Barrett Business Services (BBSI) 10-K 7 Mar 22 2021 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2021	Feb. 21, 2022	Jun. 30, 2021
Cover [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2021
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	FY
Trading Symbol	BBSI
Entity Registrant Name	BARRETT BUSINESS SERVICES, INC.
Entity Central Index Key	0000902791
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Accelerated Filer
Entity Shell Company	false
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Entity Common Stock, Shares Outstanding		7,422,523
Entity Public Float			$ 534,958,957
Entity Interactive Data Current	Yes
Title of 12(b) Security	Common Stock, Par Value $0.01 Per Share
Security Exchange Name	NASDAQ
Entity Incorporation, State or Country Code	MD
Entity File Number	0-21886
Document Annual Report	true
Document Transition Report	false
Entity Tax Identification Number	52-0812977
Entity Address, Address Line One	8100 NE Parkway Drive
Entity Address, Address Line Two	Suite 200
Entity Address, City or Town	Vancouver
Entity Address, State or Province	WA
Entity Address, Postal Zip Code	98662
City Area Code	360
Local Phone Number	828-0700
Auditor Name	Deloitte & Touche LLP
Auditor Location	Portland, Oregon
Auditor Firm ID	34
Documents Incorporated by Reference	DOCUMENTS INCORPORATED BY REFERENCE Portions of the definitive Proxy Statement for the 2022 Annual Meeting of Stockholders are hereby incorporated by reference in Part III of Form 10-K.

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 69,405	$ 68,688
Investments	96,763	101,244
Trade accounts receivable, net	155,707	118,506
Income taxes receivable		6,485
Prepaid expenses and other	17,606	15,961
Restricted cash and investments	67,238	96,991
Total current assets	406,719	407,875
Property, equipment and software, net	36,277	34,916
Operating lease right-of-use assets	20,697	23,025
Restricted cash and investments	232,965	258,153
Goodwill	47,820	47,820
Other assets	2,474	3,161
Total assets	746,952	774,950
Current liabilities:
Current portion of long-term debt	3,510	221
Accounts payable	4,485	4,746
Accrued payroll, payroll taxes and related benefits	199,067	149,989
Income taxes payable	1,673
Current operating lease liabilities	7,191	7,539
Other accrued liabilities	15,120	7,275
Workers' compensation claims liabilities	80,028	102,040
Safety incentives liability	4,322	18,827
Total current liabilities	315,396	290,637
Long-term workers' compensation claims liabilities	199,379	255,706
Long-term debt		3,510
Deferred income taxes	1,687	4,518
Long-term operating lease liabilities	14,598	16,419
Customer deposits and other long-term liabilities	7,362	5,925
Total liabilities	538,422	576,715
Commitments and contingencies (Notes 6, 8 and 12)
Stockholders' equity:
Common stock, $.01 par value; 20,500 shares authorized, 7,415 and 7,566 shares issued and outstanding in 2021 and 2020, respectively	74	76
Additional paid-in capital	29,054	24,885
Accumulated other comprehensive income	1,079	7,564
Retained earnings	178,323	165,710
Total stockholders' equity	208,530	198,235
Total liabilities and stockholders' equity	$ 746,952	$ 774,950

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2021	Dec. 31, 2020
Statement Of Financial Position [Abstract]
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	20,500,000	20,500,000
Common stock, shares issued	7,415,000	7,566,000
Common stock, shares outstanding	7,415,000	7,566,000

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Revenues:
Total revenues	$ 955,166	$ 880,824	$ 942,311
Cost of revenues:
Total cost of revenues	750,658	697,917	734,058
Gross margin	204,508	182,907	208,253
Selling, general and administrative expenses	155,259	141,916	153,879
Depreciation and amortization	5,326	4,844	3,886
Income from operations	43,923	36,147	50,488
Other income (expense):
Investment income, net	7,215	7,977	12,520
Interest expense	(372)	(1,244)	(1,789)
Other, net	(105)	(284)	(81)
Other income, net	6,738	6,449	10,650
Income before income taxes	50,661	42,596	61,138
Provision for income taxes	12,582	8,831	12,846
Net income	$ 38,079	$ 33,765	$ 48,292
Basic income per common share	$ 5.05	$ 4.46	$ 6.48
Weighted average number of basic common shares outstanding	7,540	7,577	7,451
Diluted income per common share	$ 5	$ 4.39	$ 6.27
Weighted average number of diluted common shares outstanding	7,621	7,688	7,699
Professional Employer Service Fees [Member]
Revenues:
Total revenues	$ 843,815	$ 777,430	$ 819,873
Staffing Services [Member]
Revenues:
Total revenues	111,351	103,394	122,438
Direct Payroll Costs [Member]
Cost of revenues:
Total cost of revenues	83,821	78,380	92,455
Payroll Taxes and Benefits [Member]
Cost of revenues:
Total cost of revenues	469,888	418,793	429,713
Workers' Compensation [Member]
Cost of revenues:
Total cost of revenues	$ 196,949	$ 200,744	$ 211,890

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 38,079	$ 33,765	$ 48,292
Unrealized (losses) gains on investments, net of tax of ($2,478), $1,814, and $3,014 in 2021, 2020, and 2019, respectively	(6,485)	4,745	7,887
Comprehensive income	$ 31,594	$ 38,510	$ 56,179

Consolidated Statements of Co_2

Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Statement Of Income And Comprehensive Income [Abstract]
Unrealized gains (losses) on investments, tax	$ (2,478)	$ 1,814	$ 3,014

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Other Comprehensive (Loss) Income [Member]	Retained Earnings [Member]
Beginning Balance at Dec. 31, 2018	$ 119,037	$ 74	$ 15,437	$ (5,068)	$ 108,594
Beginning Balance, shares at Dec. 31, 2018		7,395
Common stock issued on exercise of options and vesting of restricted stock units	754	$ 1	753
Common stock issued on exercise of options and vesting of restricted stock units, shares		157
Common stock repurchased on vesting of restricted stock units/stock awards	(3,136)		(3,136)
Common stock repurchased on vesting of restricted stock units/stock awards, shares		(38)
Share-based compensation expense	7,173		7,173
Cash dividends on common stock	(8,208)				(8,208)
Unrealized gain (loss) on investments, net of tax	7,887			7,887
Net income	48,292				48,292
Ending Balance at Dec. 31, 2019	171,799	$ 75	20,227	2,819	148,678
Ending Balance, shares at Dec. 31, 2019		7,514
Common stock issued on exercise of options and vesting of restricted stock units	3,084	$ 2	3,082
Common stock issued on exercise of options and vesting of restricted stock units, shares		223
Common stock repurchased on vesting of restricted stock units/stock awards	(1,417)		(1,417)
Common stock repurchased on vesting of restricted stock units/stock awards, shares		(27)
Share-based compensation expense	3,436		3,436
Company repurchase of common stock	(8,056)	$ (1)	(443)		(7,612)
Company repurchase of common stock, shares		(144)
Cash dividends on common stock	(9,121)				(9,121)
Unrealized gain (loss) on investments, net of tax	4,745			4,745
Net income	33,765				33,765
Ending Balance at Dec. 31, 2020	198,235	$ 76	24,885	7,564	165,710
Ending Balance, shares at Dec. 31, 2020		7,566
Common stock issued on exercise of options and vesting of restricted stock units	1,156	$ 1	1,155
Common stock issued on exercise of options and vesting of restricted stock units, shares		106
Common stock repurchased on vesting of restricted stock units/stock awards	(1,465)		(1,465)
Common stock repurchased on vesting of restricted stock units/stock awards, shares		(20)
Share-based compensation expense	5,366		5,366
Company repurchase of common stock	(17,287)	$ (3)	(887)		(16,397)
Company repurchase of common stock, shares		(237)
Cash dividends on common stock	(9,069)				(9,069)
Unrealized gain (loss) on investments, net of tax	(6,485)			(6,485)
Net income	38,079				38,079
Ending Balance at Dec. 31, 2021	$ 208,530	$ 74	$ 29,054	$ 1,079	$ 178,323
Ending Balance, shares at Dec. 31, 2021		7,415

Consolidated Statements of St_2

Consolidated Statements of Stockholders' Equity (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Statement Of Stockholders Equity [Abstract]
Cash dividends on common stock per share	$ 1.10	$ 1.10	$ 1.10

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Cash flows from operating activities:
Net income	$ 38,079	$ 33,765	$ 48,292
Reconciliations of net income to net cash (used in) provided by operating activities:
Depreciation and amortization	5,326	4,844	3,886
Non-cash operating lease expense	8,045	7,246	6,991
Investment amortization and losses recognized	1,433	587	1,117
Loss recognized on disposal of property and equipment	114	574
Deferred income taxes	(347)	5,492	2,656
Share-based compensation	5,366	3,436	7,173
Changes in certain operating assets and liabilities:
Trade accounts receivable	(37,201)	45,055	(11,964)
Income taxes	8,158	(5,150)	(5,738)
Prepaid expenses and other	(1,645)	(1,042)	(1,039)
Accounts payable	(261)	(1,247)	1,657
Accrued payroll, payroll taxes and related benefits	49,739	(22,608)	17,858
Other accrued liabilities	7,753	(1,671)	(11,720)
Workers' compensation claims liabilities	(77,640)	(80,783)	25,477
Safety incentives liability	(14,505)	(9,123)	(1,260)
Operating lease liabilities	(7,886)	(7,062)	(6,242)
Other assets and liabilities, net	13	(228)	(7)
Net cash (used in) provided by operating activities	(15,459)	(27,915)	77,137
Cash flows from investing activities:
Purchase of property, equipment and software	(6,801)	(8,610)	(10,798)
Purchase of investments	(54,835)	(65,738)	(54,343)
Proceeds from sales and maturities of investments	75,256	47,922	88,771
Purchase of restricted investments	(253,781)	(34,968)	(9,812)
Proceeds from sales and maturities of restricted investments	127,298	65,535	52,495
Net cash (used in) provided by investing activities	(112,863)	4,141	66,313
Cash flows from financing activities:
Proceeds from credit-line borrowings	2,718		18,843
Payments on credit-line borrowings	(2,718)		(18,843)
Payments on long-term debt	(221)	(220)	(221)
Repurchase of common stock	(17,287)	(8,056)
Common stock repurchased on vesting of stock awards	(1,465)	(1,417)	(3,136)
Dividends paid	(9,069)	(9,121)	(8,208)
Proceeds from exercise of stock options	1,156	3,084	754
Net cash used in financing activities	(26,886)	(15,730)	(10,811)
Net (decrease) increase in cash, cash equivalents and restricted cash	(155,208)	(39,504)	132,639
Cash, cash equivalents and restricted cash, beginning of period	233,837	273,341	140,702
Cash, cash equivalents and restricted cash, end of period	$ 78,629	$ 233,837	$ 273,341

Summary of Operations and Signi

Summary of Operations and Significant Accounting Policies	12 Months Ended
	Dec. 31, 2021
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Summary of Operations and Significant Accounting Policies	Note 1 - Summary of Operations and Significant Accounting Policies Nature of operations Barrett Business Services, Inc. (“BBSI” or the “Company”), is a leading provider of business management solutions for small and mid-sized companies. The Company has developed a management platform that integrates a knowledge-based approach from the management consulting industry with tools from the human resource outsourcing industry. This platform, through the effective leveraging of human capital, helps our business owner clients run their businesses more effectively. We believe this platform, delivered through our decentralized organizational structure, differentiates BBSI from our competitors. The Company operates through a network of 50 branch offices throughout Arizona, California, Colorado, Delaware, Idaho, Maryland, Nevada, New Mexico, North Carolina, Oregon, Pennsylvania, Tennessee, Utah, Virginia and Washington. Approximately 73%, 75% and 77%, respectively, of our revenue during 2021, 2020, and 2019 was attributable to our California operations. BBSI was incorporated in Maryland in 1965. The Company operates a wholly owned, fully licensed captive insurance company, Associated Insurance Company for Excess ("AICE") and a wholly owned, fully licensed insurance company, Ecole. AICE and Ecole provide access to more competitive and cost-effective insurance markets and provide cost-effective risk management. See “Note 5 – Workers’ Compensation Claims” for additional information in the Company’s insurance programs. Principles of consolidation The accompanying financial statements are prepared on a consolidated basis. All intercompany account balances and transactions between BBSI, AICE, and Ecole have been eliminated in consolidation. Reportable segment The Company has one operating and reporting segment. The chief operating decision maker (our Chief Executive Officer) regularly reviews the financial information of our business at a consolidated level in deciding how to allocate resources and in assessing performance. Revenue recognition Professional employer (“PEO”) services are normally used by organizations to satisfy ongoing needs related to the management of human capital and are governed by the terms of a client services agreement which covers all employees at a particular work site. Staffing revenues relate primarily to short-term staffing, contract staffing and on-site management services. The Company’s performance obligations for PEO and staffing services are satisfied, and the related revenue is recognized, as services are rendered by our workforce. Our PEO client service agreements have a minimum term of one year, are renewable on an annual basis and typically require 30 days’ written notice to cancel or terminate the contract by either party. In addition, our client service agreements provide for immediate termination upon any payment default of the client regardless of when notice is given. PEO customers are invoiced following the end of each payroll processing cycle, with payment generally due on the invoice date. Staffing customers are generally invoiced weekly based on agreed rates per employee and actual hours worked, typically with payment terms of 30 days. The amount of earned but unbilled revenue is classified as a receivable on the consolidated balance sheets. We report PEO revenues net of direct payroll costs because we are not the primary obligor for these payments to our clients’ employees. afety incentives, because these incentives represent consideration payable to customers Cost of revenues Our cost of revenues for PEO services includes employer payroll-related taxes and workers' compensation costs. Our cost of revenues for staffing services includes direct payroll costs, employer payroll-related taxes, employee benefits, and workers’ compensation costs. Direct payroll costs represent the gross payroll earned by staffing services employees based on salary or hourly wages. Payroll taxes and employee benefits consist of the employer's portion of Social Security and Medicare taxes, federal and state unemployment taxes, and staffing services employee reimbursements for materials, supplies and other expenses, which are paid by our customer. Workers' compensation costs consist primarily of premiums paid to third-party insurers, claims reserves, claims administration fees, legal fees, medical cost containment (“MCC”) expense, state administrative agency fees, third-party broker commissions, risk manager payroll, as well as costs associated with operating our two wholly owned insurance companies, AICE and Ecole. Cash and cash equivalents We consider non-restricted short-term investments that are highly liquid, readily convertible into cash, and have maturities at acquisition of less than three months to be cash equivalents for purposes of the consolidated statements of cash flows and consolidated balance sheets. The Company maintains cash balances in bank accounts that normally exceed FDIC insured limits. The Company has not experienced any losses related to its cash concentration. Investments The Company classifies investments as available-for-sale. The Company’s investments are reported at fair value with unrealized gains and losses, net of taxes, shown as a component of accumulated other comprehensive income (loss) in stockholders' equity. Investments are recorded as current on the consolidated balance sheets as the invested funds are available for current operations. Management considers available evidence in evaluating potential impairment of investments, including the extent to which fair value is less than cost and adverse conditions related to the security. In the event of a credit loss, an allowance would be recognized to the extent that the fair value of the security is less than the present value of the expected future cash flows. Realized gains and losses on sales of investments are included in investment income in our consolidated statements of operations. Restricted cash and investments The Company holds restricted cash and investments primarily for the future payment of workers’ compensation claims. These investments are categorized as available-for-sale. They are reported at fair value with unrealized gains and losses, net of taxes, shown as a component of accumulated other comprehensive income (loss) in stockholders’ equity. Restricted cash and investments are classified as current and noncurrent on the consolidated balance sheets based on the nature of the restriction. Management considers available evidence in evaluating potential impairment of restricted investments, including the extent to which fair value is less than cost and adverse conditions related to the security. In the event of a credit loss, an allowance would be recognized to the extent that the fair value of the security is less than the present value of the expected future cash flows. Realized gains and losses on sales of restricted investments are included in investment income in our consolidated statements of operations. Restricted cash and investments also includes investments held as part of the Company’s deferred compensation plan. These investments are classified as trading securities and are recorded at fair value with unrealized gains and losses reported as a component of income (loss) from operations. Allowance for doubtful accounts The Company had an allowance for doubtful accounts of $460,000 and $757,000 at December 31, 2021 and 2020, respectively. We make estimates of the collectability of our accounts receivable for services provided to our customers based on future expected credit losses. Management analyzes historical bad debts, customer concentrations, customer credit-worthiness, current economic trends and changes in customers' payment trends when evaluating the adequacy of the allowance for doubtful accounts. If the financial condition of our customers deteriorates resulting in an impairment of their ability to make payments, additional allowances may be required. Our allowance for doubtful accounts activity is summarized as follows (in thousands): 2021 2020 2019 Balance at January 1, Allowance for doubtful accounts $ 757 $ 888 $ 533 Charges to expense 193 125 459 Write-offs of uncollectible accounts, net of recoveries (490 ) (256 ) (104 ) Balance at December 31, Allowance for doubtful accounts $ 460 $ 757 $ 888 Income taxes Our income taxes are accounted for using an asset and liability approach. This requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of temporary differences between the financial statement and tax basis of assets and liabilities at the applicable tax rates. A valuation allowance is recorded against deferred tax assets if, based on the weight of the available evidence, it is more likely than not that some or all of the deferred tax assets will not be realized. The factors used to assess the likelihood of realization include the Company’s forecast of the reversal of temporary differences, future taxable income and available tax planning strategies that could be implemented to realize the net deferred tax assets. Failure to achieve forecasted taxable income in applicable tax jurisdictions could affect the ultimate realization of deferred tax assets and could result in an increase in the Company’s effective tax rate on future earnings. The determination of our provision for income taxes requires significant judgment, the use of estimates, and the interpretation and application of complex tax laws. Significant judgment is required in assessing the timing and amounts of deductible and taxable items and the probability of sustaining uncertain tax positions. The Company recognizes the tax benefit from uncertain tax positions if it is more likely than not that the tax positions will be sustained on examination by the tax authorities. The tax benefit is measured based on the largest benefit that has a greater than 50% likelihood of being realized upon ultimate settlement. As facts and circumstances change, we reassess these probabilities and record any changes in the consolidated financial statements as appropriate. The Company recognizes interest and penalties related to unrecognized tax benefits in income tax expense. Goodwill and intangible assets Goodwill is recorded as the difference, if any, between the aggregate consideration paid for a business combination and the fair value of the net assets acquired. Goodwill is not amortized but is evaluated for impairment annually, or more frequently if circumstances indicate that it is more likely than not that the fair value of the reporting unit is below its carrying value. The Company has one reporting unit and evaluates the carrying value of goodwill annually at December 31. No impairment has been recognized in the periods presented. Property, equipment and software Property, equipment and software are stated at cost. Expenditures for maintenance and repairs are charged to selling, general and administrative expenses as incurred and expenditures for additions and improvements to property and equipment are capitalized. The cost of assets sold or otherwise disposed of and the related accumulated depreciation are eliminated from the accounts, and any resulting gain or loss is reflected in the consolidated statements of operations. We capitalize software development costs incurred during the application development stage, which is the stage when preliminary project planning ends and software development begins. Capitalized costs generally include both internal and external costs associated with coding and testing. Capitalized costs are amortized on a straight-line basis over the estimated useful life, commencing when the software is placed into service. Costs incurred during the preliminary project stage and the postimplementation stage, as well as general and administrative and overhead costs, are expensed as they are incurred. Depreciation of property and equipment and amortization of software is calculated using the straight-line method over estimated useful lives of the related assets or lease terms, as follows: Years Buildings 39 Office furniture and fixtures 7 Computer hardware, software and software development costs 3 - 10 Leasehold improvements 1 - 7 Impairment of long-lived assets Long-lived assets, such as property, equipment and software and acquired intangibles subject to amortization, are reviewed for impairment annually, or whenever events or changes in circumstances indicate that the remaining estimated useful life may warrant revision or that the carrying amount of an asset may not be recoverable. Some of the events or changes in circumstances that would trigger an impairment review include, but are not limited to, significant under-performance relative to expected and/or historical results, significant negative industry or economic trends, or knowledge of transactions involving the sale of similar property at amounts below the carrying value. Assets are grouped for measurement of impairment at the lowest level for which identifiable cash flows are largely independent of the cash flows of other assets. If the carrying amount of an asset group exceeds the estimated undiscounted future cash flows expected to be generated by the asset group, then an impairment charge is recognized to the extent the carrying amount exceeds the asset group’s fair value. In determining fair value, management considers current results, trends, future prospects, and other economic factors. Leases The Company leases office facilities and equipment under operating leases. In February 2016, the Financial Accounting Standards Board (“FASB”) issued ASU No. 2016-02, “Leases” (Topic 842) which requires lessees to recognize a right-of-use (“ROU”) asset and a lease liability for all leases with terms greater than 12 months and also requires disclosures by lessees and lessors about the amount, timing and uncertainty of cash flows arising from leases. We determine whether an arrangement is or contains a lease at inception. We record our operating lease liabilities and right-of-use (ROU) assets at the lease commencement date. Operating lease liabilities are based on the present value of future minimum lease payments over the lease term, and include options to renew a lease in the future minimum lease payments if it is reasonably certain that the Company will exercise that option. ROU assets are based on the lease liability, adjusted for any lease prepayments and lease incentives. If a lease does not provide an implicit interest rate, we use our incremental borrowing rate on a collateralized basis from the information available at commencement date in determining the present value of lease payments. Leases with initial terms of 12 months or less are considered short-term lease costs and are not recorded as ROU assets on the consolidated balance sheets. ROU assets are reviewed for impairment in the same manner as long-lived assets. No impairment has been recorded in the periods presented. The Company has elected the practical expedient not to separate non-lease components from lease components for all classes of assets. Our lease agreements contain $3.7 million of residual value guarantees and generally do not contain material variable lease payments or restrictive covenants. Workers’ compensation claims liabilities Our workers’ compensation claims liabilities do not represent an exact calculation of liability but rather management’s best estimate, utilizing actuarial expertise and projection techniques, at a given reporting date. The estimated liability for open workers’ compensation claims is based on an evaluation of information provided by our third-party administrator for workers’ compensation claims, coupled with an actuarial estimate of future loss development with respect to reported claims and incurred but not reported claims (together, “IBNR”). Workers’ compensation claims liabilities include case reserve estimates for reported losses, plus additional amounts for estimated IBNR claims, MCC and legal costs, unallocated loss adjustment expenses and estimated future recoveries. The estimate of incurred costs expected to be paid within one year is included in current liabilities, while the estimate of incurred costs expected to be paid beyond one year is included in long-term liabilities on our consolidated balance sheets. These estimates are reviewed at least quarterly and adjustments to estimated liabilities are reflected in current operating results as they become known. The process of arriving at an estimate of unpaid claims and claims adjustment expense involves a high degree of judgment and is affected by both internal and external events, including changes in claims handling practices, changes in reserve estimation procedures , inflation, trends in the litigation and settlement of pending claims, and legislative changes. Our estimates are based on actuarial analysis and informed judgment, derived from individual experience and expertise applied to multiple sets of data and analyses. We consider significant facts and circumstances known both at the time that loss reserves are initially established and as new facts and circumstances become known. Due to the inherent uncertainty underlying loss reserve estimates, the expenses incurred through final resolution of our liability for our workers’ compensation claims will likely vary from the related loss reserves at the reporting date. Therefore, as specific claims are paid out in the future, actual paid losses may be materially different from our current loss reserves. A basic premise in most actuarial analyses is that historical data and past patterns demonstrated in the incurred and paid historical data form a reasonable basis upon which to project future outcomes, absent a material change. Significant structural changes to the available data can materially impact the reserve estimation process. To the extent a material change affecting the ultimate claim liability becomes known, such change is quantified to the extent possible through an analysis of internal Company data and, if available and when appropriate, external data. Nonetheless, actuaries exercise a considerable degree of judgment in the evaluation of these factors and the need for such actuarial judgment is more pronounced when faced with material uncertainties. Safety incentives We accrue for and present expected safety incentives as a reduction of revenue. Safety incentives represent cash incentives paid to certain PEO client companies for maintaining safe work practices and minimizing workplace injuries. The incentive is based on a percentage of annual payroll and is paid annually to customers who meet predetermined workers’ compensation claims cost objectives. Safety incentive payments are made only after closure of all workers' compensation claims incurred during the customer’s contract period. The safety incentive liability is estimated and accrued each month based upon contract year-to-date payroll and the then current amount of the customer’s estimated workers’ compensation claims reserves as established by us and our third-party administrator. In July 2020, the Company began limiting its safety incentive offering in certain markets. The Company provided $4.3 million and $18.8 million at December 31, 2021 and 2020, respectively, as an estimate of the liability for unpaid safety incentives. Customer deposits We require deposits from certain PEO customers to cover a portion of our accounts receivable due from such customers in the event of default of payment. Comprehensive income (loss) Comprehensive income (loss) includes all changes in equity during a period except those that resulted from investments by or distributions to the Company's stockholders. Other comprehensive income (loss) refers to revenues, expenses, gains and losses that under U.S. generally accepted accounting principles (“GAAP”) are included in comprehensive income (loss), but excluded from net income (loss) as these amounts are recorded directly as an adjustment to stockholders' equity. Our other comprehensive income (loss) comprises unrealized holding gains and losses on our available-for-sale investments. Statements of cash flows Interest paid in 2021, 2020, and 2019 did not materially differ from interest expense. Income taxes paid by the Company totaled $4.7 million, $8.5 million, and $15.4 million in 2021, 2020, and 2019, respectively. Bank deposits and other cash equivalents that are restricted for use are classified as restricted cash. The table below reconciles the cash, cash equivalents and restricted cash balances from our consolidated balance sheets to the amounts reported on the consolidated statements of cash flows (in thousands): December 31, December 31, December 31, 2021 2020 2019 Cash and cash equivalents $ 69,405 $ 68,688 $ 44,570 Restricted cash, included in restricted cash and investments 9,224 165,149 228,771 Total cash, cash equivalents and restricted cash shown in the statement of cash flows $ 78,629 $ 233,837 $ 273,341 Basic and diluted earnings per share Basic earnings per share are computed based on the weighted average number of common shares outstanding for each year using the treasury method. Diluted earnings per share reflect the potential effects of the issuance of shares in connection with the Year Ended December 31, 2021 2020 2019 Weighted average number of basic shares outstanding 7,540 7,577 7,451 Effect of dilutive securities 81 111 248 Weighted average number of diluted shares outstanding 7,621 7,688 7,699 Accounting estimates The preparation of our consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions. These affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting periods. Management bases its estimates on historical experience and on various other assumptions that are believed to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Estimates are used for fair value measurement of investments, allowance for doubtful accounts, deferred income taxes, carrying values for goodwill and property, equipment and software, accrued workers' compensation liabilities and safety incentive liabilities. Actual results may or may not differ from such estimates. Recent accounting pronouncements There were no new or pending accounting pronouncements in 2021 that had, or will have, a material impact on our results of operations or financial condition.

Concentration of Credit Risk

Concentration of Credit Risk	12 Months Ended
	Dec. 31, 2021
Risks And Uncertainties [Abstract]
Concentration of Credit Risk	Note 2 - Concentration of Credit Risk Financial instruments that potentially subject us to concentration of credit risk consist primarily of cash equivalents, investments, restricted cash and investments, and trade accounts receivable. We limit investment of cash equivalents and investments to financial institutions with high credit ratings. Credit risk on trade accounts is minimized as a result of the large and diverse nature of our customer base. At December 31, 2021, we had concentrations of credit risk as follows: • $159.5 million, at fair value, in corporate bonds • $82.6 million, at fair value, in mortgage backed securities • $67.3 million, at fair value, in U.S. treasuries • $42.0 million, at fair value, in U.S. government agency securities • $29.6 million, at fair value, in asset backed securities • $13.9 million, at fair value, in money market funds • $6.3 million, at fair value, in mutual funds

Fair Value Measurement

Fair Value Measurement	12 Months Ended
	Dec. 31, 2021
Fair Value Disclosures [Abstract]
Fair Value Measurement	Note 3 - Fair Value Measurement Fair value is the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. All of our financial instruments are recognized in our consolidated balance sheets. Carrying values approximate fair value of most financial assets and liabilities. Investments and restricted cash and investments are recorded at market value. The interest rates on our investments approximate current market rates for these types of investments. In determining the fair value of our financial assets, the Company predominately uses the market approach. In determining the fair value of all its corporate bonds, mortgage backed securities, U.S. treasuries, U.S. government agency securities, supranational, mutual funds, money market funds, asset backed securities, and municipal bonds, the Company utilizes non-binding quotes provided by our investment brokers. Factors used in determining the fair value of our financial assets and liabilities are summarized into three levels as established in the fair value hierarchy framework. The three levels of the fair value hierarchy are described below. Level 1 – Inputs to the valuation methodology are unadjusted quoted prices for identical assets or liabilities in active markets. Level 2 – Inputs to the valuation methodology include: • Quoted prices for similar assets or liabilities in active markets; • Quoted prices for identical or similar assets or liabilities in inactive markets; • Inputs other than quoted prices that are observable for the asset or liability; • Inputs that are derived principally from or corroborated by observable market data by correlation or other means. Level 3 - Inputs to the valuation methodology are unobservable and significant to the fair value measurement. In determining the fair value measurement of our financial assets, the fair value measurement level within the hierarchy is based on the lowest level input and is applied to each financial asset. Valuation techniques are used to maximize the use of observable inputs and minimize the use of unobservable inputs. The following table summarizes the Company’s investments at December 31, 2021 and 2020 measured at fair value on a recurring basis (in thousands): December 31, 2021 December 31, 2020 Gross Gross Unrealized Unrealized Gains Recorded Gains Recorded Cost (Losses) Basis Cost (Losses) Basis Current: Cash equivalents: Money market funds $ 13,384 $ — $ 13,384 $ 42,007 $ — $ 42,007 Total cash equivalents 13,384 — 13,384 42,007 — 42,007 Investments: Corporate bonds 41,954 (136 ) 41,818 50,918 884 51,802 Asset backed securities 29,533 (38 ) 29,495 36,948 (146 ) 36,802 U.S. government agency securities 7,383 418 7,801 7,396 752 8,148 Mortgage backed securities 18,089 (440 ) 17,649 4,367 24 4,391 U.S. treasuries — — — 100 1 101 Total current investments 96,959 (196 ) 96,763 99,729 1,515 101,244 Restricted cash and investments (1) Corporate bonds 117,700 (17 ) 117,683 88,902 4,091 92,993 Mortgage backed securities 64,217 764 64,981 48,795 2,356 51,151 Money market funds 528 — 528 40,063 (4 ) 40,059 U.S. government agency securities 32,898 1,281 34,179 29,737 2,466 32,203 Mutual funds 6,273 — 6,273 5,036 — 5,036 Supranational bonds — — — 4,775 3 4,778 U.S. treasuries 67,614 (342 ) 67,272 4,371 19 4,390 Asset backed securities 107 1 108 256 4 260 Total restricted cash and investments 289,337 1,687 291,024 221,935 8,935 230,870 Total investments $ 399,680 $ 1,491 $ 401,171 $ 363,671 $ 10,450 $ 374,121 (1) Included in restricted cash and investments within the consolidated balance sheets as of December 31, 2021 and 2020 is restricted cash of $9.2 million and $124.3 million, respectively, which is excluded from the table above. Restricted cash and investments are classified as current and noncurrent on the balance sheet based on the nature of the restriction. The following table summarizes the Company's investments at December 31, 2021 and 2020 measured at fair value on a recurring basis by fair value hierarchy level (in thousands): December 31, 2021 December 31, 2020 Total Total Recorded Recorded Basis Level 1 Level 2 Level 3 Other (1) Basis Level 1 Level 2 Level 3 Other (1) Cash equivalents: Money market funds 13,384 $ — $ — $ — $ 13,384 $ 42,007 $ — $ — $ — $ 42,007 Investments: Corporate bonds 41,818 — 41,818 — — 51,802 — 51,802 — — Asset backed securities 29,495 — 29,495 — — 36,802 — 36,802 — — U.S. government agency securities 7,801 — 7,801 — — 8,148 — 8,148 — — Mortgage backed securities 17,649 — 17,649 — — 4,391 — 4,391 — — U.S. treasuries — — — — — 101 — 101 — — Restricted cash and investments: Corporate bonds 117,683 — 117,683 — — 92,993 — 92,993 — — Mortgage backed securities 64,981 — 64,981 — — 51,151 — 51,151 — — Money market funds 528 — — — 528 40,059 — — — 40,059 U.S. government agency securities 34,179 — 34,179 — — 32,203 — 32,203 — — Mutual funds 6,273 6,273 — — — 5,036 5,036 — — — Supranational bonds — — — — — 4,778 — 4,778 — — U.S. treasuries 67,272 — 67,272 — — 4,390 — 4,390 — — Asset backed securities 108 — 108 — — 260 — 260 — — Total investments $ 401,171 $ 6,273 $ 380,986 $ — $ 13,912 $ 374,121 $ 5,036 $ 287,019 $ — $ 82,066 (1) Investments in money market funds measured at fair value using the net asset value per share practical expedient are not subject to hierarchy level classification disclosure. The Company invests in money market funds that seek to maintain a stable net asset value. These investments include commingled funds that comprise high-quality short-term securities representing liquid debt and monetary instruments where the redemption value is likely to be the fair value. Redemption is permitted daily without written notice. The following table summarizes the contractual maturities of the Company’s available for sale securities at December 31, 2021 and 2020. Actual maturities may differ from contractual maturities because borrowers may have the right to prepay obligations with or without prepayment penalties. December 31, 2021 (In thousands) Less than 1 Year Between 1 to 5 Years Between 5 to 10 Years After 10 Years Total Corporate bonds $ 24,601 $ 35,570 $ 99,180 $ 150 $ 159,501 Money market funds 13,657 — — — 13,657 U.S. government agency securities — 25,171 16,809 — 41,980 Asset backed securities — 108 2,200 27,295 29,603 Supranational bonds — — — — — U.S. treasuries 953 4,295 62,024 — 67,272 Total $ 39,211 $ 65,144 $ 180,213 $ 27,445 $ 312,013 December 31, 2020 (In thousands) Less than 1 Year Between 1 to 5 Years Between 5 to 10 Years After 10 Years Total Corporate bonds $ 49,308 $ 61,315 $ 34,172 $ — $ 144,795 Money market funds 82,066 — — — 82,066 U.S. government agency securities 1,013 18,668 20,670 — 40,351 Asset backed securities 2 267 — 36,793 37,062 Supranational bonds 4,778 — — — 4,778 U.S. treasuries 1,367 1,504 1,620 — 4,491 Total $ 138,534 $ 81,754 $ 56,462 $ 36,793 $ 313,543 The average contractual maturity of mortgage backed securities, which are excluded from the table above, was 23 years

Property, Equipment and Softwar

Property, Equipment and Software	12 Months Ended
	Dec. 31, 2021
Property Plant And Equipment [Abstract]
Property, Equipment and Software	Note 4 - Property, Equipment and Software Property, equipment and software consists of the following (in thousands): December 31, 2021 2020 Buildings $ 16,857 $ 16,498 Office furniture and fixtures 14,159 13,691 Computer hardware and software 11,458 11,591 Software development costs 23,332 18,353 Other 512 437 66,318 60,570 Less accumulated depreciation and amortization (31,531 ) (27,144 ) 34,787 33,426 Land 1,490 1,490 $ 36,277 $ 34,916 We recognized $3.1 million, $3.4 million and $3.3 million in depreciation expense associated with our property and equipment in 2021, 2020 and 2019, respectively. We recognized $2.2 million, $1.4 million, and $531,000 in amortization of capitalized software development costs in 2021, 2020 and 2019, respectively. We capitalized $5.0 million, $6.0 million and $8.3 million of software development costs in 2021, 2020 and 2019, respectively.

Workers' Compensation Claims

Workers' Compensation Claims	12 Months Ended
	Dec. 31, 2021
Text Block [Abstract]
Workers' Compensation Claims	Note 5 - Workers' Compensation Claims The following table summarizes the aggregate workers' compensation reserve activity (in thousands): Years Ended December 31, 2021 2020 2019 Beginning balance Workers' compensation claims liabilities $ 357,746 $ 438,986 $ 413,397 Add: claims expense accrual Current period 75,786 147,097 161,691 Prior periods (9,225 ) (6,383 ) (13,355 ) 66,561 140,714 148,336 Less: claim payments related to Current period 15,063 22,877 24,414 Prior periods 129,138 198,620 98,445 144,201 221,497 122,859 Change in claims incurred in excess of retention limits (699 ) (457 ) 112 Ending balance Workers' compensation claims liabilities $ 279,407 $ 357,746 $ 438,986 Incurred but not reported (IBNR) $ 153,838 $ 210,798 $ 285,191 Ratio of IBNR to workers' compensation claims liabilities 55 % 59 % 65 % Insured program The Company provides workers’ compensation coverage for client employees primarily through arrangements with fully licensed, third-party insurers (the “insured program”). Under this program, carriers issue policies or afford coverage to the Company’s clients under a program maintained by the Company. Approximately 82% of the Company’s workers’ compensation exposure is covered through the insured program. The Company entered into a new arrangement for its insured program effective July 1, 2021 whereby third-party insurers assume all risk of loss for claims incurred after June 30, 2021. The agreement continues to June 30, 2022 and includes a renewal commitment through June 30, 2023. The arrangement allows for premium adjustments depending on overall portfolio performance. If claims develop favorably, BBSI can participate in the savings up to $20.0 million for a twelve-month policy period. If claims develop adversely, additional premium may be charged up to $7.5 million for a twelve-month policy period. For claims incurred under the insured program prior to July 1, 2021, the Company retains risk of loss up to the first $3.0 million per occurrence on policies issued after June 30, 2020 and $5.0 million per occurrence on policies issued before that date. On June 29, 2020, the Company entered into a loss portfolio transfer agreement (“LPT 1”) to remove all outstanding workers’ compensation claims obligations for claims incurred under its insured program between February 1, 2014 and December 31, 2017. This transaction reduced the Company’s outstanding workers’ compensation liabilities and trust account balances by $115.7 million. On June 30, 2021, the Company entered into a loss portfolio transfer agreement (“LPT 2”) to remove all remaining outstanding workers’ compensation claims obligations for client policies issued under its insured program up to June 30, 2018. This transaction reduced the Company’s outstanding workers’ compensation liabilities by $53.1 million. The payment terms of LPT 2 required $5.0 million to be paid prior to June 30, 2021, with the remaining amount paid in July 2021. The following is a summary of the risk retained by the Company under its insured program after considering the effects of the loss portfolio transfers and current insurance arrangements: Year Claims risk retained 2014 No 2015 No 2016 No 2017 No 2018 (1) No 2019 (1) Yes 2020 Yes 2021 - Through June 30 Yes 2021 - July 1 and after No ( 1) LPT 2 excluded approximately 10% of claims from 2018 and included an approximately offsetting amount of claims from 2019. The Company is required to maintain minimum collateral levels for certain policies issued under the insured program, which is held in trust accounts (the “trust accounts”). The balance in the trust accounts was $273.6 million and $290.7 million at December 31, 2021 and December 31, 2020, respectively. The trust account balances are included as a component of the current and long-term restricted cash and investments in the Company’s condensed consolidated balance sheets. Self-insured programs The Company is a self-insured employer with respect to workers' compensation coverage for all employees, including employees of PEO clients that elect to participate in our workers’ compensation program, working in Colorado, Maryland and Oregon For all claims incurred under the Company’s self-insured programs, the Company retains risk of loss up to the first $3.0 million per occurrence, except in Maryland and Colorado, where the Company’s retention per occurrence is $1.0 million and $2.0 million, respectively. For claims incurred under the Company’s self-insured programs prior to July 1, 2020, the Company retains risk of loss up to the first $5.0 million per occurrence, except in Maryland and Colorado, where the retention per occurrence is $1.0 million and $2.0 million, respectively. The states of California, Maryland, Oregon, Washington, Colorado and Delaware required the Company to maintain collateral totaling $58.4 million and $60.1 million at December 31, 2021 and 2020, respectively, to cover potential workers’ compensation claims losses related to the Company’s current and former status as a self-insured employer. At December 31, 2021, the Company provided surety bonds and standby letters of credit totaling $58.4 Claims liabilities The Company provided a total of $279.4 million and $357.7 million at December 31, 2021 and 2020, respectively, as an estimated future liability for unsettled workers' compensation claims liabilities. Of this amount, $2.2 million and $2.9 million at December 31, 2021 and 2020, respectively, represent case reserves incurred in excess of the Company’s retention. The accrual for costs incurred in excess of retention limits is offset by a receivable from insurance carriers of $2.2 million and $2.9 million at December 31, 2021 and 2020, respectively, included in other assets in the consolidated balance sheets.

Revolving Credit Facility and L

Revolving Credit Facility and Long-Term Debt	12 Months Ended
	Dec. 31, 2021
Debt Disclosure [Abstract]
Revolving Credit Facility and Long-Term Debt	Note 6 - Revolving Credit Facility and Long-Term Debt In March 2022, the Company entered into an amended credit agreement (the “Amended Agreement”) with Wells Fargo Bank, N.A. (the “Bank”), which supersedes the previous agreement. The Amended Agreement increased the revolving credit line from $33.0 million to $50.0 million and maintained the sublimit for standby letters of credit at $8.0 million. Advances under the credit line bear interest, as selected by the Company, of (a) the daily Simple Secured Overnight Financing Rate (“SOFR”) plus 1.75% or (b) the one-month Term SOFR plus 1.75%. The Amended Agreement also provides for an unused commitment fee of 0.30% per year on the average daily unused amount of the revolving credit line. The Amended Agreement replaced the financial covenants in the Agreement (as defined below) with the following financial covenants: • adjusted free cash flow [net profit after taxes plus interest expense (net of capitalized interest), depreciation, expense and amortization expense, less dividends/distributions] not less than $10 million as of each fiscal quarter end, determined on a rolling 4-quarter basis • tangible net worth [aggregate of total stockholders' equity plus subordinated debt less any intangible assets and less any loans or advances to, or investments in, any related entities or individuals] not less than $100 million at each fiscal quarter end Other than as described above, the Agreement (as defined below) previously in place during 2021 is substantially unchanged. At December 31, 2021, the Company maintained an agreement (the “Agreement”) with the Bank for a revolving credit line of $33.0 million and a sublimit for standby letters of credit of $8.0 million. At December 31, 2021, $6.2 million of the sublimit for standby letters of credit was used. The Agreement also provided a $63.7 million standby letter of credit (the “Letter of Credit”). In April 2021, the Company and the insurance carrier reached an agreement to replace the Letter of Credit with other collateral assets and cancel the Letter of Credit in its entirety. As part of the transaction, the Bank released the $38.7 million of collateral held in support of the Letter of Credit and the Company transferred the $38.7 million along with an additional $25.0 million to the trust accounts to satisfy the collateral requirements of the insured program. The Agreement required the satisfaction of certain financial covenants as follows: • EBITDA [net income before taxes plus interest expense (net of capitalized interest expense), depreciation expense, and amortization expense] on a rolling four-quarter basis must be not less than $30 million at the end of each fiscal quarter; • the ratio of restricted and unrestricted cash and investments to workers’ compensation and safety incentive liabilities must be at least 1.0:1.0 The Agreement imposed certain additional restrictions unless the Bank provides its prior written consent as follows: • incurring additional indebtedness is prohibited, other than purchase financing for the acquisition of assets, provided that the aggregate of all purchase financing does not exceed $1 million at any time; • the Company may not terminate or cancel any of the AICE policies; and • if an event of default would occur, and is continuing, including on a pro forma basis, no dividends or distributions would be permitted to be paid and redemptions and repurchases of the Company’s stock would be permitted only up to $15 million in any rolling 12-month period The Agreement also contained customary events of default a nd specified cross-defaults under the Company's workers' compensation insurance arrangements. If an event of default under the Agreement occurs and is continuing, the Bank may declare any outstanding obligations under the Agreement to be immediately due and payable. At December 31, 2021 , the Company was in compliance with all covenants. The Company maintained a mortgage loan with the Bank with a balance of approximately $3.5 million and $3.7 million at December 31, 2021 and 2020, respectively, secured by the Company’s corporate office building in Vancouver, Washington. This loan required payment of monthly installments of $18,375, bearing interest at the one-month LIBOR plus 2.0%, with the unpaid principal balance due July 1, 2022. On January 31, 2022, the Company paid the outstanding balance of the mortgage loan.

Benefit Plans

Benefit Plans	12 Months Ended
	Dec. 31, 2021
Compensation And Retirement Disclosure [Abstract]
Benefit Plans	Note 7 – Benefit Plans We have a 401(k) Retirement Savings Plan for the benefit of our eligible employees. Employees covered under a PEO arrangement may participate in the plan at the sole discretion of the PEO client. We make matching contributions to the 401(k) plan under a safe harbor provision. The determination of any discretionary Company contributions to the plan is at the sole discretion of our Board of Directors. No discretionary Company contributions were made to the plan for the years ended December 31, 2021, 2020 and 2019. We made matching contributions of $1.9 million, $1.8 million and $1.9 million in 2021, 2020, and 2019, respectively. The Company allows certain highly compensated employees of the Company to defer compensation under a nonqualified deferred compensation plan. The long-term portion of the deferred compensation plan liability was $6.3 million and $4.9 million at December 31, 2021 and 2020, respectively, and is recorded in customer deposits and other long-term liabilities on the consolidated balance sheets. The current portion of the deferred compensation plan liability was $0.2 million and $0.1 million at December 31, 2021 and 2020, respectively, and is recorded in other accrued liabilities on the consolidated balance sheets. The fair value of the long-term portion of this plan was $6.3 million and $4.9 million at December 31, 2021 and 2020, respectively, and is recorded in noncurrent restricted cash and investments on the consolidated balance sheets. The fair value of the current portion of this plan was $0.2 million and $0.1 million at December 31, 2021 and 2020, respectively, and is recorded in current restricted cash and investments on the consolidated balance sheets.

Leases

Leases	12 Months Ended
	Dec. 31, 2021
Leases [Abstract]
Leases	Note 8 – Leases The Company primarily leases office buildings under operating leases which are included in Operating lease right-of-use (“ROU”) assets, Current operating lease liabilities, and Long-term operating lease liabilities on the consolidated balance sheets. The Company’s leases have remaining terms of 1 to 7 years. Information related to the Company's total lease costs was as follows (in thousands): Year Ended December 31, 2021 December 31, 2020 Operating lease cost $ 8,957 $ 8,352 Variable lease cost 689 928 Short-term lease cost 94 709 Total lease cost $ 9,740 $ 9,989 Information related to the Company's ROU assets and related lease liabilities was as follows (in thousands): Year Ended December 31, 2021 December 31, 2020 Cash paid for operating lease liabilities $ 8,854 $ 8,136 Right-of-use assets obtained in exchange for new operating lease obligations 5,717 6,444 December 31, 2021 December 31, 2020 Weighted-average remaining lease term 3.6 years 3.7 years Weighted-average discount rate 3.6 % 3.9 % The table below reconciles the undiscounted future minimum lease payments (displayed by year and in the aggregate) under noncancellable operating leases with terms of more than one year to the total operating lease liabilities recognized on the consolidated balance sheets as of December 31, 2021 (in thousands): 2022 $ 7,807 2023 6,405 2024 4,359 2025 2,231 2026 1,322 Thereafter 1,038 Total undiscounted future minimum lease payments 23,162 Less: Difference between undiscounted lease payments and discounted operating lease liabilities 1,373 Total operating lease liabilities $ 21,789 Current operating lease liabilities $ 7,191 Long-term operating lease liabilities 14,598 Total operating lease liabilities $ 21,789

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Income Taxes	Note 9 - Income Taxes The provision for income taxes is as follows (in thousands): Year Ended December 31, 2021 2020 2019 Current: Federal $ 9,527 $ 2,943 $ 8,806 State 3,408 396 1,381 12,935 3,339 10,187 Deferred: Federal 143 4,156 (774 ) State (496 ) 1,336 3,433 (353 ) 5,492 2,659 Total provision $ 12,582 $ 8,831 $ 12,846 Deferred income tax assets and liabilities consist of the following components (in thousands): December 31, 2021 2020 Deferred income tax assets: Workers' compensation claims liabilities $ 7,870 $ 9,946 Deferred compensation 6,109 2,235 Operating lease liability 5,870 6,107 Other 1,388 1,154 Payroll tax deferral 749 1,668 Equity based compensation 678 555 State credit carryforward 329 518 MCC accrual 167 1,062 Customer incentives 12 54 23,172 23,299 Less: valuation allowance 163 163 23,009 23,136 Deferred income tax liabilities: Tax amortization of goodwill (10,120 ) (10,375 ) Tax depreciation in excess of book depreciation (7,433 ) (7,187 ) Operating lease right-of-use (5,527 ) (5,766 ) Other (1,223 ) (1,455 ) Tax effect of unrealized gains, net (393 ) (2,871 ) (24,696 ) (27,654 ) Net deferred income taxes $ (1,687 ) $ (4,518 ) The effective tax rate differed from the U.S. statutory federal tax rate due to the following: Year Ended December 31, 2021 2020 2019 Statutory federal tax rate 21.0 % 21.0 % 21.0 % State taxes, net of federal benefit 4.5 3.2 6.2 Adjustment for final positions on filed returns 0.9 0.6 (0.2 ) Nondeductible expenses and other, net 0.5 0.7 1.3 Federal and state tax credits (2.1 ) (4.9 ) (7.5 ) Other, net — 0.1 0.2 24.8 % 20.7 % 21.0 % Under ASC 740, “Income Taxes,” management evaluates the realizability of the deferred tax assets on a quarterly basis under a “more-likely-than-not” standard. As part of this evaluation, management reviews all evidence both positive and negative to determine if a valuation allowance is needed. One component of this analysis is to determine whether the Company was in a cumulative loss position for the most recent 12 quarters. The Company was in a cumulative income position for the 12 quarters ended The Company’s realization of a portion of net deferred tax assets is based in part on our estimates of the timing of reversals of certain temporary differences and on the generation of taxable income before such reversals. The Company is subject to income taxes in U.S. federal and multiple state and local tax jurisdictions. The Internal Revenue Service is examining the Company’s federal tax returns for the years ended December 31, 2011 through 2014 and 2017 through 2019. In July 2020, BBSI received notice that the IRS intends to disallow certain wage-based tax credits claimed for years 2011 to 2014, which would result in an estimated total additional tax due of approximately $2.3 million for the tax years 2012 through 2015, including the impact on carryover tax attributes. In November 2021, BBSI received notice that the IRS intends to disallow certain wage-based tax credits claimed for the year 2017, which could result in an estimated total additional taxes and penalties due of $1.7 million for 2017. Years 2018 and 2019 remain under audit, however, disallowance of similar wage-based credits for these years would result in additional estimated tax due of $1.7 million and $1.6 million for 2018 and 2019, respectively. The Company disagrees with the IRS determination to disallow certain wage-based credits taken by the Company and believes that the Company has the technical merits to defend its position. Based on management’s more-likely-than-not assessment that the position is sustainable, no reserve for the aforementioned IRS notice of disallowance of wage-based tax credits or underpayment penalties has been recorded in the financial statements. In the major jurisdictions where it operates, the Company is generally no longer subject to income tax examinations by tax authorities for the 2015 and 2016 tax years and tax years before 2011. As of December 31, 2021, 2020 and 2019, the Company had no material unrecognized tax benefits. A portion of the consolidated income the Company generates is not subject to state income tax. Depending on the percentage of this income as compared to total consolidated income, the Company's state effective tax rate could fluctuate from expectations. At December 31, 2021,

Stock Incentive Plans

Stock Incentive Plans	12 Months Ended
	Dec. 31, 2021
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock Incentive Plans	Note 10 - Stock Incentive Plans The Company's 2020 Stock Incentive Plan (the "2020 Plan"), which provides for share-based awards to Company employees, non-employee directors and outside consultants or advisors, was approved by stockholders on May 27, 2020. The number of shares of common stock reserved for issuance under the 2020 Plan is 375,000, of which the maximum number of shares for which incentive stock options may be granted is 375,000. The 2020 Plan replaced the Company’s 2015 Stock Incentive Plan (the “2015 Plan”), and no new share-based awards may be granted under the 2015 Plan. The number of shares available for grant at December 31, 2021 was 185,665. Share-based compensation expense included in selling, general and administrative expenses during the years ended December 31, 2021, 2020 and 2019, was $5.4 million, $3.4 million and $7.2 million, respectively. Related income tax benefits for the years ended December 31, 2021, 2020 and 2019, were $1.3 million, $0.8 million and $1.3 million, respectively. Stock Options Outstanding stock options generally vest over either four or eight years and expire ten years after the date of grant. A summary of the status of the Company’s stock options at December 31, 2021, together with changes during the periods then ended, is presented below: Weighted Weighted Average Aggregate Average Remaining Intrinsic Number Exercise Contractual Value of Options Price Term (Years) (In Thousands) Outstanding at December 31, 2020 139,648 $ 56.13 — — Options exercised (34,773 ) 17.60 — — Outstanding at December 31, 2021 104,875 68.91 5.32 1,068 Exercisable at December 31, 2021 24,875 $ 26.12 2.40 $ 1,068 No stock options were granted during the years ended December 31, 2021, 2020, and 2019. The intrinsic value of stock options exercised for the years ended December 31, 2021, 2020 and 2019 was $1.7 million, $4.1 million, and $3.8 million, respectively. No stock options vested during the year ended December 31, 2021. The fair value of stock options vested for the years ended December 31, 2020 and 2019 was $43,000 and $312,000, respectively. As of December 31, 2021, unrecognized compensation expense related to stock options was $2.2 million with a weighted average remaining amortization period of 4.2 years. Restricted Stock Units Restricted stock units generally vest in four equal annual installments beginning one year following the date of grant. The following table presents restricted stock unit activity: Weighted Average Grant Date Units Fair Value Nonvested at December 31, 2020 181,823 $ 59.16 Granted 91,409 72.23 Vested (60,038 ) 60.48 Cancelled/Forfeited (17,130 ) 53.08 Nonvested at December 31, 2021 196,064 $ 65.38 The total fair value of restricted stock units vested during the years ended December 31, 2021, 2020 and 2019 was $3.6 million, $3.8 million and $5.8 million, respectively. As of December 31, 2021, unrecognized compensation expense related to restricted stock units was $10.0 Performance Share Units Performance share units (“PSUs”) are granted to key employees of the Company and are conditioned on attaining specified financial performance metrics. Awards are subject to upward or downward adjustments depending on whether the actual financial metrics are above or below the target level, with a maximum payout up to 200% of a target number of shares. PSUs fully vest on the date that the Compensation Committee determines the level of attainment of specified performance goals, generally over a three-year The following table presents PSU activity: Weighted Average Grant Date Units Fair Value Nonvested at December 31, 2020 8,464 $ 76.78 Granted 29,821 69.17 Vested (3,360 ) 82.21 Cancelled/Forfeited (592 ) 82.21 Nonvested at December 31, 2021 34,333 $ 69.54 The total fair value of PSUs vested during the years ended December 31, 2021, 2020 and 2019 was $276,000, $743,000, and $296,000. Employee Stock Purchase Plan The Company offers employees the right to purchase shares at a discount from the market price under the Company’s 2019 Employee Stock Purchase Plan. Subject to the annual statutory limit, employees are eligible to participate through payroll deductions of up to 15% of their compensation. At the end of each six-month offering period, shares are purchased by the participants at 85% of the fair market value at the end of the offering period. As of December 31, 2021, approximately 284,000 shares were reserved for future issuance under the 2019 Employee Stock Purchase Plan.

Stock Repurchase Program

Stock Repurchase Program	12 Months Ended
	Dec. 31, 2021
Text Block [Abstract]
Stock Repurchase Program	Note 11 - Stock Repurchase Program The Company maintains a stock repurchase program approved by the Board of Directors, which authorizes the repurchase of shares from time to time in open market purchases. On August 6, 2019, the Board of Directors authorized the repurchase of up to $50.0 million of the Company's common stock over a three-year On February 28, 2022, the Board of Directors authorized the repurchase of up to $75.0 million of the Company’s common stock over a two-year

Litigation

Litigation	12 Months Ended
	Dec. 31, 2021
Commitments And Contingencies Disclosure [Abstract]
Litigation	Note 12 - Litigation On November 21, 2012, David Kaanaana (“Kaanaana”), a former staffing employee, filed a class action wage and hour lawsuit against BBSI in the California Superior Court on behalf of himself and certain other employees who worked at County Sanitation District No. 2 of Los Angeles County (“the District”). The trial court ruled in plaintiffs’ favor regarding certain alleged meal break violations but ruled in favor of BBSI with respect to the application of the California prevailing wage law to the District and other claims. These latter rulings were appealed by the plaintiffs to the California Court of Appeal. On November 30, 2018, the California Court of Appeal for the Second Appellate District returned its decision in Kaanaana v. Barrett Business Services, Inc., overruling the trial court's decision to dismiss the prevailing wage claim, ruling that the work in question at the District constitutes “public works” under the applicable law, and also ruling that plaintiffs’ are entitled to additional remedies with regard to the meal break violations under California law. On January 9, 2019, BBSI filed a petition of review to the California Supreme Court. On February 27, 2019, the California Supreme Court granted the petition to review the Court of Appeal’s decision with respect to the prevailing wage issue. An amicus brief in support of BBSI’s appeal was filed by the District and certain associations of special districts, cities and counties in California. Oral argument took place on January 5, 2021. A decision from the California Supreme Court was issued March 29, 2021 affirming the Court of Appeal decision and concluding that the recycling sorting work performed by the staffing employees in question was a “public work” and therefore would be subject to prevailing wage requirements. No damages were awarded in the appeals process. The case has been remanded to Superior Court for any such determination with respect to both the prevailing wage issue and any additional remedies for the meal break violations. On December 7, 2021 the parties engaged in a mediation effort which resulted in a settlement agreement on December 22, 2021. The settlement is subject to customary court approval. In addition to the matter above, BBSI is subject to other legal proceedings and claims that arise in the ordinary course of our business. There are significant uncertainties surrounding litigation. For the settlement discussed above, as well as other cases, management has recorded estimated liabilities of $2.6

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2021
Subsequent Events [Abstract]
Subsequent Events	Note 13 - Subsequent Events We have evaluated events and transactions occurring after the balance sheet date through our filing date and noted no events that are subject to recognition or disclosure.

Summary of Operations and Sig_2

Summary of Operations and Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2021
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Nature of operations	Nature of operations Barrett Business Services, Inc. (“BBSI” or the “Company”), is a leading provider of business management solutions for small and mid-sized companies. The Company has developed a management platform that integrates a knowledge-based approach from the management consulting industry with tools from the human resource outsourcing industry. This platform, through the effective leveraging of human capital, helps our business owner clients run their businesses more effectively. We believe this platform, delivered through our decentralized organizational structure, differentiates BBSI from our competitors. The Company operates through a network of 50 branch offices throughout Arizona, California, Colorado, Delaware, Idaho, Maryland, Nevada, New Mexico, North Carolina, Oregon, Pennsylvania, Tennessee, Utah, Virginia and Washington. Approximately 73%, 75% and 77%, respectively, of our revenue during 2021, 2020, and 2019 was attributable to our California operations. BBSI was incorporated in Maryland in 1965. The Company operates a wholly owned, fully licensed captive insurance company, Associated Insurance Company for Excess ("AICE") and a wholly owned, fully licensed insurance company, Ecole. AICE and Ecole provide access to more competitive and cost-effective insurance markets and provide cost-effective risk management. See “Note 5 – Workers’ Compensation Claims” for additional information in the Company’s insurance programs.
Principles of consolidation	Principles of consolidation The accompanying financial statements are prepared on a consolidated basis. All intercompany account balances and transactions between BBSI, AICE, and Ecole have been eliminated in consolidation.
Reportable Segment	Reportable segment The Company has one operating and reporting segment. The chief operating decision maker (our Chief Executive Officer) regularly reviews the financial information of our business at a consolidated level in deciding how to allocate resources and in assessing performance.
Revenue recognition	Revenue recognition Professional employer (“PEO”) services are normally used by organizations to satisfy ongoing needs related to the management of human capital and are governed by the terms of a client services agreement which covers all employees at a particular work site. Staffing revenues relate primarily to short-term staffing, contract staffing and on-site management services. The Company’s performance obligations for PEO and staffing services are satisfied, and the related revenue is recognized, as services are rendered by our workforce. Our PEO client service agreements have a minimum term of one year, are renewable on an annual basis and typically require 30 days’ written notice to cancel or terminate the contract by either party. In addition, our client service agreements provide for immediate termination upon any payment default of the client regardless of when notice is given. PEO customers are invoiced following the end of each payroll processing cycle, with payment generally due on the invoice date. Staffing customers are generally invoiced weekly based on agreed rates per employee and actual hours worked, typically with payment terms of 30 days. The amount of earned but unbilled revenue is classified as a receivable on the consolidated balance sheets. We report PEO revenues net of direct payroll costs because we are not the primary obligor for these payments to our clients’ employees. afety incentives, because these incentives represent consideration payable to customers
Cost of revenues	Cost of revenues Our cost of revenues for PEO services includes employer payroll-related taxes and workers' compensation costs. Our cost of revenues for staffing services includes direct payroll costs, employer payroll-related taxes, employee benefits, and workers’ compensation costs. Direct payroll costs represent the gross payroll earned by staffing services employees based on salary or hourly wages. Payroll taxes and employee benefits consist of the employer's portion of Social Security and Medicare taxes, federal and state unemployment taxes, and staffing services employee reimbursements for materials, supplies and other expenses, which are paid by our customer. Workers' compensation costs consist primarily of premiums paid to third-party insurers, claims reserves, claims administration fees, legal fees, medical cost containment (“MCC”) expense, state administrative agency fees, third-party broker commissions, risk manager payroll, as well as costs associated with operating our two wholly owned insurance companies, AICE and Ecole.
Cash and cash equivalents	Cash and cash equivalents We consider non-restricted short-term investments that are highly liquid, readily convertible into cash, and have maturities at acquisition of less than three months to be cash equivalents for purposes of the consolidated statements of cash flows and consolidated balance sheets. The Company maintains cash balances in bank accounts that normally exceed FDIC insured limits. The Company has not experienced any losses related to its cash concentration.
Investments	Investments The Company classifies investments as available-for-sale. The Company’s investments are reported at fair value with unrealized gains and losses, net of taxes, shown as a component of accumulated other comprehensive income (loss) in stockholders' equity. Investments are recorded as current on the consolidated balance sheets as the invested funds are available for current operations. Management considers available evidence in evaluating potential impairment of investments, including the extent to which fair value is less than cost and adverse conditions related to the security. In the event of a credit loss, an allowance would be recognized to the extent that the fair value of the security is less than the present value of the expected future cash flows. Realized gains and losses on sales of investments are included in investment income in our consolidated statements of operations.
Restricted cash and investments	Restricted cash and investments The Company holds restricted cash and investments primarily for the future payment of workers’ compensation claims. These investments are categorized as available-for-sale. They are reported at fair value with unrealized gains and losses, net of taxes, shown as a component of accumulated other comprehensive income (loss) in stockholders’ equity. Restricted cash and investments are classified as current and noncurrent on the consolidated balance sheets based on the nature of the restriction. Management considers available evidence in evaluating potential impairment of restricted investments, including the extent to which fair value is less than cost and adverse conditions related to the security. In the event of a credit loss, an allowance would be recognized to the extent that the fair value of the security is less than the present value of the expected future cash flows. Realized gains and losses on sales of restricted investments are included in investment income in our consolidated statements of operations. Restricted cash and investments also includes investments held as part of the Company’s deferred compensation plan. These investments are classified as trading securities and are recorded at fair value with unrealized gains and losses reported as a component of income (loss) from operations.
Allowance for doubtful accounts	Allowance for doubtful accounts The Company had an allowance for doubtful accounts of $460,000 and $757,000 at December 31, 2021 and 2020, respectively. We make estimates of the collectability of our accounts receivable for services provided to our customers based on future expected credit losses. Management analyzes historical bad debts, customer concentrations, customer credit-worthiness, current economic trends and changes in customers' payment trends when evaluating the adequacy of the allowance for doubtful accounts. If the financial condition of our customers deteriorates resulting in an impairment of their ability to make payments, additional allowances may be required. Our allowance for doubtful accounts activity is summarized as follows (in thousands): 2021 2020 2019 Balance at January 1, Allowance for doubtful accounts $ 757 $ 888 $ 533 Charges to expense 193 125 459 Write-offs of uncollectible accounts, net of recoveries (490 ) (256 ) (104 ) Balance at December 31, Allowance for doubtful accounts $ 460 $ 757 $ 888
Income taxes	Income taxes Our income taxes are accounted for using an asset and liability approach. This requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of temporary differences between the financial statement and tax basis of assets and liabilities at the applicable tax rates. A valuation allowance is recorded against deferred tax assets if, based on the weight of the available evidence, it is more likely than not that some or all of the deferred tax assets will not be realized. The factors used to assess the likelihood of realization include the Company’s forecast of the reversal of temporary differences, future taxable income and available tax planning strategies that could be implemented to realize the net deferred tax assets. Failure to achieve forecasted taxable income in applicable tax jurisdictions could affect the ultimate realization of deferred tax assets and could result in an increase in the Company’s effective tax rate on future earnings. The determination of our provision for income taxes requires significant judgment, the use of estimates, and the interpretation and application of complex tax laws. Significant judgment is required in assessing the timing and amounts of deductible and taxable items and the probability of sustaining uncertain tax positions. The Company recognizes the tax benefit from uncertain tax positions if it is more likely than not that the tax positions will be sustained on examination by the tax authorities. The tax benefit is measured based on the largest benefit that has a greater than 50% likelihood of being realized upon ultimate settlement. As facts and circumstances change, we reassess these probabilities and record any changes in the consolidated financial statements as appropriate. The Company recognizes interest and penalties related to unrecognized tax benefits in income tax expense.
Goodwill and intangible assets	Goodwill and intangible assets Goodwill is recorded as the difference, if any, between the aggregate consideration paid for a business combination and the fair value of the net assets acquired. Goodwill is not amortized but is evaluated for impairment annually, or more frequently if circumstances indicate that it is more likely than not that the fair value of the reporting unit is below its carrying value. The Company has one reporting unit and evaluates the carrying value of goodwill annually at December 31. No impairment has been recognized in the periods presented.
Property, equipment and software	Property, equipment and software Property, equipment and software are stated at cost. Expenditures for maintenance and repairs are charged to selling, general and administrative expenses as incurred and expenditures for additions and improvements to property and equipment are capitalized. The cost of assets sold or otherwise disposed of and the related accumulated depreciation are eliminated from the accounts, and any resulting gain or loss is reflected in the consolidated statements of operations. We capitalize software development costs incurred during the application development stage, which is the stage when preliminary project planning ends and software development begins. Capitalized costs generally include both internal and external costs associated with coding and testing. Capitalized costs are amortized on a straight-line basis over the estimated useful life, commencing when the software is placed into service. Costs incurred during the preliminary project stage and the postimplementation stage, as well as general and administrative and overhead costs, are expensed as they are incurred. Depreciation of property and equipment and amortization of software is calculated using the straight-line method over estimated useful lives of the related assets or lease terms, as follows: Years Buildings 39 Office furniture and fixtures 7 Computer hardware, software and software development costs 3 - 10 Leasehold improvements 1 - 7
Impairment of long-lived assets	Impairment of long-lived assets Long-lived assets, such as property, equipment and software and acquired intangibles subject to amortization, are reviewed for impairment annually, or whenever events or changes in circumstances indicate that the remaining estimated useful life may warrant revision or that the carrying amount of an asset may not be recoverable. Some of the events or changes in circumstances that would trigger an impairment review include, but are not limited to, significant under-performance relative to expected and/or historical results, significant negative industry or economic trends, or knowledge of transactions involving the sale of similar property at amounts below the carrying value. Assets are grouped for measurement of impairment at the lowest level for which identifiable cash flows are largely independent of the cash flows of other assets. If the carrying amount of an asset group exceeds the estimated undiscounted future cash flows expected to be generated by the asset group, then an impairment charge is recognized to the extent the carrying amount exceeds the asset group’s fair value. In determining fair value, management considers current results, trends, future prospects, and other economic factors.
Leases	Leases The Company leases office facilities and equipment under operating leases. In February 2016, the Financial Accounting Standards Board (“FASB”) issued ASU No. 2016-02, “Leases” (Topic 842) which requires lessees to recognize a right-of-use (“ROU”) asset and a lease liability for all leases with terms greater than 12 months and also requires disclosures by lessees and lessors about the amount, timing and uncertainty of cash flows arising from leases. We determine whether an arrangement is or contains a lease at inception. We record our operating lease liabilities and right-of-use (ROU) assets at the lease commencement date. Operating lease liabilities are based on the present value of future minimum lease payments over the lease term, and include options to renew a lease in the future minimum lease payments if it is reasonably certain that the Company will exercise that option. ROU assets are based on the lease liability, adjusted for any lease prepayments and lease incentives. If a lease does not provide an implicit interest rate, we use our incremental borrowing rate on a collateralized basis from the information available at commencement date in determining the present value of lease payments. Leases with initial terms of 12 months or less are considered short-term lease costs and are not recorded as ROU assets on the consolidated balance sheets. ROU assets are reviewed for impairment in the same manner as long-lived assets. No impairment has been recorded in the periods presented. The Company has elected the practical expedient not to separate non-lease components from lease components for all classes of assets. Our lease agreements contain $3.7 million of residual value guarantees and generally do not contain material variable lease payments or restrictive covenants.
Workers' compensation claims liabilities	Workers’ compensation claims liabilities Our workers’ compensation claims liabilities do not represent an exact calculation of liability but rather management’s best estimate, utilizing actuarial expertise and projection techniques, at a given reporting date. The estimated liability for open workers’ compensation claims is based on an evaluation of information provided by our third-party administrator for workers’ compensation claims, coupled with an actuarial estimate of future loss development with respect to reported claims and incurred but not reported claims (together, “IBNR”). Workers’ compensation claims liabilities include case reserve estimates for reported losses, plus additional amounts for estimated IBNR claims, MCC and legal costs, unallocated loss adjustment expenses and estimated future recoveries. The estimate of incurred costs expected to be paid within one year is included in current liabilities, while the estimate of incurred costs expected to be paid beyond one year is included in long-term liabilities on our consolidated balance sheets. These estimates are reviewed at least quarterly and adjustments to estimated liabilities are reflected in current operating results as they become known. The process of arriving at an estimate of unpaid claims and claims adjustment expense involves a high degree of judgment and is affected by both internal and external events, including changes in claims handling practices, changes in reserve estimation procedures , inflation, trends in the litigation and settlement of pending claims, and legislative changes. Our estimates are based on actuarial analysis and informed judgment, derived from individual experience and expertise applied to multiple sets of data and analyses. We consider significant facts and circumstances known both at the time that loss reserves are initially established and as new facts and circumstances become known. Due to the inherent uncertainty underlying loss reserve estimates, the expenses incurred through final resolution of our liability for our workers’ compensation claims will likely vary from the related loss reserves at the reporting date. Therefore, as specific claims are paid out in the future, actual paid losses may be materially different from our current loss reserves. A basic premise in most actuarial analyses is that historical data and past patterns demonstrated in the incurred and paid historical data form a reasonable basis upon which to project future outcomes, absent a material change. Significant structural changes to the available data can materially impact the reserve estimation process. To the extent a material change affecting the ultimate claim liability becomes known, such change is quantified to the extent possible through an analysis of internal Company data and, if available and when appropriate, external data. Nonetheless, actuaries exercise a considerable degree of judgment in the evaluation of these factors and the need for such actuarial judgment is more pronounced when faced with material uncertainties.
Safety incentives	Safety incentives We accrue for and present expected safety incentives as a reduction of revenue. Safety incentives represent cash incentives paid to certain PEO client companies for maintaining safe work practices and minimizing workplace injuries. The incentive is based on a percentage of annual payroll and is paid annually to customers who meet predetermined workers’ compensation claims cost objectives. Safety incentive payments are made only after closure of all workers' compensation claims incurred during the customer’s contract period. The safety incentive liability is estimated and accrued each month based upon contract year-to-date payroll and the then current amount of the customer’s estimated workers’ compensation claims reserves as established by us and our third-party administrator. In July 2020, the Company began limiting its safety incentive offering in certain markets. The Company provided $4.3 million and $18.8 million at December 31, 2021 and 2020, respectively, as an estimate of the liability for unpaid safety incentives.
Customer deposits	Customer deposits We require deposits from certain PEO customers to cover a portion of our accounts receivable due from such customers in the event of default of payment.
Comprehensive income (loss)	Comprehensive income (loss) Comprehensive income (loss) includes all changes in equity during a period except those that resulted from investments by or distributions to the Company's stockholders. Other comprehensive income (loss) refers to revenues, expenses, gains and losses that under U.S. generally accepted accounting principles (“GAAP”) are included in comprehensive income (loss), but excluded from net income (loss) as these amounts are recorded directly as an adjustment to stockholders' equity. Our other comprehensive income (loss) comprises unrealized holding gains and losses on our available-for-sale investments.
Statements of cash flows	Statements of cash flows Interest paid in 2021, 2020, and 2019 did not materially differ from interest expense. Income taxes paid by the Company totaled $4.7 million, $8.5 million, and $15.4 million in 2021, 2020, and 2019, respectively. Bank deposits and other cash equivalents that are restricted for use are classified as restricted cash. The table below reconciles the cash, cash equivalents and restricted cash balances from our consolidated balance sheets to the amounts reported on the consolidated statements of cash flows (in thousands): December 31, December 31, December 31, 2021 2020 2019 Cash and cash equivalents $ 69,405 $ 68,688 $ 44,570 Restricted cash, included in restricted cash and investments 9,224 165,149 228,771 Total cash, cash equivalents and restricted cash shown in the statement of cash flows $ 78,629 $ 233,837 $ 273,341
Basic and diluted earnings per share	Basic and diluted earnings per share Basic earnings per share are computed based on the weighted average number of common shares outstanding for each year using the treasury method. Diluted earnings per share reflect the potential effects of the issuance of shares in connection with the Year Ended December 31, 2021 2020 2019 Weighted average number of basic shares outstanding 7,540 7,577 7,451 Effect of dilutive securities 81 111 248 Weighted average number of diluted shares outstanding 7,621 7,688 7,699
Accounting estimates	Accounting estimates The preparation of our consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions. These affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting periods. Management bases its estimates on historical experience and on various other assumptions that are believed to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Estimates are used for fair value measurement of investments, allowance for doubtful accounts, deferred income taxes, carrying values for goodwill and property, equipment and software, accrued workers' compensation liabilities and safety incentive liabilities. Actual results may or may not differ from such estimates.
Recent accounting pronouncements	Recent accounting pronouncements There were no new or pending accounting pronouncements in 2021 that had, or will have, a material impact on our results of operations or financial condition.

Summary of Operations and Sig_3

Summary of Operations and Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2021
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Summary of Allowance for Doubtful Accounts	Our allowance for doubtful accounts activity is summarized as follows (in thousands): 2021 2020 2019 Balance at January 1, Allowance for doubtful accounts $ 757 $ 888 $ 533 Charges to expense 193 125 459 Write-offs of uncollectible accounts, net of recoveries (490 ) (256 ) (104 ) Balance at December 31, Allowance for doubtful accounts $ 460 $ 757 $ 888
Summary of Property, Equipment and Software Over Estimated Useful Life	Depreciation of property and equipment and amortization of software is calculated using the straight-line method over estimated useful lives of the related assets or lease terms, as follows: Years Buildings 39 Office furniture and fixtures 7 Computer hardware, software and software development costs 3 - 10 Leasehold improvements 1 - 7
Schedule of Reconciles of Cash, Cash Equivalents and Restricted Cash Balances	The table below reconciles the cash, cash equivalents and restricted cash balances from our consolidated balance sheets to the amounts reported on the consolidated statements of cash flows (in thousands): December 31, December 31, December 31, 2021 2020 2019 Cash and cash equivalents $ 69,405 $ 68,688 $ 44,570 Restricted cash, included in restricted cash and investments 9,224 165,149 228,771 Total cash, cash equivalents and restricted cash shown in the statement of cash flows $ 78,629 $ 233,837 $ 273,341
Summary of Basic and Diluted Common Shares Outstanding	Basic and diluted shares outstanding are summarized as follows (in thousands): Year Ended December 31, 2021 2020 2019 Weighted average number of basic shares outstanding 7,540 7,577 7,451 Effect of dilutive securities 81 111 248 Weighted average number of diluted shares outstanding 7,621 7,688 7,699

Fair Value Measurement (Tables)

Fair Value Measurement (Tables)	12 Months Ended
	Dec. 31, 2021
Fair Value Disclosures [Abstract]
Summary of Investments Measured at Fair Value on Recurring Basis	The following table summarizes the Company’s investments at December 31, 2021 and 2020 measured at fair value on a recurring basis (in thousands): December 31, 2021 December 31, 2020 Gross Gross Unrealized Unrealized Gains Recorded Gains Recorded Cost (Losses) Basis Cost (Losses) Basis Current: Cash equivalents: Money market funds $ 13,384 $ — $ 13,384 $ 42,007 $ — $ 42,007 Total cash equivalents 13,384 — 13,384 42,007 — 42,007 Investments: Corporate bonds 41,954 (136 ) 41,818 50,918 884 51,802 Asset backed securities 29,533 (38 ) 29,495 36,948 (146 ) 36,802 U.S. government agency securities 7,383 418 7,801 7,396 752 8,148 Mortgage backed securities 18,089 (440 ) 17,649 4,367 24 4,391 U.S. treasuries — — — 100 1 101 Total current investments 96,959 (196 ) 96,763 99,729 1,515 101,244 Restricted cash and investments (1) Corporate bonds 117,700 (17 ) 117,683 88,902 4,091 92,993 Mortgage backed securities 64,217 764 64,981 48,795 2,356 51,151 Money market funds 528 — 528 40,063 (4 ) 40,059 U.S. government agency securities 32,898 1,281 34,179 29,737 2,466 32,203 Mutual funds 6,273 — 6,273 5,036 — 5,036 Supranational bonds — — — 4,775 3 4,778 U.S. treasuries 67,614 (342 ) 67,272 4,371 19 4,390 Asset backed securities 107 1 108 256 4 260 Total restricted cash and investments 289,337 1,687 291,024 221,935 8,935 230,870 Total investments $ 399,680 $ 1,491 $ 401,171 $ 363,671 $ 10,450 $ 374,121 (1) Included in restricted cash and investments within the consolidated balance sheets as of December 31, 2021 and 2020 is restricted cash of $9.2 million and $124.3 million, respectively, which is excluded from the table above. Restricted cash and investments are classified as current and noncurrent on the balance sheet based on the nature of the restriction.
Summary of Assets Measured at Fair Value on Recurring Basis	The following table summarizes the Company's investments at December 31, 2021 and 2020 measured at fair value on a recurring basis by fair value hierarchy level (in thousands): December 31, 2021 December 31, 2020 Total Total Recorded Recorded Basis Level 1 Level 2 Level 3 Other (1) Basis Level 1 Level 2 Level 3 Other (1) Cash equivalents: Money market funds 13,384 $ — $ — $ — $ 13,384 $ 42,007 $ — $ — $ — $ 42,007 Investments: Corporate bonds 41,818 — 41,818 — — 51,802 — 51,802 — — Asset backed securities 29,495 — 29,495 — — 36,802 — 36,802 — — U.S. government agency securities 7,801 — 7,801 — — 8,148 — 8,148 — — Mortgage backed securities 17,649 — 17,649 — — 4,391 — 4,391 — — U.S. treasuries — — — — — 101 — 101 — — Restricted cash and investments: Corporate bonds 117,683 — 117,683 — — 92,993 — 92,993 — — Mortgage backed securities 64,981 — 64,981 — — 51,151 — 51,151 — — Money market funds 528 — — — 528 40,059 — — — 40,059 U.S. government agency securities 34,179 — 34,179 — — 32,203 — 32,203 — — Mutual funds 6,273 6,273 — — — 5,036 5,036 — — — Supranational bonds — — — — — 4,778 — 4,778 — — U.S. treasuries 67,272 — 67,272 — — 4,390 — 4,390 — — Asset backed securities 108 — 108 — — 260 — 260 — — Total investments $ 401,171 $ 6,273 $ 380,986 $ — $ 13,912 $ 374,121 $ 5,036 $ 287,019 $ — $ 82,066 (1) Investments in money market funds measured at fair value using the net asset value per share practical expedient are not subject to hierarchy level classification disclosure. The Company invests in money market funds that seek to maintain a stable net asset value. These investments include commingled funds that comprise high-quality short-term securities representing liquid debt and monetary instruments where the redemption value is likely to be the fair value. Redemption is permitted daily without written notice.
Summary of Contractual Maturities of Available for Sale Securities	The following table summarizes the contractual maturities of the Company’s available for sale securities at December 31, 2021 and 2020. Actual maturities may differ from contractual maturities because borrowers may have the right to prepay obligations with or without prepayment penalties. December 31, 2021 (In thousands) Less than 1 Year Between 1 to 5 Years Between 5 to 10 Years After 10 Years Total Corporate bonds $ 24,601 $ 35,570 $ 99,180 $ 150 $ 159,501 Money market funds 13,657 — — — 13,657 U.S. government agency securities — 25,171 16,809 — 41,980 Asset backed securities — 108 2,200 27,295 29,603 Supranational bonds — — — — — U.S. treasuries 953 4,295 62,024 — 67,272 Total $ 39,211 $ 65,144 $ 180,213 $ 27,445 $ 312,013 December 31, 2020 (In thousands) Less than 1 Year Between 1 to 5 Years Between 5 to 10 Years After 10 Years Total Corporate bonds $ 49,308 $ 61,315 $ 34,172 $ — $ 144,795 Money market funds 82,066 — — — 82,066 U.S. government agency securities 1,013 18,668 20,670 — 40,351 Asset backed securities 2 267 — 36,793 37,062 Supranational bonds 4,778 — — — 4,778 U.S. treasuries 1,367 1,504 1,620 — 4,491 Total $ 138,534 $ 81,754 $ 56,462 $ 36,793 $ 313,543

Property, Equipment and Softw_2

Property, Equipment and Software (Tables)	12 Months Ended
	Dec. 31, 2021
Property Plant And Equipment [Abstract]
Summary of Property, Equipment and Software	Property, equipment and software consists of the following (in thousands): December 31, 2021 2020 Buildings $ 16,857 $ 16,498 Office furniture and fixtures 14,159 13,691 Computer hardware and software 11,458 11,591 Software development costs 23,332 18,353 Other 512 437 66,318 60,570 Less accumulated depreciation and amortization (31,531 ) (27,144 ) 34,787 33,426 Land 1,490 1,490 $ 36,277 $ 34,916

Workers' Compensation Claims (T

Workers' Compensation Claims (Tables)	12 Months Ended
	Dec. 31, 2021
Text Block [Abstract]
Summarizes Aggregate Workers' Compensation Reserve Activity	The following table summarizes the aggregate workers' compensation reserve activity (in thousands): Years Ended December 31, 2021 2020 2019 Beginning balance Workers' compensation claims liabilities $ 357,746 $ 438,986 $ 413,397 Add: claims expense accrual Current period 75,786 147,097 161,691 Prior periods (9,225 ) (6,383 ) (13,355 ) 66,561 140,714 148,336 Less: claim payments related to Current period 15,063 22,877 24,414 Prior periods 129,138 198,620 98,445 144,201 221,497 122,859 Change in claims incurred in excess of retention limits (699 ) (457 ) 112 Ending balance Workers' compensation claims liabilities $ 279,407 $ 357,746 $ 438,986 Incurred but not reported (IBNR) $ 153,838 $ 210,798 $ 285,191 Ratio of IBNR to workers' compensation claims liabilities 55 % 59 % 65 %
Summary of Risk Retained by Insured Program after Considering Loss Portfolio Transfers and Current Insurance Arrangements	The following is a summary of the risk retained by the Company under its insured program after considering the effects of the loss portfolio transfers and current insurance arrangements: Year Claims risk retained 2014 No 2015 No 2016 No 2017 No 2018 (1) No 2019 (1) Yes 2020 Yes 2021 - Through June 30 Yes 2021 - July 1 and after No ( 1) LPT 2 excluded approximately 10% of claims from 2018 and included an approximately offsetting amount of claims from 2019.

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2021
Leases [Abstract]
Summary of Lease Costs	Information related to the Company's total lease costs was as follows (in thousands): Year Ended December 31, 2021 December 31, 2020 Operating lease cost $ 8,957 $ 8,352 Variable lease cost 689 928 Short-term lease cost 94 709 Total lease cost $ 9,740 $ 9,989
Summary of Information Related to ROU Assets and Related Lease Liabilities	Information related to the Company's ROU assets and related lease liabilities was as follows (in thousands): Year Ended December 31, 2021 December 31, 2020 Cash paid for operating lease liabilities $ 8,854 $ 8,136 Right-of-use assets obtained in exchange for new operating lease obligations 5,717 6,444 December 31, 2021 December 31, 2020 Weighted-average remaining lease term 3.6 years 3.7 years Weighted-average discount rate 3.6 % 3.9 %
Reconciliation of Undiscounted Future Minimum Lease Payments Under Noncancellable Operating Leases	The table below reconciles the undiscounted future minimum lease payments (displayed by year and in the aggregate) under noncancellable operating leases with terms of more than one year to the total operating lease liabilities recognized on the consolidated balance sheets as of December 31, 2021 (in thousands): 2022 $ 7,807 2023 6,405 2024 4,359 2025 2,231 2026 1,322 Thereafter 1,038 Total undiscounted future minimum lease payments 23,162 Less: Difference between undiscounted lease payments and discounted operating lease liabilities 1,373 Total operating lease liabilities $ 21,789 Current operating lease liabilities $ 7,191 Long-term operating lease liabilities 14,598 Total operating lease liabilities $ 21,789

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Summary of Provision for Income Taxes	The provision for income taxes is as follows (in thousands): Year Ended December 31, 2021 2020 2019 Current: Federal $ 9,527 $ 2,943 $ 8,806 State 3,408 396 1,381 12,935 3,339 10,187 Deferred: Federal 143 4,156 (774 ) State (496 ) 1,336 3,433 (353 ) 5,492 2,659 Total provision $ 12,582 $ 8,831 $ 12,846
Summary of Deferred Income Tax Assets and Liabilities	Deferred income tax assets and liabilities consist of the following components (in thousands): December 31, 2021 2020 Deferred income tax assets: Workers' compensation claims liabilities $ 7,870 $ 9,946 Deferred compensation 6,109 2,235 Operating lease liability 5,870 6,107 Other 1,388 1,154 Payroll tax deferral 749 1,668 Equity based compensation 678 555 State credit carryforward 329 518 MCC accrual 167 1,062 Customer incentives 12 54 23,172 23,299 Less: valuation allowance 163 163 23,009 23,136 Deferred income tax liabilities: Tax amortization of goodwill (10,120 ) (10,375 ) Tax depreciation in excess of book depreciation (7,433 ) (7,187 ) Operating lease right-of-use (5,527 ) (5,766 ) Other (1,223 ) (1,455 ) Tax effect of unrealized gains, net (393 ) (2,871 ) (24,696 ) (27,654 ) Net deferred income taxes $ (1,687 ) $ (4,518 )
Summary of Effective Tax Rate Differed from U.S. Statutory Federal Tax Rate	The effective tax rate differed from the U.S. statutory federal tax rate due to the following: Year Ended December 31, 2021 2020 2019 Statutory federal tax rate 21.0 % 21.0 % 21.0 % State taxes, net of federal benefit 4.5 3.2 6.2 Adjustment for final positions on filed returns 0.9 0.6 (0.2 ) Nondeductible expenses and other, net 0.5 0.7 1.3 Federal and state tax credits (2.1 ) (4.9 ) (7.5 ) Other, net — 0.1 0.2 24.8 % 20.7 % 21.0 %

Stock Incentive Plans (Tables)

Stock Incentive Plans (Tables)	12 Months Ended
	Dec. 31, 2021
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Summary of Stock Options Activity	A summary of the status of the Company’s stock options at December 31, 2021, together with changes during the periods then ended, is presented below: Weighted Weighted Average Aggregate Average Remaining Intrinsic Number Exercise Contractual Value of Options Price Term (Years) (In Thousands) Outstanding at December 31, 2020 139,648 $ 56.13 — — Options exercised (34,773 ) 17.60 — — Outstanding at December 31, 2021 104,875 68.91 5.32 1,068 Exercisable at December 31, 2021 24,875 $ 26.12 2.40 $ 1,068
Schedule of Restricted Stock Unit Activity	The following table presents restricted stock unit activity: Weighted Average Grant Date Units Fair Value Nonvested at December 31, 2020 181,823 $ 59.16 Granted 91,409 72.23 Vested (60,038 ) 60.48 Cancelled/Forfeited (17,130 ) 53.08 Nonvested at December 31, 2021 196,064 $ 65.38
Schedule of Performance Share Unit Activity	The following table presents PSU activity: Weighted Average Grant Date Units Fair Value Nonvested at December 31, 2020 8,464 $ 76.78 Granted 29,821 69.17 Vested (3,360 ) 82.21 Cancelled/Forfeited (592 ) 82.21 Nonvested at December 31, 2021 34,333 $ 69.54

Summary of Operations and Sig_4

Summary of Operations and Significant Accounting Policies - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2021USD ($)BranchSegmentCompany	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)
Basis Of Presentation Of Interim Period Statements [Line Items]
Number Of Branch Offices | Branch	50
Number of operating segment | Segment	1
Revenue recognition professional employer service contracts term	1 year
Professional employer service contract cancellation and termination period	30 days
Payment term for staffing customers	30 days
Number of wholly-owned insurance companies | Company	2
Cash and cash equivalents, maturity term	3 months
Allowance for doubtful accounts	$ 460,000	$ 757,000	$ 888,000	$ 533,000
Number of reporting units | Segment	1
Goodwill and intangible assets impairment	$ 0
Impairment of long lived asset	0
Residual value of leased asset	3,700,000
Estimate of liability for unpaid safety incentives	4,300,000	18,800,000
Income taxes paid	$ 4,700,000	$ 8,500,000	$ 15,400,000
Minimum [Member]
Basis Of Presentation Of Interim Period Statements [Line Items]
Likelihood of tax benefit being realized upon settlement	50.00%
California [Member] | Revenue [Member] | Geographic Concentration Risk [Member]
Basis Of Presentation Of Interim Period Statements [Line Items]
Percentage of revenue attributable to geographic area	73.00%	75.00%	77.00%

Summary of Operations and Sig_5

Summary of Operations and Significant Accounting Policies - Summary of Allowance for Doubtful Accounts (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Receivables [Abstract]
Allowance for doubtful accounts, beginning balance	$ 757,000	$ 888,000	$ 533,000
Charges to expense	193,000	125,000	459,000
Write-offs of uncollectible accounts, net of recoveries	(490,000)	(256,000)	(104,000)
Allowance for doubtful accounts, ending balance	$ 460,000	$ 757,000	$ 888,000

Summary of Operations and Sig_6

Summary of Operations and Significant Accounting Policies - Summary of Property, Equipment and Software Over Estimated Useful Life (Detail)	12 Months Ended
	Dec. 31, 2021
Buildings [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	39 years
Office Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	7 years
Minimum [Member] | Computer Hardware, Software and Software Development Costs [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	3 years
Minimum [Member] | Leaseholds and Leasehold Improvements
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	1 year
Maximum [Member] | Computer Hardware, Software and Software Development Costs [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	10 years
Maximum [Member] | Leaseholds and Leasehold Improvements
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	7 years

Summary of Operations and Sig_7

Summary of Operations and Significant Accounting Policies - Schedule of Reconciles of Cash, Cash Equivalents and Restricted Cash Balances (Detail) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents [Abstract]
Cash and cash equivalents	$ 69,405	$ 68,688	$ 44,570
Restricted cash, included in restricted cash and investments	9,224	165,149	228,771
Total cash, cash equivalents and restricted cash shown in the statement of cash flows	$ 78,629	$ 233,837	$ 273,341

Summary of Operations and Sig_8

Summary of Operations and Significant Accounting Policies - Summary of Basic and Diluted Common Shares Outstanding (Detail) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Weighted Average Number Of Shares Outstanding Diluted Disclosure Items [Abstract]
Weighted average number of basic shares outstanding	7,540	7,577	7,451
Effect of dilutive securities	81	111	248
Weighted average number of diluted shares outstanding	7,621	7,688	7,699

Concentration of Credit Risk -

Concentration of Credit Risk - Additional Information (Detail) - Credit Concentration Risk [Member] $ in Millions	Dec. 31, 2021USD ($)
Corporate Bonds [Member]
Concentration Risk [Line Items]
Fair value of financial instruments	$ 159.5
Mortgage Backed Securities [Member]
Concentration Risk [Line Items]
Fair value of financial instruments	82.6
U.S. Treasuries [Member]
Concentration Risk [Line Items]
Fair value of financial instruments	67.3
U.S. Government Agency Securities [Member]
Concentration Risk [Line Items]
Fair value of financial instruments	42
Asset Backed Securities [Member]
Concentration Risk [Line Items]
Fair value of financial instruments	29.6
Money Market Funds [Member]
Concentration Risk [Line Items]
Fair value of financial instruments	13.9
Mutual Funds [Member]
Concentration Risk [Line Items]
Fair value of financial instruments	$ 6.3

Fair Value Measurement - Summar

Fair Value Measurement - Summary of Investments Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cost	$ 399,680	$ 363,671
Gross Unrealized Gains (Losses)	1,491	10,450
Recorded Basis	401,171	374,121
Investments Current [Member] | Cash and Cash Equivalents [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cost	13,384	42,007
Recorded Basis	13,384	42,007
Investments Current [Member] | Cash and Cash Equivalents [Member] | Money Market Funds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cost	13,384	42,007
Recorded Basis	13,384	42,007
Investments Current [Member] | Investments [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cost	96,959	99,729
Gross Unrealized Gains (Losses)	(196)	1,515
Recorded Basis	96,763	101,244
Investments Current [Member] | Investments [Member] | Corporate Bonds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cost	41,954	50,918
Gross Unrealized Gains (Losses)	(136)	884
Recorded Basis	41,818	51,802
Investments Current [Member] | Investments [Member] | Asset Backed Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cost	29,533	36,948
Gross Unrealized Gains (Losses)	(38)	(146)
Recorded Basis	29,495	36,802
Investments Current [Member] | Investments [Member] | U.S. Government Agency Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cost	7,383	7,396
Gross Unrealized Gains (Losses)	418	752
Recorded Basis	7,801	8,148
Investments Current [Member] | Investments [Member] | Mortgage Backed Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cost	18,089	4,367
Gross Unrealized Gains (Losses)	(440)	24
Recorded Basis	17,649	4,391
Investments Current [Member] | Investments [Member] | U.S. Treasuries [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cost		100
Gross Unrealized Gains (Losses)		1
Recorded Basis		101
Investments Noncurrent [Member] | Restricted Cash and Investments [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cost	289,337	221,935
Gross Unrealized Gains (Losses)	1,687	8,935
Recorded Basis	291,024	230,870
Investments Noncurrent [Member] | Restricted Cash and Investments [Member] | Money Market Funds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cost	528	40,063
Gross Unrealized Gains (Losses)		(4)
Recorded Basis	528	40,059
Investments Noncurrent [Member] | Restricted Cash and Investments [Member] | Corporate Bonds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cost	117,700	88,902
Gross Unrealized Gains (Losses)	(17)	4,091
Recorded Basis	117,683	92,993
Investments Noncurrent [Member] | Restricted Cash and Investments [Member] | Asset Backed Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cost	107	256
Gross Unrealized Gains (Losses)	1	4
Recorded Basis	108	260
Investments Noncurrent [Member] | Restricted Cash and Investments [Member] | U.S. Government Agency Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cost	32,898	29,737
Gross Unrealized Gains (Losses)	1,281	2,466
Recorded Basis	34,179	32,203
Investments Noncurrent [Member] | Restricted Cash and Investments [Member] | Mortgage Backed Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cost	64,217	48,795
Gross Unrealized Gains (Losses)	764	2,356
Recorded Basis	64,981	51,151
Investments Noncurrent [Member] | Restricted Cash and Investments [Member] | U.S. Treasuries [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cost	67,614	4,371
Gross Unrealized Gains (Losses)	(342)	19
Recorded Basis	67,272	4,390
Investments Noncurrent [Member] | Restricted Cash and Investments [Member] | Mutual Funds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cost	6,273	5,036
Recorded Basis	$ 6,273	5,036
Investments Noncurrent [Member] | Restricted Cash and Investments [Member] | Supranational Bonds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cost		4,775
Gross Unrealized Gains (Losses)		3
Recorded Basis		$ 4,778

Fair Value Measurement - Summ_2

Fair Value Measurement - Summary of Investments Measured at Fair Value on Recurring Basis (Parenthetical) (Detail) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Fair Value Disclosures [Abstract]
Restricted cash	$ 9.2	$ 124.3

Fair Value Measurement - Summ_3

Fair Value Measurement - Summary of Assets Measured at Fair Value on Recurring Basis (Detail) - Fair Value, Measurements, Recurring [Member] - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Recorded Basis	$ 401,171	$ 374,121
Other [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Recorded Basis	13,912	82,066
Level 1 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Recorded Basis	6,273	5,036
Level 2 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Recorded Basis	380,986	287,019
Cash and Cash Equivalents [Member] | Money Market Funds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Recorded Basis	13,384	42,007
Cash and Cash Equivalents [Member] | Money Market Funds [Member] | Other [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Recorded Basis	13,384	42,007
Investments [Member] | Corporate Bonds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Recorded Basis	41,818	51,802
Investments [Member] | Corporate Bonds [Member] | Level 2 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Recorded Basis	41,818	51,802
Investments [Member] | Mortgage Backed Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Recorded Basis	17,649	4,391
Investments [Member] | Mortgage Backed Securities [Member] | Level 2 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Recorded Basis	17,649	4,391
Investments [Member] | U.S. Treasuries [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Recorded Basis		101
Investments [Member] | U.S. Treasuries [Member] | Level 2 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Recorded Basis		101
Investments [Member] | U.S. Government Agency Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Recorded Basis	7,801	8,148
Investments [Member] | U.S. Government Agency Securities [Member] | Level 2 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Recorded Basis	7,801	8,148
Investments [Member] | Asset Backed Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Recorded Basis	29,495	36,802
Investments [Member] | Asset Backed Securities [Member] | Level 2 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Recorded Basis	29,495	36,802
Restricted Cash and Investments [Member] | Money Market Funds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Recorded Basis	528	40,059
Restricted Cash and Investments [Member] | Money Market Funds [Member] | Other [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Recorded Basis	528	40,059
Restricted Cash and Investments [Member] | Corporate Bonds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Recorded Basis	117,683	92,993
Restricted Cash and Investments [Member] | Corporate Bonds [Member] | Level 2 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Recorded Basis	117,683	92,993
Restricted Cash and Investments [Member] | Mortgage Backed Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Recorded Basis	64,981	51,151
Restricted Cash and Investments [Member] | Mortgage Backed Securities [Member] | Level 2 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Recorded Basis	64,981	51,151
Restricted Cash and Investments [Member] | U.S. Treasuries [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Recorded Basis	67,272	4,390
Restricted Cash and Investments [Member] | U.S. Treasuries [Member] | Level 2 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Recorded Basis	67,272	4,390
Restricted Cash and Investments [Member] | U.S. Government Agency Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Recorded Basis	34,179	32,203
Restricted Cash and Investments [Member] | U.S. Government Agency Securities [Member] | Level 2 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Recorded Basis	34,179	32,203
Restricted Cash and Investments [Member] | Asset Backed Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Recorded Basis	108	260
Restricted Cash and Investments [Member] | Asset Backed Securities [Member] | Level 2 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Recorded Basis	108	260
Restricted Cash and Investments [Member] | Supranational Bonds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Recorded Basis		4,778
Restricted Cash and Investments [Member] | Supranational Bonds [Member] | Level 2 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Recorded Basis		4,778
Restricted Cash and Investments [Member] | Mutual Funds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Recorded Basis	6,273	5,036
Restricted Cash and Investments [Member] | Mutual Funds [Member] | Level 1 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Recorded Basis	$ 6,273	$ 5,036

Fair Value Measurement - Summ_4

Fair Value Measurement - Summary of Contractual Maturities of Available for Sale Securities (Detail) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Schedule Of Available For Sale Securities [Line Items]
Available for sale securities, contractual maturities less than 1 year	$ 39,211	$ 138,534
Available for sale securities, contractual maturities between 1 to 5 years	65,144	81,754
Available for sale securities, contractual maturities between 5 to 10 years	180,213	56,462
Available for sale securities, contractual maturities after 10 years	27,445	36,793
Available for sale securities, contractual maturities, Total	312,013	313,543
Corporate Bonds [Member]
Schedule Of Available For Sale Securities [Line Items]
Available for sale securities, contractual maturities less than 1 year	24,601	49,308
Available for sale securities, contractual maturities between 1 to 5 years	35,570	61,315
Available for sale securities, contractual maturities between 5 to 10 years	99,180	34,172
Available for sale securities, contractual maturities after 10 years	150
Available for sale securities, contractual maturities, Total	159,501	144,795
U.S. Treasuries [Member]
Schedule Of Available For Sale Securities [Line Items]
Available for sale securities, contractual maturities less than 1 year	953	1,367
Available for sale securities, contractual maturities between 1 to 5 years	4,295	1,504
Available for sale securities, contractual maturities between 5 to 10 years	62,024	1,620
Available for sale securities, contractual maturities, Total	67,272	4,491
U.S. Government Agency Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Available for sale securities, contractual maturities less than 1 year		1,013
Available for sale securities, contractual maturities between 1 to 5 years	25,171	18,668
Available for sale securities, contractual maturities between 5 to 10 years	16,809	20,670
Available for sale securities, contractual maturities, Total	41,980	40,351
Supranational Bonds [Member]
Schedule Of Available For Sale Securities [Line Items]
Available for sale securities, contractual maturities less than 1 year		4,778
Available for sale securities, contractual maturities, Total		4,778
Money Market Funds [Member]
Schedule Of Available For Sale Securities [Line Items]
Available for sale securities, contractual maturities less than 1 year	13,657	82,066
Available for sale securities, contractual maturities, Total	13,657	82,066
Asset Backed Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Available for sale securities, contractual maturities less than 1 year		2
Available for sale securities, contractual maturities between 1 to 5 years	108	267
Available for sale securities, contractual maturities between 5 to 10 years	2,200
Available for sale securities, contractual maturities after 10 years	27,295	36,793
Available for sale securities, contractual maturities, Total	$ 29,603	$ 37,062

Fair Value Measurement - Additi

Fair Value Measurement - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Mortgage Backed Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Average contractual maturity period	23 years	23 years

Property, Equipment and Softw_3

Property, Equipment and Software - Summary of Property, Equipment and Software (Detail) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment	$ 66,318	$ 60,570
Less accumulated depreciation and amortization	(31,531)	(27,144)
Property, Plant and Equipment, Gross	34,787	33,426
Land	1,490	1,490
Property, Plant and Equipment, Net	36,277	34,916
Buildings [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment	16,857	16,498
Office Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment	14,159	13,691
Computer Hardware and Software [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment	11,458	11,591
Software Development Costs [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment	23,332	18,353
Other [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment	$ 512	$ 437

Property, Equipment and Softw_4

Property, Equipment and Software - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Property Plant And Equipment [Abstract]
Depreciation expense	$ 3,100,000	$ 3,400,000	$ 3,300,000
Amortization of capitalized software development costs	2,200,000	1,400,000	531,000
Capitalized software development costs	$ 5,000,000	$ 6,000,000	$ 8,300,000

Workers' Compensation Claims -

Workers' Compensation Claims - Summarizes Aggregate Workers' Compensation Reserve Activity (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Workers Compensation Reserve [Abstract]
Workers' compensation claims liabilities, Beginning balance	$ 357,746	$ 438,986	$ 413,397
Add: claims expense accrual
Current period	75,786	147,097	161,691
Prior periods	(9,225)	(6,383)	(13,355)
Total expense accrual	66,561	140,714	148,336
Less: claim payments related to
Current period	15,063	22,877	24,414
Prior periods	129,138	198,620	98,445
Total paid	144,201	221,497	122,859
Change in claims incurred in excess of retention limits	(699)	(457)	112
Workers' compensation claims liabilities, Ending balance	279,407	357,746	438,986
Incurred but not reported (IBNR)	$ 153,838	$ 210,798	$ 285,191
Ratio of IBNR to workers' compensation claims liabilities	55.00%	59.00%	65.00%

Workers' Compensation Claims _2

Workers' Compensation Claims - Additional Information (Detail) - USD ($)	Jul. 01, 2021	Jun. 29, 2020	Jun. 30, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Description of renewed agreement				The Company entered into a new arrangement for its insured program effective July 1, 2021 whereby third-party insurers assume all risk of loss for claims incurred after June 30, 2021. The agreement continues to June 30, 2022 and includes a renewal commitment through June 30, 2023. The arrangement allows for premium adjustments depending on overall portfolio performance. If claims develop favorably, BBSI can participate in the savings up to $20.0 million for a twelve-month policy period. If claims develop adversely, additional premium may be charged up to $7.5 million for a twelve-month policy period.
Maximum savings amount for twelve month policy period, if claims develop favorably				$ 20,000,000
Maximum additional premium charged amount for twelve month policy period, if claims develop adversely				7,500,000
Balance in Chubb trust accounts		$ 115,700,000		273,600,000	$ 290,700,000
Workers compensation liability				279,407,000	357,746,000	$ 438,986,000	$ 413,397,000
Workers compensation liability, current				80,028,000	102,040,000
Collateral securities maintain to cover potential workers compensation claims losses				58,400,000	60,100,000
Surety bonds and standby letters of credit				58,400,000
Reserves incurred in excess of retention limits				2,200,000	2,900,000
Other Assets [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Accrual for costs incurred in excess of retention limits offset by a receivable				2,200,000	$ 2,900,000
California [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Surety bonds and standby letters of credit				$ 32,600,000
Insured Program [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of worker's compensation exposure covered				82.00%
Worker's compensation risk claim maximum	$ 3,000,000
Worker's compensation risk claim maximum		$ 5,000,000
Workers compensation liability				$ 53,100,000
Workers compensation liability, current				$ 5,000,000
Self Insured Programs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of worker's compensation exposure covered				18.00%
Worker's compensation risk claim maximum			$ 5,000,000	$ 3,000,000
Self Insured Programs [Member] | Maryland [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Reinsurance coverage			1,000,000	1,000,000
Self Insured Programs [Member] | Colorado [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Reinsurance coverage			$ 2,000,000	$ 2,000,000

Worker's Compensation Claims -

Worker's Compensation Claims - Summary of Risk Retained by Insured Program after Considering Loss Portfolio Transfers and Current Insurance Arrangements (Details)	12 Months Ended
	Dec. 31, 2021
2014 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Claims risk retained	No
2015 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Claims risk retained	No
2016 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Claims risk retained	No
2017 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Claims risk retained	No
2018 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Claims risk retained	No
2019 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Claims risk retained	Yes
2020 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Claims risk retained	Yes
2021 - Through June 30 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Claims risk retained	Yes
2021 - July 1 and After [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Claims risk retained	No

Worker's Compensation Claims _2

Worker's Compensation Claims - Summary of Risk Retained by Insured Program after Considering Loss Portfolio Transfers and Current Insurance Arrangements (Parenthetical) (Details)	12 Months Ended
	Dec. 31, 2021
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Percentage of claim excluded	10.00%

Revolving Credit Facility and_2

Revolving Credit Facility and Long-Term Debt - Additional Information (Detail) - USD ($)	1 Months Ended		3 Months Ended				12 Months Ended
	Mar. 31, 2022	Apr. 30, 2021	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2021	Dec. 31, 2020	Jun. 29, 2020
Line of Credit Facility [Line Items]
Line of credit facility commitment fee description							The Amended Agreement also provides for an unused commitment fee of 0.30% per year on the average daily unused amount of the revolving credit line
Balance in Chubb trust accounts			$ 273,600,000				$ 273,600,000	$ 290,700,000	$ 115,700,000
Agreement [Member]
Line of Credit Facility [Line Items]
Line of credit facility commitment fee description							The Agreement also provided for an unused commitment fee of 0.375% per year on the average daily unused amount of the revolving credit line, as well as a fee of 1.75% of the face amount of each letter of credit reserved under the line of credit.
Credit facility borrowing used			6,200,000				$ 6,200,000
Outstanding balance on term loan and revolving credit facility			$ 0				0	0
Balance in Chubb trust accounts		$ 25,000,000
Ratio of restricted and unrestricted cash and investments to workers' compensation and claim liabilities			1.00%	1.00%	1.00%	1.00%
Dividends or distributions paid							0
Maximum amount to redeem retire repurchase or acquire stock upon agreement							15,000,000
Minimum [Member]
Line of Credit Facility [Line Items]
Adjusted free cash flow amount			$ 10,000,000	$ 10,000,000	$ 10,000,000	$ 10,000,000
Tangible net worth amount			100,000,000	100,000,000	100,000,000	100,000,000
Minimum [Member] | Agreement [Member]
Line of Credit Facility [Line Items]
EBITDA			30,000,000	$ 30,000,000	$ 30,000,000	$ 30,000,000	30,000,000
Maximum [Member] | Agreement [Member]
Line of Credit Facility [Line Items]
Prohibition on incurring additional indebtedness without the prior approval of the Bank in purchase money financing							1,000,000
Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Credit facility borrowing capacity			50,000,000				50,000,000
Revolving Credit Facility [Member] | Agreement [Member]
Line of Credit Facility [Line Items]
Credit facility borrowing capacity			33,000,000				$ 33,000,000
Unused commitment fee on unused amount during period							0.375%
Revolving Credit Facility [Member] | SOFR [Member]
Line of Credit Facility [Line Items]
Term loan from bank interest rate description							) the daily Simple Secured Overnight Financing Rate (“SOFR”) plus 1.75% or (b) the one-month Term SOFR plus 1.75%.
Revolving Credit Facility [Member] | One-Month Term SOFR [Member]
Line of Credit Facility [Line Items]
Term loan from bank interest rate description							the one-month Term SOFR plus 1.75%.
Revolving Credit Facility [Member] | Daily Floating Rate [Member] | Agreement [Member]
Line of Credit Facility [Line Items]
Term loan from bank interest rate description							the daily floating rate of one-month London Inter-Bank Offered Rate (“LIBOR”) plus 1.75%
SOFR plus rate							1.75%
Revolving Credit Facility [Member] | Fixed Rate [Member] | Agreement [Member]
Line of Credit Facility [Line Items]
Term loan from bank interest rate description							the fixed rate of LIBOR plus 1.75%
SOFR plus rate							1.75%
Standby Letters of Credit [Member] | Agreement [Member]
Line of Credit Facility [Line Items]
Credit facility borrowing capacity			8,000,000				$ 8,000,000
Line of Credit [Member] | Agreement [Member]
Line of Credit Facility [Line Items]
Unused commitment fee on unused amount							1.75%
Chubb Letter of Credit [Member] | Agreement [Member]
Line of Credit Facility [Line Items]
Credit facility borrowing capacity			63,700,000				$ 63,700,000
Collateral transferred		$ 38,700,000
Term Loan [Member] | Agreement [Member]
Line of Credit Facility [Line Items]
Term loan from bank interest rate description							one-month LIBOR plus 2.0%
Term loan with principal bank			$ 3,500,000				$ 3,500,000	$ 3,700,000
Payment of monthly principal of term loan							$ 18,375
Term Loan [Member] | London Interbank Offered Rate (LIBOR) [Member] | Agreement [Member]
Line of Credit Facility [Line Items]
SOFR plus rate							2.00%
Scenario Forecast [Member] | Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Credit facility borrowing capacity	$ 33,000,000
Unused commitment fee on unused amount during period	0.30%
Scenario Forecast [Member] | Revolving Credit Facility [Member] | SOFR [Member]
Line of Credit Facility [Line Items]
SOFR plus rate	1.75%
Scenario Forecast [Member] | Revolving Credit Facility [Member] | One-Month Term SOFR [Member]
Line of Credit Facility [Line Items]
SOFR plus rate	1.75%
Scenario Forecast [Member] | Standby Letters of Credit [Member]
Line of Credit Facility [Line Items]
Credit facility borrowing capacity	$ 8,000,000

Benefit Plans - Additional Info

Benefit Plans - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Compensation And Retirement Disclosure [Abstract]
Discretionary Company contributions	$ 0	$ 0	$ 0
Employer matching contribution	1,900,000	1,800,000	$ 1,900,000
Long term portion of deferred compensation plan liability	6,300,000	4,900,000
Current portion of deferred compensation plan liability	200,000	100,000
Fair value of long term portion of deferred compensation plan liability	6,300,000	4,900,000
Fair value of current portion of deferred compensation plan liability	$ 200,000	$ 100,000

Leases - Additional Information

Leases - Additional Information (Detail) $ in Millions	Dec. 31, 2021USD ($)
Lessee Lease Description [Line Items]
Residual value of leased asset	$ 3.7
Operating lease not yet commenced	$ 2.1
Term of operating lease not yet commenced	7 years
Minimum [Member]
Lessee Lease Description [Line Items]
Remaining lease term, operating lease	1 year
Maximum [Member]
Lessee Lease Description [Line Items]
Remaining lease term, operating lease	7 years

Leases - Summary of Lease Costs

Leases - Summary of Lease Costs (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Lease Cost [Abstract]
Operating lease cost	$ 8,957	$ 8,352
Variable lease cost	689	928
Short-term lease cost	94	709
Total lease cost	$ 9,740	$ 9,989

Leases - Summary of Information

Leases - Summary of Information Related to ROU Assets and Related Lease Liabilities (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Assets And Liabilities Lessee [Abstract]
Cash paid for operating lease liabilities	$ 8,854	$ 8,136
Right-of-use assets obtained in exchange for new operating lease obligations	$ 5,717	$ 6,444
Weighted-average remaining lease term	3 years 7 months 6 days	3 years 8 months 12 days
Weighted-average discount rate	3.60%	3.90%

Leases - Reconciliation of Undi

Leases - Reconciliation of Undiscounted Future Minimum Lease Payments Under Noncancellable Operating Leases (Detail) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Operating Lease Liabilities Payments Due [Abstract]
2022	$ 7,807
2023	6,405
2024	4,359
2025	2,231
2026	1,322
Thereafter	1,038
Total undiscounted future minimum lease payments	23,162
Less: Difference between undiscounted lease payments and discounted operating lease liabilities	1,373
Total operating lease liabilities	21,789
Current operating lease liabilities	7,191	$ 7,539
Long-term operating lease liabilities	$ 14,598	$ 16,419

Income Taxes - Summary of Provi

Income Taxes - Summary of Provision for Income Taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Current:
Federal	$ 9,527	$ 2,943	$ 8,806
State	3,408	396	1,381
Current income tax expense	12,935	3,339	10,187
Deferred:
Federal	143	4,156	(774)
State	(496)	1,336	3,433
Deferred income taxes	(353)	5,492	2,659
Total provision	$ 12,582	$ 8,831	$ 12,846

Income Taxes - Summary of Defer

Income Taxes - Summary of Deferred Income Tax Assets and Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Deferred income tax assets:
Workers' compensation claims liabilities	$ 7,870	$ 9,946
Deferred compensation	6,109	2,235
Operating lease liability	5,870	6,107
Other	1,388	1,154
Payroll tax deferral	749	1,668
Equity based compensation	678	555
State credit carryforward	329	518
MCC accrual	167	1,062
Customer incentives	12	54
Deferred tax assets, gross total	23,172	23,299
Less: valuation allowance	163	163
Deferred tax assets, net total	23,009	23,136
Deferred income tax liabilities:
Tax amortization of goodwill	(10,120)	(10,375)
Tax depreciation in excess of book depreciation	(7,433)	(7,187)
Operating lease right-of-use	(5,527)	(5,766)
Other	(1,223)	(1,455)
Tax effect of unrealized gains, net	(393)	(2,871)
Deferred Tax Liabilities, gross total	(24,696)	(27,654)
Net deferred income taxes	$ (1,687)	$ (4,518)

Income Taxes - Summary of Effec

Income Taxes - Summary of Effective Tax Rate Differed from U.S. Statutory Federal Tax Rate (Detail)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Statutory federal tax rate	21.00%	21.00%	21.00%
State taxes, net of federal benefit	4.50%	3.20%	6.20%
Adjustment for final positions on filed returns	0.90%	0.60%	(0.20%)
Nondeductible expenses and other, net	0.50%	0.70%	1.30%
Federal and state tax credits	(2.10%)	(4.90%)	(7.50%)
Other, net		0.10%	0.20%
Total	24.80%	20.70%	21.00%

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($)	1 Months Ended		12 Months Ended
	Nov. 30, 2021	Jul. 31, 2020	Dec. 31, 2021	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Contingency [Line Items]
Operating loss carryforward			$ 0
Federal General Business Tax Credit Carry Forward [Member]
Income Tax Contingency [Line Items]
Tax credit carryforwards			0
Alternative Minimum Tax Credit Carry Forward [Member]
Income Tax Contingency [Line Items]
Tax credit carryforwards			$ 0
Internal Revenue Service [Member]
Income Tax Contingency [Line Items]
Federal tax return years			2011 through 2014 and 2017 through 2019
Ongoing audit for tax years	2017
Wage based tax credits claimed amount to be disallowed results estimated additional tax due		$ 2,300,000
Wage-based tax credits claimed amount disallowed, tax years		2012 through 2015
Estimated additional tax						$ 1,700,000
Estimated tax due				$ 1,600,000	$ 1,700,000
Internal Revenue Service [Member] | Minimum [Member]
Income Tax Contingency [Line Items]
Ongoing audit for tax years		2011
Internal Revenue Service [Member] | Maximum [Member]
Income Tax Contingency [Line Items]
Ongoing audit for tax years		2014

Stock Incentive Plans - Additio

Stock Incentive Plans - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2021USD ($)Installmentshares	Dec. 31, 2020USD ($)shares	Dec. 31, 2019USD ($)shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
New grants of stock option | shares	0
Outstanding options expiration period from the date of grant	10 years
Share-based compensation expense included in selling, general and administrative expenses	$ 5,400,000	$ 3,400,000	$ 7,200,000
Share-based compensation, income tax benefits	$ 1,300,000	$ 800,000	$ 1,300,000
2019 Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares reserved for issuance | shares		284,000
Percentage in payroll deductions to acquire shares	15.00%
Discount rate of fair market value available for share purchase	85.00%
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Outstanding options exercisable period after date of grant	10 years
Stock options granted | shares	0	0	0
Intrinsic value of stock options exercised	$ 1,700,000	$ 4,100,000	$ 3,800,000
Fair value of shares vested during the period	0	43,000	312,000
Unrecognized compensation expense	$ 2,200,000
Weighted average remaining amortization period	4 years 2 months 12 days
Stock Options [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Outstanding stock options vesting period	8 years
Stock Options [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Outstanding stock options vesting period	4 years
Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Outstanding options exercisable period after date of grant	1 year
Fair value of shares vested during the period	$ 3,600,000	3,800,000	5,800,000
Unrecognized compensation expense	$ 10,000,000
Weighted average remaining amortization period	2 years 8 months 12 days
Number of equal annual installments in which restricted stock units generally vest | Installment	4
Performance Share Units ("PSUs") [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value of shares vested during the period	$ 276,000	$ 743,000	$ 296,000
Vesting period	3 years
Maximum payout percentage	200.00%
Two Thousand And Twenty Stock Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares reserved for issuance | shares	375,000
Aggregate number of shares for which incentive stock options may be granted under the Plan | shares	375,000
Two Thousand And Fifteen Stock Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares available for grant | shares	185,665

Stock Incentive Plans - Summary

Stock Incentive Plans - Summary of Stock Options Activity (Detail) - Stock Options [Member] $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2021USD ($)$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Outstanding beginning balance, Number of Options | shares	139,648
Options exercised, Number of Options | shares	(34,773)
Outstanding ending balance, Number of Options | shares	104,875
Number of Options, exercisable stock options | shares	24,875
Outstanding beginning balance, Weighted Average Exercise Price | $ / shares	$ 56.13
Options exercised, Weighted Average Exercise Price | $ / shares	17.60
Outstanding ending balance, Weighted Average Exercise Price | $ / shares	68.91
Weighted Average Exercise Price, exercisable stock options | $ / shares	$ 26.12
Weighted Average Remaining Contractual Term of outstanding stock options	5 years 3 months 25 days
Weighted Average Remaining Contractual Term of exercisable stock options	2 years 4 months 24 days
Aggregate Intrinsic Value, outstanding stock option | $	$ 1,068
Aggregate Intrinsic Value, exercisable stock option | $	$ 1,068

Stock Incentive Plans - Schedul

Stock Incentive Plans - Schedule of Restricted Stock Unit Activity (Detail) - Restricted Stock Units [Member]	12 Months Ended
	Dec. 31, 2021$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Nonvested beginning balance, Units | shares	181,823
Granted, Units | shares	91,409
Vested, Units | shares	(60,038)
Cancelled/Forfeited, Units | shares	(17,130)
Nonvested ending balance, Units | shares	196,064
Nonvested beginning balance, Weighted Average Grant Date Fair Value | $ / shares	$ 59.16
Granted, Weighted Average Grant Date Fair Value | $ / shares	72.23
Vested, Weighted Average Grant Date Fair Value | $ / shares	60.48
Cancelled/Forfeited, Weighted Average Grant Date Fair Value | $ / shares	53.08
Nonvested ending balance, Weighted Average Grant Date Fair Value | $ / shares	$ 65.38

Stock Incentive Plans - Sched_2

Stock Incentive Plans - Schedule of Performance Share Unit Activity (Detail) - Performance Share Units ("PSUs") [Member]	12 Months Ended
	Dec. 31, 2021$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Nonvested beginning balance, Units | shares	8,464
Granted, Units | shares	29,821
Vested, Units | shares	(3,360)
Cancelled/Forfeited, Units | shares	(592)
Nonvested ending balance, Units | shares	34,333
Nonvested beginning balance, Weighted Average Grant Date Fair Value | $ / shares	$ 76.78
Granted, Weighted Average Grant Date Fair Value | $ / shares	69.17
Vested, Weighted Average Grant Date Fair Value | $ / shares	82.21
Cancelled/Forfeited, Weighted Average Grant Date Fair Value | $ / shares	82.21
Nonvested ending balance, Weighted Average Grant Date Fair Value | $ / shares	$ 69.54

Stock Repurchase Program - Addi

Stock Repurchase Program - Additional Information (Detail) - USD ($) $ in Thousands	Feb. 28, 2022	Aug. 06, 2019	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Equity Class Of Treasury Stock [Line Items]
Cost of repurchase		50,000,000
Company repurchase of common stock, shares		237,587		144,470	0
Aggregate purchase price		$ 17,300	$ 17,287	$ 8,056
Vested restricted stock units withheld for tax withholding obligations		20,308		25,922	38,356
Period of stock repurchase program				3 years
Stock repurchase program beginning date				Aug. 15, 2019
Subsequent Event [Member]
Equity Class Of Treasury Stock [Line Items]
Cost of repurchase	75,000,000
Period of stock repurchase program	2 years
Stock repurchase program beginning date	Feb. 28, 2022

Litigation - Additional Informa

Litigation - Additional Information (Detail) $ in Millions	Dec. 31, 2021USD ($)
Accrued Liabilities [Member]
Loss Contingencies [Line Items]
Estimated liability	$ 2.6