed at the acquisition date. The acquirer must present separately on the income statement, or disclose in the notes, the amount recorded in current‑period earnings that would have been recorded in previous reporting periods if the provisional amount had been recognized at the acquisition date. The amendments in this ASU were effective for fiscal years beginning after December 15, 2015. The Company adopted this new authoritative guidance on January 1, 2016, and it did not have an impact on the Company’s Consolidated Financial Statements, but may in the future. Recognition and Measurement of Financial Assets and Financial Liabilities —In January 2016, FASB issued ASU No. 2016‑01, . The amendments in this ASU require equity securities to be measured at fair value with changes in the fair value recognized through net income. The amendments allow equity investments that do not have readily determinable fair values to be remeasured at fair value under certain circumstances and require enhanced disclosures about those investments. The amendments simplify the impairment assessment of equity investments without readily determinable fair values. The amendments also eliminate the requirement to disclose the method(s) and significant assumptions used to estimate the fair value that is required to be disclosed for financial instruments measured at amortized cost on the balance sheet. The amendments in this ASU require separate presentation in other comprehensive income of the portion of the total change in the fair value of a liability resulting from a change in the instrument‑specific credit risk when the entity has elected to measure the liability at fair value in accordance with the fair value option for financial instruments. This amendment excludes from net income gains or losses that the entity may not realize because those financial liabilities are not usually transferred or settled at their fair values before maturity. The amendments in this ASU require separate presentation of financial assets and financial liabilities by measurement category and form of financial asset (that is, securities or loans and receivables) on the balance sheet or in the accompanying notes to the financial statements. The amendments in this ASU are effective for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years. The Company is currently evaluating the provisions of ASU No. 2016‑01 to determine the potential impact the new standard will have on the Company’s Consolidated Financial Statements. Assuming the Company remains an emerging growth company, the new authoritative guidance will be effective for reporting periods beginning January 1, 2019 and is not expected to have a significant impact on the Company’s Consolidated Financial Statements. Leases (Topic 842) —In February 2016, FASB issued ASU No. 2016‑02, . The amendments in this ASU require lessees to recognize the following for all leases (with the exception of short‑term) at the commencement date; a lease liability, which is a lessee’s obligation to make lease payments arising from a lease, measured on a discounted basis; and a right‑of‑use asset, which is an asset that represents the lessee’s right to use, or control the use of, a specified asset for the lease term. The amendments in this ASU leave lessor accounting largely unchanged, although certain targeted improvements were made to align lessor accounting with the lessee accounting model. This ASU simplifies the accounting for sale and leaseback transactions primarily because lessees must recognize lease assets and lease liabilities. Lessees will no longer be provided with a source of off‑balance sheet financing. The amendments in this ASU are effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. Early application is permitted upon issuance. Lessees (for capital and operating leases) and lessors (for sales‑type, direct financing, and operating leases) must apply a modified retrospective transition approach for leases existing at, or entered into after, the beginning of the earliest comparative period presented in the financial statements. The modified retrospective approach would not require any transition accounting for leases that expired before the earliest comparative period presented. Lessees and lessors may not apply a full retrospective transition approach. The Company is evaluating the new guidance and its impact on the Company’s Consolidated Statements of Operations and Consolidated Statements of Financial Condition. Assuming the Company remains an emerging growth company, the new authoritative guidance will be effective for reporting periods after January 1, 2020. The Company expects an increase in assets and liabilities as a result of recognizing additional lease contracts where the Company is lessee. Derivatives and Hedging (Topic 815) —In March 2016, FASB issued ASU No. 2016‑05, . The amendments in this ASU clarify that a change in the counterparty to a derivative instrument that has been designated as the hedging instrument under Topic 815 (Derivatives and Hedging) does not, in and of itself, require dedesignation of that hedging relationship provided that all other hedge accounting criteria continue to be met. The amendments in this ASU are effective for financial statements issued for fiscal years beginning after December 15, 2016, and interim periods within those fiscal years. An entity has an option to apply the amendments in this ASU on either a prospective basis or a modified retrospective basis. Early adoption is permitted, including adoption in an interim period. This ASU became effective for the Company on January 1, 2017 and did not have a material impact on the Company’s Consolidated Financial Statements. Note 2—Recently Issued Accounting Pronouncements (continued) In March 2016, FASB issued ASU No. 2016‑06, Contingent Put and Call Options in Debt Instruments In August 2017, FASB issued ASU No. 2017‑12, Targeted Improvements to Accounting for Hedging Activities Compensation—Stock Compensation (Topic 718) —In March 2016, FASB issued ASU No. 2016‑09, . FASB issued this ASU as part of its Simplification Initiative. The areas for simplification in this ASU involve several aspects of the accounting for share‑based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities, and classification on the statement of cash flows. Amendments in this ASU relate to the timing of when excess tax benefits are recognized, minimum statutory withholding requirements, forfeitures, and intrinsic value should be applied using a modified retrospective transition method by means of a cumulative‑effect adjustment to equity as of the beginning of the period in which the guidance is adopted. Amendments related to the presentation of employee taxes paid on the statement of cash flows when an employer withholds shares to meet the minimum statutory withholding requirement should be applied retrospectively. Amendments in this ASU require recognition of excess tax benefits and tax deficiencies in the income statement and the practical expedient for estimating expected term should be applied prospectively. An entity may elect to apply the amendments in this ASU related to the presentation of excess tax benefits on the statement of cash flows using either a prospective transition method or a retrospective transition method. The amendments in this ASU are effective for annual periods beginning after December 15, 2016, and interim periods within those annual periods. This ASU became effective for the Company on January 1, 2017 and did not have a material impact on the Company’s Consolidated Financial Statements. In May 2017, FASB issued ASU No. 2017-09, Scope of Modification Accounting Note 2—Recently Issued Accounting Pronouncements (continued) company, the new authoritative guidance will be effective for reporting periods after January 1, 2019. The Company is evaluating the new guidance and its impact on the Company’s Consolidated Statements of Operations and Consolidated Statements of Financial Condition. . Financial Instruments—Credit Losses (Topic 326) —In June 2016, FASB issued ASU No. 2016‑13, . Current GAAP requires an “incurred loss” methodology for recognizing credit losses that delays recognition until it is probable a loss has been incurred. The main objective of this ASU is to provide financial statement users with more decision‑useful information about the expected credit losses on financial instruments and other commitments to extend credit held by a reporting entity at each reporting date. The amendments in this ASU 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. The amendments in this ASU require a financial asset (or group of financial assets) measured at amortized cost basis to be presented at the net amount expected to be collected. The allowance for credit losses is a valuation account that is deducted from the amortized cost basis of the financial asset(s) to present the net carrying value at the amount expected to be collected on the financial asset. The measurement of expected credit losses will be based on relevant information about past events, including historical experience, current conditions, and reasonable and supportable forecasts that affect the collectability of the reported amount. The amendments in this ASU broaden the information that an entity must consider in developing its expected credit loss estimate for assets measured either collectively or individually. The use of forecasted information incorporates more timely information in the estimate of expected credit loss, which will be more decision useful to users of the financial statements. The amendments in this ASU will be effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. Assuming the Company remains an emerging growth company, the new authoritative guidance will be effective for reporting periods after January 1, 2021. The Company is still evaluating the effects this ASU will have on the Company’s Consolidated Financial Statements. While the Company has not quantified the impact of this ASU, it does expect changing from the current incurred loss model to an expected loss model will result in an earlier recognition of losses. Statement of Cash Flows (Topic 230) —In August 2016, FASB issued ASU No. 2016‑15, . There is diversity in practice in how certain cash receipts and cash payments are presented and classified in the statement of cash flows under Topic 230 and other Topics. This ASU addresses eight specific cash flow issues with the objective of reducing the existing diversity in practice. Those eight issues are (1) debt prepayment or debt extinguishment costs, (2) settlement of zero‑coupon debt instruments or other debt instruments with coupon interest rates that are insignificant in relation to the effective interest rate of the borrowing, (3) contingent consideration payments made 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 investees, (7) beneficial interests in securitization transactions, and (8) separately identifiable cash flows and application of the predominance principle. Current GAAP either is unclear or does not include specific guidance on these eight cash flow classification issues. These amendments provide guidance for each of the eight issues, thereby reducing current and potential future diversity in practice. The amendments in this ASU 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. Assuming the Company remains an emerging growth company, the new authoritative guidance will be effective for reporting periods after January 1, 2019. The Company is currently evaluating the provisions of ASU No. 2016‑15 to determine the potential impact the new standard will have on the Company’s Consolidated Financial Statements. In November 2016, the FASB issued ASU No. 2016‑18, Statement of Cash Flows (230), Restricted Cash Income Taxes (Topic 740) —In October 2016, the FASB issued ASU No. 2016‑16, . The ASU was issued to improve the accounting for income tax consequences of intra‑entity transfers of assets other than inventory. Current GAAP prohibits the recognition of current and deferred income taxes for an intra‑entity asset transfer until the asset has been sold to an outside party; this update clarifies that an entity should recognize the income tax consequences of an intra‑entity transfer of assets other than inventory when the transfer occurs. The amendment is effective for annual Note 2—Recently Issued Accounting Pronouncements (continued) reporting periods beginning after December 15, 2017, and interim periods within those fiscal years. Early adoption of the update is permitted. Assuming the Company remains an emerging growth company, the new authoritative guidance will be effective for reporting periods after January 1, 2019. The Company does not expect this ASU to have a material impact on the Company’s Consolidated Financial Statements. Consolidation (Topic 810)— In October 2016, the FASB issued ASU No. 2016‑17, . The ASU was issued to amend the consolidation guidance on how a reporting entity that is the single decision maker of a variable interest entity (“VIE”) should treat indirect interests in the entity held through related parties that are under common control with the reporting entity when determining whether it is the primary beneficiary of that VIE. The primary beneficiary of a VIE is the reporting entity that has a controlling financial interest in a VIE and, therefore, consolidates the VIE. A reporting entity has an indirect interest in a VIE if it has a direct interest in a related party that, in turn, has a direct interest in the VIE. The amendment is effective for annual reporting periods beginning after December 15, 2016, and interim periods within those fiscal years. Early adoption of the update is permitted. The Company adopted this new authoritative guidance on January 1, 2017 and it did not have an impact on the Company’s Consolidated Financial Statements. Business Combinations (Topic 805) —In January 2017, the FASB issued ASU No. 2017‑01, . The guidance clarifies the definition of a business to assist entities with evaluating whether transactions should be accounted for as acquisitions or disposals of assets or businesses. This guidance is effective for annual and interim periods beginning after December 15, 2017. Early adoption is permitted. Assuming the Company remains an emerging growth company, the new authoritative guidance will be effective for reporting periods after January 1, 2019. The Company does not expect a material impact of this ASU on the Company’s Consolidated Financial Statements. Intangibles—Goodwill and Other (Topic 350) —In January 2017, FASB issued ASU No. 2017‑04, . The amendments in this ASU are intended to reduce the cost and complexity of the goodwill impairment test by eliminating step two from the impairment test. The amendments modify the concept of impairment from the condition that exists when the carrying amount of goodwill exceeds its implied fair value to the condition that exists when the carrying amount of a reporting unit exceeds its fair value. Under the amendments in this ASU, if an entity performs a quantitative annual, or interim, goodwill impairment test by comparing the fair value of the reporting unit with its carrying amount. An impairment charge should be recognized for the amount which the carrying amount exceeds the reporting unit’s fair value; however, the loss recognized should not exceed the total amount of goodwill allocated to that reporting unit. The amendments in this ASU are effective for the Company’s annual or any interim goodwill impairment test in fiscal years beginning after December 15, 2019. Early adoption is permitted for interim or annual goodwill impairment tests performed on testing dates after January 1, 2017. The Company is early adopting these amendments in 2017 and does not expect a material impact on the Company’s Consolidated Financial Statements. Other Income (Subtopic 610‑20) —In February 2017, the FASB issued ASU No. 2017‑05, . This ASU will clarify the scope of Subtopic 610‑20 and add guidance for partial sales of nonfinancial assets. The amendments should be applied either on retrospectively to each period presented or with a modified retrospective approach. The amendment is effective for annual periods beginning after December 15, 2018, and interim periods within annual periods beginning after December 15, 2019. The Company is currently evaluating the provisions of ASU No. 2017‑05 to determine the potential impact the new standard will have on the Company’s Consolidated Financial Statements. Nonrefundable Fees and Other Costs (Subtopic 310‑20) —In March 2017, FASB issued ASU No. 2017‑08, . The amendments in the ASU shorten the amortization period for certain callable debt securities held at a premium at the earliest call date. Under current GAAP, the Company amortizes the premium as an adjustment of yield over the contractual life of the instrument. As a result, upon exercise of a call on a callable debt security held at a premium, the unamortized premium is charged to earnings. The ASU shortens the amortization period for certain callable debt securities held at a premium and requires the premium to be amortized to the earliest call date. However, the amendments do not require an accounting change for securities held at a discount; the discount continues to be amortized to maturity. The amendments are effective for annual periods beginning after December 15, 2019, and interim periods within annual periods beginning after December 15, 2020. Early adoption is permitted. The Company is required to apply the amendments on a modified retrospective basis through a cumulative‑effect adjustment directly to retained earnings as of the beginning of the period of adoption. Assuming the Company remains an emerging growth company, the new authoritative guidance will be effective for reporting periods after January 1, 2020. The Company is currently evaluating the provisions of ASU No. 2017‑08 to determine the potential impact the new standard will have on the Company’s Consolidated Financial Statements. Note 2—Recently Issued Accounting Pronouncements (continued) Earnings Per share (Topic 260), Distinguishing Liabilities from Equity (Topic 480), Derivatives and Hedging (Topic 815 )—In July 2017, FASB issued ASU No. 2017-11, . The ASU simplifies the accounting for certain financial instruments with down round features, a provision in an equity-linked financial instrument (or embedded feature) that provides a downward adjustment of the current exercise price based on the price of future equity offerings. Down round features are common in warrants, convertible preferred shares, and convertible debt instruments. The ASU requires companies to disregard the down round feature when assessing whether the instrument is indexed to its own stock, for purposes of determining liability or equity classification. Companies that provide earnings per share (EPS) data will adjust their basic EPS calculation for the effect of the feature when triggered (i.e., when the exercise price of the related equity-linked financial instrument is adjusted downward because of the down round feature) and will also recognize the effect of the trigger within equity. The amendments are effective for annual periods beginning after December 15, 2019, and interim periods within annual periods beginning after December 15, 2020. Early adoption is permitted. Assuming the Company remains an emerging growth company, the new authoritative guidance will be effective for reporting periods after January 1, 2020. The Company is currently evaluating the provisions of ASU No. 2017‑11 to determine the potential impact the new standard will have on the Company’s Consolidated Financial Statements. Income Statement—Reporting Comprehensive Income (Topic 220) )—In February 2018, FASB issued ASU No.2018-02, . The ASU helps organizations address certain stranded income tax effects in accumulated other comprehensive income (AOCI) resulting from the Tax Cuts and Jobs Act. The ASU provides reporting entities with an option to reclassify stranded tax effects within AOCI to retained earnings in each period in which the effect of the change in the U.S. federal corporate income tax rate in the Tax Cuts and Jobs Act (or portion thereof) is recorded. The ASU requires reporting entities to disclose: a description of the accounting policy for releasing income tax effects from AOCI; whether they elect to reclassify the stranded income tax effects from the Tax Cuts and Jobs Act; and information about the other income tax effects that are reclassified. The amendments affect any organization that is required to apply the provisions of Topic 220, , and has items of other comprehensive income for which the related tax effects are presented in other comprehensive income as required by GAAP. The amendments are effective for annual periods beginning after December 15, 2018, and interim periods within those fiscal years. The Company early adopted the new guidance on January 1, 2018, and determined it will not have a significant impact on the Company’s statements of operations or financial condition.

Acquisition of a Business (Tabl

Acquisition of a Business (Tables)	12 Months Ended
	Dec. 31, 2017
Business Combinations [Abstract]
Summary of Estimates of fair Values of Assets and Liabilities Assumed as of Acquisition Date	The following table presents a summary of the estimates of fair values of assets acquired and liabilities assumed as of the acquisition date: Assets Cash and cash equivalents $ 25,480 Securities available-for-sale 27,662 Restricted stock 931 Loans held for sale 15,363 Loans 351,820 Servicing assets 20,295 Premises and equipment 2,011 Other real estate owned 1,525 Other intangible assets 486 Bank-owned life insurance 2,352 Other assets 8,228 Total assets acquired $ 456,153 Liabilities Deposits $ 361,370 Federal Home Loan Bank advances 9,773 Junior subordinated debentures 1,339 Accrued expenses and other liabilities 4,958 Total liabilities assumed 377,440 Net assets acquired $ 78,713 Consideration paid Common stock (4,199,791 shares issued at $16.25 per share) $ 68,247 Cash paid 36,753 Total consideration paid 105,000 Goodwill $ 26,287
Summary of Acquired Non-Impaired Loans as of Acquisition Date	The following table presents the acquired non-impaired loans as of the acquisition date: Fair value $ 312,166 Gross contractual amounts receivable 450,292 Estimate of contractual cash flows not expected to be collected ( 1) 19,661 Estimate of contractual cash flows expected to be collected 430,631 (1) Includes interest payments not expected to be collected due to loan prepayments as well as principal and interest payments not expected to be collected due to customer default.
Summary of Pro Forma Information for Results of Operations	The following table provides the pro forma information for the results of operations for the years ended December 31, 2016 and 2015, as if the acquisition had occurred on January 1, 2015. The pro forma results combine the historical results of Ridgestone into the Company’s Consolidated Statements of Operations, including the impact of certain acquisition accounting adjustments, which includes loan discount accretion, intangible assets amortization, deposit premium accretion and borrowing net discount amortization. The pro forma results have been prepared for comparative purposes only and are not necessarily indicative of the results that would have been obtained had the acquisition actually occurred on January 1, 2015. No assumptions have been applied to the pro forma results of operations regarding possible revenue enhancements, provision for credit losses, expense efficiencies or asset dispositions. The acquisition-related expenses that have been recognized are included in net income (loss) in the following table. Years ended December 31, 2016 2015 Total revenues (net interest income and non-interest income) $ 171,059 $ 151,054 Net income (loss) $ 82,252 $ (1,437 ) Earnings per share—basic $ 3.54 $ (0.07 ) Earnings per share—diluted $ 3.50 $ (0.07 )

Securities (Tables)

Securities (Tables)	12 Months Ended
	Dec. 31, 2017
Investments Debt And Equity Securities [Abstract]
Summary of Amortized Cost and Fair Values of Securities Available-for-sale and Held to Maturity	The following tables summarize the amortized cost and fair values of securities available-for-sale and securities held-to-maturity at December 31, 2017 and 2016 and the corresponding amounts of gross unrealized gains and losses: 2017 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Available-for-sale U.S. Treasury Notes $ 14,999 $ — $ (136 ) $ 14,863 U.S. Government agencies 54,248 — (1,290 ) 52,958 Obligations of states, municipalities, and political subdivisions 33,405 100 (335 ) 33,170 Residential mortgage-backed securities Agency 315,103 — (7,646 ) 307,457 Non-agency 39,485 104 (75 ) 39,514 Commercial mortgage-backed securities Agency 70,964 45 (1,966 ) 69,043 Non-agency 31,763 — (792 ) 30,971 Corporate securities 29,573 507 (104 ) 29,976 Other securities 3,627 1,730 (73 ) 5,284 Total $ 593,167 $ 2,486 $ (12,417 ) $ 583,236 Note 4—Securities (continued) 2017 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Held-to-maturity Obligations of states, municipalities, and political subdivisions $ 24,030 $ 197 $ (82 ) $ 24,145 Residential mortgage-backed securities Agency 53,731 79 (203 ) 53,607 Non-agency 39,402 174 (51 ) 39,525 Total $ 117,163 $ 450 $ (336 ) $ 117,277 2016 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Available-for-sale U.S. Treasury Notes $ 14,995 $ 4 $ (79 ) $ 14,920 U.S. Government agencies 60,180 — (1,323 ) 58,857 Obligations of states, municipalities, and political subdivisions 16,271 60 (272 ) 16,059 Residential mortgage-backed securities Agency 376,800 — (8,640 ) 368,160 Non-agency 20,107 — (174 ) 19,933 Commercial mortgage-backed securities Agency 78,954 — (1,551 ) 77,403 Non-agency 32,061 — (1,009 ) 31,052 Corporate securities 17,065 350 (86 ) 17,329 Other securities 4,161 742 (56 ) 4,847 Total $ 620,594 $ 1,156 $ (13,190 ) $ 608,560 2016 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Held-to-maturity Obligations of states, municipalities, and political subdivisions $ 24,878 $ 105 $ (229 ) $ 24,754 Residential mortgage-backed securities Agency 67,692 35 (283 ) 67,444 Non-agency 46,276 50 (442 ) 45,884 Total $ 138,846 $ 190 $ (954 ) $ 138,082
Summary of Gross Unrealized Losses and Fair Values, Aggregated by Investment Category and Length of Individual Securities Continuous Unrealized Loss Position Available-for-sale and Held to Maturity	Gross unrealized losses and fair values, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position as of December 31, 2017 and 2016 are summarized as follows: Less than 12 Months 12 Months or Longer Total 2017 # of Securities Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses Available-for-sale U.S. Treasury Notes 5 $ 4,998 $ (2 ) $ 9,865 $ (134 ) $ 14,863 $ (136 ) U.S. Government agencies 9 992 (7 ) 51,966 (1,283 ) 52,958 (1,290 ) Obligations of states, municipalities and political subdivisions 29 16,059 (137 ) 4,453 (198 ) 20,512 (335 ) Residential mortgage-backed securities Agency 41 15,441 (181 ) 292,016 (7,465 ) 307,457 (7,646 ) Non-agency 1 — — 4,565 (75 ) 4,565 (75 ) Commercial mortgage-backed securities Agency 7 — — 57,442 (1,966 ) 57,442 (1,966 ) Non-agency 5 — — 30,971 (792 ) 30,971 (792 ) Corporate securities 3 2,406 (80 ) 2,489 (24 ) 4,895 (104 ) Other securities 1 — — 1,921 (73 ) 1,921 (73 ) Total 101 $ 39,896 $ (407 ) $ 455,688 $ (12,010 ) $ 495,584 $ (12,417 ) Less than 12 Months 12 Months or Longer Total 2017 # of Securities Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses Held-to-maturity Obligations of states, municipalities, and political subdivisions 12 $ 7,409 $ (38 ) $ 1,548 $ (44 ) $ 8,957 $ (82 ) Residential mortgage-backed securities Agency 13 24,344 (107 ) 7,935 (96 ) 32,279 (203 ) Non-agency 3 10,458 (10 ) 4,382 (41 ) 14,840 (51 ) Total 28 $ 42,211 $ (155 ) $ 13,865 $ (181 ) $ 56,076 $ (336 ) Note 4—Securities (continued) Less than 12 Months 12 Months or Longer Total 2016 # of Securities Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses Available-for-sale U.S. Treasury Notes 3 $ 9,918 $ (79 ) $ — $ — $ 9,918 $ (79 ) U.S. Government agencies 10 58,857 (1,323 ) — — 58,857 (1,323 ) Obligations of states, municipalities and political subdivisions 14 7,799 (259 ) 115 (13 ) 7,914 (272 ) Residential mortgage-backed securities Agency 41 364,713 (8,483 ) 3,447 (157 ) 368,160 (8,640 ) Non-agency 2 19,933 (174 ) — — 19,933 (174 ) Commercial mortgage-backed securities Agency 8 70,762 (1,488 ) 6,641 (63 ) 77,403 (1,551 ) Non-agency 5 31,052 (1,009 ) — — 31,052 (1,009 ) Corporate securities 4 5,097 (78 ) 2,522 (8 ) 7,619 (86 ) Other securities 1 — — 1,994 (56 ) 1,994 (56 ) Total 88 $ 568,131 $ (12,893 ) $ 14,719 $ (297 ) $ 582,850 $ (13,190 ) Less than 12 Months 12 Months or Longer Total 2016 # of Securities Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses Held-to-maturity Obligations of states, municipalities, and political subdivisions 22 $ 16,235 $ (229 ) $ — $ — $ 16,235 $ (229 ) Residential mortgage-backed securities Agency 15 52,156 (283 ) — — 52,156 (283 ) Non-agency 5 29,245 (442 ) — — 29,245 (442 ) Total 42 $ 97,636 $ (954 ) $ — $ — $ 97,636 $ (954 )
Summary of Proceeds From Sales of Securities Available-for-sale and Associated Gains and Losses	The proceeds from all sales of securities were available-for-sale, and the associated gains and losses for the years ended December 31, 2017, 2016, and 2015 are listed below: 2017 2016 2015 Proceeds $ 8 $ 534,418 $ 511,028 Gross gains 8 3,358 3,124 Gross losses — 131 60
Schedule of Amortized Cost and Fair Value of Debt Securities by Contractual Maturity	At December 31, 2017, the amortized cost and fair value of debt securities are shown by contractual maturity. Expected maturities may differ from contractual maturities if borrowers have the right to call or prepay obligations with or without call or prepayment penalties. Securities not due at a single maturity date are shown separately. Amortized Cost Fair Value Available-for-sale Due in one year or less $ 8,285 $ 8,268 Due from one to five years 72,432 71,826 Due from five to ten years 40,439 39,812 Due after ten years 11,604 11,738 Mortgage-backed securities 457,315 446,985 Other securities with no defined maturity 3,092 4,607 Total $ 593,167 $ 583,236 Held-to-maturity Due from one to five years $ 1,719 $ 1,732 Due from five to ten years 13,532 13,546 Due after ten years 8,779 8,867 Mortgage-backed securities 93,133 93,132 Total $ 117,163 $ 117,277

Loan and Lease Receivables (Tab

Loan and Lease Receivables (Tables)	12 Months Ended
	Dec. 31, 2018
Receivables [Abstract]
Schedule of Outstanding Loan and Lease Receivables	Outstanding loan and lease receivables as of December 31, 2017 and 2016 were categorized as follows: 2017 2016 Commercial real estate $ 891,971 $ 796,950 Residential real estate 577,123 610,699 Construction, land development, and other land 105,996 141,122 Commercial and industrial 522,254 439,476 Installment and other 4,182 2,917 Lease financing receivables 174,165 155,999 Total loans and leases 2,275,691 2,147,163 Net unamortized deferred fees and costs (1,720 ) (2,119 ) Initial direct costs 3,521 2,967 Allowance for loan and lease losses (16,706 ) (10,923 ) Net loans and leases $ 2,260,786 $ 2,137,088 2017 2016 Lease financing receivables Net minimum lease payments $ 188,986 $ 168,345 Unguaranteed residual values 1,644 1,787 Unearned income (16,465 ) (14,133 ) Total lease financing receivables 174,165 155,999 Initial direct costs 3,521 2,967 Lease financial receivables before allowance for lease losses $ 177,686 $ 158,966
Summary of Minimum Annual Lease Payments for Lease Financing Receivables	The minimum annual lease payments for lease financing receivables as of December 31, 2017 are summarized as follows: Minimum Lease Payments 2018 $ 65,770 2019 53,702 2020 37,914 2021 21,743 2022 8,922 Thereafter 935 Total $ 188,986
Summary of Balances for Each Respective Loan and Lease Category	The following tables summarize the balances for each respective loan and lease category as of December 31, 2017 and 2016: 2017 Originated Acquired Impaired Acquired Non- Impaired Total Commercial real estate $ 513,622 $ 166,712 $ 211,359 $ 891,693 Residential real estate 400,571 144,562 32,085 577,218 Construction, land development, and other land 97,638 5,946 1,845 105,429 Commercial and industrial 416,499 10,008 94,731 521,238 Installment and other 3,724 462 42 4,228 Lease financing receivables 141,329 — 36,357 177,686 Total loans and leases $ 1,573,383 $ 327,690 $ 376,419 $ 2,277,492 2016 Originated Acquired Impaired Acquired Non- Impaired Total Commercial real estate $ 338,752 $ 207,303 $ 250,289 $ 796,344 Residential real estate 394,168 175,717 40,853 610,738 Construction, land development, and other land 119,357 6,979 14,430 140,766 Commercial and industrial 309,097 13,464 115,677 438,238 Installment and other 2,021 574 364 2,959 Lease financing receivables 118,493 — 40,473 158,966 Total loans and leases $ 1,281,888 $ 404,037 $ 462,086 $ 2,148,011
Schedule of Estimated Fair Value of Impaired Loans Acquired at Acquisition	The following table presents a reconciliation of the undiscounted contractual cash flows, non‑accretable difference, accretable yield, and fair value of acquired impaired loans as of the acquisition date of October 14, 2016: Undiscounted contractual cash flows $ 66,488 Undiscounted cash flows not expected to be collected (non-accretable difference) (19,918 ) Undiscounted cash flows expected to be collected 46,570 Accretable yield at acquisition (6,916 ) Estimated fair value of impaired loans acquired at acquisition $ 39,654
Summary of Outstanding Balance and Carrying Amount of All Acquired Impaired Loans	The outstanding balance and carrying amount of all acquired impaired loans are summarized below. The balances do not include an allowance for loan and lease losses of $3.9 million and $1.6 million, respectively, at December 31, 2017 and 2016. 2017 2016 Outstanding Balance Carrying Value Outstanding Balance Carrying Value Commercial real estate $ 235,898 $ 166,712 $ 278,893 $ 207,303 Residential real estate 207,660 144,562 236,384 175,717 Construction, land development, and other land 13,270 5,946 15,292 6,979 Commercial and industrial 18,333 10,008 23,164 13,464 Installment and other 1,819 462 1,976 574 Total acquired impaired loans $ 476,980 $ 327,690 $ 555,709 $ 404,037
Summary of Changes in Accretable Yield for Acquired Impaired Loans	The following table summarizes the changes in accretable yield for acquired impaired loans for the years ended December 31, 2017, 2016, and 2015: 2017 2016 2015 Beginning balance $ 36,868 $ 43,915 $ 68,238 Additions — 6,916 — Accretion to interest income (24,597 ) (26,208 ) (35,547 ) Reclassification from nonaccretable difference 24,175 12,245 11,224 Ending balance $ 36,446 $ 36,868 $ 43,915
Schedule of Unpaid Principal Balance and Carrying Value for Acquired Non-Impaired Loans and Leases	The unpaid principal balance and carrying value for acquired non‑impaired loans and leases at December 31, 2017 and 2016 were as follows: 2017 2016 Unpaid Principal Balance Carrying Value Unpaid Principal Balance Carrying Value Commercial real estate $ 221,710 $ 211,359 $ 259,055 $ 250,289 Residential real estate 32,605 32,085 41,282 40,853 Construction, land development, and other land 1,926 1,845 14,619 14,430 Commercial and industrial 105,529 94,731 125,806 115,677 Installment and other 355 42 402 364 Lease financing receivables 37,476 36,357 40,205 40,473 Total acquired non-impaired loans and leases $ 399,601 $ 376,419 $ 481,369 $ 462,086

Allowance for Loan and Lease 38

Allowance for Loan and Lease Losses and Reserve for Unfunded Commitments (Tables)	12 Months Ended
	Dec. 31, 2017
Receivables [Abstract]
Summary of Allowance for Loan and Lease Losses and Corresponding Loan and Lease Balances	The following tables summarize the balance and activity within the allowance for loan and lease losses, the components of the allowance for loan and lease losses in terms of loans and leases individually and collectively evaluated for impairment, and corresponding loan and lease balances by type for the years ended December 31, 2017, 2016 and 2015 are as follows: 2017 Commercial Real Estate Residential Real Estate Construction, Land Development, and Other Land Commercial and Industrial Installment and Other Lease Financing Receivables Total Allowance for loan and lease losses Beginning balance $ 1,945 $ 2,483 $ 742 $ 4,196 $ 334 $ 1,223 $ 10,923 Provisions 4,343 (405 ) (520 ) 6,058 34 3,143 12,653 Charge-offs (1,494 ) (440 ) — (2,836 ) (327 ) (3,099 ) (8,196 ) Recoveries — — — — — 1,326 1,326 Ending balance $ 4,794 $ 1,638 $ 222 $ 7,418 $ 41 $ 2,593 $ 16,706 Ending balance: Individually evaluated for impairment $ 1,101 $ 158 $ — $ 2,692 $ 14 $ — $ 3,965 Collectively evaluated for impairment 1,765 1,047 145 3,308 9 2,593 8,867 Loans acquired with deteriorated credit quality 1,928 433 77 1,418 18 — 3,874 Total allowance for loan and lease losses $ 4,794 $ 1,638 $ 222 $ 7,418 $ 41 $ 2,593 $ 16,706 2017 Commercial Real Estate Residential Real Estate Construction, Land Development, and Other Land Commercial and Industrial Installment and Other Lease Financing Receivables Total Loans and leases ending balance: Individually evaluated for impairment $ 13,884 $ 2,429 $ — $ 14,784 $ 14 $ — $ 31,111 Collectively evaluated for impairment 711,097 430,227 99,483 496,446 3,752 177,686 1,918,691 Loans acquired with deteriorated credit quality 166,712 144,562 5,946 10,008 462 — 327,690 Total loans and leases $ 891,693 $ 577,218 $ 105,429 $ 521,238 $ 4,228 $ 177,686 $ 2,277,492 Note 6—Allowance for Loan and Lease Losses and Reserve for Unfunded Commitments (continued) 2016 Commercial Real Estate Residential Real Estate Construction, Land Development, and Other Land Commercial and Industrial Installment and Other Lease Financing Receivables Total Allowance for loan and lease losses Beginning balance $ 2,280 $ 2,981 $ 232 $ 1,403 $ 357 $ 379 $ 7,632 Provisions 4,032 135 605 2,869 (11 ) 2,722 10,352 Charge-offs (4,367 ) (633 ) (95 ) (76 ) (12 ) (2,634 ) (7,817 ) Recoveries — — — — — 756 756 Ending balance $ 1,945 $ 2,483 $ 742 $ 4,196 $ 334 $ 1,223 $ 10,923 Ending balance: Individually evaluated for impairment $ — $ 293 $ — $ 396 $ 328 $ — $ 1,017 Collectively evaluated for impairment 1,456 1,743 742 3,126 5 1,223 8,295 Loans acquired with deteriorated credit quality 489 447 — 674 1 — 1,611 Total allowance for loan and lease losses $ 1,945 $ 2,483 $ 742 $ 4,196 $ 334 $ 1,223 $ 10,923 2016 Commercial Real Estate Residential Real Estate Construction, Land Development, and Other Land Commercial and Industrial Installment and Other Lease Financing Receivables Total Loans and leases ending balance: Individually evaluated for impairment $ 8,916 $ 1,300 $ — $ 1,382 $ 328 $ — $ 11,926 Collectively evaluated for impairment 580,125 433,721 133,787 423,392 2,057 158,966 1,732,048 Loans acquired with deteriorated credit quality 207,303 175,717 6,979 13,464 574 — 404,037 Total loans and leases $ 796,344 $ 610,738 $ 140,766 $ 438,238 $ 2,959 $ 158,966 $ 2,148,011 2015 Commercial Real Estate Residential Real Estate Construction, Land Development, and Other Land Commercial and Industrial Installment and Other Lease Financing Receivables Total Allowance for loan and lease losses Beginning balance $ 1,112 $ 1,936 $ 834 $ 648 $ 121 $ 143 $ 4,794 Provisions 2,464 1,873 (585 ) 782 237 2,195 6,966 Charge-offs (1,296 ) (828 ) (17 ) (30 ) (1 ) (2,187 ) (4,359 ) Recoveries — — — 3 — 228 231 Ending balance $ 2,280 $ 2,981 $ 232 $ 1,403 $ 357 $ 379 $ 7,632 Ending balance: Individually evaluated for impairment $ 1,076 $ 615 $ 137 $ 171 $ 327 $ — $ 2,326 Collectively evaluated for impairment 470 476 95 596 — 379 2,016 Loans acquired with deteriorated credit quality 734 1,890 — 636 30 — 3,290 Total allowance for loan and lease losses $ 2,280 $ 2,981 $ 232 $ 1,403 $ 357 $ 379 $ 7,632 Note 6—Allowance for Loan and Lease Losses and Reserve for Unfunded Commitments (continued) 2015 Commercial Real Estate Residential Real Estate Construction, Land Development, and Other Land Commercial and Industrial Installment and Other Lease Financing Receivables Total Loans and leases ending balance: Individually evaluated for impairment $ 4,160 $ 4,042 $ 208 $ 171 $ 327 $ — $ 8,908 Collectively evaluated for impairment 285,571 256,555 31,390 155,955 594 119,553 849,618 Loans acquired with deteriorated credit quality 243,964 223,738 8,634 9,570 1,005 — 486,911 Total loans and leases $ 533,695 $ 484,335 $ 40,232 $ 165,696 $ 1,926 $ 119,553 $ 1,345,437
Summary of Recorded Investment, Unpaid Principal Balance, Related Allowance, Average Recorded Investment, and Interest Income Recognized for Loans and Leases	The following tables summarize the recorded investment, unpaid principal balance, related allowance, average recorded investment, and interest income recognized for loans and leases considered impaired as of December 31, 2017, 2016, and 2015, which excludes acquired impaired loans: 2017 Recorded Investment Unpaid Principal Balance Related Allowance Average Recorded Investment Interest Income Recognized With no related allowance recorded Commercial real estate $ 11,425 $ 12,936 $ — $ 10,482 $ 525 Residential real estate 2,075 2,046 — 1,781 72 Construction, land development and other land — — — 295 2 Commercial and industrial 5,470 6,774 — 2,875 265 With an allowance recorded Commercial real estate 2,459 2,634 1,101 1,988 187 Residential real estate 354 351 158 422 6 Construction, land development and other land — — — 14 — Commercial and industrial 9,314 9,724 2,692 3,460 486 Installment and other 14 14 14 162 12 Total impaired loans $ 31,111 $ 34,479 $ 3,965 $ 21,479 $ 1,555 2016 Recorded Investment Unpaid Principal Balance Related Allowance Average Recorded Investment Interest Income Recognized With no related allowance recorded Commercial real estate $ 8,916 $ 9,502 $ — $ 8,975 $ 305 Residential real estate 804 1,999 — 827 45 Commercial and Industrial 521 524 — 516 (2 ) With an allowance recorded Residential real estate 496 528 293 519 1 Commercial and industrial 861 869 396 914 — Installment and other 328 361 328 328 16 Total impaired loans $ 11,926 $ 13,783 $ 1,017 $ 12,079 $ 365 Note 6—Allowance for Loan and Lease Losses and Reserve for Unfunded Commitments (continued) 2015 Recorded Investment Unpaid Principal Balance Related Allowance Average Recorded Investment Interest Income Recognized With no related allowance recorded Commercial real estate $ 1,362 $ 1,922 $ — $ 1,394 $ 64 Residential real estate 2,821 4,222 — 2,865 63 With an allowance recorded Commercial real estate 2,798 2,797 1,076 2,826 46 Residential real estate 1,221 1,216 615 1,250 15 Construction, land development and other land 208 1,201 137 208 — Commercial and industrial 171 171 171 185 1 Installment and other 327 335 327 327 23 Total impaired loans $ 8,908 $ 11,864 $ 2,326 $ 9,055 $ 212
Summary of Risk Rating Categories of Loans and Leases Considered for Inclusion in Allowance for Loan and Lease Losses Calculation	Note 6—Allowance for Loan and Lease Losses and Reserve for Unfunded Commitments (continued) The following tables summarize the risk rating categories of the loans and leases considered for inclusion in the allowance for loan and lease losses calculation, excluding acquired impaired loans, as of December 31, 2017 and 2016: 2017 Commercial Real Estate Residential Real Estate Construction, Land Development, and Other Land Commercial and Industrial Installment and Other Lease Financing Receivables Total Pass $ 638,066 $ 398,743 $ 73,935 $ 415,163 $ 3,732 $ 174,672 $ 1,704,311 Watch 58,217 29,165 22,380 67,024 20 190 176,996 Special Mention 14,645 2,251 3,168 13,535 — 1,293 34,892 Substandard 14,053 2,497 — 15,508 14 1,259 33,331 Doubtful — — — — — 272 272 Loss — — — — — — — Total $ 724,981 $ 432,656 $ 99,483 $ 511,230 $ 3,766 $ 177,686 $ 1,949,802 2016 Commercial Real Estate Residential Real Estate Construction, Land Development, and Other Land Commercial and Industrial Installment and Other Lease Financing Receivables Total Pass $ 536,499 $ 419,880 $ 129,732 $ 369,136 $ 2,052 $ 157,296 $ 1,614,595 Watch 38,707 10,885 2,897 52,872 4 324 105,689 Special Mention 5,377 3,116 1,158 1,258 1 512 11,422 Substandard 8,458 1,140 — 1,508 328 739 12,173 Doubtful — — — — — 95 95 Loss — — — — — — — Total $ 589,041 $ 435,021 $ 133,787 $ 424,774 $ 2,385 $ 158,966 $ 1,743,974
Summary of Contractual Delinquency Information	The following tables summarize contractual delinquency information for acquired non-impaired and originated loans and leases by category as of December 31, 2017 and 2016: 2017 30-59 Days Past Due 60-89 Days Past Due Greater than 90 Days and Accruing Non- accrual Total Past Due Current Total Commercial real estate $ 4,783 $ 968 $ — $ 8,459 $ 14,210 $ 710,771 $ 724,981 Residential real estate 148 — — 2,092 2,240 430,416 432,656 Construction, land development, and other land — — — - - 99,483 99,483 Commercial and industrial 6,667 967 — 4,348 11,982 499,248 511,230 Installment and other 18 — — 14 32 3,734 3,766 Lease financing receivables 997 638 — 851 2,486 175,200 177,686 Total $ 12,613 $ 2,573 $ — $ 15,764 $ 30,950 $ 1,918,852 $ 1,949,802 Note 6—Allowance for Loan and Lease Losses and Reserve for Unfunded Commitments (continued) 2016 30-59 Days Past Due 60-89 Days Past Due Greater than 90 Days and Accruing Non- accrual Total Past Due Current Total Commercial real estate $ 2,944 $ 648 $ — $ 3,935 $ 7,527 $ 581,514 $ 589,041 Residential real estate 243 — — 1,118 1,361 433,660 435,021 Construction, land development, and other land 1,363 — — — 1,363 132,424 133,787 Commercial and industrial 6,066 374 — 958 7,398 417,376 424,774 Installment and other — — — 328 328 2,057 2,385 Lease financing receivables 2,070 390 — 445 2,905 156,061 158,966 Total $ 12,686 $ 1,412 $ — $ 6,784 $ 20,882 $ 1,723,092 $ 1,743,974
Summary of TDR's by Loan Category	. The tables below present TDRs by loan category as of December 31, 2017, 2016, and 2015. Refer to Note 1—Summary of Significant Accounting Policies for the accounting policy for TDRs. December 31, 2017 Number of Loans Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment Charge-offs Specific Reserves Troubled Debt Restructurings: Commercial real estate 5 $ 1,655 $ 1,655 $ — $ 111 Commercial and industrial 3 1,246 759 487 246 Residential real estate 2 216 216 — — Total 10 $ 3,117 $ 2,630 $ 487 $ 357 December 31, 2016 Number of Loans Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment Charge-offs Specific Reserves Troubled Debt Restructurings: Commercial real estate 2 $ 898 $ 898 $ — $ — Residential real estate 3 256 256 — — Total 5 $ 1,154 $ 1,154 $ — $ — December 31, 2015 Number of Loans Pre-Modification Outstanding Recorded Investment Post-Modification Outstanding Recorded Investment Charge-offs Specific Reserves Troubled Debt Restructurings: Commercial real estate 2 $ 979 $ 979 $ — $ — Residential real estate 4 1,762 1,762 — — Total 6 $ 2,741 $ 2,741 $ — $ —

Servicing Assets (Tables)

Servicing Assets (Tables)	12 Months Ended
	Dec. 31, 2017
Transfers And Servicing [Abstract]
Unpaid Principal Balances of Loans Serviced for Others	The unpaid principal balances of these loans serviced for others were as follows as December 31, 2017 and 2016: 2017 2016 Loan portfolios serviced for: SBA $ 1,021,143 $ 911,803 USDA 91,758 106,125 Total $ 1,112,901 $ 1,017,928
Activity for Servicing Assets and Related Changes in Fair Value	Activity for servicing assets and the related changes in fair value for the years ended December 31, 2017 and 2016 is as follows: 2017 2016 Beginning balance $ 21,091 $ — Acquired servicing assets at fair value — $ 20,295 Additions, net 6,250 539 Changes in fair value (5,941 ) 257 Ending balance $ 21,400 $ 21,091

Other Real Estate Owned (Tables

Other Real Estate Owned (Tables)	12 Months Ended
	Dec. 31, 2017
Banking And Thrift [Abstract]
Change in Other Real Estate Owned	The following table presents the change in other real estate owned (“OREO”) for the years ended December 31, 2017, 2016, and 2015: 2017 2016 2015 Beginning balance $ 16,570 $ 26,715 $ 56,181 Acquisition of OREO through business combination — 1,525 — Net additions to OREO 6,266 6,672 13,793 Dispositions of OREO (11,750 ) (17,389 ) (33,994 ) Valuation adjustments (460 ) (953 ) (9,265 ) Ending balance $ 10,626 $ 16,570 $ 26,715

Premises and Equipment and As41

Premises and Equipment and Assets Held for Sale (Tables)	12 Months Ended
	Dec. 31, 2017
Property Plant And Equipment [Abstract]
Schedule for Classification of Premises and Equipment	Classifications of premises and equipment as of December 31, 2017 and 2016 and were as follows: 2017 2016 Premises $ 51,743 $ 53,495 Furniture, fixtures and equipment 10,295 7,214 Leasehold improvements 1,538 1,093 Total cost 63,576 61,802 Less accumulated depreciation and amortization (13,906 ) (9,780 ) Net book value of premises, furniture, fixtures, equipment, leasehold improvements 49,670 52,022 Construction in progress 899 3,869 Land 44,655 46,183 Premises and equipment, net $ 95,224 $ 102,074
Change in Assets Held for Sale	The following table presents the change in assets held for sale for the years ended December 31, 2017, 2016, and 2015: 2017 2016 2015 Beginning balance $ 14,748 $ 2,259 $ — Transfers in 3,372 14,496 2,259 Proceeds from sales (5,373 ) (2,566 ) — Internally financed sales (1,800 ) — — Net gains (losses) on sales (217 ) 967 — Impairment loss (951 ) (408 ) — Ending balance $ 9,779 $ 14,748 $ 2,259

Goodwill, Core Deposit Intang42

Goodwill, Core Deposit Intangible and Other Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2017
Goodwill And Intangible Assets Disclosure [Abstract]
Summary of Changes in Goodwill and Core Deposit Intangible Assets	The following table summarizes the changes in the Company’s goodwill and core deposit intangible assets for the years ended December 31, 2017, 2016 and 2015: 2017 2016 2015 Goodwill Core Intangible Goodwill Core Deposit Intangible Goodwill Core Deposit Intangible Beginning balance $ 51,975 $ 19,776 $ 25,688 $ 22,275 $ 25,613 $ 25,245 Additions — — 26,287 486 75 — Amortization or accretion — (3,056 ) — (2,985 ) — (2,970 ) Ending balance $ 51,975 $ 16,720 $ 51,975 $ 19,776 $ 25,688 $ 22,275 Accumulated amortization or accretion N/A $ 13,466 N/A $ 10,410 N/A $ 7,425 Weighted average remaining amortization or accretion period N/A 5.6 Years N/A 6.6 Years N/A 7.5 Years
Estimated Amortization Expense for Core Deposit Intangible and Other Intangible Assets Recognized	The following table presents the estimated amortization expense for core deposit intangible and other intangible assets recognized at December 31, 2017: Estimated Amortization 2018 $ 3,061 2019 3,050 2020 3,026 2021 3,017 2022 3,010 Thereafter 1,592 Total $ 16,756

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Schedule of components of provision for income taxes	The following were the components of provision for income taxes for the years ended December 31, 2017, 2016, and 2015: 2017 2016 2015 Current tax expense: Federal $ 1,010 $ — $ 250 State and local 1,485 — 57 Total current tax expense 2,495 — 307 Deferred tax expense: Federal 13,554 478 4,929 State and local 686 136 656 Remeasurement of net deferred tax assets 2,364 — — Total deferred tax expense before reversal of valuation allowance 16,604 614 5,585 Deferred tax valuation allowance — (61,859 ) (5,585 ) Provision (benefit) for income taxes $ 19,099 $ (61,245 ) $ 307
Schedule of reconciliation between statutory U.S. federal income tax rate and effective tax rate	The following is a reconciliation between the statutory U.S. federal income tax rate of 35% and the effective tax rate: 2017 2016 2015 Calculated tax benefit at statutory rate 35.0 % 35.0 % 35.0 % Increase (decrease) in income taxes resulting from: Reversal of valuation allowance, net of change in estimated Section 382 impact — (1,167.6 ) 73.4 State taxes, net of federal income tax 6.5 6.1 5.0 Tax exempt income (0.7 ) (5.3 ) 24.2 Non-deductible expenses 0.2 14.8 (137.6 ) Remeasurement of net deferred tax assets 5.8 — — Total income tax expense (benefit) 46.8 % (1,117.0 ) % — %
Schedule of components of deferred tax assets and liabilities	The following were the significant components of the deferred tax assets and liabilities as of December 31, 2017 and 2016: 2017 2016 Deferred tax assets: Net operating losses and tax credits $ 42,062 $ 61,906 Interest on non-accrual loans 2,755 2,882 Allowance for loan losses and loan basis 13,839 22,017 Deposits 5 316 Alternative minimum tax ("AMT") credit carryforward 2,140 1,073 Other real estate owned — 214 Net unrealized holding losses on securities available-for-sale 2,766 4,818 Other 2,413 3,241 Total deferred tax assets 65,980 96,467 Deferred tax liabilities: Other real estate owned (24 ) — Premises and equipment (3,385 ) (6,907 ) Core deposit intangibles (4,656 ) (7,858 ) Servicing assets (3,505 ) (7,899 ) Trust preferred securities (2,465 ) (3,809 ) Unrealized holding gain on cash flow hedges (1,390 ) (1,491 ) Other (592 ) (743 ) Total deferred tax liabilities (16,017 ) (28,707 ) Less valuation allowance on net deferred tax asset — — Net deferred tax assets after valuation allowance $ 49,963 $ 67,760
Operating Loss and Credit Carryforwards	2017 2016 NOL carryforwards available to offset future taxable income: Federal gross NOL carryforwards - begin to expire in 2027 $ 63,964 $ 116,315 Illinois gross NLD carryforwards - begin to expire in 2021 381,471 420,764 AMT credit carryforward - no expiration date 2,140 1,073

Federal Home Loan Bank Advanc44

Federal Home Loan Bank Advances (Tables)	12 Months Ended
	Dec. 31, 2017
Federal Home Loan Banks [Abstract]
Summary of FHLB Advances Including Acquisition Accounting Adjustments Along with Weighted Average Costs and Scheduled Maturities	The following table summarizes the FHLB advances as of December 31, 2017 and 2016, which include acquisition accounting adjustments of $19,000 and $228,000, respectively, along with weighted average costs and scheduled maturities: 2017 2016 Federal Home Loan Bank advances $ 361,506 $ 313,715 Weighted average cost 1.49 % 0.73 % Scheduled Maturities 2018 $ 361,506 Total $ 361,506

Other Borrowings (Tables)

Other Borrowings (Tables)	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Summary of Other Borrowings	The following is a summary of the Company’s other borrowings as of December 31, 2017 and 2016: 2017 2016 Securities sold under agreements to repurchase $ 31,187 $ 17,249 Line of credit — 20,650 Total $ 31,187 $ 37,899
Summary of Short-term Credit Lines Available for Use	The following table presents short-term credit lines available for use, for which the Company did not have an outstanding balance as of December 31, 2017 and 2016: 2017 2016 Federal Reserve Bank of Chicago discount window line $ 144,248 $ 110,600 Available federal funds lines 55,000 20,000

Deposits (Tables)

Deposits (Tables)	12 Months Ended
	Dec. 31, 2017
Deposits [Abstract]
Schedule of Deposits	The following is a summary of the Company’s deposits as of December 31, 2017 and 2016: 2017 2016 Non-interest bearing demand deposits $ 760,887 $ 724,457 Interest bearing checking accounts 186,611 173,929 Money market demand accounts 349,862 369,074 Other savings 437,212 446,418 Time deposits (below $250,000) 627,255 659,129 Time deposits ($250,000 and above) 81,502 117,387 Total deposits $ 2,443,329 $ 2,490,394
Schedule of Maturities of Time Deposits	At December 31, 2017, the scheduled maturities of time deposits were as follows: Scheduled Maturities 2018 $ 548,208 2019 139,748 2020 9,552 2021 6,703 2022 4,546 Total $ 708,757

Junior Subordinated Debentures

Junior Subordinated Debentures (Tables)	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Junior Subordinated Debentures by Issuance	At December 31, 2017 and 2016, the Company’s junior subordinated debentures by issuance were as follows: Name of Trust Aggregate Principal Amount 2017 Aggregate Principal Amount 2016 Stated Maturity Contractual Rate at December 31, 2017 Interest Rate Spread Metropolitan $ 35,000 $ 35,000 March 4.39 % Three-month LIBOR + 2.79% RidgeStone Capital Trust I 1,500 1,500 June 30, 2033 5.09 % Five-year LIBOR + 3.50% Total liability, at par 36,500 36,500 Discount (8,853 ) (9,574 ) Total liability, at carrying value $ 27,647 $ 26,926

Commitments and Contingent Li48

Commitments and Contingent Liabilities (Tables)	12 Months Ended
	Dec. 31, 2017
Commitments And Contingencies Disclosure [Abstract]
Summary of Minimum Annual Rental Commitments for Operating Leases	The minimum annual rental commitments for operating leases subsequent to December 31, 2017, exclusive of taxes and other charges, are summarized as follows: Minimum Commitments 2018 $ 3,000 2019 2,522 2020 2,023 2021 1,776 2022 972 Thereafter 2,073 Total $ 12,366
Summary of Contract or Notional Amount of Outstanding Loan and Lease Commitments	The following table summarizes the contract or notional amount of outstanding loan and lease commitments at December 31, 2017 and 2016: 2017 2016 Fixed Rate Variable Fixed Variable Commitments to extend credit $ 55,924 $ 467,429 $ 37,731 $ 332,928 Standby letters of credit 1,226 3,337 1,060 4,135 Total $ 57,150 $ 470,766 $ 38,791 $ 337,063

Fair Value Measurement (Tables)

Fair Value Measurement (Tables)	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Summary of Company's Financial Assets and Liabilities Measured at Fair Value on Recurring Basis	The following tables summarize the Company’s financial assets and liabilities that were measured at fair value on a recurring basis at December 31, 2017 and 2016: Fair Value Measurements Using 2017 Fair Value Level 1 Level 2 Level 3 Financial assets Securities available-for-sale U.S. Treasury Notes $ 14,863 $ 14,863 $ — $ — U.S. Government agencies 52,958 — 52,958 — Obligations of states, municipalities, and political subdivisions 33,170 — 32,795 375 Mortgage-backed securities; residential Agency 307,457 — 307,457 — Non-Agency 39,514 — 39,514 — Mortgage-backed securities; commercial Agency 69,043 — 69,043 — Non-Agency 30,971 — 30,971 — Corporate securities 29,976 — 29,976 — Other securities 5,284 1,921 2,686 677 Servicing assets 21,400 — — 21,400 Derivative assets 5,981 — 5,981 — Financial liabilities Derivative liabilities 994 — 994 — Fair Value Measurements Using 2016 Fair Value Level 1 Level 2 Level 3 Financial assets Securities available-for-sale U.S. Treasury Notes $ 14,920 $ 14,920 $ — $ — U.S. Government agencies 58,857 — 58,857 — Obligations of states, municipalities, and political subdivisions 16,059 — 15,509 550 Mortgage-backed securities; residential Agency 368,160 — 368,160 — Non-Agency 19,933 — 19,933 — Mortgage-backed securities; commercial Agency 77,403 — 77,403 — Non-Agency 31,052 — 31,052 — Corporate securities 17,329 — 17,329 — Other securities 4,847 1,938 2,379 530 Servicing assets 21,091 — — 21,091 Derivative assets 4,317 — 4,317 — Financial liabilities Derivative liabilities 559 — 559 —
Summary of Financial Assets Measured at Fair Value on Recurring Basis Using Significant Unobservable Inputs	The following table presents additional information about financial assets measured at fair value on recurring basis for which the Company used significant unobservable inputs (Level 3): Twelve Months Ended December 31, 2017 2016 2017 2016 Investment Securities Servicing Assets Balance, beginning of period $ 1,080 $ — $ 21,091 $ — Acquired at fair value — 548 — 20,295 Additions, net — 550 6,250 539 Maturities (175 ) — — — Amortization 5 — — — Change in unrealized loss 142 (18 ) — — Change in fair value — — (5,941 ) 257 Balance, end of period $ 1,052 $ 1,080 $ 21,400 $ 21,091
Summary of Unobservable Inputs Used in the Fair Value Measurements on Recurring Basis	The following table presents additional information about the unobservable inputs used in the fair value measurements on recurring basis that were categorized within Level 3 of the fair value hierarchy as of December 31, 2017: Financial Instruments Valuation Technique Unobservable Inputs Range of Inputs Weighted Average Range Impact to Valuation from an Increased or Higher Input Value Obligations of states, municipalities, and political obligations Discounted Probability of default 2.2%—2.4% 2.3 % Decrease Single issuer trust preferred Discounted cash flow Probability of default 7.5%—9.9% 8.9 % Decrease Servicing assets Discounted cash flow Prepayment speeds 1.6%—9.9% 8.6 % Decrease Discount rate 9.9%—18.4% 13.8 % Decrease Expected weighted average loan life 0.2—8.2 years 5.8 years Increase
Summary of Company's Assets Measured at Fair Value on a Non-Recurring Basis	The following tables summarize the Company’s assets that were measured at fair value on a non-recurring basis, excluding acquired impaired loans, as of December 31, 2017 and 2016: Fair Value Measurements Using 2017 Fair Value Level 1 Level 2 Level 3 Non-recurring Impaired loans (excluding acquired impaired loans) Commercial real estate $ 12,783 $ — $ — $ 12,783 Residential real estate 2,271 — — 2,271 Construction, land development, and other land — — — — Commercial and industrial 12,092 — — 12,092 Installment and other — — — — Assets held for sale 9,779 — — 9,779 Other real estate owned 10,626 — — 10,626 Fair Value Measurements Using 2016 Fair Value Level 1 Level 2 Level 3 Non-recurring Impaired loans (excluding acquired impaired loans) Commercial real estate $ 8,916 $ — $ — $ 8,916 Residential real estate 1,007 — — 1,007 Construction, land development, and other land — — — — Commercial and industrial 986 — — 986 Installment and other — — — — Assets held for sale 14,748 — — 14,748 Other real estate owned 16,570 — — 16,570
Summary of the Valuation Technique, Unobservable Inputs and Qualitative Information About the Company's Assets and Liabilities	The following table provides a description of the valuation technique, unobservable inputs and qualitative information about the Company’s assets and liabilities classified as Level 3 and measured at fair value on a non-recurring basis as of December 31, 2017 and 2016: Financial Instruments Valuation Technique Unobservable Inputs Range of Inputs Impact to Valuation from an Increased or Higher Input Value Impaired loans (excluding acquired impaired loans) Appraisals Appraisal adjustments, sales costs and other discount adjustments for market conditions 6% - 10% Decrease Assets held for sale List price, contract price Sales costs and other discount adjustments for market conditions 7% Decrease Other real estate owned Appraisals Appraisal adjustments, sales costs and other discount adjustments for market conditions 7% - 20% Decrease
Estimated Fair Values of Financial Instruments	The estimated fair values of financial instruments and levels within the fair value hierarchy are as follows: Fair Value 2017 2016 Hierarchy Level Carrying Amount Estimated Fair Value Carrying Amount Estimated Fair Value Financial assets Cash and due from banks 1 $ 19,404 $ 19,404 $ 17,735 $ 17,735 Interest bearing deposits with other banks 2 38,945 38,945 28,798 28,798 Securities held-to-maturity 2 117,163 117,277 138,846 138,082 Other restricted stock 2 16,343 16,343 14,993 14,993 Loans held for sale 3 5,212 5,851 23,976 26,487 Loans and lease receivables, net 3 2,260,786 2,240,235 2,137,088 2,068,157 Accrued interest receivable 3 7,670 7,670 6,866 6,866 Financial liabilities Non-interest bearing deposits 2 760,887 760,887 724,457 724,457 Interest bearing deposits 2 1,682,442 1,678,535 1,765,937 1,764,078 Accrued interest payable 2 1,306 1,306 2,427 2,427 Line of credit 2 — — 20,650 20,650 Federal Home Loan Bank advances 2 361,506 361,500 313,715 313,646 Securities sold under repurchase agreement 2 31,187 31,187 17,249 17,249 Junior subordinated debentures 3 27,647 33,907 26,926 26,943

Share-Based Compensation (Table

Share-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2017
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Summary of Stock Compensation Expense	The following table summarizes stock option compensation expense for the years ended December 31, 2017 and 2016: Years Ended December 31, 2017 2016 Total share-based compensation - stock options $ 1,294 $ 899 Income tax benefit 521 360 Unrecognized compensation expense 729 1,752 Weighted-average amortization period remaining 1.2 years 1.8 years
Restricted Shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Summary of Stock Compensation Expense	The following table summarizes restricted stock compensation expense for the year ended December 31, 2017: Year Ended December 31 2017 Total share-based compensation - restricted stock $ 203 Income tax benefit 83 Unrecognized compensation expense 1,227 Weighted-average amortization period remaining 2.8 years
Omnibus Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Summary of Changes in Restricted Shares	The following table discloses the changes in restricted shares for the year ended December 31, 2017: Omnibus Plan Number of Shares Weighted Average Grant Date Fair Value Beginning balance — $ — Granted 70,798 20.31 Vested — — Forfeited (400 ) 20.18 Ending balance outstanding at December 31, 2017 70,398 $ 20.31
BYB Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Fair Value Assumptions of Stock Options	The fair values of the stock options were determined using the Black-Scholes-Merton model for Time Options and a Monte Carlo simulation model for Performance Options. The fair values of options under the BYB Plan were determined using the following assumptions as of the grant dates: Time Options Grants 2016 2015 Risk-free interest rate 1.34% - 1.40% 1.68% - 1.85% Expected term (years) 5.2 - 5.6 5.7 - 6.3 Expected stock price volatility 20.39 % 16.18% - 16.55% Expected dividend yield 0.00 % 0.00 % Weighted average grant date fair value $ 3.55 $ 2.25 Performance Options Grants 2016 2015 Risk-free interest rate Implied forward rates Implied forward rates Expected term (years) Variable Variable Expected stock price volatility 20.34% - 20.39% 16.18% - 16.55% Expected dividend yield 0.00 % 0.00 % Weighted average grant date fair value $ 3.75 $ 1.65
Summary of Activity in shares Subjected to Options and Weighted Average Exercise Prices	The following table discloses the activity in shares subject to options and the weighted average exercise prices, in actual dollars, for the year ended December 31, 2017: BYB Plan Number of Shares Weighted Average Exercise Price Intrinsic Value Weighted Average Remaining Contractual Term (in Years) Beginning balance 1,798,220 $ 11.95 $ 15,788 8.6 Granted — Expired — Exercised — Forfeited (15,200 ) 16.25 Ending balance outstanding at December 31, 2017 1,783,020 $ 11.91 $ 19,718 7.6 Exercisable at December 31, 2017 1,304,257 $ 11.51 $ 14,953 7.5

Regulatory Capital Requiremen51

Regulatory Capital Requirements (Tables)	12 Months Ended
	Dec. 31, 2017
Regulatory Capital Requirements [Abstract]
Summary of Bank's Actual Capital Amounts and Ratios	The Company’s and the Bank’s actual capital amounts and ratios as of December 31, 2017 and 2016 are also presented. Actual Minimum Capital Required Required to be Considered Well Capitalized 2017 Amount Ratio Amount Ratio Amount Ratio Total capital to risk weighted assets: Company $ 410,831 15.98 % $ 205,661 8.00 % N/A N/A Bank 367,972 14.28 % 206,083 8.00 % 257,604 10.00 % Tier 1 capital to risk weighted assets: Company $ 392,520 15.27 % $ 154,246 6.00 % N/A N/A Bank 349,662 13.57 % 154,562 6.00 % 206,083 8.00 % Common Equity Tier 1 (CET1) to risk weighted assets: Company $ 353,995 13.77 % $ 115,684 4.50 % N/A N/A Bank 349,662 13.57 % 115,922 4.50 % 167,442 6.50 % Tier 1 capital to average assets: . Company $ 392,520 12.25 % $ 128,178 4.00 % N/A N/A Bank 349,662 10.89 % 128,409 4.00 % 160,511 5.00 % Actual Minimum Capital Required Required to be Considered Well Capitalized 2016 Amount Ratio Amount Ratio Amount Ratio Total capital to risk weighted assets: Company $ 316,314 13.28 % $ 190,257 8.00 % N/A N/A Bank 325,465 13.61 % 191,267 8.00 % 239,084 10.00 % Tier 1 capital to risk weighted assets: Company $ 304,324 12.78 % $ 142,895 6.00 % N/A N/A Bank 313,474 13.11 % 143,450 6.00 % 191,267 8.00 % Common Equity Tier 1 (CET1) to risk weighted assets: Company $ 266,760 11.20 % $ 107,171 4.50 % N/A N/A Bank 313,474 13.11 % 107,588 4.50 % 155,404 6.50 % Tier 1 capital to average assets: Company $ 304,324 10.07 % $ 120,850 4.00 % N/A N/A Bank 313,474 10.35 % 121,169 4.00 % 151,461 5.00 %

Derivative Instruments and He52

Derivative Instruments and Hedge Activities (Tables)	12 Months Ended
	Dec. 31, 2017
Summary of Derivative Financial Instruments and Classification on Consolidated Statements of Financial Condition	The following tables present the fair value of the Company’s derivative financial instruments and classification on the Consolidated Statements of Financial Condition as of December 31, 2017 and 2016: 2017 2016 Fair Value Fair Value Notional Amount Other Assets Other Liabilities Notional Amount Other Assets Other Liabilities Derivatives designated as hedging instruments Interest rate swaps designated as cash flow hedges $ 250,000 $ 5,030 $ 38 $ 100,000 $ 3,719 $ — Derivatives not designated as hedging instruments Other interest rate swaps 94,726 951 956 51,213 598 559 Total derivatives $ 344,726 $ 5,981 $ 994 $ 151,213 $ 4,317 $ 559
Summary of Net Gains (Losses) Recorded in Accumulated Other Comprehensive Income (Loss) and Consolidated Statements of Operations Relating to Cash Flow Derivative Instruments	The following table reflects the net gains (losses) recorded in accumulated other comprehensive income (loss) and the Consolidated Statements of Operations relating to the cash flow derivative instruments for the year ended December 31, 2017: Amount of Gain Recognized in OCI (Effective Portion) Amount of Loss Reclassified from OCI to Income as an Increase to Interest Expense Amount of Gain (Loss) Recognized in Other Non-Interest Income (Ineffective Portion) Interest rate swaps $ 688 $ (579 ) $ —
Summary of Other Interest Rate Swaps	The following table reflects other interest rate swaps as of December 31, 2017: Notional amounts $ 94,726 Derivative assets fair value 951 Derivative liabilities fair value 956 Weighted average pay rates 4.38 % Weighted average receive rates 3.73 % Weighted average maturity 6.3 years
Summary of Company's Interest Rate Derivative and Offsetting Positions	The Company records interest rate derivatives subject to master netting agreements at their gross value and does not offset derivative asset and liabilities on the Consolidated Statements of Financial Condition. The table below summarizes the Company’s interest rate derivatives and offsetting positions as of December 31, 2017: Derivative Assets Fair Value Derivative Liabilities Fair Value Gross amounts recognized $ 5,981 $ 994 Less: Amounts offset in the Consolidated Statements of Financial Condition — — Net amount presented in the Consolidated Statements of Financial Condition $ 5,981 $ 994 Gross amounts not offset in the Consolidated Statements of Financial Condition Offsetting derivative positions (232 ) (232 ) Collateral posted (5,371 ) (745 ) Net credit exposure $ 378 $ 17
Cash Flow Hedges
Summary of Cash Flow Hedges	The following table reflects the cash flow hedges as of December 31, 2017: Notional amounts $ 250,000 Derivative assets fair value 5,030 Derivative liabilities fair value 38 Weighted average pay rates 1.67 % Weighted average receive rates 1.63 % Weighted average maturity 4.2 years

Parent Company Only Condensed53

Parent Company Only Condensed Financial Statements (Tables)	12 Months Ended
	Dec. 31, 2017
Condensed Financial Information Of Parent Company Only Disclosure [Abstract]
Schedule of Statements of Condensed Financial Statements	The following represents the condensed financial statements of Byline Bancorp, Inc., the Parent Company: Statements of Financial Condition Parent Company Only As of December 31, 2017 2016 ASSETS Cash 39,626 9,965 Investment in banking subsidiary 445,786 419,801 Other assets 1,236 2,755 Total assets $ 486,648 $ 432,521 LIABILITIES AND STOCKHOLDERS’ EQUITY Line of credit — 20,650 Junior subordinated debentures issued to capital trusts, net 27,647 26,926 Accrued expenses and other liabilities 423 2,287 Stockholders' equity 458,578 382,658 Total liabilities and stockholders' equity $ 486,648 $ 432,521 Note 23—Parent Company Only Condensed Financial Statements (continued) Statements of Operations Parent Company Only Years ended December 31, 2017 2016 2015 INCOME Dividends from subsidiary $ 2,800 $ - $ - Other noninterest income 9 57 - Total Income 2,809 57 — EXPENSES Interest expense 2,782 2,460 2,295 Other noninterest expense 1,804 381 312 Total Expenses 4,586 2,841 2,607 Loss before provision for income taxes and equity in undistributed income (loss) of subsidiary (1,777 ) (2,784 ) (2,607 ) Provision (benefit) for income taxes (1,166 ) 204 8 Loss before equity in undistributed income (loss) of subsidiary (611 ) (2,988 ) (2,615 ) Equity in undistributed income (loss) of subsidiary 22,306 69,717 (12,359 ) Net income (loss) $ 21,695 $ 66,729 $ (14,974 ) Statements of Cash Flows Parent Company Only Years ended December 31, 2017 2016 2015 CASH FLOWS FROM OPERATING ACTIVITIES Net income (loss) $ 21,695 $ 66,729 $ (14,974 ) Adjustments to reconcile net income (loss) to net cash from operating activities: Equity in undistributed income (loss) of subsidiary (22,306 ) (69,717 ) 12,359 Stock-based compensation expense 1,497 899 1,045 Exercise of share-based awards — 40 — Accretion of junior subordinated debentures discount 721 876 944 Changes in other assets and other liabilities (2,893 ) 16 (5,546 ) Net cash used in operating activities (1,286 ) (1,157 ) (6,172 ) CASH FLOWS FROM INVESTING ACTIVITIES Investments in and advances from subsidiary — (32,019 ) — Net cash paid in acquisition of business — (36,586 ) — Net cash used in investing activities — (68,605 ) — CASH FLOWS FROM FINANCING ACTIVITIES Proceeds from revolving line of credit — 30,000 — Repayments of revolving line of credit (20,650 ) (9,350 ) — Dividends paid on preferred stock (11,277 ) — — Cash paid in lieu of fractional shares (2 ) — — Proceeds from issuance of common stock, net 76,829 49,592 — Proceeds from issuance of preferred stock 1,050 9,388 Repurchase of preferred stock (15,003 ) — — Net cash provided by financing activities 30,947 79,630 — NET CHANGE IN CASH AND CASH EQUIVALENTS 29,661 9,868 (6,172 ) CASH AND CASH EQUIVALENTS, beginning of period 9,965 97 6,269 CASH AND CASH EQUIVALENTS, end of period $ 39,626 $ 9,965 $ 97

Earnings per Share (Tables)

Earnings per Share (Tables)	12 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
Schedule of Calculation of Basic and Diluted Earnings per Share	Years ended December 31, 2017 2016 2015 Net income (loss) $ 21,695 $ 66,729 $ (14,974 ) Less: Dividends on preferred shares 11,277 — — Net income (loss) available to common stockholders $ 10,418 $ 66,729 $ (14,974 ) Weighted-average common stock outstanding: Weighted-average common stock outstanding (basic) 26,963,517 20,141,630 17,332,775 Incremental shares 583,797 289,153 — Weighted-average common stock outstanding (dilutive) 27,547,314 20,430,783 17,332,775 Basic earnings per common share $ 0.39 $ 3.31 $ (0.86 ) Diluted earnings per common share $ 0.38 $ 3.27 $ (0.86 )

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2017
Equity [Abstract]
Summary of Preferred and Common Stock	A summary of the Company’s preferred and common stock at December 31, 2017 and 2016 is as follows: 2017 2016 Series A non-cumulative perpetual preferred stock Par value $ — $ 0.01 Shares authorized — 15,003 Shares issued — 15,003 Shares outstanding — 15,003 Series B 7.5% fixed non-cumulative perpetual preferred stock Par value $ 0.01 $ 0.01 Shares authorized 50,000 50,000 Shares issued 10,438 9,388 Subscription receivable — 1,050 Shares outstanding 10,438 9,388 Common stock, voting Par value $ 0.01 $ — Shares authorized 150,000,000 150,000,000 Shares issued 29,317,298 24,616,706 Shares outstanding 29,317,298 24,616,706

Selected Quarterly Financial 56

Selected Quarterly Financial Data (unaudited) (Tables)	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Selected Quarterly Financial Data (unaudited)	For the year ended December 31, 2017 First Quarter Second Quarter Third Quarter Fourth Quarter Interest and Dividend Income $ 32,488 $ 33,315 $ 35,044 $ 35,956 Interest Expense 2,950 3,504 3,632 3,805 Net interest income 29,538 29,811 31,412 32,151 Provision for loan and lease losses 1,891 3,515 3,900 3,347 Net interest income after provision for loan and lease losses 27,647 26,296 27,512 28,804 Non-interest income 12,308 13,193 11,918 12,639 Non-interest expense 28,851 29,249 31,065 30,358 Income before provision for income taxes 11,104 10,240 8,365 11,085 Provision (benefit) for income taxes 4,544 4,094 (1,390 ) 11,851 Net income (loss) 6,560 6,146 9,755 (766 ) Dividends on preferred shares 189 10,697 195 196 Income (loss) available (attributable) to common stockholders $ 6,371 $ (4,551 ) $ 9,560 $ (962 ) Basic earnings (loss) per common share $ 0.26 $ (0.18 ) $ 0.33 $ (0.03 ) Diluted earnings (loss) per common share $ 0.25 $ (0.18 ) $ 0.32 $ (0.03 ) For the year ended December 31, 2016 First Quarter Second Quarter Third Quarter Fourth Quarter Interest and Dividend Income $ 22,877 $ 22,055 $ 22,657 $ 30,776 Interest Expense 1,757 1,674 1,792 2,524 Net interest income 21,120 20,381 20,865 28,252 Provision for loan and lease losses 2,513 1,152 1,683 5,004 Net interest income after provision for loan and lease losses 18,607 19,229 19,182 23,248 Non-interest income 4,288 6,198 4,776 10,642 Non-interest expense 24,487 22,817 22,384 30,998 Income before provision for income taxes (1,592 ) 2,610 1,574 2,892 Provision (benefit) for income taxes (240 ) 9 9 (61,023 ) Net income (loss) (1,352 ) 2,601 1,565 63,915 Dividends on preferred shares - - - - Income (loss) available (attributable) to common stockholders $ (1,352 ) $ 2,601 $ 1,565 $ 63,915 Basic earnings (loss) per common share $ (0.08 ) $ 0.13 $ 0.08 $ 2.66 Diluted earnings (loss) per common share $ (0.08 ) $ 0.13 $ 0.08 $ 2.62

Business and Summary of Signi57

Business and Summary of Significant Accounting Policies - Nature of business (Details)	Jun. 14, 2017USD ($)$ / shares	Dec. 31, 2017item
Nature of business
Merger transaction, the number of shares into which each share of common stock issued and outstanding prior to merger was converted	0.20
Merger transaction, cash paid to stockholders for remaining fractional shares | $	$ 2,000
Offering price per share | $ / shares	$ 19
Chicago metropolitan area
Nature of business
Number of bank branches		55
Wisconsin
Nature of business
Number of bank branches		1

Business and Summary of Signi58

Business and Summary of Significant Accounting Policies - Cash and cash equivalents (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Business Description And Accounting Policies [Abstract]
Reserve requirement	$ 15.8	$ 14.1

Business and Summary of Signi59

Business and Summary of Significant Accounting Policies - Premises and equipment (Details)	12 Months Ended
	Dec. 31, 2017
Minimum
Premises and equipment
Estimated useful lives (in years)	3 years
Maximum
Premises and equipment
Estimated useful lives (in years)	39 years

Business and Summary of Signi60

Business and Summary of Significant Accounting Policies - Goodwill (Details)	12 Months Ended
	Dec. 31, 2017USD ($)
Business Description And Accounting Policies [Abstract]
Goodwill, impairment loss	$ 0

Business and Summary of Signi61

Business and Summary of Significant Accounting Policies - Other intangible assets (Details)	12 Months Ended
	Dec. 31, 2017USD ($)
Finite Lived Intangible Assets [Line Items]
Core deposit intangibles amortization period (in years)	10 years
Core Deposits
Finite Lived Intangible Assets [Line Items]
Impairment on intangible assets	$ 0

Business and Summary of Signi62

Business and Summary of Significant Accounting Policies - Income taxes (Details) - USD ($)	Dec. 31, 2017	Dec. 31, 2016
Business Description And Accounting Policies [Abstract]
Uncertain tax positions	$ 0	$ 0

Business and Summary of Signi63

Business and Summary of Significant Accounting Policies - Segment reporting (Details)	12 Months Ended
	Dec. 31, 2017segment
Business Description And Accounting Policies [Abstract]
Number of reportable segment	1

Acquisition of a Business - Add

Acquisition of a Business - Additional Information (Details)	Oct. 14, 2016USD ($)Subsidiary$ / sharesshares	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)
Business Acquisition [Line Items]
Goodwill		$ 51,975,000	$ 51,975,000	$ 25,688,000	$ 25,613,000
Ridgestone
Business Acquisition [Line Items]
Business acquisition date of agreement		Oct. 14, 2016
Number of operated wholly owned subsidiaries | Subsidiary	2
Total consideration included aggregate cash	$ 36,753,000
Issuance of common shares | shares	4,199,791
Common stock issued price per share | $ / shares	$ 16.25
Goodwill	$ 26,287,000
Acquisition advisory expenses	1,600,000
Contingent assets or liabilities arising from the acquisition	$ 0

Acquisition of a Business - Sum

Acquisition of a Business - Summary of Estimates of fair Values of Assets and Liabilities Assumed as of Acquisition Date (Details) - USD ($) $ in Thousands	Oct. 14, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Consideration paid
Goodwill		$ 51,975	$ 51,975	$ 25,688	$ 25,613
Ridgestone
Assets
Cash and cash equivalents	$ 25,480
Securities available-for-sale	27,662
Restricted stock	931
Loans held for sale	15,363
Loans	351,820
Servicing assets	20,295
Premises and equipment	2,011
Other real estate owned	1,525
Other intangible assets	486
Bank-owned life insurance	2,352
Other assets	8,228
Total assets acquired	456,153
Liabilities
Deposits	361,370
Federal Home Loan Bank advances	9,773
Junior subordinated debentures	1,339
Accrued expenses and other liabilities	4,958
Total liabilities assumed	377,440
Net assets acquired	78,713
Consideration paid
Common stock (4,199,791 shares issued at $16.25 per share)	68,247
Cash paid	36,753
Total consideration paid	105,000
Goodwill	$ 26,287

Acquisition of a Business - S66

Acquisition of a Business - Summary of Estimates of fair Values of Assets and Liabilities Assumed as of Acquisition Date (Parenthetical) (Details) - Ridgestone	Oct. 14, 2016$ / sharesshares
Business Acquisition [Line Items]
Stock issued (in shares) | shares	4,199,791
Stock issued (in dollars per share) | $ / shares	$ 16.25

Acquisition of a Business - S67

Acquisition of a Business - Summary of Acquired Non-Impaired Loans as of Acquisition Date (Details) $ in Thousands	Oct. 14, 2016USD ($)
Business Combinations [Abstract]
Fair value	$ 312,166
Gross contractual amounts receivable	450,292
Estimate of contractual cash flows not expected to be collected	19,661	[1]
Estimate of contractual cash flows expected to be collected	$ 430,631
[1]	Includes interest payments not expected to be collected due to loan prepayments as well as principal and interest payments not expected to be collected due to customer default

Acquisition of a Business - S68

Acquisition of a Business - Summary of Pro Forma Information for Results of Operations (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Business Combinations [Abstract]
Total revenues (net interest income and non-interest income)	$ 171,059	$ 151,054
Net income (loss)	$ 82,252	$ (1,437)
Earnings per share—basic	$ 3.54	$ (0.07)
Earnings per share—diluted	$ 3.50	$ (0.07)

Securities - Summary of Amortiz

Securities - Summary of Amortized Cost and Fair Values of Securities Available-for-sale (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost	$ 593,167	$ 620,594
Available-for-sale Securities, Gross Unrealized Gains	2,486	1,156
Available-for-sale Securities, Gross Unrealized Losses	(12,417)	(13,190)
Available-for-sale Securities, Fair Value	583,236	608,560
U.S. Treasury Notes
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost	14,999	14,995
Available-for-sale Securities, Gross Unrealized Gains		4
Available-for-sale Securities, Gross Unrealized Losses	(136)	(79)
Available-for-sale Securities, Fair Value	14,863	14,920
U.S. Government Agencies
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost	54,248	60,180
Available-for-sale Securities, Gross Unrealized Losses	(1,290)	(1,323)
Available-for-sale Securities, Fair Value	52,958	58,857
Obligations of States, Municipalities, and Political Subdivisions
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost	33,405	16,271
Available-for-sale Securities, Gross Unrealized Gains	100	60
Available-for-sale Securities, Gross Unrealized Losses	(335)	(272)
Available-for-sale Securities, Fair Value	33,170	16,059
Agency, Residential Mortgage-Backed Securities
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost	315,103	376,800
Available-for-sale Securities, Gross Unrealized Losses	(7,646)	(8,640)
Available-for-sale Securities, Fair Value	307,457	368,160
Non-Agency, Residential Mortgage-Backed Securities
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost	39,485	20,107
Available-for-sale Securities, Gross Unrealized Gains	104
Available-for-sale Securities, Gross Unrealized Losses	(75)	(174)
Available-for-sale Securities, Fair Value	39,514	19,933
Agency, Commercial Mortgage-Backed Securities
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost	70,964	78,954
Available-for-sale Securities, Gross Unrealized Gains	45
Available-for-sale Securities, Gross Unrealized Losses	(1,966)	(1,551)
Available-for-sale Securities, Fair Value	69,043	77,403
Non-Agency, Commercial Mortgage-Backed Securities
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost	31,763	32,061
Available-for-sale Securities, Gross Unrealized Losses	(792)	(1,009)
Available-for-sale Securities, Fair Value	30,971	31,052
Corporate Securities
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost	29,573	17,065
Available-for-sale Securities, Gross Unrealized Gains	507	350
Available-for-sale Securities, Gross Unrealized Losses	(104)	(86)
Available-for-sale Securities, Fair Value	29,976	17,329
Other Securities
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost	3,627	4,161
Available-for-sale Securities, Gross Unrealized Gains	1,730	742
Available-for-sale Securities, Gross Unrealized Losses	(73)	(56)
Available-for-sale Securities, Fair Value	$ 5,284	$ 4,847

Securities - Summary of Amort70

Securities - Summary of Amortized Cost and Fair Values of Securities Held-to-maturity (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Schedule Of Held To Maturity Securities [Line Items]
Held-to-maturity Securities, Amortized Cost	$ 117,163	$ 138,846
Held-to-maturity Securities, Gross Unrealized Gains	450	190
Held-to-maturity Securities, Gross Unrealized Losses	(336)	(954)
Securities held-to-maturity, fair value	117,277	138,082
Obligations of States, Municipalities, and Political Subdivisions
Schedule Of Held To Maturity Securities [Line Items]
Held-to-maturity Securities, Amortized Cost	24,030	24,878
Held-to-maturity Securities, Gross Unrealized Gains	197	105
Held-to-maturity Securities, Gross Unrealized Losses	(82)	(229)
Securities held-to-maturity, fair value	24,145	24,754
Agency, Residential Mortgage-Backed Securities
Schedule Of Held To Maturity Securities [Line Items]
Held-to-maturity Securities, Amortized Cost	53,731	67,692
Held-to-maturity Securities, Gross Unrealized Gains	79	35
Held-to-maturity Securities, Gross Unrealized Losses	(203)	(283)
Securities held-to-maturity, fair value	53,607	67,444
Non-Agency, Residential Mortgage-Backed Securities
Schedule Of Held To Maturity Securities [Line Items]
Held-to-maturity Securities, Amortized Cost	39,402	46,276
Held-to-maturity Securities, Gross Unrealized Gains	174	50
Held-to-maturity Securities, Gross Unrealized Losses	(51)	(442)
Securities held-to-maturity, fair value	$ 39,525	$ 45,884

Securities - Additional Informa

Securities - Additional Information (Details)	12 Months Ended
	Dec. 31, 2017USD ($)Security	Dec. 31, 2016USD ($)Security	Dec. 31, 2015USD ($)
Schedule Of Investments [Line Items]
Trading securities	$ 0	$ 0
Net gains or (losses) reclassified from accumulated other comprehensive income (loss) into earnings	8,000	3,200,000	$ 3,100,000
Carrying amount of securities pledged as collateral	$ 262,500,000	$ 178,600,000
Minimum
Schedule Of Investments [Line Items]
Percentage of shareholders equity for which securities holdings exceeds for no issuer other than U.S. Government and agencies	10.00%	10.00%
Federal Home Loan Bank Advances
Schedule Of Investments [Line Items]
Carrying amount of securities pledged as collateral	$ 128,400,000	$ 58,700,000
Public Fund Deposits
Schedule Of Investments [Line Items]
Carrying amount of securities pledged as collateral	99,300,000	93,200,000
Customer Repurchase Agreements
Schedule Of Investments [Line Items]
Carrying amount of securities pledged as collateral	$ 34,800,000	$ 19,900,000
Available-for-sale Securities
Schedule Of Investments [Line Items]
Investment securities with unrealized losses | Security	101	88
Held-to-maturity Securities
Schedule Of Investments [Line Items]
Investment securities with unrealized losses | Security	28	42

Securities - Summary of Gross U

Securities - Summary of Gross Unrealized Losses and Fair Values, Aggregated by Investment Category and Length of Individual Securities Continuous Unrealized Loss Position Available-for-sale (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)Security	Dec. 31, 2016USD ($)Security
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Number of Securities | Security	101	88
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	$ 39,896	$ 568,131
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Unrealized Losses	(407)	(12,893)
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value	455,688	14,719
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Unrealized Losses	(12,010)	(297)
Available-for-sale Securities, Continuous Unrealized Loss Position, Total Fair Value	495,584	582,850
Available-for-sale Securities, Continuous Unrealized Loss Position, Total Unrealized Losses	$ (12,417)	$ (13,190)
U.S. Treasury Notes
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Number of Securities | Security	5	3
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	$ 4,998	$ 9,918
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Unrealized Losses	(2)	(79)
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value	9,865
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Unrealized Losses	(134)
Available-for-sale Securities, Continuous Unrealized Loss Position, Total Fair Value	14,863	9,918
Available-for-sale Securities, Continuous Unrealized Loss Position, Total Unrealized Losses	$ (136)	$ (79)
U.S. Government Agencies
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Number of Securities | Security	9	10
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	$ 992	$ 58,857
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Unrealized Losses	(7)	(1,323)
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value	51,966
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Unrealized Losses	(1,283)
Available-for-sale Securities, Continuous Unrealized Loss Position, Total Fair Value	52,958	58,857
Available-for-sale Securities, Continuous Unrealized Loss Position, Total Unrealized Losses	$ (1,290)	$ (1,323)
Obligations of States, Municipalities, and Political Subdivisions
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Number of Securities | Security	29	14
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	$ 16,059	$ 7,799
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Unrealized Losses	(137)	(259)
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value	4,453	115
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Unrealized Losses	(198)	(13)
Available-for-sale Securities, Continuous Unrealized Loss Position, Total Fair Value	20,512	7,914
Available-for-sale Securities, Continuous Unrealized Loss Position, Total Unrealized Losses	$ (335)	$ (272)
Agency, Residential Mortgage-Backed Securities
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Number of Securities | Security	41	41
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	$ 15,441	$ 364,713
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Unrealized Losses	(181)	(8,483)
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value	292,016	3,447
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Unrealized Losses	(7,465)	(157)
Available-for-sale Securities, Continuous Unrealized Loss Position, Total Fair Value	307,457	368,160
Available-for-sale Securities, Continuous Unrealized Loss Position, Total Unrealized Losses	$ (7,646)	$ (8,640)
Non-Agency, Residential Mortgage-Backed Securities
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Number of Securities | Security	1	2
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value		$ 19,933
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Unrealized Losses		(174)
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value	$ 4,565
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Unrealized Losses	(75)
Available-for-sale Securities, Continuous Unrealized Loss Position, Total Fair Value	4,565	19,933
Available-for-sale Securities, Continuous Unrealized Loss Position, Total Unrealized Losses	$ (75)	$ (174)
Agency, Commercial Mortgage-Backed Securities
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Number of Securities | Security	7	8
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value		$ 70,762
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Unrealized Losses		(1,488)
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value	$ 57,442	6,641
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Unrealized Losses	(1,966)	(63)
Available-for-sale Securities, Continuous Unrealized Loss Position, Total Fair Value	57,442	77,403
Available-for-sale Securities, Continuous Unrealized Loss Position, Total Unrealized Losses	$ (1,966)	$ (1,551)
Non-Agency, Commercial Mortgage-Backed Securities
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Number of Securities | Security	5	5
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value		$ 31,052
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Unrealized Losses		(1,009)
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value	$ 30,971
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Unrealized Losses	(792)
Available-for-sale Securities, Continuous Unrealized Loss Position, Total Fair Value	30,971	31,052
Available-for-sale Securities, Continuous Unrealized Loss Position, Total Unrealized Losses	$ (792)	$ (1,009)
Corporate Securities
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Number of Securities | Security	3	4
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	$ 2,406	$ 5,097
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Unrealized Losses	(80)	(78)
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value	2,489	2,522
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Unrealized Losses	(24)	(8)
Available-for-sale Securities, Continuous Unrealized Loss Position, Total Fair Value	4,895	7,619
Available-for-sale Securities, Continuous Unrealized Loss Position, Total Unrealized Losses	$ (104)	$ (86)
Other Securities
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Number of Securities | Security	1	1
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value	$ 1,921	$ 1,994
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Unrealized Losses	(73)	(56)
Available-for-sale Securities, Continuous Unrealized Loss Position, Total Fair Value	1,921	1,994
Available-for-sale Securities, Continuous Unrealized Loss Position, Total Unrealized Losses	$ (73)	$ (56)

Securities - Summary of Gross73

Securities - Summary of Gross Unrealized Losses and Fair Values, Aggregated by Investment Category and Length of Individual Securities Continuous Unrealized Loss Position Held-to-maturity (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)Security	Dec. 31, 2016USD ($)Security
Schedule Of Held To Maturity Securities [Line Items]
Held-to-maturity Securities, Continuous Unrealized Loss Position, Number of Securities | Security	28	42
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	$ 42,211	$ 97,636
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Unrealized Losses	(155)	(954)
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value	13,865
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Unrealized Losses	(181)
Held-to-maturity Securities, Continuous Unrealized Loss Position, Total Fair Value	56,076	97,636
Held-to-maturity Securities, Continuous Unrealized Loss Position, Total Unrealized Losses	$ (336)	$ (954)
Obligations of States, Municipalities, and Political Subdivisions
Schedule Of Held To Maturity Securities [Line Items]
Held-to-maturity Securities, Continuous Unrealized Loss Position, Number of Securities | Security	12	22
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	$ 7,409	$ 16,235
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Unrealized Losses	(38)	(229)
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value	1,548
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Unrealized Losses	(44)
Held-to-maturity Securities, Continuous Unrealized Loss Position, Total Fair Value	8,957	16,235
Held-to-maturity Securities, Continuous Unrealized Loss Position, Total Unrealized Losses	$ (82)	$ (229)
Agency, Residential Mortgage-Backed Securities
Schedule Of Held To Maturity Securities [Line Items]
Held-to-maturity Securities, Continuous Unrealized Loss Position, Number of Securities | Security	13	15
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	$ 24,344	$ 52,156
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Unrealized Losses	(107)	(283)
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value	7,935
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Unrealized Losses	(96)
Held-to-maturity Securities, Continuous Unrealized Loss Position, Total Fair Value	32,279	52,156
Held-to-maturity Securities, Continuous Unrealized Loss Position, Total Unrealized Losses	$ (203)	$ (283)
Non-Agency, Residential Mortgage-Backed Securities
Schedule Of Held To Maturity Securities [Line Items]
Held-to-maturity Securities, Continuous Unrealized Loss Position, Number of Securities | Security	3	5
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	$ 10,458	$ 29,245
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Unrealized Losses	(10)	(442)
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value	4,382
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Unrealized Losses	(41)
Held-to-maturity Securities, Continuous Unrealized Loss Position, Total Fair Value	14,840	29,245
Held-to-maturity Securities, Continuous Unrealized Loss Position, Total Unrealized Losses	$ (51)	$ (442)

Securities - Summary of Proceed

Securities - Summary of Proceeds From Sales of Securities Available-for-sale and Associated Gains and Losses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Available For Sale Securities Gross Realized Gain Loss [Abstract]
Proceeds	$ 8	$ 534,418	$ 511,028
Gross gains	$ 8	3,358	3,124
Gross losses		$ 131	$ 60

Securities - Schedule of Amorti

Securities - Schedule of Amortized Cost and Fair Value of Debt Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Available-for-sale Securities Debt Maturities, Amortized Cost [Abstract]
Available-for-sale Securities, Due in one year or less, Amortized Cost	$ 8,285
Available-for-sale Securities, Due from one to five years, Amortized Cost	72,432
Available-for-sale Securities, Due from five to ten years, Amortized Cost	40,439
Available-for-sale Securities, Due after ten years, Amortized Cost	11,604
Available-for-sale Securities, Amortized Cost	593,167	$ 620,594
Held-to-maturity Securities Debt Maturities, Amortized Cost [Abstract]
Held-to-maturity Securities, Due from one to five years, Amortized Cost	1,719
Held-to-maturity Securities, Due from five to ten years, Amortized Cost	13,532
Held-to-maturity Securities, Due after ten years, Amortized Cost	8,779
Held-to-maturity Securities, Amortized Cost	117,163	138,846
Available-for-sale Securities Debt Maturities, Fair Value [Abstract]
Available-for-sale Securities, Due in one year or less, Fair Value	8,268
Available-for-sale Securities, Due from one to five years, Fair Value	71,826
Available-for-sale Securities, Due from five to ten years, Fair Value	39,812
Available-for-sale Securities, Due after ten years, Fair Value	11,738
Total	583,236	608,560
Held-to-maturity Securities Debt Maturities, Fair Value [Abstract]
Held-to-maturity Securities, Due from one to five years, Fair Value	1,732
Held-to-maturity Securities, Due from five to ten years, Fair Value	13,546
Held-to-maturity Securities, Due after ten years, Fair Value	8,867
Total	117,277	138,082
Mortgage-Backed Securities
Available-for-sale Securities Debt Maturities, Amortized Cost [Abstract]
Available-for-sale Securities, Not due at single maturity, Amortized Cost	457,315
Held-to-maturity Securities Debt Maturities, Amortized Cost [Abstract]
Held-to-maturity Securities, Mortgage-backed securities, Amortized Cost	93,133
Available-for-sale Securities Debt Maturities, Fair Value [Abstract]
Available-for-sale Securities, Not due at single maturity, Fair Value	446,985
Held-to-maturity Securities Debt Maturities, Fair Value [Abstract]
Held-to-maturity Securities, Mortgage-backed securities, Fair Value	93,132
Other Securities
Available-for-sale Securities Debt Maturities, Amortized Cost [Abstract]
Available-for-sale Securities, Not due at single maturity, Amortized Cost	3,092
Available-for-sale Securities, Amortized Cost	3,627	4,161
Available-for-sale Securities Debt Maturities, Fair Value [Abstract]
Available-for-sale Securities, Not due at single maturity, Fair Value	4,607
Total	$ 5,284	$ 4,847

Loan and Lease Receivables - Sc

Loan and Lease Receivables - Schedule of Outstanding Loan and Lease Receivables (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Accounts Notes And Loans Receivable [Line Items]
Total loans and leases	$ 2,275,691	$ 2,147,163
Net unamortized deferred fees and costs	(1,720)	(2,119)
Initial direct costs	3,521	2,967
Allowance for loan and lease losses	(16,706)	(10,923)	$ (7,632)	$ (4,794)
Net loans and leases	2,260,786	2,137,088
Lease financing receivables
Net minimum lease payments	188,986	168,345
Unguaranteed residual values	1,644	1,787
Unearned income	(16,465)	(14,133)
Total lease financing receivables	174,165	155,999
Initial direct costs	3,521	2,967
Lease financial receivables before allowance for lease losses	177,686	158,966
Commercial Real Estate
Accounts Notes And Loans Receivable [Line Items]
Total loans and leases	891,971	796,950
Allowance for loan and lease losses	(4,794)	(1,945)	(2,280)	(1,112)
Residential Real Estate
Accounts Notes And Loans Receivable [Line Items]
Total loans and leases	577,123	610,699
Allowance for loan and lease losses	(1,638)	(2,483)	(2,981)	(1,936)
Construction, Land Development, and Other Land
Accounts Notes And Loans Receivable [Line Items]
Total loans and leases	105,996	141,122
Allowance for loan and lease losses	(222)	(742)	(232)	(834)
Commercial and Industrial
Accounts Notes And Loans Receivable [Line Items]
Total loans and leases	522,254	439,476
Allowance for loan and lease losses	(7,418)	(4,196)	(1,403)	(648)
Installment and Other
Accounts Notes And Loans Receivable [Line Items]
Total loans and leases	4,182	2,917
Allowance for loan and lease losses	(41)	(334)	(357)	(121)
Lease Financing Receivables
Accounts Notes And Loans Receivable [Line Items]
Total loans and leases	174,165	155,999
Allowance for loan and lease losses	$ (2,593)	$ (1,223)	$ (379)	$ (143)

Loan and Lease Receivables - Ad

Loan and Lease Receivables - Additional Information (Details) - USD ($)	Dec. 31, 2017	Dec. 31, 2016	Oct. 14, 2016	Dec. 31, 2015	Dec. 31, 2014
Accounts Notes And Loans Receivable [Line Items]
Total loans and leases	$ 2,275,691,000	$ 2,147,163,000
Loans held for sale pledged as security for borrowings	516,900,000	507,200,000
Allowance for loan and lease losses	16,706,000	10,923,000		$ 7,632,000	$ 4,794,000
Acquired Impaired Loans
Accounts Notes And Loans Receivable [Line Items]
Loans acquired	0	0	$ 39,654,000
Allowance for loan and lease losses	3,900,000	1,600,000
Acquired Non-Impaired Loans and Leases | Ridgestone
Accounts Notes And Loans Receivable [Line Items]
Loans acquired	312,200,000
U.S. Government Guaranteed Loans
Accounts Notes And Loans Receivable [Line Items]
Total loans and leases	77,000,000	34,800,000
Installment and Other
Accounts Notes And Loans Receivable [Line Items]
Total loans and leases	4,182,000	2,917,000
Overdraft deposits reclassified as loans	617,000	1,000,000
Allowance for loan and lease losses	$ 41,000	$ 334,000		$ 357,000	$ 121,000

Loan and Lease Receivables - Su

Loan and Lease Receivables - Summary of Minimum Annual Lease Payments for Lease Financing Receivables (Details) $ in Thousands	Dec. 31, 2017USD ($)
Receivables [Abstract]
2,018	$ 65,770
2,019	53,702
2,020	37,914
2,021	21,743
2,022	8,922
Thereafter	935
Total	$ 188,986

Loan and Lease Receivables - 79

Loan and Lease Receivables - Summary of Balances for Each Respective Loan and Lease Category (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accounts Notes And Loans Receivable [Line Items]
Total loans and leases	$ 2,277,492	$ 2,148,011	$ 1,345,437
Originated
Accounts Notes And Loans Receivable [Line Items]
Total loans and leases	1,573,383	1,281,888
Acquired Impaired
Accounts Notes And Loans Receivable [Line Items]
Total loans and leases	327,690	404,037
Acquired Non-Impaired
Accounts Notes And Loans Receivable [Line Items]
Total loans and leases	376,419	462,086
Commercial Real Estate
Accounts Notes And Loans Receivable [Line Items]
Total loans and leases	891,693	796,344	533,695
Commercial Real Estate | Originated
Accounts Notes And Loans Receivable [Line Items]
Total loans and leases	513,622	338,752
Commercial Real Estate | Acquired Impaired
Accounts Notes And Loans Receivable [Line Items]
Total loans and leases	166,712	207,303
Commercial Real Estate | Acquired Non-Impaired
Accounts Notes And Loans Receivable [Line Items]
Total loans and leases	211,359	250,289
Residential Real Estate
Accounts Notes And Loans Receivable [Line Items]
Total loans and leases	577,218	610,738	484,335
Residential Real Estate | Originated
Accounts Notes And Loans Receivable [Line Items]
Total loans and leases	400,571	394,168
Residential Real Estate | Acquired Impaired
Accounts Notes And Loans Receivable [Line Items]
Total loans and leases	144,562	175,717
Residential Real Estate | Acquired Non-Impaired
Accounts Notes And Loans Receivable [Line Items]
Total loans and leases	32,085	40,853
Construction, Land Development, and Other Land
Accounts Notes And Loans Receivable [Line Items]
Total loans and leases	105,429	140,766	40,232
Construction, Land Development, and Other Land | Originated
Accounts Notes And Loans Receivable [Line Items]
Total loans and leases	97,638	119,357
Construction, Land Development, and Other Land | Acquired Impaired
Accounts Notes And Loans Receivable [Line Items]
Total loans and leases	5,946	6,979
Construction, Land Development, and Other Land | Acquired Non-Impaired
Accounts Notes And Loans Receivable [Line Items]
Total loans and leases	1,845	14,430
Commercial and Industrial
Accounts Notes And Loans Receivable [Line Items]
Total loans and leases	521,238	438,238	165,696
Commercial and Industrial | Originated
Accounts Notes And Loans Receivable [Line Items]
Total loans and leases	416,499	309,097
Commercial and Industrial | Acquired Impaired
Accounts Notes And Loans Receivable [Line Items]
Total loans and leases	10,008	13,464
Commercial and Industrial | Acquired Non-Impaired
Accounts Notes And Loans Receivable [Line Items]
Total loans and leases	94,731	115,677
Installment and Other
Accounts Notes And Loans Receivable [Line Items]
Total loans and leases	4,228	2,959	1,926
Installment and Other | Originated
Accounts Notes And Loans Receivable [Line Items]
Total loans and leases	3,724	2,021
Installment and Other | Acquired Impaired
Accounts Notes And Loans Receivable [Line Items]
Total loans and leases	462	574
Installment and Other | Acquired Non-Impaired
Accounts Notes And Loans Receivable [Line Items]
Total loans and leases	42	364
Lease Financing Receivables
Accounts Notes And Loans Receivable [Line Items]
Total loans and leases	177,686	158,966	$ 119,553
Lease Financing Receivables | Originated
Accounts Notes And Loans Receivable [Line Items]
Total loans and leases	141,329	118,493
Lease Financing Receivables | Acquired Non-Impaired
Accounts Notes And Loans Receivable [Line Items]
Total loans and leases	$ 36,357	$ 40,473

Loan and Lease Receivables - Es

Loan and Lease Receivables - Estimated Fair Value of Impaired Loans Acquired at Acquisition (Details) - Acquired Impaired Loans - USD ($)	Dec. 31, 2017	Dec. 31, 2016	Oct. 14, 2016
Accounts Notes And Loans Receivable [Line Items]
Undiscounted contractual cash flows			$ 66,488,000
Undiscounted cash flows not expected to be collected (non-accretable difference)			(19,918,000)
Undiscounted cash flows expected to be collected			46,570,000
Accretable yield at acquisition			(6,916,000)
Estimated fair value of impaired loans acquired at acquisition	$ 0	$ 0	$ 39,654,000

Loan and Lease Receivables - 81

Loan and Lease Receivables - Summary of Outstanding Balance and Carrying Amount of All Acquired Impaired Loans (Details) - Acquired Impaired Loans - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Accounts Notes And Loans Receivable [Line Items]
Outstanding Balance	$ 476,980	$ 555,709
Carrying Value	327,690	404,037
Commercial Real Estate
Accounts Notes And Loans Receivable [Line Items]
Outstanding Balance	235,898	278,893
Carrying Value	166,712	207,303
Residential Real Estate
Accounts Notes And Loans Receivable [Line Items]
Outstanding Balance	207,660	236,384
Carrying Value	144,562	175,717
Construction, Land Development, and Other Land
Accounts Notes And Loans Receivable [Line Items]
Outstanding Balance	13,270	15,292
Carrying Value	5,946	6,979
Commercial and Industrial
Accounts Notes And Loans Receivable [Line Items]
Outstanding Balance	18,333	23,164
Carrying Value	10,008	13,464
Installment and Other
Accounts Notes And Loans Receivable [Line Items]
Outstanding Balance	1,819	1,976
Carrying Value	$ 462	$ 574

Loan and Lease Receivables - 82

Loan and Lease Receivables - Summary of Changes in Accretable Yield for Acquired Impaired Loans (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Receivables [Abstract]
Beginning balance	$ 36,868	$ 43,915	$ 68,238
Additions		6,916
Accretion to interest income	(24,597)	(26,208)	(35,547)
Reclassification from nonaccretable difference	24,175	12,245	11,224
Ending balance	$ 36,446	$ 36,868	$ 43,915

Loan and Lease Receivables - 83

Loan and Lease Receivables - Schedule of Unpaid Principal Balance and Carrying Value for Acquired Non-impaired Loans and Leases (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accounts Notes And Loans Receivable [Line Items]
Loans and leases	$ 2,277,492	$ 2,148,011	$ 1,345,437
Acquired Non-Impaired
Accounts Notes And Loans Receivable [Line Items]
Unpaid Principal Balance	399,601	481,369
Loans and leases	376,419	462,086
Commercial Real Estate
Accounts Notes And Loans Receivable [Line Items]
Loans and leases	891,693	796,344	533,695
Commercial Real Estate | Acquired Non-Impaired
Accounts Notes And Loans Receivable [Line Items]
Unpaid Principal Balance	221,710	259,055
Loans and leases	211,359	250,289
Residential Real Estate
Accounts Notes And Loans Receivable [Line Items]
Loans and leases	577,218	610,738	484,335
Residential Real Estate | Acquired Non-Impaired
Accounts Notes And Loans Receivable [Line Items]
Unpaid Principal Balance	32,605	41,282
Loans and leases	32,085	40,853
Construction, Land Development, and Other Land
Accounts Notes And Loans Receivable [Line Items]
Loans and leases	105,429	140,766	40,232
Construction, Land Development, and Other Land | Acquired Non-Impaired
Accounts Notes And Loans Receivable [Line Items]
Unpaid Principal Balance	1,926	14,619
Loans and leases	1,845	14,430
Commercial and Industrial
Accounts Notes And Loans Receivable [Line Items]
Loans and leases	521,238	438,238	165,696
Commercial and Industrial | Acquired Non-Impaired
Accounts Notes And Loans Receivable [Line Items]
Unpaid Principal Balance	105,529	125,806
Loans and leases	94,731	115,677
Installment and Other
Accounts Notes And Loans Receivable [Line Items]
Loans and leases	4,228	2,959	1,926
Installment and Other | Acquired Non-Impaired
Accounts Notes And Loans Receivable [Line Items]
Unpaid Principal Balance	355	402
Loans and leases	42	364
Lease Financing Receivables
Accounts Notes And Loans Receivable [Line Items]
Loans and leases	177,686	158,966	$ 119,553
Lease Financing Receivables | Acquired Non-Impaired
Accounts Notes And Loans Receivable [Line Items]
Unpaid Principal Balance	37,476	40,205
Loans and leases	$ 36,357	$ 40,473

Allowance for Loan and Lease 84

Allowance for Loan and Lease Losses and Reserve for Unfunded Commitments - Summary of Allowance for Loan and Lease Losses and Corresponding Loan and Lease Balances (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	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Allowance for loan and lease losses
Beginning balance				$ 10,923				$ 7,632	$ 10,923	$ 7,632	$ 4,794
Provisions	$ 3,347	$ 3,900	$ 3,515	1,891	$ 5,004	$ 1,683	$ 1,152	2,513	12,653	10,352	6,966
Charge-offs									(8,196)	(7,817)	(4,359)
Recoveries									1,326	756	231
Ending balance	16,706				10,923				16,706	10,923	7,632
Ending balance:
Individually evaluated for impairment												$ 3,965	$ 1,017	$ 2,326
Collectively evaluated for impairment												8,867	8,295	2,016
Allowance for loan and lease losses	16,706			10,923	10,923			7,632	16,706	10,923	7,632	16,706	10,923	7,632
Loans and leases ending balance:
Individually evaluated for impairment												31,111	11,926	8,908
Collectively evaluated for impairment												1,918,691	1,732,048	849,618
Total loans and leases												2,277,492	2,148,011	1,345,437
Receivables Acquired with Deteriorated Credit Quality
Ending balance:
Loans acquired with deteriorated credit quality												3,874	1,611	3,290
Loans and leases ending balance:
Loans acquired with deteriorated credit quality												327,690	404,037	486,911
Commercial Real Estate
Allowance for loan and lease losses
Beginning balance				1,945				2,280	1,945	2,280	1,112
Provisions									4,343	4,032	2,464
Charge-offs									(1,494)	(4,367)	(1,296)
Ending balance	4,794				1,945				4,794	1,945	2,280
Ending balance:
Individually evaluated for impairment												1,101		1,076
Collectively evaluated for impairment												1,765	1,456	470
Allowance for loan and lease losses	4,794			1,945	1,945			2,280	1,945	1,945	2,280	4,794	1,945	2,280
Loans and leases ending balance:
Individually evaluated for impairment												13,884	8,916	4,160
Collectively evaluated for impairment												711,097	580,125	285,571
Total loans and leases												891,693	796,344	533,695
Commercial Real Estate | Receivables Acquired with Deteriorated Credit Quality
Ending balance:
Loans acquired with deteriorated credit quality												1,928	489	734
Loans and leases ending balance:
Loans acquired with deteriorated credit quality												166,712	207,303	243,964
Residential Real Estate
Allowance for loan and lease losses
Beginning balance				2,483				2,981	2,483	2,981	1,936
Provisions									(405)	135	1,873
Charge-offs									(440)	(633)	(828)
Ending balance	1,638				2,483				1,638	2,483	2,981
Ending balance:
Individually evaluated for impairment												158	293	615
Collectively evaluated for impairment												1,047	1,743	476
Allowance for loan and lease losses	1,638			2,483	2,483			2,981	2,483	2,483	2,981	1,638	2,483	2,981
Loans and leases ending balance:
Individually evaluated for impairment												2,429	1,300	4,042
Collectively evaluated for impairment												430,227	433,721	256,555
Total loans and leases												577,218	610,738	484,335
Residential Real Estate | Receivables Acquired with Deteriorated Credit Quality
Ending balance:
Loans acquired with deteriorated credit quality												433	447	1,890
Loans and leases ending balance:
Loans acquired with deteriorated credit quality												144,562	175,717	223,738
Construction, Land Development, and Other Land
Allowance for loan and lease losses
Beginning balance				742				232	742	232	834
Provisions									(520)	605	(585)
Charge-offs										(95)	(17)
Ending balance	222				742				222	742	232
Ending balance:
Individually evaluated for impairment														137
Collectively evaluated for impairment												145	742	95
Allowance for loan and lease losses	222			742	742			232	742	742	232	222	742	232
Loans and leases ending balance:
Individually evaluated for impairment														208
Collectively evaluated for impairment												99,483	133,787	31,390
Total loans and leases												105,429	140,766	40,232
Construction, Land Development, and Other Land | Receivables Acquired with Deteriorated Credit Quality
Ending balance:
Loans acquired with deteriorated credit quality												77
Loans and leases ending balance:
Loans acquired with deteriorated credit quality												5,946	6,979	8,634
Commercial and Industrial
Allowance for loan and lease losses
Beginning balance				4,196				1,403	4,196	1,403	648
Provisions									6,058	2,869	782
Charge-offs									(2,836)	(76)	(30)
Recoveries											3
Ending balance	7,418				4,196				7,418	4,196	1,403
Ending balance:
Individually evaluated for impairment												2,692	396	171
Collectively evaluated for impairment												3,308	3,126	596
Allowance for loan and lease losses	7,418			4,196	4,196			1,403	4,196	4,196	1,403	7,418	4,196	1,403
Loans and leases ending balance:
Individually evaluated for impairment												14,784	1,382	171
Collectively evaluated for impairment												496,446	423,392	155,955
Total loans and leases												521,238	438,238	165,696
Commercial and Industrial | Receivables Acquired with Deteriorated Credit Quality
Ending balance:
Loans acquired with deteriorated credit quality												1,418	674	636
Loans and leases ending balance:
Loans acquired with deteriorated credit quality												10,008	13,464	9,570
Installment and Other
Allowance for loan and lease losses
Beginning balance				334				357	334	357	121
Provisions									34	(11)	237
Charge-offs									(327)	(12)	(1)
Ending balance	41				334				41	334	357
Ending balance:
Individually evaluated for impairment												14	328	327
Collectively evaluated for impairment												9	5
Allowance for loan and lease losses	41			334	334			357	334	334	357	41	334	357
Loans and leases ending balance:
Individually evaluated for impairment												14	328	327
Collectively evaluated for impairment												3,752	2,057	594
Total loans and leases												4,228	2,959	1,926
Installment and Other | Receivables Acquired with Deteriorated Credit Quality
Ending balance:
Loans acquired with deteriorated credit quality												18	1	30
Loans and leases ending balance:
Loans acquired with deteriorated credit quality												462	574	1,005
Lease Financing Receivables
Allowance for loan and lease losses
Beginning balance				1,223				379	1,223	379	143
Provisions									3,143	2,722	2,195
Charge-offs									(3,099)	(2,634)	(2,187)
Recoveries									1,326	756	228
Ending balance	2,593				1,223				2,593	1,223	379
Ending balance:
Collectively evaluated for impairment												2,593	1,223	379
Allowance for loan and lease losses	$ 2,593			$ 1,223	$ 1,223			$ 379	$ 1,223	$ 1,223	$ 379	2,593	1,223	379
Loans and leases ending balance:
Collectively evaluated for impairment												177,686	158,966	119,553
Total loans and leases												$ 177,686	$ 158,966	$ 119,553

Allowance for Loan and Lease 85

Allowance for Loan and Lease Losses and Reserve for Unfunded Commitments - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Loans And Leases Receivable Disclosure [Line Items]
Increase (decrease) in allowance for loan and lease losses	$ 5,800,000	$ 3,300,000
Commitments outstanding on troubled debt restructurings	0	0
Recorded investment in troubled debt restructurings that subsequently defaulted within twelve months	144,000	477,000	$ 750,000
Troubled debt restructurings classified as non-accrual	1,600,000	552,000
Reserve for unfunded commitments	923,000	760,000
Provisions for unfunded commitments	162,000	493,000
Charge-offs or recoveries related to reserve for unfunded commitments	0	0
Acquired Impaired Loans
Loans And Leases Receivable Disclosure [Line Items]
Increase (decrease) in allowance for loan and lease losses	$ 2,300,000	$ (1,700,000)

Allowance for Loan and Lease 86

Allowance for Loan and Lease Losses and Reserve for Unfunded Commitments - Summary of Recorded Investment, Unpaid Principal Balance, Related Allowance, Average Recorded Investment and Interest Income Recognized (Details) - Loans Excluding Acquired Impaired Loans - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Financing Receivable Impaired [Line Items]
Related Allowance	$ 3,965	$ 1,017	$ 2,326
Recorded Investment	31,111	11,926	8,908
Unpaid Principal Balance	34,479	13,783	11,864
Average Recorded Investment	21,479	12,079	9,055
Interest Income Recognized	1,555	365	212
Commercial Real Estate
Financing Receivable Impaired [Line Items]
Recorded Investment, With no related allowance recorded	11,425	8,916	1,362
Unpaid Principal Balance, With no related allowance recorded	12,936	9,502	1,922
Average Recorded Investment, With no related allowance recorded	10,482	8,975	1,394
Interest Income Recognized, With no related allowance recorded	525	305	64
Recorded Investment, With an allowance recorded	2,459		2,798
Unpaid Principal Balance, With an allowance recorded	2,634		2,797
Related Allowance	1,101		1,076
Average Recorded Investment, With an allowance recorded	1,988		2,826
Interest Income Recognized, With an allowance recorded	187		46
Residential Real Estate
Financing Receivable Impaired [Line Items]
Recorded Investment, With no related allowance recorded	2,075	804	2,821
Unpaid Principal Balance, With no related allowance recorded	2,046	1,999	4,222
Average Recorded Investment, With no related allowance recorded	1,781	827	2,865
Interest Income Recognized, With no related allowance recorded	72	45	63
Recorded Investment, With an allowance recorded	354	496	1,221
Unpaid Principal Balance, With an allowance recorded	351	528	1,216
Related Allowance	158	293	615
Average Recorded Investment, With an allowance recorded	422	519	1,250
Interest Income Recognized, With an allowance recorded	6	1	15
Construction, Land Development, and Other Land
Financing Receivable Impaired [Line Items]
Average Recorded Investment, With no related allowance recorded	295
Interest Income Recognized, With no related allowance recorded	2
Recorded Investment, With an allowance recorded			208
Unpaid Principal Balance, With an allowance recorded			1,201
Related Allowance			137
Average Recorded Investment, With an allowance recorded	14		208
Commercial and Industrial
Financing Receivable Impaired [Line Items]
Recorded Investment, With no related allowance recorded	5,470	521
Unpaid Principal Balance, With no related allowance recorded	6,774	524
Average Recorded Investment, With no related allowance recorded	2,875	516
Interest Income Recognized, With no related allowance recorded	265	(2)
Recorded Investment, With an allowance recorded	9,314	861	171
Unpaid Principal Balance, With an allowance recorded	9,724	869	171
Related Allowance	2,692	396	171
Average Recorded Investment, With an allowance recorded	3,460	914	185
Interest Income Recognized, With an allowance recorded	486		1
Installment and Other
Financing Receivable Impaired [Line Items]
Recorded Investment, With an allowance recorded	14	328	327
Unpaid Principal Balance, With an allowance recorded	14	361	335
Related Allowance	14	328	327
Average Recorded Investment, With an allowance recorded	162	328	327
Interest Income Recognized, With an allowance recorded	$ 12	$ 16	$ 23

Allowance for Loan and Lease 87

Allowance for Loan and Lease Losses and Reserve for Unfunded Commitments - Summary of Risk Rating Categories of Loans and Leases Considered for Inclusion in Allowance for Loan and Lease Losses Calculation (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Financing Receivable Recorded Investment [Line Items]
Total loans and leases	$ 2,277,492	$ 2,148,011	$ 1,345,437
Commercial Real Estate
Financing Receivable Recorded Investment [Line Items]
Total loans and leases	891,693	796,344	533,695
Residential Real Estate
Financing Receivable Recorded Investment [Line Items]
Total loans and leases	577,218	610,738	484,335
Construction, Land Development, and Other Land
Financing Receivable Recorded Investment [Line Items]
Total loans and leases	105,429	140,766	40,232
Commercial and Industrial
Financing Receivable Recorded Investment [Line Items]
Total loans and leases	521,238	438,238	165,696
Installment and Other
Financing Receivable Recorded Investment [Line Items]
Total loans and leases	4,228	2,959	1,926
Lease Financing Receivables
Financing Receivable Recorded Investment [Line Items]
Total loans and leases	177,686	158,966	$ 119,553
Loans Excluding Acquired Impaired Loans
Financing Receivable Recorded Investment [Line Items]
Total loans and leases	1,949,802	1,743,974
Loans Excluding Acquired Impaired Loans | Commercial Real Estate
Financing Receivable Recorded Investment [Line Items]
Total loans and leases	724,981	589,041
Loans Excluding Acquired Impaired Loans | Residential Real Estate
Financing Receivable Recorded Investment [Line Items]
Total loans and leases	432,656	435,021
Loans Excluding Acquired Impaired Loans | Construction, Land Development, and Other Land
Financing Receivable Recorded Investment [Line Items]
Total loans and leases	99,483	133,787
Loans Excluding Acquired Impaired Loans | Commercial and Industrial
Financing Receivable Recorded Investment [Line Items]
Total loans and leases	511,230	424,774
Loans Excluding Acquired Impaired Loans | Installment and Other
Financing Receivable Recorded Investment [Line Items]
Total loans and leases	3,766	2,385
Loans Excluding Acquired Impaired Loans | Lease Financing Receivables
Financing Receivable Recorded Investment [Line Items]
Total loans and leases	177,686	158,966
Loans Excluding Acquired Impaired Loans | Pass
Financing Receivable Recorded Investment [Line Items]
Total loans and leases	1,704,311	1,614,595
Loans Excluding Acquired Impaired Loans | Pass | Commercial Real Estate
Financing Receivable Recorded Investment [Line Items]
Total loans and leases	638,066	536,499
Loans Excluding Acquired Impaired Loans | Pass | Residential Real Estate
Financing Receivable Recorded Investment [Line Items]
Total loans and leases	398,743	419,880
Loans Excluding Acquired Impaired Loans | Pass | Construction, Land Development, and Other Land
Financing Receivable Recorded Investment [Line Items]
Total loans and leases	73,935	129,732
Loans Excluding Acquired Impaired Loans | Pass | Commercial and Industrial
Financing Receivable Recorded Investment [Line Items]
Total loans and leases	415,163	369,136
Loans Excluding Acquired Impaired Loans | Pass | Installment and Other
Financing Receivable Recorded Investment [Line Items]
Total loans and leases	3,732	2,052
Loans Excluding Acquired Impaired Loans | Pass | Lease Financing Receivables
Financing Receivable Recorded Investment [Line Items]
Total loans and leases	174,672	157,296
Loans Excluding Acquired Impaired Loans | Watch
Financing Receivable Recorded Investment [Line Items]
Total loans and leases	176,996	105,689
Loans Excluding Acquired Impaired Loans | Watch | Commercial Real Estate
Financing Receivable Recorded Investment [Line Items]
Total loans and leases	58,217	38,707
Loans Excluding Acquired Impaired Loans | Watch | Residential Real Estate
Financing Receivable Recorded Investment [Line Items]
Total loans and leases	29,165	10,885
Loans Excluding Acquired Impaired Loans | Watch | Construction, Land Development, and Other Land
Financing Receivable Recorded Investment [Line Items]
Total loans and leases	22,380	2,897
Loans Excluding Acquired Impaired Loans | Watch | Commercial and Industrial
Financing Receivable Recorded Investment [Line Items]
Total loans and leases	67,024	52,872
Loans Excluding Acquired Impaired Loans | Watch | Installment and Other
Financing Receivable Recorded Investment [Line Items]
Total loans and leases	20	4
Loans Excluding Acquired Impaired Loans | Watch | Lease Financing Receivables
Financing Receivable Recorded Investment [Line Items]
Total loans and leases	190	324
Loans Excluding Acquired Impaired Loans | Special Mention
Financing Receivable Recorded Investment [Line Items]
Total loans and leases	34,892	11,422
Loans Excluding Acquired Impaired Loans | Special Mention | Commercial Real Estate
Financing Receivable Recorded Investment [Line Items]
Total loans and leases	14,645	5,377
Loans Excluding Acquired Impaired Loans | Special Mention | Residential Real Estate
Financing Receivable Recorded Investment [Line Items]
Total loans and leases	2,251	3,116
Loans Excluding Acquired Impaired Loans | Special Mention | Construction, Land Development, and Other Land
Financing Receivable Recorded Investment [Line Items]
Total loans and leases	3,168	1,158
Loans Excluding Acquired Impaired Loans | Special Mention | Commercial and Industrial
Financing Receivable Recorded Investment [Line Items]
Total loans and leases	13,535	1,258
Loans Excluding Acquired Impaired Loans | Special Mention | Installment and Other
Financing Receivable Recorded Investment [Line Items]
Total loans and leases		1
Loans Excluding Acquired Impaired Loans | Special Mention | Lease Financing Receivables
Financing Receivable Recorded Investment [Line Items]
Total loans and leases	1,293	512
Loans Excluding Acquired Impaired Loans | Substandard
Financing Receivable Recorded Investment [Line Items]
Total loans and leases	33,331	12,173
Loans Excluding Acquired Impaired Loans | Substandard | Commercial Real Estate
Financing Receivable Recorded Investment [Line Items]
Total loans and leases	14,053	8,458
Loans Excluding Acquired Impaired Loans | Substandard | Residential Real Estate
Financing Receivable Recorded Investment [Line Items]
Total loans and leases	2,497	1,140
Loans Excluding Acquired Impaired Loans | Substandard | Commercial and Industrial
Financing Receivable Recorded Investment [Line Items]
Total loans and leases	15,508	1,508
Loans Excluding Acquired Impaired Loans | Substandard | Installment and Other
Financing Receivable Recorded Investment [Line Items]
Total loans and leases	14	328
Loans Excluding Acquired Impaired Loans | Substandard | Lease Financing Receivables
Financing Receivable Recorded Investment [Line Items]
Total loans and leases	1,259	739
Loans Excluding Acquired Impaired Loans | Doubtful
Financing Receivable Recorded Investment [Line Items]
Total loans and leases	272	95
Loans Excluding Acquired Impaired Loans | Doubtful | Lease Financing Receivables
Financing Receivable Recorded Investment [Line Items]
Total loans and leases	$ 272	$ 95

Allowance for Loan and Lease 88

Allowance for Loan and Lease Losses and Reserve for Unfunded Commitments - Summary of Contractual Delinquency Information (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Financing Receivable Recorded Investment Past Due [Line Items]
Total loans and leases	$ 2,277,492	$ 2,148,011	$ 1,345,437
Commercial Real Estate
Financing Receivable Recorded Investment Past Due [Line Items]
Total loans and leases	891,693	796,344	533,695
Residential Real Estate
Financing Receivable Recorded Investment Past Due [Line Items]
Total loans and leases	577,218	610,738	484,335
Construction, Land Development, and Other Land
Financing Receivable Recorded Investment Past Due [Line Items]
Total loans and leases	105,429	140,766	40,232
Commercial and Industrial
Financing Receivable Recorded Investment Past Due [Line Items]
Total loans and leases	521,238	438,238	165,696
Installment and Other
Financing Receivable Recorded Investment Past Due [Line Items]
Total loans and leases	4,228	2,959	1,926
Lease Financing Receivables
Financing Receivable Recorded Investment Past Due [Line Items]
Total loans and leases	177,686	158,966	$ 119,553
Acquired Non-Impaired and Originated Loans
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	30,950	20,882
Non-accrual	15,764	6,784
Current	1,918,852	1,723,092
Total loans and leases	1,949,802	1,743,974
Acquired Non-Impaired and Originated Loans | 30-59 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	12,613	12,686
Acquired Non-Impaired and Originated Loans | 60-89 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	2,573	1,412
Acquired Non-Impaired and Originated Loans | Commercial Real Estate
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	14,210	7,527
Non-accrual	8,459	3,935
Current	710,771	581,514
Total loans and leases	724,981	589,041
Acquired Non-Impaired and Originated Loans | Commercial Real Estate | 30-59 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	4,783	2,944
Acquired Non-Impaired and Originated Loans | Commercial Real Estate | 60-89 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	968	648
Acquired Non-Impaired and Originated Loans | Residential Real Estate
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	2,240	1,361
Non-accrual	2,092	1,118
Current	430,416	433,660
Total loans and leases	432,656	435,021
Acquired Non-Impaired and Originated Loans | Residential Real Estate | 30-59 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	148	243
Acquired Non-Impaired and Originated Loans | Construction, Land Development, and Other Land
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due		1,363
Current	99,483	132,424
Total loans and leases	99,483	133,787
Acquired Non-Impaired and Originated Loans | Construction, Land Development, and Other Land | 30-59 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due		1,363
Acquired Non-Impaired and Originated Loans | Commercial and Industrial
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	11,982	7,398
Non-accrual	4,348	958
Current	499,248	417,376
Total loans and leases	511,230	424,774
Acquired Non-Impaired and Originated Loans | Commercial and Industrial | 30-59 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	6,667	6,066
Acquired Non-Impaired and Originated Loans | Commercial and Industrial | 60-89 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	967	374
Acquired Non-Impaired and Originated Loans | Installment and Other
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	32	328
Non-accrual	14	328
Current	3,734	2,057
Total loans and leases	3,766	2,385
Acquired Non-Impaired and Originated Loans | Installment and Other | 30-59 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	18
Acquired Non-Impaired and Originated Loans | Lease Financing Receivables
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	2,486	2,905
Non-accrual	851	445
Current	175,200	156,061
Total loans and leases	177,686	158,966
Acquired Non-Impaired and Originated Loans | Lease Financing Receivables | 30-59 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	997	2,070
Acquired Non-Impaired and Originated Loans | Lease Financing Receivables | 60-89 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Total Past Due	$ 638	$ 390

Allowance for Loan and Lease 89

Allowance for Loan and Lease Losses and Reserve for Unfunded Commitments - Summary of TDR's by Loan Category (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Financing Receivable Modifications [Line Items]
Number of Loans	10	5	6
Pre-Modification Outstanding Recorded Investment	$ 3,117	$ 1,154	$ 2,741
Post-Modification Outstanding Recorded Investment	2,630	$ 1,154	$ 2,741
Charge-offs	487
Specific Reserves	$ 357
Commercial Real Estate
Financing Receivable Modifications [Line Items]
Number of Loans	5	2	2
Pre-Modification Outstanding Recorded Investment	$ 1,655	$ 898	$ 979
Post-Modification Outstanding Recorded Investment	1,655	$ 898	$ 979
Specific Reserves	$ 111
Commercial and Industrial
Financing Receivable Modifications [Line Items]
Number of Loans	3
Pre-Modification Outstanding Recorded Investment	$ 1,246
Post-Modification Outstanding Recorded Investment	759
Charge-offs	487
Specific Reserves	$ 246
Residential Real Estate
Financing Receivable Modifications [Line Items]
Number of Loans	2	3	4
Pre-Modification Outstanding Recorded Investment	$ 216	$ 256	$ 1,762
Post-Modification Outstanding Recorded Investment	$ 216	$ 256	$ 1,762

Servicing Assets - Unpaid Princ

Servicing Assets - Unpaid Principal Balances of Loans Serviced for Others (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Loan portfolios serviced for:
Unpaid principal balances of loans serviced	$ 1,112,901	$ 1,017,928
SBA guaranteed loans
Loan portfolios serviced for:
Unpaid principal balances of loans serviced	1,021,143	911,803
USDA guaranteed loans
Loan portfolios serviced for:
Unpaid principal balances of loans serviced	$ 91,758	$ 106,125

Servicing Assets - Activity for

Servicing Assets - Activity for Servicing Assets and Related Changes in Fair Value (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Transfers And Servicing [Abstract]
Beginning balance	$ 21,091
Acquired servicing assets at fair value		$ 20,295
Additions, net	6,250	539
Changes in fair value	(5,941)	257
Ending balance	$ 21,400	$ 21,091

Servicing Assets - Additional I

Servicing Assets - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Transfers And Servicing [Abstract]
Servicing fees	$ 3,658,000	$ 1,906,000	$ 0

Other Real Estate Owned - Chang

Other Real Estate Owned - Change in Other Real Estate Owned (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Banking And Thrift [Abstract]
Other real estate owned, beginning balance	$ 16,570	$ 26,715	$ 56,181
Acquisition of OREO through business combination		1,525
Net additions to OREO	6,266	6,672	13,793
Dispositions of OREO	(11,750)	(17,389)	(33,994)
Valuation adjustments	(460)	(953)	(9,265)
Other real estate owned, ending balance	$ 10,626	$ 16,570	$ 26,715

Other Real Estate Owned - Addit

Other Real Estate Owned - Additional Information (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Real Estate [Line Items]
Foreclosed real estate properties recorded as result of obtaining physical possession of property	$ 10,626	$ 16,570	$ 26,715	$ 56,181
Residential consumer mortgage loans in process of foreclosure	1,900	2,700
Residential Real Estate
Real Estate [Line Items]
Foreclosed real estate properties recorded as result of obtaining physical possession of property	$ 3,600	$ 3,300

Premises and Equipment and As95

Premises and Equipment and Assets Held For Sale - Schedule for Classification of Premises and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Premises and equipment
Premises	$ 51,743	$ 53,495
Furniture, fixtures and equipment	10,295	7,214
Leasehold improvements	1,538	1,093
Total cost	63,576	61,802
Less accumulated depreciation and amortization	(13,906)	(9,780)
Premises and equipment, net	95,224	102,074
Net book value of premises, furniture, fixtures, equipment, leasehold improvements
Premises and equipment
Premises and equipment, net	49,670	52,022
Construction in progress
Premises and equipment
Premises and equipment, net	899	3,869
Land
Premises and equipment
Premises and equipment, net	$ 44,655	$ 46,183

Premises and Equipment and As96

Premises and Equipment and Assets Held For Sale - Additional Information (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)item	Dec. 31, 2016USD ($)item	Dec. 31, 2015USD ($)item
Property Plant And Equipment [Abstract]
Depreciation and amortization of premises and equipment | $	$ 5,193	$ 5,060	$ 5,800
Number of branches closure | item	2	12	16

Premises and Equipment and As97

Premises and Equipment and Assets Held For Sale - Change in Assets Held for Sale (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Property Plant And Equipment [Abstract]
Beginning balance	$ 14,748	$ 2,259
Transfers in	3,372	14,496	$ 2,259
Proceeds from sales	(5,373)	(2,566)
Internally financed sales	(1,800)
Net gains (losses) on sales	(217)	967
Impairment loss	(951)	(408)
Ending balance	$ 9,779	$ 14,748	$ 2,259

Goodwill, Core Deposit Intang98

Goodwill, Core Deposit Intangible and Other Intangible Assets - Summary of Changes in Goodwill and Core Deposit Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Schedule Of Goodwill And Intangible Assets [Line Items]
Beginning balance, Goodwill	$ 51,975	$ 25,688	$ 25,613
Additions		26,287	75
Ending balance, Goodwill	51,975	51,975	25,688
Amortization or accretion	(3,074)	(3,003)	(2,980)
Core Deposits
Schedule Of Goodwill And Intangible Assets [Line Items]
Beginning balance	19,776	22,275	25,245
Additions		486
Amortization or accretion	(3,056)	(2,985)	(2,970)
Ending balance	16,720	19,776	22,275
Accumulated amortization or accretion	$ 13,466	$ 10,410	$ 7,425
Weighted average remaining amortization or accretion period	5 years 7 months 6 days	6 years 7 months 6 days	7 years 6 months

Goodwill, Core Deposit Intang99

Goodwill, Core Deposit Intangible and Other Intangible Assets - Additional Information (Details) - USD ($)	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Indefinite Lived Intangible Assets By Major Class [Line Items]
Other intangible assets, net	$ 16,756,000	$ 19,826,000
Trademark
Indefinite Lived Intangible Assets By Major Class [Line Items]
Other intangible assets, net	$ 36,000	$ 50,000	$ 51,000

Goodwill, Core Deposit Intan100

Goodwill, Core Deposit Intangible and Other Intangible Assets - Estimated Amortization Expense for Core Deposit Intangible and Other Intangible Assets Recognized (Details) $ in Thousands	Dec. 31, 2017USD ($)
Goodwill And Intangible Assets Disclosure [Abstract]
2,018	$ 3,061
2,019	3,050
2,020	3,026
2,021	3,017
2,022	3,010
Thereafter	1,592
Total	$ 16,756

Income Taxes - Provision for in

Income Taxes - Provision for 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
Current tax expense:
Federal									$ 1,010		$ 250
State and local									1,485		57
Total current tax expense									2,495		307
Deferred tax expense:
Federal									13,554	$ 478	4,929
State and local									686	136	656
Remeasurement of net deferred tax assets									2,364
Total deferred tax expense before reversal of valuation allowance									16,604	614	5,585
Deferred tax valuation allowance										(61,859)	(5,585)
Provision (benefit) for income taxes	$ 11,851	$ (1,390)	$ 4,094	$ 4,544	$ (61,023)	$ 9	$ 9	$ (240)	$ 19,099	$ (61,245)	$ 307

Income Taxes - Reconciliation b

Income Taxes - Reconciliation between statutory and effective tax rate (Details)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Reconciliation between statutory U.S. federal income tax rate and effective tax rate
Calculated tax benefit at statutory rate	35.00%	35.00%	35.00%
Increase (decrease) in income taxes resulting from:
Reversal of valuation allowance, net of change in estimated Section 382 impact		(1167.60%)	73.40%
State taxes, net of federal income tax	6.50%	6.10%	5.00%
Tax exempt income	(0.70%)	(5.30%)	24.20%
Non-deductible expenses	0.20%	14.80%	(137.60%)
Remeasurement of net deferred tax assets	5.80%
Total income tax expense (benefit)	46.80%	(1117.00%)

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($)	3 Months Ended	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax [Line Items]
Corporate federal income tax rate			35.00%	35.00%	35.00%
Net income tax expense	$ 7,200,000		$ 7,200,000
Reversal of valuation allowance				$ 61,400,000
Operating loss carryforwards, limitations on use			Pursuant to Sections 382 and 383 of the Internal Revenue Code, annual use of net operating loss and credit carryforwards may be limited in the event a cumulative change in ownership of more than 50 percent occurs within a three-year period.
Cumulative change in ownership Percentage	50.00%		50.00%
Period for cumulative change in ownership			3 years
Estimated net operating losses available eah year	$ 756,000		$ 756,000
Scenario, Plan
Income Tax [Line Items]
Corporate federal income tax rate		21.00%

Income Taxes - Deferred tax ass

Income Taxes - Deferred tax assets and liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Deferred tax assets:
Net operating losses and tax credits	$ 42,062	$ 61,906
Interest on non-accrual loans	2,755	2,882
Allowance for loan losses and loan basis	13,839	22,017
Deposits	5	316
Alternative minimum tax ("AMT") credit carryforward	2,140	1,073
Other real estate owned		214
Net unrealized holding losses on securities available-for-sale	2,766	4,818
Other	2,413	3,241
Total deferred tax assets	65,980	96,467
Deferred tax liabilities:
Other real estate owned	(24)
Premises and equipment	(3,385)	(6,907)
Core deposit intangibles	(4,656)	(7,858)
Servicing assets	(3,505)	(7,899)
Trust preferred securities	(2,465)	(3,809)
Unrealized holding gain on cash flow hedges	(1,390)	(1,491)
Other	(592)	(743)
Total deferred tax liabilities	(16,017)	(28,707)
Net deferred tax assets after valuation allowance	$ 49,963	$ 67,760

Income Taxes - Operating loss a

Income Taxes - Operating loss and credit carryforwards (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Alternative minimum tax credits
Operating loss carryforwards
Tax credit carryforwards	$ 2,140	$ 1,073
Federal
Operating loss carryforwards
Net operating loss carryforwards	63,964	116,315
Illinois
Operating loss carryforwards
Net operating loss carryforwards	$ 381,471	$ 420,764

Income Taxes - Operating los106

Income Taxes - Operating loss and credit carryforwards (Parenthetical) (Details)	12 Months Ended
	Dec. 31, 2017
Federal
Operating loss carryforwards
Operating loss carryforwards expiration year	2,027
Illinois
Operating loss carryforwards
Operating loss carryforwards expiration year	2,021

Federal Home Loan Bank Advan107

Federal Home Loan Bank Advances - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Federal Home Loan Bank Advances [Line Items]
Federal home loan bank advances, acquisition accounting adjustments	$ 19,000	$ 228,000
Federal home loan bank, required investment conversion ratio	0.05
Additional borrowing capacity from FHLB	$ 795,000,000	647,900,000
Federal home loan bank advances maximum borrowing capacity as percentage of total assets	35.00%
Federal home loan bank, advances, putable option	$ 361,506,000	$ 313,715,000
Ridgestone
Federal Home Loan Bank Advances [Line Items]
Federal home loan bank, advances, putable option	$ 1,500,000
Minimum
Federal Home Loan Bank Advances [Line Items]
Federal home loan bank advances, Fixed interest rate	1.32%
Federal home loan bank fixed rate advances, maturity date	2018-01
Maximum
Federal Home Loan Bank Advances [Line Items]
Federal home loan bank advances, Fixed interest rate	3.22%
Federal home loan bank fixed rate advances, maturity date	2018-03

Federal Home Loan Bank Advan108

Federal Home Loan Bank Advances - Summary of FHLB Advances Including Acquisition Accounting Adjustments Along with Weighted Average Costs and Scheduled Maturities (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Federal Home Loan Banks [Abstract]
Federal Home Loan Bank advances	$ 361,506	$ 313,715
Weighted average cost	1.49%	0.73%
2,018	$ 361,506
Total	$ 361,506	$ 313,715

Other Borrowings - Summary of O

Other Borrowings - Summary of Other Borrowings (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Debt Disclosure [Abstract]
Securities sold under agreements to repurchase	$ 31,187	$ 17,249
Line of credit		20,650
Total	$ 31,187	$ 37,899

Other Borrowings - Additional I

Other Borrowings - Additional Information (Details) - USD ($)	Oct. 12, 2017	Jul. 31, 2017	Dec. 31, 2017	Dec. 31, 2016	Apr. 30, 2017	Oct. 13, 2016
Line Of Credit Facility [Line Items]
Line of credit facility, amount				$ 20,650,000
Repayment of lines of credit		$ 16,200,000	$ 20,650,000	9,350,000
Short-term credit lines available for use, outstanding			$ 0	$ 0
Ridgestone | CIBC Bank USA | Credit agreement
Line Of Credit Facility [Line Items]
Line of credit facility, amount						$ 30,000,000
Line of credit facility, commitment fee payable						$ 300,000
Line of credit facility, maturity date			Oct. 12, 2017
Line of credit facility, interest rate				3.75%
Ridgestone | CIBC Bank USA | Amended Credit Agreement
Line Of Credit Facility [Line Items]
Line of credit facility, revolving credit conversion to non-revolving line of credit, description			In April 2017, the revolving line of credit was amended to a non-revolving line of credit as long as the outstanding balance exceeds $5.0 million.
Line of credit facility, revolving credit conversion to non-revolving line of credit, threshold amount					$ 5,000,000
Threshold amount for conversion of line of credit into revolving line of credit					5,000,000
Revolving line of credit facility, maximum borrowing capacity					$ 5,000,000
Line of credit facility, extended maturity date	Oct. 11, 2018
Line of credit facility, interest rate terms	The amended revolving line of credit bears interest at either the London Interbank Offered Rate (“LIBOR”) Rate plus 250 basis points or the Prime Rate minus 25 basis points, based on the Company’s election, which is required to be communicated to CIBC at least three business days prior to the commencement of an interest period. If the Company fails to provide timely notification, the interest rate will be Prime Rate minus 25 basis points. As of December 31, 2017, the line of credit has not been drawn upon, so an interest rate option has not been selected.
Ridgestone | CIBC Bank USA | Amended Credit Agreement | LIBOR Rate
Line Of Credit Facility [Line Items]
Interest rate spread	2.50%
Ridgestone | CIBC Bank USA | Amended Credit Agreement | Prime Rate
Line Of Credit Facility [Line Items]
Interest rate spread	0.25%

Other Borrowings - Summary of S

Other Borrowings - Summary of Short-term Credit Lines Available for Use (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Federal Reserve Bank of Chicago Discount Window Line
Debt Instrument [Line Items]
Short-term credit lines available for use	$ 144,248	$ 110,600
Available Federal Funds Line
Debt Instrument [Line Items]
Short-term credit lines available for use	$ 55,000	$ 20,000

Deposits - Schedule of Deposits

Deposits - Schedule of Deposits (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Deposits [Abstract]
Non-interest bearing demand deposits	$ 760,887	$ 724,457
Interest bearing checking accounts	186,611	173,929
Money market demand accounts	349,862	369,074
Other savings	437,212	446,418
Time deposits (below $250,000)	627,255	659,129
Time deposits ($250,000 and above)	81,502	117,387
Total deposits	$ 2,443,329	$ 2,490,394

Deposits - Additional Informati

Deposits - Additional Information (Details) - USD ($)	Dec. 31, 2017	Dec. 31, 2016
Deposits [Abstract]
Brokered deposits	$ 0	$ 30,800,000

Deposits - Scheduled Maturities

Deposits - Scheduled Maturities of Time Deposits (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Time Deposit [Abstract]
2,018	$ 548,208
2,019	139,748
2,020	9,552
2,021	6,703
2,022	4,546
Total	$ 708,757	$ 776,516

Junior Subordinated Debentur115

Junior Subordinated Debentures - Junior Subordinated Debentures by Issuance (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Shares Subject To Mandatory Redemption By Settlement Terms [Line Items]
Total liability, at par	$ 36,500	$ 36,500
Total liability, at carrying value	27,647	26,926
Metropolitan Statutory Trust 1
Shares Subject To Mandatory Redemption By Settlement Terms [Line Items]
Total liability, at par	35,000	35,000
RidgeStone Capital Trust I
Shares Subject To Mandatory Redemption By Settlement Terms [Line Items]
Total liability, at par	1,500	1,500
Junior Subordinated Debentures
Shares Subject To Mandatory Redemption By Settlement Terms [Line Items]
Discount	$ (8,853)	$ (9,574)
Junior Subordinated Debentures | Metropolitan Statutory Trust 1
Shares Subject To Mandatory Redemption By Settlement Terms [Line Items]
Stated Maturity	Mar. 17, 2034
Contractual Rate	4.39%	3.78%
Junior Subordinated Debentures | Metropolitan Statutory Trust 1 | Three-month LIBOR
Shares Subject To Mandatory Redemption By Settlement Terms [Line Items]
Interest Rate Spread, Description	Three-month LIBOR
Interest rate spread	2.79%	2.79%
Junior Subordinated Debentures | RidgeStone Capital Trust I
Shares Subject To Mandatory Redemption By Settlement Terms [Line Items]
Stated Maturity	Jun. 30, 2033
Contractual Rate	5.09%	5.09%
Junior Subordinated Debentures | RidgeStone Capital Trust I | Five-year LIBOR
Shares Subject To Mandatory Redemption By Settlement Terms [Line Items]
Interest Rate Spread, Description	Five-year LIBOR
Interest rate spread	3.50%	3.50%

Junior Subordinated Debentur116

Junior Subordinated Debentures - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Principal amount	$ 36,500,000	$ 36,500,000
Accrued interest payable	1,306,000	2,427,000
Metropolitan Statutory Trust 1
Debt Instrument [Line Items]
Principal amount	$ 35,000,000	$ 35,000,000
Metropolitan Statutory Trust 1 | Junior Subordinated Debentures
Debt Instrument [Line Items]
Contractual rate	4.39%	3.78%
Accrued interest payable	$ 62,000	$ 50,000
Metropolitan Statutory Trust 1 | Junior Subordinated Debentures | Three-month LIBOR
Debt Instrument [Line Items]
Interest rate spread	2.79%	2.79%
RidgeStone Capital Trust I
Debt Instrument [Line Items]
Principal amount	$ 1,500,000	$ 1,500,000
RidgeStone Capital Trust I | Junior Subordinated Debentures
Debt Instrument [Line Items]
Contractual rate	5.09%	5.09%
Accrued interest payable	$ 0	$ 0
RidgeStone Capital Trust I | Junior Subordinated Debentures | Five-year LIBOR
Debt Instrument [Line Items]
Interest rate spread	3.50%	3.50%

Employee Benefit Plans - Additi

Employee Benefit Plans - Additional Information (Details) - USD ($)	Jan. 01, 2017	Feb. 01, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Employee Benefit Plans
Profit sharing contributions			$ 0	$ 0
Employer matching contribution		50.00%
Contribution by employees		4.00%
Employer contribution to Plan			1,500,000	655,000
Compensation expense			$ 1,294,000	899,000
Employee Stock Purchase Plan
Employee Benefit Plans
Common stock reserved and available for sale			200,000
Compensation expense			$ 0	$ 0	$ 0
3% contributed by employees
Employee Benefit Plans
Employer matching contribution	100.00%
Contribution by employees	3.00%
2% contributed by employees
Employee Benefit Plans
Employer matching contribution	50.00%
Contribution by employees	2.00%

Commitments and Contingent L118

Commitments and Contingent Liabilities - Summary of Minimum Annual Rental Commitments for Operating Leases (Details) $ in Thousands	Dec. 31, 2017USD ($)
Commitments And Contingencies Disclosure [Abstract]
2,018	$ 3,000
2,019	2,522
2,020	2,023
2,021	1,776
2,022	972
Thereafter	2,073
Total	$ 12,366

Commitments and Contingent L119

Commitments and Contingent Liabilities - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Commitments And Contingencies Liabilities [Line Items]
Rental expenses	$ 4,600,000	$ 3,800,000	$ 3,600,000
Sublease income	702,000	$ 737,000	$ 744,000
Minimum rental to be received in future on subleases	$ 1,800,000
Fixed rate loan commitments maturity year	2,020
Variable rate loan commitments maturity year	2,040
Maximum
Commitments And Contingencies Liabilities [Line Items]
Commitments to make loans period	90 days
Loan commitments fixed interest rate	19.50%
Loan commitments variable interest rate	9.25%
Minimum
Commitments And Contingencies Liabilities [Line Items]
Loan commitments fixed interest rate	3.05%
Loan commitments variable interest rate	2.45%

Commitments and Contingent L120

Commitments and Contingent Liabilities - Summary of Contract or Notional Amount of Outstanding Loan and Lease Commitments (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Commitments And Contingencies Liabilities [Line Items]
Fixed Rate	$ 57,150	$ 38,791
Variable Rate	470,766	337,063
Commitments to Extend Credit
Commitments And Contingencies Liabilities [Line Items]
Fixed Rate	55,924	37,731
Variable Rate	467,429	332,928
Standby Letters of Credit
Commitments And Contingencies Liabilities [Line Items]
Fixed Rate	1,226	1,060
Variable Rate	$ 3,337	$ 4,135

Fair Value Measurement - Summar

Fair Value Measurement - Summary of Financial Assets And Liabilities Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value	$ 583,236	$ 608,560
Servicing assets, at fair value	21,400	21,091
Derivative assets	5,981
Derivative liabilities	994
U.S. Treasury Notes
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value	14,863	14,920
U.S. Government Agencies
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value	52,958	58,857
Obligations of States, Municipalities, and Political Subdivisions
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value	33,170	16,059
Corporate Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value	29,976	17,329
Other Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value	5,284	4,847
Fair Value, Measurements, Recurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Servicing assets, at fair value	21,400	21,091
Derivative assets	5,981	4,317
Derivative liabilities	994	559
Fair Value, Measurements, Recurring | U.S. Treasury Notes
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value	14,863	14,920
Fair Value, Measurements, Recurring | U.S. Government Agencies
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value	52,958	58,857
Fair Value, Measurements, Recurring | Obligations of States, Municipalities, and Political Subdivisions
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value	33,170	16,059
Fair Value, Measurements, Recurring | Mortgage-Backed Securities; Residential | Agency
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value	307,457	368,160
Fair Value, Measurements, Recurring | Mortgage-Backed Securities; Residential | Non-Agency
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value	39,514	19,933
Fair Value, Measurements, Recurring | Mortgage-Backed Securities; Commercial | Agency
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value	69,043	77,403
Fair Value, Measurements, Recurring | Mortgage-Backed Securities; Commercial | Non-Agency
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value	30,971	31,052
Fair Value, Measurements, Recurring | Corporate Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value	29,976	17,329
Fair Value, Measurements, Recurring | Other Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value	5,284	4,847
Fair Value, Measurements, Recurring | Level 1 | U.S. Treasury Notes
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value	14,863	14,920
Fair Value, Measurements, Recurring | Level 1 | Other Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value	1,921	1,938
Fair Value, Measurements, Recurring | Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative assets	5,981	4,317
Derivative liabilities	994	559
Fair Value, Measurements, Recurring | Level 2 | U.S. Government Agencies
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value	52,958	58,857
Fair Value, Measurements, Recurring | Level 2 | Obligations of States, Municipalities, and Political Subdivisions
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value	32,795	15,509
Fair Value, Measurements, Recurring | Level 2 | Mortgage-Backed Securities; Residential | Agency
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value	307,457	368,160
Fair Value, Measurements, Recurring | Level 2 | Mortgage-Backed Securities; Residential | Non-Agency
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value	39,514	19,933
Fair Value, Measurements, Recurring | Level 2 | Mortgage-Backed Securities; Commercial | Agency
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value	69,043	77,403
Fair Value, Measurements, Recurring | Level 2 | Mortgage-Backed Securities; Commercial | Non-Agency
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value	30,971	31,052
Fair Value, Measurements, Recurring | Level 2 | Corporate Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value	29,976	17,329
Fair Value, Measurements, Recurring | Level 2 | Other Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value	2,686	2,379
Fair Value, Measurements, Recurring | Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Servicing assets, at fair value	21,400	21,091
Fair Value, Measurements, Recurring | Level 3 | Obligations of States, Municipalities, and Political Subdivisions
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value	375	550
Fair Value, Measurements, Recurring | Level 3 | Other Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value	$ 677	$ 530

Fair Value Measurement - Additi

Fair Value Measurement - Additional Information (Details) - USD ($)	Dec. 31, 2017	Dec. 31, 2016
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Abstract]
Fair value, assets, level 1 to level 2 transfers, amount	$ 0	$ 0
Fair value, assets, level 2 to level 1 transfers, amount	0	0
Fair value, liabilities, level 1 to level 2 transfers, amount	0	0
Fair value, liabilities, level 2 to level 1 transfers, amount	0	0
Fair value, equity, level 1 to level 2 transfers, amount	0	0
Fair value, equity, level 2 to level 1 transfers, amount	$ 0	$ 0

Fair Value Measurement - Sum123

Fair Value Measurement - Summary of Financial Assets Measured at Fair Value on Recurring Basis Using Significant Unobservable Inputs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Investment Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Balance, beginning of period	$ 1,080
Acquired at fair value		$ 548
Additions, net		550
Maturities	(175)
Amortization	5
Change in unrealized loss	142	(18)
Balance, end of period	1,052	1,080
Servicing Assets
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Balance, beginning of period	21,091
Acquired at fair value		20,295
Additions, net	6,250	539
Change in fair value	(5,941)	257
Balance, end of period	$ 21,400	$ 21,091

Fair Value Measurement - Sum124

Fair Value Measurement - Summary of Unobservable Inputs Used in Fair Value Measurements on Recurring Basis Categorized Within Level 3 of Fair Value Hierarchy (Details) - Fair Value, Measurements, Recurring - Level 3	12 Months Ended
	Dec. 31, 2017
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Impact to Valuation from an Increased or Higher Input Value	Decrease
Minimum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Discount rate	9.90%
Expected weighted average loan life	2 months 12 days
Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Discount rate	18.40%
Expected weighted average loan life	8 years 2 months 12 days
Weighted Average
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Discount rate	13.80%
Expected weighted average loan life	5 years 9 months 18 days
Obligations of States, Municipalities, and Political Subdivisions
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Valuation Technique	Discounted cash flow
Impact to Valuation from an Increased or Higher Input Value	Decrease
Obligations of States, Municipalities, and Political Subdivisions | Minimum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Probability of default	2.20%
Obligations of States, Municipalities, and Political Subdivisions | Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Probability of default	2.40%
Obligations of States, Municipalities, and Political Subdivisions | Weighted Average
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Probability of default	2.30%
Single Issuer Trust Preferred
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Valuation Technique	Discounted cash flow
Impact to Valuation from an Increased or Higher Input Value	Decrease
Single Issuer Trust Preferred | Minimum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Probability of default	7.50%
Single Issuer Trust Preferred | Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Probability of default	9.90%
Single Issuer Trust Preferred | Weighted Average
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Probability of default	8.90%
Servicing Assets
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Valuation Technique	Discounted cash flow
Impact to Valuation from an Increased or Higher Input Value	Decrease
Servicing Assets | Minimum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Prepayment speeds	1.60%
Servicing Assets | Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Prepayment speeds	9.90%
Servicing Assets | Weighted Average
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Prepayment speeds	8.60%

Fair Value Measurement - Sum125

Fair Value Measurement - Summary of Assets Measured at Fair Value on Non-recurring Basis, Excluding Acquired Impaired Loans (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Commercial Real Estate
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Assets, Fair Value	$ 12,783	$ 8,916
Residential Real Estate
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Assets, Fair Value	2,271	1,007
Commercial and Industrial
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Assets, Fair Value	12,092	986
Other Real Estate Owned
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Assets, Fair Value	10,626	16,570
Level 3 | Commercial Real Estate
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Assets, Fair Value	12,783	8,916
Level 3 | Residential Real Estate
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Assets, Fair Value	2,271	1,007
Level 3 | Commercial and Industrial
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Assets, Fair Value	12,092	986
Level 3 | Other Real Estate Owned
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Assets, Fair Value	10,626	16,570
Assets Held For Sale
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Assets, Fair Value	9,779	14,748
Assets Held For Sale | Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Assets, Fair Value	$ 9,779	$ 14,748

Fair Value Measurement - Sum126

Fair Value Measurement - Summary of Valuation Technique, Unobservable Inputs and Qualitative Information of Assets and Liabilities Measured at Fair Value on Non-recurring Basis (Details) - Level 3 - Fair Value Measurements, Non-recurring	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Impaired Loans
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Valuation Technique	Appraisals	Appraisals
Impact to Valuation from an Increased or Higher Input Value	Decrease	Decrease
Impaired Loans | Minimum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Appraisal adjustments, sales costs and other discount adjsutments for market conditions	6.00%	6.00%
Impaired Loans | Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Appraisal adjustments, sales costs and other discount adjsutments for market conditions	10.00%	10.00%
Asset Held For Sale
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Valuation Technique	List price, contract price	List price, contract price
Appraisal adjustments, sales costs and other discount adjsutments for market conditions	7.00%	7.00%
Impact to Valuation from an Increased or Higher Input Value	Decrease	Decrease
Other Real Estate Owned
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Valuation Technique	Appraisals	Appraisals
Impact to Valuation from an Increased or Higher Input Value	Decrease	Decrease
Other Real Estate Owned | Minimum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Appraisal adjustments, sales costs and other discount adjsutments for market conditions	7.00%	7.00%
Other Real Estate Owned | Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Appraisal adjustments, sales costs and other discount adjsutments for market conditions	20.00%	20.00%

Fair Value Measurement - Sum127

Fair Value Measurement - Summary of Estimated Fair Values of Financial Instruments and Levels Within Fair Value Hierarchy (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Financial assets
Cash and due from banks	$ 19,404	$ 17,735
Interest bearing deposits with other banks	38,945	28,798
Securities held-to-maturity, fair value	117,277	138,082
Restricted stock, at cost	16,343	14,993
Loans held for sale	5,212	23,976
Loans and lease receivables, net	2,260,786	2,137,088
Accrued interest receivable	7,670	6,866
Financial liabilities
Line of credit		20,650
Federal Home Loan Bank advances	361,506	313,715
Securities sold under agreements to repurchase	31,187	17,249
Junior subordinated debentures issued to capital trusts, net	27,647	26,926
Carrying Amount | Level 1
Financial assets
Cash and due from banks	19,404	17,735
Carrying Amount | Level 2
Financial assets
Interest bearing deposits with other banks	38,945	28,798
Securities held-to-maturity, fair value	117,163	138,846
Restricted stock, at cost	16,343	14,993
Financial liabilities
Non-interest bearing deposits	760,887	724,457
Interest bearing deposits	1,682,442	1,765,937
Accrued interest payable	1,306	2,427
Line of credit		20,650
Federal Home Loan Bank advances	361,506	313,715
Securities sold under agreements to repurchase	31,187	17,249
Carrying Amount | Level 3
Financial assets
Loans held for sale	5,212	23,976
Loans and lease receivables, net	2,260,786	2,137,088
Accrued interest receivable	7,670	6,866
Financial liabilities
Junior subordinated debentures issued to capital trusts, net	27,647	26,926
Estimated Fair Value | Level 1
Financial assets
Cash and due from banks	19,404	17,735
Estimated Fair Value | Level 2
Financial assets
Interest bearing deposits with other banks	38,945	28,798
Securities held-to-maturity, fair value	117,277	138,082
Restricted stock, at cost	16,343	14,993
Financial liabilities
Non-interest bearing deposits	760,887	724,457
Interest bearing deposits	1,678,535	1,764,078
Accrued interest payable	1,306	2,427
Line of credit		20,650
Federal Home Loan Bank advances	361,500	313,646
Securities sold under agreements to repurchase	31,187	17,249
Estimated Fair Value | Level 3
Financial assets
Loans held for sale	5,851	26,487
Loans and lease receivables, net	2,240,235	2,068,157
Accrued interest receivable	7,670	6,866
Financial liabilities
Junior subordinated debentures issued to capital trusts, net	$ 33,907	$ 26,943

Share-Based Compensation - Addi

Share-Based Compensation - Additional Information (Details) - USD ($) $ in Millions	Oct. 03, 2017	Jul. 06, 2017	Oct. 31, 2014	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Jun. 30, 2017
Restricted Shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Fair value of unvested restricted stock awards				$ 1.6
Performance Options Grants
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options vested	414,894
Common Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Issuance of common stock in connection with restricted stock awards, shares				70,798
Forfeiture of restricted stock awards, shares				400
Number of options exercised					6,065
Omnibus Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of common stock reserved and available for issuance							1,550,000
Number of common shares available for future grants				1,479,602
Omnibus Plan | Restricted Shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Forfeiture of restricted stock awards, shares		400
Award vesting period				4 years
Restricted shares vested				0
Restricted shares outstanding				70,398,000	0
Omnibus Plan | Common Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Issuance of common stock in connection with restricted stock awards, shares		58,900		11,898
MBG Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of options granted							0
Number of options exercised							0
BYB Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of common shares available for future grants				0
Number of options granted				0	212,400	1,634,568
Number of options exercised				0
Number of shares outstanding				1,783,020	1,798,220		1,783,020
Award contractual term				7 years 7 months 6 days	8 years 7 months 6 days
BYB Plan | Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of common stock reserved and available for issuance			2,476,122
Number of common shares available for future grants			2,476,122
BYB Plan | Time Options Grants
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Award contractual term			10 years
BYB Plan | Time Options Grants | Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Award vesting period			5 years
BYB Plan | Time Options Grants | Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Award vesting period			1 year
BYB Plan | Performance Options Grants
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Award contractual term			10 years
BYB Plan | Performance Options Grants | Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Award vesting period			5 years
BYB Plan | Performance Options Grants | Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Award vesting period			1 year

Share-Based Compensation - Summ

Share-Based Compensation - Summary of Changes in Restricted Shares (Details) - Omnibus Plan - Restricted Shares	12 Months Ended
	Dec. 31, 2017$ / sharesshares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares, beginning balance	0
Number of shares, granted	70,798,000
Number of shares, vested	0
Number of shares, forfeited	(400,000)
Number of shares, ending balance	70,398,000
Weighted average grant date fair value, granted | $ / shares	$ 20.31
Weighted average grant date fair value, forfeited | $ / shares	20.18
Weighted average grant date fair value, ending balance | $ / shares	$ 20.31

Share-Based Compensation - S130

Share-Based Compensation - Summary of Stock Compensation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total share-based compensation - restricted stock	$ 1,294	$ 899
Income tax benefit	521	360
Unrecognized compensation expense	$ 729	$ 1,752
Weighted-average amortization period remaining	1 year 2 months 12 days	1 year 9 months 18 days
Restricted Shares
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total share-based compensation - restricted stock	$ 203
Income tax benefit	83
Unrecognized compensation expense	$ 1,227
Weighted-average amortization period remaining	2 years 9 months 18 days

Share-Based Compensation - Fair

Share-Based Compensation - Fair Value Assumptions of Stock Options (Details) - BYB Plan - $ / shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Time Options Grants
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Risk-free interest rate, minimum	1.34%	1.68%
Risk-free interest rate, maximum	1.40%	1.85%
Expected stock price volatility	20.39%
Expected stock price volatility, minimum		16.18%
Expected stock price volatility, maximum		16.55%
Expected dividend yield	0.00%	0.00%
Weighted average grant date fair value	$ 3.55	$ 2.25
Time Options Grants | Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (years)	5 years 2 months 12 days	5 years 8 months 12 days
Time Options Grants | Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (years)	5 years 7 months 6 days	6 years 3 months 18 days
Performance Options Grants
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Risk-free interest rate	Implied forward rates	Implied forward rates
Expected term (years)	Variable	Variable
Expected stock price volatility, minimum	20.34%	16.18%
Expected stock price volatility, maximum	20.39%	16.55%
Expected dividend yield	0.00%	0.00%
Weighted average grant date fair value	$ 3.75	$ 1.65

Share-Based Compensation - S132

Share-Based Compensation - Summary Activity in shares Subjected to Options and Weighted Average Exercise Prices (Details) - BYB Plan - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended			18 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Jun. 30, 2017
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares, beginning balance	1,798,220
Number of shares, granted	0	212,400	1,634,568
Number of options exercised	0
Number of shares, forfeited	(15,200)
Number of shares, ending balance	1,783,020	1,798,220		1,783,020
Number of shares, exercisable	1,304,257
Weighted average exercise price, beginning balance	$ 11.95
Weighted average exercise price, forfeited	16.25
Weighted average exercise price, ending balance	11.91	$ 11.95
Weighted average exercise price, exercisable	$ 11.51
Intrinsic value, balance	$ 19,718	$ 15,788
Intrinsic value, exercisable	$ 14,953
Weighted average remaining contractual life (in years)	7 years 7 months 6 days	8 years 7 months 6 days
Weighted average remaining contractual life (in years), exercisable	7 years 6 months

Related Party Transactions (Det

Related Party Transactions (Details) - USD ($)	Dec. 31, 2017	Dec. 31, 2016
Related Party Transactions [Abstract]
Loans to related parties	$ 0	$ 0
Short-term receivable from related party		$ 100,000
Receivables outstanding from related parties	$ 0

Regulatory Capital Requireme134

Regulatory Capital Requirements (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Total capital to risk weighted assets:
Total capital to risk weighted assets, Actual Amount	$ 410,831	$ 316,314
Total capital to risk weighted assets, Actual Ratio ( as a percentage)	15.98%	13.28%
Total capital to risk weighted assets, Minimum Amount Required for Adequately Capitalized Amount	$ 205,661	$ 190,257
Total capital to risk weighted assets, Minimum Amount Required for Adequately Capitalized Ratio ( as a percentage)	8.00%	8.00%
Tier 1 capital to risk weighted assets:
Tier 1 capital to risk weighted assets, Actual Amount	$ 392,520	$ 304,324
Tier 1 capital to risk weighted assets, Actual Ratio ( as a percentage)	15.27%	12.78%
Tier 1 capital to risk weighted assets, Minimum Amount Required for Adequately Capitalized Amount	$ 154,246	$ 142,895
Tier 1 capital to risk weighted assets, Minimum Amount Required for Adequately Capitalized Ratio ( as a percentage)	6.00%	6.00%
Common Equity Tier 1 (CET1) to risk weighted assets:
Common Equity Tier 1 (CET1) to risk weighted, Actual Amount	$ 353,995	$ 266,760
Common Equity Tier 1 (CET1) to risk weighted, Actual Ratio ( as a percentage)	13.77%	11.20%
Common Equity Tier 1 (CET1) to risk weighted, Minimum Amount Required for Adequately Capitalized Amount	$ 115,684	$ 107,171
Common Equity Tier 1 (CET1) to risk weighted, Minimum Amount Required for Adequately Capitalized Ratio ( as a percentage)	4.50%	4.50%
Tier 1 capital to average assets:
Tier 1 capital to average, Actual Amount	$ 392,520	$ 304,324
Tier 1 capital to average, Actual Ratio ( as a percentage)	12.25%	10.07%
Tier 1 capital to average, Minimum Amount Required for Adequately Capitalized Amount	$ 128,178	$ 120,850
Tier 1 capital to average, Minimum Amount Required for Adequately Capitalized Ratio ( as a percentage)	4.00%	4.00%
Bank
Total capital to risk weighted assets:
Total capital to risk weighted assets, Actual Amount	$ 367,972	$ 325,465
Total capital to risk weighted assets, Actual Ratio ( as a percentage)	14.28%	13.61%
Total capital to risk weighted assets, Minimum Amount Required for Adequately Capitalized Amount	$ 206,083	$ 191,267
Total capital to risk weighted assets, Minimum Amount Required for Adequately Capitalized Ratio ( as a percentage)	8.00%	8.00%
Total capital to risk weighted assets, Minimum Amount To Be Well Capitalized Amount	$ 257,604	$ 239,084
Total capital to risk weighted assets, Minimum Amount To Be Well Capitalized Ratio (as a percentage)	10.00%	10.00%
Tier 1 capital to risk weighted assets:
Tier 1 capital to risk weighted assets, Actual Amount	$ 349,662	$ 313,474
Tier 1 capital to risk weighted assets, Actual Ratio ( as a percentage)	13.57%	13.11%
Tier 1 capital to risk weighted assets, Minimum Amount Required for Adequately Capitalized Amount	$ 154,562	$ 143,450
Tier 1 capital to risk weighted assets, Minimum Amount Required for Adequately Capitalized Ratio ( as a percentage)	6.00%	6.00%
Tier 1 capital to risk weighted assets, Minimum Amount To Be Well Capitalized Amount	$ 206,083	$ 191,267
Tier 1 capital to risk weighted assets, Minimum Amount To Be Well Capitalized Ratio (asa percentage)	8.00%	8.00%
Common Equity Tier 1 (CET1) to risk weighted assets:
Common Equity Tier 1 (CET1) to risk weighted, Actual Amount	$ 349,662	$ 313,474
Common Equity Tier 1 (CET1) to risk weighted, Actual Ratio ( as a percentage)	13.57%	13.11%
Common Equity Tier 1 (CET1) to risk weighted, Minimum Amount Required for Adequately Capitalized Amount	$ 115,922	$ 107,588
Common Equity Tier 1 (CET1) to risk weighted, Minimum Amount Required for Adequately Capitalized Ratio ( as a percentage)	4.50%	4.50%
Common Equity Tier 1 (CET1) to risk weighted, Minimum Amount To Be Well Capitalized Amount	$ 167,442	$ 155,404
Common Equity Tier 1 (CET1) to risk weighted, Minimum Amount To Be Well Capitalized Ratio (as a percentage)	6.50%	6.50%
Tier 1 capital to average assets:
Tier 1 capital to average, Actual Amount	$ 349,662	$ 313,474
Tier 1 capital to average, Actual Ratio ( as a percentage)	10.89%	10.35%
Tier 1 capital to average, Minimum Amount Required for Adequately Capitalized Amount	$ 128,409	$ 121,169
Tier 1 capital to average, Minimum Amount Required for Adequately Capitalized Ratio ( as a percentage)	4.00%	4.00%
Tier 1 capital to average, Minimum Amount To Be Well Capitalized Amount	$ 160,511	$ 151,461
Tier 1 capital to average, Minimum Amount To Be Well Capitalized Ratio ( as a percentage)	5.00%	5.00%

Regulatory Capital Requireme135

Regulatory Capital Requirements - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Bank
Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Proceeds from Dividends Received		$ 0
Bank | Line of Credit Interest and Trust Preferred Securities Interest and Preferred Dividends
Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Proceeds from Dividends Received	$ 2,800,000
Federal Deposit Corporation And Federal Reserve Board | Rules Phased in beginning January 2016
Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Additional capital conservation buffer requirement subsequent years ratio	2.50%
New capital conservation buffer requirement beginning ratio	0.625%
Capital conservation buffer requirement ratio	1.25%

Derivative Instruments and H136

Derivative Instruments and Hedge Activities - Summary of Derivative Financial Instruments and Classification on Consolidated Statements of Financial Condition (Details) - USD ($)	Dec. 31, 2017	Dec. 31, 2016
Derivatives Fair Value [Line Items]
Notional Amount	$ 344,726,000	$ 151,213,000
Other Assets	5,981,000	4,317,000
Other Liabilities	994,000	559,000
Cash Flow Hedges
Derivatives Fair Value [Line Items]
Notional Amount	250,000,000
Other Assets	5,030,000
Other Liabilities	38,000
Other Interest Rate Swaps
Derivatives Fair Value [Line Items]
Notional Amount	94,726,000
Other Assets	951,000
Other Liabilities	956,000
Derivatives Designated as Hedging Instruments | Interest Rate Swaps | Cash Flow Hedges
Derivatives Fair Value [Line Items]
Notional Amount	250,000,000	100,000,000
Other Assets	5,030,000	3,719,000
Other Liabilities	38,000
Derivatives Not Designated As Hedging Instruments | Other Interest Rate Swaps
Derivatives Fair Value [Line Items]
Notional Amount	94,726,000	51,213,000
Other Assets	951,000	598,000
Other Liabilities	$ 956,000	$ 559,000

Derivative Instruments and H137

Derivative Instruments and Hedge Activities - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Derivative [Line Items]
Derivative notional amount	$ 344,726,000	$ 151,213,000
Unrealized gain (loss) to be reclassified as an increase to interest expense during the next twelve months	512,000
Credit valuation adjustment decrease, increase to non-interest income	(44,000)	39,000	$ 0
Cash Flow Hedges
Derivative [Line Items]
Derivative notional amount	250,000,000
Other Interest Rate Swaps
Derivative [Line Items]
Derivative notional amount	$ 94,726,000
Derivative maturity date, start year	Jan. 31, 2020
Derivative maturity date, end year	Nov. 30, 2027
Derivative instruments transaction fees	$ 393,000	679,000	$ 0
Derivatives Designated as Hedging Instruments | Interest Rate Swaps | Cash Flow Hedges
Derivative [Line Items]
Derivative notional amount	250,000,000	100,000,000
Federal Home Loan Bank Advances | Interest Rate Swaps
Derivative [Line Items]
Interest expense on swap transaction	579,000	40,000
Federal Home Loan Bank Advances | Derivatives Designated as Hedging Instruments | Interest Rate Swaps | Cash Flow Hedges
Derivative [Line Items]
Derivative notional amount	$ 250,000,000	$ 100,000,000

Derivative Instruments and H138

Derivative Instruments and Hedge Activities - Summary of Cash Flow Hedges (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Derivative [Line Items]
Notional Amount	$ 344,726,000	$ 151,213,000
Derivative assets fair value	5,981,000	4,317,000
Derivative liabilities fair value	994,000	$ 559,000
Cash Flow Hedges
Derivative [Line Items]
Notional Amount	250,000,000
Derivative assets fair value	5,030,000
Derivative liabilities fair value	$ 38,000
Weighted average pay rates	1.67%
Weighted average receive rates	1.63%
Weighted average maturity	4 years 2 months 12 days

Derivative Instruments and H139

Derivative Instruments and Hedge Activities - Summary of Net Gains (Losses) Recorded in Accumulated Other Comprehensive Income (Loss) and Consolidated Statements of Operations Relating to Cash Flow Derivative Instruments (Details) - Interest Rate Swaps $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)
Derivative [Line Items]
Amount of Gain Recognized in OCI (Effective Portion)	$ 688
Amount of Loss Reclassified from OCI to Income as an Increase to Interest Expense	$ (579)

Derivative Instruments and H140

Derivative Instruments and Hedge Activities - Summary of Other Interest Rate Swaps (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Derivative [Line Items]
Notional Amount	$ 344,726,000	$ 151,213,000
Derivative assets fair value	5,981,000	4,317,000
Derivative liabilities fair value	994,000	$ 559,000
Other Interest Rate Swaps
Derivative [Line Items]
Notional Amount	94,726,000
Derivative assets fair value	951,000
Derivative liabilities fair value	$ 956,000
Weighted average pay rates	4.38%
Weighted average receive rates	3.73%
Weighted average maturity	6 years 3 months 18 days

Derivative Instruments and H141

Derivative Instruments and Hedge Activities - Summary of Company's Interest Rate Derivative and Offsetting Positions (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Derivative Instruments And Hedging Activities Disclosure [Abstract]
Derivative assets fair value	$ 5,981	$ 4,317
Net amount presented in the Consolidated Statements of Financial Condition	5,981
Gross amounts not offset in the Consolidated Statements of Financial Condition
Offsetting derivative positions	(232)
Collateral posted	(5,371)
Net credit exposure	378
Derivative liabilities fair value	994	$ 559
Net amount presented in the Consolidated Statements of Financial Condition	994
Gross amounts not offset in the Consolidated Statements of Financial Condition
Offsetting derivative positions	(232)
Collateral posted	(745)
Net credit exposure	$ 17

Parent Company Only Condense142

Parent Company Only Condensed Financial Statements - Statements of Financial Condition (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
ASSETS
Other assets	$ 16,106	$ 18,367
Total assets	3,366,130	3,295,830
LIABILITIES AND STOCKHOLDERS’ EQUITY
Line of credit		20,650
Junior subordinated debentures issued to capital trusts, net	27,647	26,926
Accrued expenses and other liabilities	42,577	41,811
Stockholders' equity	458,578	382,658	$ 188,274	$ 209,071
Total liabilities and stockholders’ equity	3,366,130	3,295,830
Company
ASSETS
Cash	39,626	9,965
Investment in banking subsidiary	445,786	419,801
Other assets	1,236	2,755
Total assets	486,648	432,521
LIABILITIES AND STOCKHOLDERS’ EQUITY
Line of credit		20,650
Junior subordinated debentures issued to capital trusts, net	27,647	26,926
Accrued expenses and other liabilities	423	2,287
Stockholders' equity	458,578	382,658
Total liabilities and stockholders’ equity	$ 486,648	$ 432,521

Parent Company Only Condense143

Parent Company Only Condensed Financial Statements - Statements of Financial Operations (Details) - USD ($)	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
Other noninterest income									$ 2,201,000	$ 4,927,000	$ 2,720,000
EXPENSES
Interest expense	$ 3,805,000	$ 3,632,000	$ 3,504,000	$ 2,950,000	$ 2,524,000	$ 1,792,000	$ 1,674,000	$ 1,757,000	13,891,000	7,747,000	6,631,000
Other non-interest expense									8,852,000	8,120,000	9,456,000
Provision (benefit) for income taxes	11,851,000	(1,390,000)	4,094,000	4,544,000	(61,023,000)	9,000	9,000	(240,000)	19,099,000	(61,245,000)	307,000
NET INCOME (LOSS)	$ (766,000)	$ 9,755,000	$ 6,146,000	$ 6,560,000	$ 63,915,000	$ 1,565,000	$ 2,601,000	$ (1,352,000)	21,695,000	66,729,000	(14,974,000)
Company
INCOME
Dividends from subsidiary									2,800,000
Other noninterest income									9,000	57,000
Total Income									2,809,000	57,000
EXPENSES
Interest expense									2,782,000	2,460,000	2,295,000
Other non-interest expense									1,804,000	381,000	312,000
Total Expenses									4,586,000	2,841,000	2,607,000
Loss before provision for income taxes and equity in undistributed income (loss) of subsidiary									(1,777,000)	(2,784,000)	(2,607,000)
Provision (benefit) for income taxes									(1,166,000)	204,000	8,000
Loss before equity in undistributed income (loss) of subsidiary									(611,000)	(2,988,000)	(2,615,000)
Equity in undistributed income (loss) of subsidiary									22,306,000	69,717,000	(12,359,000)
NET INCOME (LOSS)									$ 21,695,000	$ 66,729,000	$ (14,974,000)

Parent Company Only Condense144

Parent Company Only Condensed Financial Statements - Statements of Financial Cash Flow (Details) - USD ($)	Jul. 06, 2017	Jul. 31, 2017	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
CASH FLOWS FROM OPERATING ACTIVITIES
Net income (loss)			$ (766,000)	$ 9,755,000	$ 6,146,000	$ 6,560,000	$ 63,915,000	$ 1,565,000	$ 2,601,000	$ (1,352,000)	$ 21,695,000	$ 66,729,000	$ (14,974,000)
Adjustments to reconcile net income (loss) to net cash from operating activities:
Share-based compensation expense											1,497,000	899,000	1,045,000
Exercise of share-based awards												40,000
Accretion of junior subordinated debentures discount											721,000	876,000	944,000
CASH FLOWS FROM INVESTING ACTIVITIES
Net cash paid in acquisition of business												(11,273,000)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from revolving line of credit												30,000,000
Repayments of revolving line of credit		$ (16,200,000)									(20,650,000)	(9,350,000)
Dividends paid on preferred stock											(11,277,000)
Cash paid in lieu of fractional shares											(2,000)
Proceeds from issuance of common stock, net	$ 82,700,000										76,829,000	49,592,000
Proceeds from issuance of preferred stock											1,050,000	9,388,000
Repurchase of preferred stock											(15,003,000)
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS											11,816,000	1,649,000	(111,769,000)
CASH AND CASH EQUIVALENTS, beginning of period						46,533,000				44,884,000	46,533,000	44,884,000	156,653,000
CASH AND CASH EQUIVALENTS, end of period			58,349,000				46,533,000				58,349,000	46,533,000	44,884,000
Company
CASH FLOWS FROM OPERATING ACTIVITIES
Net income (loss)											21,695,000	66,729,000	(14,974,000)
Adjustments to reconcile net income (loss) to net cash from operating activities:
Equity in undistributed income (loss) of subsidiary											(22,306,000)	(69,717,000)	12,359,000
Share-based compensation expense											1,497,000	899,000	1,045,000
Exercise of share-based awards												40,000
Accretion of junior subordinated debentures discount											721,000	876,000	944,000
Changes in other assets and other liabilities											(2,893,000)	16,000	(5,546,000)
Net cash used in operating activities											(1,286,000)	(1,157,000)	(6,172,000)
CASH FLOWS FROM INVESTING ACTIVITIES
Investments in and advances from subsidiary												(32,019,000)
Net cash paid in acquisition of business												(36,586,000)
Net cash used in investing activities												(68,605,000)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from revolving line of credit												30,000,000
Repayments of revolving line of credit											(20,650,000)	(9,350,000)
Dividends paid on preferred stock											(11,277,000)
Cash paid in lieu of fractional shares											(2,000)
Proceeds from issuance of common stock, net											76,829,000	49,592,000
Proceeds from issuance of preferred stock											1,050,000	9,388,000
Repurchase of preferred stock											(15,003,000)
Net cash provided by financing activities											30,947,000	79,630,000
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS											29,661,000	9,868,000	(6,172,000)
CASH AND CASH EQUIVALENTS, beginning of period						$ 9,965,000				$ 97,000	9,965,000	97,000	6,269,000
CASH AND CASH EQUIVALENTS, end of period			$ 39,626,000				$ 9,965,000				$ 39,626,000	$ 9,965,000	$ 97,000

Earnings per Share - Additional

Earnings per Share - Additional Information (Details) - shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Earnings Per Share Basic [Line Items]
Shares outstanding	26,963,517	20,141,630	17,332,775
Stock Options
Earnings Per Share Basic [Line Items]
Shares outstanding	1,783,023	1,783,023
Restricted Stock Award
Earnings Per Share Basic [Line Items]
Shares outstanding	70,798	0	0

Earnings per Share - Schedule o

Earnings per Share - Schedule of Calculation of Basic and Diluted Earnings per Share (Details) - USD ($)	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]
Net income (loss)	$ (766,000)	$ 9,755,000	$ 6,146,000	$ 6,560,000	$ 63,915,000	$ 1,565,000	$ 2,601,000	$ (1,352,000)	$ 21,695,000	$ 66,729,000	$ (14,974,000)
Dividends on preferred shares	196,000	195,000	10,697,000	189,000					11,277,000
Net income (loss) available to common stockholders	$ (962,000)	$ 9,560,000	$ (4,551,000)	$ 6,371,000	$ 63,915,000	$ 1,565,000	$ 2,601,000	$ (1,352,000)	$ 10,418,000	$ 66,729,000	$ (14,974,000)
Weighted-average common stock outstanding:
Weighted-average common stock outstanding (basic)									26,963,517	20,141,630	17,332,775
Incremental shares									583,797	289,153
Weighted-average common stock outstanding (dilutive)									27,547,314	20,430,783	17,332,775
Basic earnings per common share	$ (0.03)	$ 0.33	$ (0.18)	$ 0.26	$ 2.66	$ 0.08	$ 0.13	$ (0.08)	$ 0.39	$ 3.31	$ (0.86)
Diluted earnings per common share	$ (0.03)	$ 0.32	$ (0.18)	$ 0.25	$ 2.62	$ 0.08	$ 0.13	$ (0.08)	$ 0.38	$ 3.27	$ (0.86)

Stockholders' Equity - Summary

Stockholders' Equity - Summary of Preferred and Common Stock (Details) - $ / shares	Dec. 31, 2017	Jun. 30, 2017	Dec. 31, 2016
Class Of Stock [Line Items]
Common stock, voting par value	$ 0.01	$ 0.01
Common stock, voting shares authorized	150,000,000		150,000,000
Common stock, voting shares issued	29,317,298		24,616,706
Common stock, voting shares outstanding	29,317,298		24,616,706
Series A Non-cumulative Perpetual Preferred Stock
Class Of Stock [Line Items]
Par value			$ 0.01
Shares authorized			15,003
Shares issued			15,003
Shares outstanding			15,003
Series B 7.5% Fixed Non-Cumulative Perpetual Preferred Stock
Class Of Stock [Line Items]
Par value	$ 0.01		$ 0.01
Shares authorized	50,000		50,000
Shares issued	10,438		9,388
Subscription receivable			1,050
Shares outstanding	10,438		9,388

Stockholders' Equity - Summa148

Stockholders' Equity - Summary of Preferred and Common Stock (Parenthetical) (Details)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Series B 7.5% Fixed Non-Cumulative Perpetual Preferred Stock
Class Of Stock [Line Items]
Preferred stock, dividend rate, percentage	7.50%	7.50%

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Details)	Jul. 14, 2017USD ($)	Jul. 06, 2017USD ($)	Jun. 16, 2017$ / sharesshares	Jun. 14, 2017shares	Jun. 30, 2017$ / sharesshares	Dec. 31, 2017USD ($)$ / sharesshares	Dec. 31, 2016USD ($)$ / sharesshares	Jan. 30, 2017shares
Class Of Stock [Line Items]
Dividends declared and paid						$ 11,277,000
Common stock, par value | $ / shares					$ 0.01	$ 0.01
Proceeds from issuance of common stock		$ 82,700,000				$ 76,829,000	$ 49,592,000
Merger transaction, the number of shares into which each share of common stock issued and outstanding prior to merger was converted				0.20
Merger transaction, number of fractional shares issued | shares				0
Repurchase of shares						$ 15,003,000
Common Stock
Class Of Stock [Line Items]
Issuance of common stock, net of issuance cost, shares | shares					4,630,194	4,630,194	3,078,075
Issuance of common stock, price per share | $ / shares			$ 19
Under Writer | Common Stock
Class Of Stock [Line Items]
Issuance of common stock, net of issuance cost, shares | shares					855,000
Issuance of common stock, price per share | $ / shares					$ 19
Series B Preferred Stock
Class Of Stock [Line Items]
Preferred stock, dividend rate, percentage							7.50%
Preferred stock, liquidation preference per share | $ / shares							$ 1,000
Preferred stock, shares issued | shares								1,050
Dividends declared and paid						$ 776,000
Series A Preferred Stock
Class Of Stock [Line Items]
Preferred stock, liquidation preference per share | $ / shares			$ 1,000
Shares of common stock used to determine cash value of repurchase | shares			89.469
Repurchase of shares	$ 25,500,000
Dividends Payable						$ 10,500,000

Selected Quarterly Financial150

Selected Quarterly Financial Data (unaudited) - Schedule of Selected Quarterly Financial Data (unaudited) (Details) - USD ($)	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 and Dividend Income	$ 35,956,000	$ 35,044,000	$ 33,315,000	$ 32,488,000	$ 30,776,000	$ 22,657,000	$ 22,055,000	$ 22,877,000	$ 136,803,000	$ 98,365,000	$ 83,263,000
Interest expense	3,805,000	3,632,000	3,504,000	2,950,000	2,524,000	1,792,000	1,674,000	1,757,000	13,891,000	7,747,000	6,631,000
Net interest income	32,151,000	31,412,000	29,811,000	29,538,000	28,252,000	20,865,000	20,381,000	21,120,000	122,912,000	90,618,000	76,632,000
PROVISION FOR LOAN AND LEASE LOSSES	3,347,000	3,900,000	3,515,000	1,891,000	5,004,000	1,683,000	1,152,000	2,513,000	12,653,000	10,352,000	6,966,000
Net interest income after provision for loan and lease losses	28,804,000	27,512,000	26,296,000	27,647,000	23,248,000	19,182,000	19,229,000	18,607,000	110,259,000	80,266,000	69,666,000
Non-interest income	12,639,000	11,918,000	13,193,000	12,308,000	10,642,000	4,776,000	6,198,000	4,288,000	50,058,000	25,904,000	20,839,000
Non-interest expense	30,358,000	31,065,000	29,249,000	28,851,000	30,998,000	22,384,000	22,817,000	24,487,000	119,523,000	100,686,000	105,172,000
Income before provision for income taxes	11,085,000	8,365,000	10,240,000	11,104,000	2,892,000	1,574,000	2,610,000	(1,592,000)	40,794,000	5,484,000	(14,667,000)
PROVISION (BENEFIT) FOR INCOME TAXES	11,851,000	(1,390,000)	4,094,000	4,544,000	(61,023,000)	9,000	9,000	(240,000)	19,099,000	(61,245,000)	307,000
Net income (loss)	(766,000)	9,755,000	6,146,000	6,560,000	63,915,000	1,565,000	2,601,000	(1,352,000)	21,695,000	66,729,000	(14,974,000)
Dividends on preferred shares	196,000	195,000	10,697,000	189,000					11,277,000
Income (loss) available (attributable) to common stockholders	$ (962,000)	$ 9,560,000	$ (4,551,000)	$ 6,371,000	$ 63,915,000	$ 1,565,000	$ 2,601,000	$ (1,352,000)	$ 10,418,000	$ 66,729,000	$ (14,974,000)
Basic	$ (0.03)	$ 0.33	$ (0.18)	$ 0.26	$ 2.66	$ 0.08	$ 0.13	$ (0.08)	$ 0.39	$ 3.31	$ (0.86)
Diluted	$ (0.03)	$ 0.32	$ (0.18)	$ 0.25	$ 2.62	$ 0.08	$ 0.13	$ (0.08)	$ 0.38	$ 3.27	$ (0.86)

Selected Quarterly Financial151

Selected Quarterly Financial Data (unaudited) - Additional Information (Details) - USD ($)	3 Months Ended								6 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	Jun. 30, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Quarterly Financial Information Disclosure [Line Items]
Net income (loss)	$ (766,000)	$ 9,755,000	$ 6,146,000	$ 6,560,000	$ 63,915,000	$ 1,565,000	$ 2,601,000	$ (1,352,000)			$ 21,695,000	$ 66,729,000	$ (14,974,000)
Basic earnings per common share	$ (0.03)	$ 0.33	$ (0.18)	$ 0.26	$ 2.66	$ 0.08	$ 0.13	$ (0.08)			$ 0.39	$ 3.31	$ (0.86)
Net interest income before provision for loan losses	$ 32,151,000	$ 31,412,000	$ 29,811,000	$ 29,538,000	$ 28,252,000	$ 20,865,000	$ 20,381,000	$ 21,120,000			$ 122,912,000	$ 90,618,000	$ 76,632,000
Incremntal tax expense from enactment of Tax Cuts and Jobs Act of 2017	7,200,000										$ 7,200,000
Corporate federal income tax rate											35.00%	35.00%	35.00%
Income tax expense (benefit)	$ (11,851,000)	$ 1,390,000	(4,094,000)	$ (4,544,000)	61,023,000	$ (9,000)	$ (9,000)	$ 240,000			$ (19,099,000)	$ 61,245,000	$ (307,000)
Deferred tax assets net of valuation allowance					$ 61,900,000							$ 61,900,000
Scenario, Plan
Quarterly Financial Information Disclosure [Line Items]
Corporate federal income tax rate										21.00%
Illinois | State
Quarterly Financial Information Disclosure [Line Items]
Corporate income tax rate		7.00%							5.25%
State income tax benefit due to increased value of deferred tax asset related to net loss deduction		$ 4,600,000
IPO | Series A Preferred Stock
Quarterly Financial Information Disclosure [Line Items]
Dividends in arrears			$ 10,500,000