Barrett Business Services (BBSI) 10-Q 5 Aug 20 2020 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2020	Jul. 22, 2020
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2020
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q2
Trading Symbol	BBSI
Entity Registrant Name	BARRETT BUSINESS SERVICES INC
Entity Central Index Key	0000902791
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Current Reporting Status	Yes
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		7,635,723
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
Document Quarterly Report	true
Document Transition Report	false
Entity File Number	0-21886
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

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 62,210	$ 44,570
Investments	67,473	82,590
Trade accounts receivable, net	188,383	163,561
Income taxes receivable	3,506	1,335
Prepaid expenses and other	17,377	14,919
Restricted cash and investments	82,567	116,873
Total current assets	421,516	423,848
Property, equipment and software, net	35,278	31,724
Operating lease right-of-use assets	24,985	23,805
Restricted cash and investments	239,032	327,326
Goodwill	47,820	47,820
Other assets	3,707	3,618
Deferred income taxes		2,788
Total assets	772,338	860,929
Current liabilities:
Current portion of long-term debt	221	221
Accounts payable	4,951	5,993
Accrued payroll, payroll taxes and related benefits	181,406	174,168
Current operating lease liabilities	7,244	6,671
Other accrued liabilities	6,553	8,846
Workers' compensation claims liabilities	89,868	118,273
Safety incentives liability	25,767	27,950
Total current liabilities	316,010	342,122
Long-term workers' compensation claims liabilities	246,636	320,713
Long-term debt	3,620	3,730
Deferred income taxes	2,685
Long-term operating lease liabilities	18,630	17,883
Customer deposits and other long-term liabilities	4,869	4,682
Total liabilities	592,450	689,130
Commitments and contingencies (Notes 4 and 6)
Stockholders' equity:
Common stock, $.01 par value; 20,500 shares authorized, 7,598 and 7,514 shares issued and outstanding	76	75
Additional paid-in capital	23,421	20,227
Accumulated other comprehensive income	6,961	2,819
Retained earnings	149,430	148,678
Total stockholders' equity	179,888	171,799
Total liabilities and stockholders' equity	$ 772,338	$ 860,929

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Jun. 30, 2020	Dec. 31, 2019
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	7,598,000	7,514,000
Common stock, shares outstanding	7,598,000	7,514,000

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Revenues:
Total revenues	$ 201,031	$ 230,982	$ 420,135	$ 449,197
Cost of revenues:
Total cost of revenues	154,388	175,863	347,441	365,731
Gross margin	46,643	55,119	72,694	83,466
Selling, general and administrative expenses	33,255	39,005	65,370	72,165
Depreciation and amortization	1,171	970	2,171	1,939
Income from operations	12,217	15,144	5,153	9,362
Other income (expense):
Investment income, net	1,800	3,332	4,767	6,404
Interest expense	(306)	(481)	(541)	(958)
Other, net	172		173	12
Other income, net	1,666	2,851	4,399	5,458
Income before income taxes	13,883	17,995	9,552	14,820
Provision for income taxes	2,373	4,088	1,449	3,213
Net income	$ 11,510	$ 13,907	$ 8,103	$ 11,607
Basic income per common share	$ 1,520	$ 1,880	$ 1,070	$ 1,570
Weighted average number of basic common shares outstanding	7,557	7,410	7,539	7,408
Diluted income per common share	$ 1,510	$ 1,810	$ 1,060	$ 1,510
Weighted average number of diluted common shares outstanding	7,647	7,692	7,678	7,674
Professional Employer Service Fees [Member]
Revenues:
Total revenues	$ 180,488	$ 203,157	$ 374,080	$ 393,684
Staffing Services [Member]
Revenues:
Total revenues	20,543	27,825	46,055	55,513
Direct Payroll Costs [Member]
Cost of revenues:
Total cost of revenues	15,796	20,992	34,873	41,834
Payroll Taxes and Benefits [Member]
Cost of revenues:
Total cost of revenues	93,671	101,697	213,133	216,494
Workers' Compensation [Member]
Cost of revenues:
Total cost of revenues	$ 44,921	$ 53,174	$ 99,435	$ 107,403

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 11,510	$ 13,907	$ 8,103	$ 11,607
Unrealized gains on investments, net of tax	6,877	3,043	4,142	6,700
Comprehensive income	$ 18,387	$ 16,950	$ 12,245	$ 18,307

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Statement Of Income And Comprehensive Income [Abstract]
Unrealized gains on investments, tax	$ 2,630	$ 1,164	$ 1,584	$ 2,561

Condensed Consolidated Statem_4

Condensed 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, purchase of ESPP shares and vesting of restricted stock units and performance awards	122		122
Common stock issued on exercise of options, purchase of ESPP shares and vesting of restricted stock units and performance awards, shares		17
Common stock repurchased on vesting of restricted stock units and performance awards	(178)		(178)
Common stock repurchased on vesting of restricted stock units and performance awards, shares		(2)
Share-based compensation expense	1,387		1,387
Cash dividends on common stock	(1,852)				(1,852)
Unrealized gain (loss) on investments, net of tax	3,657			3,657
Net (loss) income	(2,300)				(2,300)
Ending Balance at Mar. 31, 2019	119,873	$ 74	16,768	(1,411)	104,442
Ending Balance, shares at Mar. 31, 2019		7,410
Beginning Balance at Dec. 31, 2018	119,037	$ 74	15,437	(5,068)	108,594
Beginning Balance, shares at Dec. 31, 2018		7,395
Unrealized gain (loss) on investments, net of tax	6,700
Net (loss) income	11,607
Ending Balance at Jun. 30, 2019	137,467	$ 74	19,265	1,632	116,496
Ending Balance, shares at Jun. 30, 2019		7,414
Beginning Balance at Mar. 31, 2019	119,873	$ 74	16,768	(1,411)	104,442
Beginning Balance, shares at Mar. 31, 2019		7,410
Common stock issued on exercise of options, purchase of ESPP shares and vesting of restricted stock units and performance awards	56		56
Common stock issued on exercise of options, purchase of ESPP shares and vesting of restricted stock units and performance awards, shares		4
Share-based compensation expense	2,441		2,441
Cash dividends on common stock	(1,853)				(1,853)
Unrealized gain (loss) on investments, net of tax	3,043			3,043
Net (loss) income	13,907				13,907
Ending Balance at Jun. 30, 2019	137,467	$ 74	19,265	1,632	116,496
Ending Balance, shares at Jun. 30, 2019		7,414
Beginning Balance at Dec. 31, 2019	171,799	$ 75	20,227	2,819	148,678
Beginning Balance, shares at Dec. 31, 2019		7,514
Common stock issued on exercise of options, purchase of ESPP shares and vesting of restricted stock units and performance awards	904	$ 1	903
Common stock issued on exercise of options, purchase of ESPP shares and vesting of restricted stock units and performance awards, shares		56
Common stock repurchased on vesting of restricted stock units and performance awards	(378)		(378)
Common stock repurchased on vesting of restricted stock units and performance awards, shares		(6)
Share-based compensation expense	342		342
Company repurchase of common stock	(2,987)	$ (1)	(169)		(2,817)
Company repurchase of common stock, shares		(59)
Cash dividends on common stock	(2,262)				(2,262)
Unrealized gain (loss) on investments, net of tax	(2,735)			(2,735)
Net (loss) income	(3,407)				(3,407)
Ending Balance at Mar. 31, 2020	161,276	$ 75	20,925	84	140,192
Ending Balance, shares at Mar. 31, 2020		7,505
Beginning Balance at Dec. 31, 2019	171,799	$ 75	20,227	2,819	148,678
Beginning Balance, shares at Dec. 31, 2019		7,514
Unrealized gain (loss) on investments, net of tax	4,142
Net (loss) income	8,103
Ending Balance at Jun. 30, 2020	179,888	$ 76	23,421	6,961	149,430
Ending Balance, shares at Jun. 30, 2020		7,598
Beginning Balance at Mar. 31, 2020	161,276	$ 75	20,925	84	140,192
Beginning Balance, shares at Mar. 31, 2020		7,505
Common stock issued on exercise of options, purchase of ESPP shares and vesting of restricted stock units and performance awards	1,810	$ 1	1,809
Common stock issued on exercise of options, purchase of ESPP shares and vesting of restricted stock units and performance awards, shares		96
Common stock repurchased on vesting of restricted stock units and performance awards	(110)		(110)
Common stock repurchased on vesting of restricted stock units and performance awards, shares		(3)
Share-based compensation expense	797		797
Cash dividends on common stock	(2,272)				(2,272)
Unrealized gain (loss) on investments, net of tax	6,877			6,877
Net (loss) income	11,510				11,510
Ending Balance at Jun. 30, 2020	$ 179,888	$ 76	$ 23,421	$ 6,961	$ 149,430
Ending Balance, shares at Jun. 30, 2020		7,598

Condensed Consolidated Statem_5

Condensed Consolidated Statements of Stockholders' Equity (Parenthetical) - $ / shares	3 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019
Statement Of Stockholders Equity [Abstract]
Cash dividends on common stock per share	$ 0.30	$ 0.30	$ 0.25	$ 0.25

Condensed Consolidated Statem_6

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Cash flows from operating activities:
Net income	$ 8,103	$ 11,607
Reconciliations of net income to net cash (used in) provided by operating activities:
Depreciation and amortization	2,171	1,939
Non-cash lease expense	3,545	3,509
Investment (accretion) amortization and (gains) losses recognized	283	26
Deferred Income taxes	3,890
Share-based compensation	1,139	3,828
Changes in certain operating assets and liabilities:
Trade accounts receivable	(24,822)	(11,631)
Income taxes	(2,171)	(1,733)
Prepaid expenses and other	(2,458)	(1,840)
Accounts payable	(1,042)	488
Accrued payroll, payroll taxes and related benefits	8,035	24,740
Other accrued liabilities	(2,759)	(4,658)
Workers' compensation claims liabilities	(102,572)	17,470
Safety incentives liability	(2,183)	(1,894)
Operating lease liabilities	(3,405)	(3,032)
Other assets and liabilities, net	(143)	46
Net cash (used in) provided by operating activities	(114,389)	38,865
Cash flows from investing activities:
Purchase of property, equipment and software	(5,725)	(5,127)
Purchase of investments	(23,722)	(117)
Proceeds from sales and maturities of investments	38,547	15,262
Purchase of restricted investments	(29,570)	(3,245)
Proceeds from sales and maturities of restricted investments	22,453	34,765
Net cash provided by investing activities	1,983	41,538
Cash flows from financing activities:
Proceeds from credit-line borrowings		18,843
Payments on credit-line borrowings		(18,843)
Payments on long-term debt	(110)	(111)
Common stock repurchased on vesting of stock awards	(488)	(178)
Dividends paid	(4,534)	(3,705)
Proceeds from exercise of stock options	2,714	178
Net cash used in financing activities	(5,405)	(3,816)
Repurchase of common stock	(2,987)
Net (decrease) increase in cash, cash equivalents and restricted cash	(117,811)	76,587
Cash, cash equivalents and restricted cash, beginning of period	273,341	140,702
Cash, cash equivalents and restricted cash, end of period	$ 155,530	$ 217,289

Basis of Presentation of Interi

Basis of Presentation of Interim Period Statements	6 Months Ended
	Jun. 30, 2020
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Basis of Presentation of Interim Period Statements	Note 1 - Basis of Presentation of Interim Period Statements The accompanying condensed consolidated financial statements are unaudited and have been prepared by Barrett Business Services, Inc. (“BBSI”, the “Company”, “our” or “we”), pursuant to the rules and regulations of the Securities and Exchange Commission. Certain information and note disclosures typically included in financial statements prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) have been condensed or omitted pursuant to such rules and regulations. In the opinion of management, the condensed consolidated financial statements include all adjustments, consisting only of normal recurring adjustments, necessary for a fair statement of the results for the interim periods presented. The accompanying condensed financial statements are prepared on a consolidated basis. All intercompany account balances and transactions have been eliminated in consolidation. The preparation of condensed consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the condensed consolidated financial statements and accompanying notes. Actual results may differ from such estimates and assumptions. The condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and notes thereto included in the Company’s 2019 Annual Report on Form 10-K at pages 32 – 58. The results of operations for an interim period are not necessarily indicative of the results of operations for a full year. 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 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 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 condensed 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. Direct payroll costs include salaries, wages, health insurance, and employee out-of-pocket expenses incurred incidental to employment. We also present revenue net of safety 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 claims reserves, claims administration fees, legal fees, medical cost containment (“MCC”) expense, state administrative agency fees, third-party broker commissions, risk manager payroll, premiums for excess insurance, and the fronted insurance program, as well as costs associated with operating our two wholly owned insurance companies, Associated Insurance Company for Excess (“AICE”) and Ecole Insurance Company (“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 condensed consolidated statements of cash flows and condensed 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 condensed 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 condensed 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 condensed 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 condensed 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 $821,000 and $888,000 at June 30, 2020 and December 31, 2019, 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. 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 condensed 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 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. 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 during the three and six months ended June 30, 2020 and 2019 did not materially differ from interest expense. No income taxes were paid during the three and six months ended June 30, 2020 and 2019 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 condensed consolidated balance sheets to the amounts reported on the condensed consolidated statements of cash flows (in thousands): June 30, December 31, June 30, December 31, 2020 2019 2019 2018 Cash and cash equivalents $ 62,210 $ 44,570 $ 23,693 $ 35,371 Restricted cash, included in restricted cash and investments 93,320 228,771 193,596 105,331 Total cash, cash equivalents and restricted cash shown in the statement of cash flows $ 155,530 $ 273,341 $ 217,289 $ 140,702 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 exercise of outstanding stock options and the issuance of stock associated with outstanding restricted stock units. Basic and diluted shares outstanding are summarized as follows (in thousands): Three Months Ended Six Months Ended June 30, June 30, 2020 2019 2020 2019 Weighted average number of basic shares outstanding 7,557 7,410 7,539 7,408 Effect of dilutive securities 90 282 139 266 Weighted average number of diluted shares outstanding 7,647 7,692 7,678 7,674 Accounting estimates The preparation of our condensed consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the condensed 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 In June 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2016-13, “Financial Instruments – Credit Losses.” The ASU requires the use of an impairment model that is based on expected credit losses rather than incurred losses. The ASU also made changes to the impairment model for available-for-sale securities and requires the use of an allowance approach rather than writing down the security’s cost. The amendments in this update were adopted January 1, 2020 and did not have a material impact on the Company’s financial statements.

Fair Value Measurement

Fair Value Measurement	6 Months Ended
	Jun. 30, 2020
Fair Value Disclosures [Abstract]
Fair Value Measurement	Note 2 - Fair Value Measurement The following table summarizes the Company’s investments at June 30, 2020 and December 31, 2019 measured at fair value on a recurring basis (in thousands): June 30, 2020 December 31, 2019 Gross Gross Unrealized Unrealized Gains Recorded Gains Recorded Cost (Losses) Basis Cost (Losses) Basis Current: Cash equivalents: Money market funds $ 58,299 $ — $ 58,299 $ 35,526 $ — $ 35,526 Total cash equivalents 58,299 — 58,299 35,526 — 35,526 Investments: Asset backed securities 36,961 (1,001 ) 35,960 14,017 (13 ) 14,004 Corporate bonds 20,167 499 20,666 53,493 156 53,649 U.S. government agency securities 7,402 702 8,104 7,408 282 7,690 U.S. treasuries 2,400 5 2,405 4,500 9 4,509 Mortgage backed securities 327 11 338 2,737 1 2,738 Total investments 67,257 216 67,473 82,155 435 82,590 Restricted cash and investments (1) Corporate bonds 95,827 4,506 100,333 98,481 1,931 100,412 Mortgage backed securities 56,551 2,356 58,907 62,930 837 63,767 Money market funds 32,864 10 32,874 29,046 — 29,046 Commercial paper 31,844 26 31,870 — — — U.S. government agency securities 25,718 2,394 28,112 27,885 642 28,527 U.S. treasuries 6,320 46 6,366 16,906 21 16,927 Supranational bonds 4,772 56 4,828 4,770 30 4,800 Mutual funds 4,262 — 4,262 3,466 — 3,466 Municipal bonds 2,473 7 2,480 — — — Asset backed securities 280 5 285 303 — 303 Total restricted cash and investments 260,911 9,406 270,317 243,787 3,461 247,248 Total investments $ 386,467 $ 9,622 $ 396,089 $ 361,468 $ 3,896 $ 365,364 (1) Included in restricted cash and investments within the condensed consolidated balance sheet is restricted cash of $51.3 million and $197.0 million as of June 30, 2020 and December 31, 2019, 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 June 30, 2020 and December 31, 2019 measured at fair value on a recurring basis by fair value hierarchy level (in thousands): June 30, 2020 December 31, 2019 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 $ 58,299 $ — $ — $ — $ 58,299 $ 35,526 $ — $ — $ — $ 35,526 Investments: Asset backed securities 35,960 — 35,960 — — 14,004 — 14,004 — — Corporate bonds 20,666 — 20,666 — — 53,649 — 53,649 — — U.S. government agency securities 8,104 — 8,104 — — 7,690 — 7,690 — — U.S. treasuries 2,405 — 2,405 — — 4,509 — 4,509 — — Mortgage backed securities 338 — 338 — — 2,738 — 2,738 — — Restricted cash and investments: Corporate bonds 100,333 — 100,333 — — 100,412 — 100,412 — — Mortgage backed securities 58,907 — 58,907 — — 63,767 — 63,767 — — Money market funds 32,874 — — — 32,874 29,046 — — — 29,046 Commercial paper 31,870 — 31,870 — — — — — — — U.S. government agency securities 28,112 — 28,112 — — 28,527 — 28,527 — — U.S. treasuries 6,366 — 6,366 — — 16,927 — 16,927 — — Supranational bonds 4,828 — 4,828 — — 4,800 — 4,800 — — Mutual funds 4,262 4,262 — — — 3,466 3,466 — — — Municipal bonds 2,480 — 2,480 — — — — — — Asset backed securities 285 — 285 — — 303 — 303 — — Total investments $ 396,089 $ 4,262 $ 300,654 $ — $ 91,173 $ 365,364 $ 3,466 $ 297,326 $ — $ 64,572 (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 June 30, 2020. Actual maturities may differ from contractual maturities because borrowers may have the right to prepay obligations with or without prepayment penalties. June 30, 2020 (In thousands) Less than 1 Year Between 1 to 5 Years Between 5 to 10 Years After 10 Years Total Corporate bonds $ 29,891 $ 63,851 $ 27,257 $ — $ 120,999 Money market funds 91,173 — — — 91,173 Asset backed securities — 298 — 35,947 36,245 U.S. government agency securities — 12,195 24,021 — 36,216 Commercial paper 31,870 — — — 31,870 U.S. treasuries 7,747 1,024 — — 8,771 Supranational bonds 4,828 — — — 4,828 Municipal bonds — 2,480 — — 2,480 Total $ 165,509 $ 79,848 $ 51,278 $ 35,947 $ 332,582 The average contractual maturity of mortgage backed securities was 17 years as of June 30, 2020 which is excluded from the table above.

Workers' Compensation Claims

Workers' Compensation Claims	6 Months Ended
	Jun. 30, 2020
Text Block [Abstract]
Workers' Compensation Claims	Note 3 – Workers’ Compensation Claims The following table summarizes the aggregate workers’ compensation reserve activity (in thousands): Three Months Ended Six Months Ended June 30, June 30, 2020 2019 2020 2019 Beginning balance Workers' compensation claims liabilities $ 445,310 $ 422,872 $ 438,986 $ 413,397 Add: claims expense accrual Current period 32,729 41,145 71,221 81,530 Prior periods (1,373 ) (2,952 ) (2,186 ) (4,652 ) 31,356 38,193 69,035 76,878 Less: claim payments related to Current period 4,527 4,145 6,077 5,604 Prior periods 135,853 26,088 165,530 53,804 140,380 30,233 171,607 59,408 Change in claims incurred in excess of retention limits 218 (96 ) 90 (131 ) Ending balance Workers' compensation claims liabilities $ 336,504 $ 430,736 $ 336,504 $ 430,736 Incurred but not reported (IBNR) $ 206,521 $ 273,114 $ 206,521 $ 273,114 Ratio of IBNR to workers' compensation claims liabilities 61 % 63 % 61 % 63 % The Company is a self-insured employer with respect to workers' compensation coverage for all of its employees (including employees co-employed through our client service agreements) working in Colorado, Maryland and Oregon. In the state of Washington, state law allows only the Company's staffing services and internal management employees to be covered under the Company's self-insured workers' compensation progra m. The Company also operates a wholly owned, fully licensed insurance company, Ecole, which provides workers’ compensation coverage to the Company’s employees working in Arizona and Utah. For all other clients, the Company obtains policies from Chubb Limited (“Chubb”) through an arrangement known as a fronted program, which provides a licensed, admitted insurance carrier to issue policies on behalf of the Company. Chubb assumes credit risk should the Company be unable to satisfy its indemnification obligations. Through various insurance arrangements, the Company retains risk of loss up to the first $5.0 million per occurrence, except in Maryland and Colorado, where our retention per occurrence is $1.0 million and $2.0 million, respectively. Effective July 1, 2020 the Company’s retention decreases from $5.0 million per occurrence to $3.0 million, except in Maryland and Colorado, where our retention per occurrence remains at $1.0 million and $2.0 million, respectively. The fronted program with Chubb requires that collateral be advanced at the inception of the policy term. To partially satisfy these collateral requirements, the Company provided a letter of credit of $63.7 million from its principal bank, Wells Fargo Bank, National Association (the “Bank”). In addition, The states of California, Maryland, Oregon, Washington, Colorado and Delaware required us to maintain collateral totaling $59.7 million and $76.1 million at June 30, 2020 and December 31, 2019, respectively, to cover potential workers’ compensation claims losses related to the Company’s current and former status as a self-insured employer. At June 30, 2020, the Company provided surety bonds and standby letters of credit totaling $59.7 million, including a California requirement of $39.2 million. On June 29, 2020, the Company entered into a loss portfolio transfer agreement to remove all outstanding workers’ compensation claims obligations for claims incurred under its fronted insurance program between February 1, 2014 and December 31, 2017. This transaction reduced the Company’s outstanding workers’ compensation liabilities and Chubb trust account balances by $115.7 million. As of June 30, 2020, the Company recorded a receivable from Chubb of $2.2 million related to claim payments made on Chubb’s behalf for claim obligations transferred to Chubb as part of the loss portfolio transfer agreement. The amount is included in prepaid expenses and other in the condensed consolidated balance sheets. The Company provided a total of $336.5 million and $439.0 million at June 30, 2020 and December 31, 2019, respectively, as an estimated future liability for unsettled workers' compensation claims liabilities. Of this amount, $3.4 million and $3.3 million at June 30, 2020 and December 31, 2019, 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 excess insurance carriers of $3.4 million and $3.3 million at June 30, 2020 and December 31, 2019, respectively, included in other assets on the condensed consolidated balance sheets.

Revolving Credit Facility and L

Revolving Credit Facility and Long-Term Debt	6 Months Ended
	Jun. 30, 2020
Debt Disclosure [Abstract]
Revolving Credit Facility and Long-Term Debt	Note 4 - Revolving Credit Facility and Long-Term Debt On May 15, 2020, the Company entered into an amended credit agreement (the “Agreement”) with the Bank, which superseded the previous agreement. The Agreement increased the revolving credit line from $33.0 million to $50.0 million; the sublimit for standby letters of credit remains at $8.0 million. At June 30, 2020, $5.8 million of the sublimit for standby letters of credit was used. The Agreement expires on July 1, 2022. Advances under the revolving credit line bear interest, as selected by the Company, of (a) the daily floating rate of one-month LIBOR plus 1.75% or (b) The Agreement also provides for a $63.7 million standby letter of credit (the “Chubb Letter of Credit”). The Chubb Letter of Credit has an expiration date of July 1, 2021, subject to automatic renewal in specified circumstances. The Bank has been granted a security interest of first priority in certain blocked securities accounts (collectively, the “Collateral Accounts”). The Company has agreed to deposit in the Collateral Accounts 50% of the Company’s consolidated net income (after tax and less cash dividends) for each quarter plus, to the extent necessary, an additional amount by May 15 each year so that the deposits in the Collateral Accounts for the prior year total at least $16 million. Through the second quarter of 2020, the Company deposited $32.5 million into the Collateral Accounts. The initial fee paid under the Chubb Letter of Credit in June 2018 was equal to 2.5% of the face amount thereof. Upon annual renewal, the fees payable to the Bank quarterly in advance include (a) a fee at the annual rate of 2.5%, calculated based on the difference between the face amount of the Chubb Letter of Credit and 95% of the aggregate value of the Collateral Accounts as of the end of the previous quarter, (b) a fee at the annual rate of 1.0% calculated based on the balance of the face amount, and (c) other fees upon the payment or negotiation of each drawing under the Chubb Letter of Credit. The Agreement requires the satisfaction of certain financial covenants as follows: • total funded debt plus the unused principal amount of the revolving credit line, divided by EBITDA [net income before taxes plus interest expense (net of capitalized interest expense), depreciation expense, and amortization expense], on a rolling four-quarter basis is not greater than 2.75 • ratio of restricted and unrestricted cash and investments to workers’ compensation claim liabilities is at least 1.15:1.0 The Agreement includes certain additional restrictions as follows: • incurring additional indebtedness is prohibited without the prior approval of the Bank, other than purchase financing for the acquisition of assets, provided that the aggregate of all purchase financing does not exceed $1,000,000 at any time; • the Company may not terminate or cancel any of the AICE policies without the Bank’s prior written consent; and • the Company is not permitted to declare or pay any dividend or distribution, or to redeem, retire or purchase any shares of the Company’s capital stock without the Bank’s prior approval, other than (i) quarterly cash dividends to holders of common stock in an amount not to exceed a total of $0.30 per share during a fiscal quarter, and (ii) acquisitions of shares of common stock at fair market value in connection with satisfaction of employee tax withholding obligations incurred with regard to employee equity compensation arrangements, in an amount totaling up to $3.5 million. The Agreement also contains customary events of default and 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 June 30, 2020, the Company was in compliance with all covenants. The Company maintains a mortgage loan with the Bank with a balance of approximately $3.8 million and $4.0 million at June 30, 2020 and December 31, 2019, respectively, secured by the Company’s corporate office building in Vancouver, Washington. This loan requires payment of monthly installments of $18,375, bearing interest at the

Income Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2020
Income Tax Disclosure [Abstract]
Income Taxes	Note 5 – Income Taxes 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 June 30, 2020. 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, 2012, 2013 and 2014. In July 2020, BBSI received a draft Revenue Agent Report in relation to the ongoing IRS audit for tax years 2011 to 2014. The report indicates that the IRS intends to disallow certain wage-based tax credits claimed, which would result in an estimated additional tax due of approximately $2.3 million for the tax years 2012 through 2014. The Company firmly disagrees with the asserted grounds for this determination and plans to pursue all available administrative and judicial remedies necessary to vigorously defend its position. Based on management’s analysis of this matter, no reserve 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 tax year and tax years before 2011. As of June 30, 2020, 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.

Litigation

Litigation	6 Months Ended
	Jun. 30, 2020
Commitments And Contingencies Disclosure [Abstract]
Litigation	Note 6 – Litigation On November 21, 2012, David Kaanaana (“Kaanaana”), a former staffing employee, filed a California wage and hour violations lawsuit against BBSI. On May 19, 2016, the court entered a ruling in favor of BBSI, which was subsequently appealed by the plaintiffs. 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 plaintiffs' claims and holding that prevailing wage requirements applicable to “public works” apply to certain types of districts. On January 9, 2019, BBSI filed a petition of review to the California Supreme Court. An amicus letter in support of the petition was filed by the Sanitation Districts of Los Angeles County, joined in by numerous other "special districts" in California. On February 27, 2019, the California Supreme Court granted the petition to review the appellate court’s decision. BBSI is subject to other legal proceedings and claims that arise in the ordinary course of our business.

Subsequent Events

Subsequent Events	6 Months Ended
	Jun. 30, 2020
Subsequent Events [Abstract]
Subsequent Events	Note 7 – 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.

Basis of Presentation of Inte_2

Basis of Presentation of Interim Period Statements (Policies)	6 Months Ended
	Jun. 30, 2020
Organization Consolidation And Presentation Of Financial Statements [Abstract]
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 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 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 condensed 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. Direct payroll costs include salaries, wages, health insurance, and employee out-of-pocket expenses incurred incidental to employment. We also present revenue net of safety 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 claims reserves, claims administration fees, legal fees, medical cost containment (“MCC”) expense, state administrative agency fees, third-party broker commissions, risk manager payroll, premiums for excess insurance, and the fronted insurance program, as well as costs associated with operating our two wholly owned insurance companies, Associated Insurance Company for Excess (“AICE”) and Ecole Insurance Company (“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 condensed consolidated statements of cash flows and condensed 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 condensed 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 condensed 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 condensed 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 condensed 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 $821,000 and $888,000 at June 30, 2020 and December 31, 2019, 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.
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 condensed 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 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.
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 during the three and six months ended June 30, 2020 and 2019 did not materially differ from interest expense. No income taxes were paid during the three and six months ended June 30, 2020 and 2019 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 condensed consolidated balance sheets to the amounts reported on the condensed consolidated statements of cash flows (in thousands): June 30, December 31, June 30, December 31, 2020 2019 2019 2018 Cash and cash equivalents $ 62,210 $ 44,570 $ 23,693 $ 35,371 Restricted cash, included in restricted cash and investments 93,320 228,771 193,596 105,331 Total cash, cash equivalents and restricted cash shown in the statement of cash flows $ 155,530 $ 273,341 $ 217,289 $ 140,702
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 exercise of outstanding stock options and the issuance of stock associated with outstanding restricted stock units. Basic and diluted shares outstanding are summarized as follows (in thousands): Three Months Ended Six Months Ended June 30, June 30, 2020 2019 2020 2019 Weighted average number of basic shares outstanding 7,557 7,410 7,539 7,408 Effect of dilutive securities 90 282 139 266 Weighted average number of diluted shares outstanding 7,647 7,692 7,678 7,674
Accounting estimates	Accounting estimates The preparation of our condensed consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the condensed 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 In June 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2016-13, “Financial Instruments – Credit Losses.” The ASU requires the use of an impairment model that is based on expected credit losses rather than incurred losses. The ASU also made changes to the impairment model for available-for-sale securities and requires the use of an allowance approach rather than writing down the security’s cost. The amendments in this update were adopted January 1, 2020 and did not have a material impact on the Company’s financial statements.

Basis of Presentation of Inte_3

Basis of Presentation of Interim Period Statements (Tables)	6 Months Ended
	Jun. 30, 2020
Organization Consolidation And Presentation Of Financial Statements [Abstract]
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 condensed consolidated balance sheets to the amounts reported on the condensed consolidated statements of cash flows (in thousands): June 30, December 31, June 30, December 31, 2020 2019 2019 2018 Cash and cash equivalents $ 62,210 $ 44,570 $ 23,693 $ 35,371 Restricted cash, included in restricted cash and investments 93,320 228,771 193,596 105,331 Total cash, cash equivalents and restricted cash shown in the statement of cash flows $ 155,530 $ 273,341 $ 217,289 $ 140,702
Summary of Basic and Diluted Common Shares Outstanding	Basic and diluted shares outstanding are summarized as follows (in thousands): Three Months Ended Six Months Ended June 30, June 30, 2020 2019 2020 2019 Weighted average number of basic shares outstanding 7,557 7,410 7,539 7,408 Effect of dilutive securities 90 282 139 266 Weighted average number of diluted shares outstanding 7,647 7,692 7,678 7,674

Fair Value Measurement (Tables)

Fair Value Measurement (Tables)	6 Months Ended
	Jun. 30, 2020
Fair Value Disclosures [Abstract]
Summary of Investments Measured at Fair Value on Recurring Basis	The following table summarizes the Company’s investments at June 30, 2020 and December 31, 2019 measured at fair value on a recurring basis (in thousands): June 30, 2020 December 31, 2019 Gross Gross Unrealized Unrealized Gains Recorded Gains Recorded Cost (Losses) Basis Cost (Losses) Basis Current: Cash equivalents: Money market funds $ 58,299 $ — $ 58,299 $ 35,526 $ — $ 35,526 Total cash equivalents 58,299 — 58,299 35,526 — 35,526 Investments: Asset backed securities 36,961 (1,001 ) 35,960 14,017 (13 ) 14,004 Corporate bonds 20,167 499 20,666 53,493 156 53,649 U.S. government agency securities 7,402 702 8,104 7,408 282 7,690 U.S. treasuries 2,400 5 2,405 4,500 9 4,509 Mortgage backed securities 327 11 338 2,737 1 2,738 Total investments 67,257 216 67,473 82,155 435 82,590 Restricted cash and investments (1) Corporate bonds 95,827 4,506 100,333 98,481 1,931 100,412 Mortgage backed securities 56,551 2,356 58,907 62,930 837 63,767 Money market funds 32,864 10 32,874 29,046 — 29,046 Commercial paper 31,844 26 31,870 — — — U.S. government agency securities 25,718 2,394 28,112 27,885 642 28,527 U.S. treasuries 6,320 46 6,366 16,906 21 16,927 Supranational bonds 4,772 56 4,828 4,770 30 4,800 Mutual funds 4,262 — 4,262 3,466 — 3,466 Municipal bonds 2,473 7 2,480 — — — Asset backed securities 280 5 285 303 — 303 Total restricted cash and investments 260,911 9,406 270,317 243,787 3,461 247,248 Total investments $ 386,467 $ 9,622 $ 396,089 $ 361,468 $ 3,896 $ 365,364 (1) Included in restricted cash and investments within the condensed consolidated balance sheet is restricted cash of $51.3 million and $197.0 million as of June 30, 2020 and December 31, 2019, 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 June 30, 2020 and December 31, 2019 measured at fair value on a recurring basis by fair value hierarchy level (in thousands): June 30, 2020 December 31, 2019 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 $ 58,299 $ — $ — $ — $ 58,299 $ 35,526 $ — $ — $ — $ 35,526 Investments: Asset backed securities 35,960 — 35,960 — — 14,004 — 14,004 — — Corporate bonds 20,666 — 20,666 — — 53,649 — 53,649 — — U.S. government agency securities 8,104 — 8,104 — — 7,690 — 7,690 — — U.S. treasuries 2,405 — 2,405 — — 4,509 — 4,509 — — Mortgage backed securities 338 — 338 — — 2,738 — 2,738 — — Restricted cash and investments: Corporate bonds 100,333 — 100,333 — — 100,412 — 100,412 — — Mortgage backed securities 58,907 — 58,907 — — 63,767 — 63,767 — — Money market funds 32,874 — — — 32,874 29,046 — — — 29,046 Commercial paper 31,870 — 31,870 — — — — — — — U.S. government agency securities 28,112 — 28,112 — — 28,527 — 28,527 — — U.S. treasuries 6,366 — 6,366 — — 16,927 — 16,927 — — Supranational bonds 4,828 — 4,828 — — 4,800 — 4,800 — — Mutual funds 4,262 4,262 — — — 3,466 3,466 — — — Municipal bonds 2,480 — 2,480 — — — — — — Asset backed securities 285 — 285 — — 303 — 303 — — Total investments $ 396,089 $ 4,262 $ 300,654 $ — $ 91,173 $ 365,364 $ 3,466 $ 297,326 $ — $ 64,572 (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 June 30, 2020. Actual maturities may differ from contractual maturities because borrowers may have the right to prepay obligations with or without prepayment penalties. June 30, 2020 (In thousands) Less than 1 Year Between 1 to 5 Years Between 5 to 10 Years After 10 Years Total Corporate bonds $ 29,891 $ 63,851 $ 27,257 $ — $ 120,999 Money market funds 91,173 — — — 91,173 Asset backed securities — 298 — 35,947 36,245 U.S. government agency securities — 12,195 24,021 — 36,216 Commercial paper 31,870 — — — 31,870 U.S. treasuries 7,747 1,024 — — 8,771 Supranational bonds 4,828 — — — 4,828 Municipal bonds — 2,480 — — 2,480 Total $ 165,509 $ 79,848 $ 51,278 $ 35,947 $ 332,582

Workers' Compensation Claims (T

Workers' Compensation Claims (Tables)	6 Months Ended
	Jun. 30, 2020
Text Block [Abstract]
Summarizes Aggregate Workers' Compensation Reserve Activity	The following table summarizes the aggregate workers’ compensation reserve activity (in thousands): Three Months Ended Six Months Ended June 30, June 30, 2020 2019 2020 2019 Beginning balance Workers' compensation claims liabilities $ 445,310 $ 422,872 $ 438,986 $ 413,397 Add: claims expense accrual Current period 32,729 41,145 71,221 81,530 Prior periods (1,373 ) (2,952 ) (2,186 ) (4,652 ) 31,356 38,193 69,035 76,878 Less: claim payments related to Current period 4,527 4,145 6,077 5,604 Prior periods 135,853 26,088 165,530 53,804 140,380 30,233 171,607 59,408 Change in claims incurred in excess of retention limits 218 (96 ) 90 (131 ) Ending balance Workers' compensation claims liabilities $ 336,504 $ 430,736 $ 336,504 $ 430,736 Incurred but not reported (IBNR) $ 206,521 $ 273,114 $ 206,521 $ 273,114 Ratio of IBNR to workers' compensation claims liabilities 61 % 63 % 61 % 63 %

Basis of Presentation of Inte_4

Basis of Presentation of Interim Period Statements - Additional Information (Detail)	3 Months Ended	6 Months Ended
	Jun. 30, 2020USD ($)Company	Jun. 30, 2020USD ($)Company	Jun. 30, 2019USD ($)	Dec. 31, 2019USD ($)
Organization Consolidation And Presentation Of Financial Statements [Abstract]
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	2
Cash and cash equivalents, maturity term		3 months
Allowance for doubtful accounts	$ 821,000	$ 821,000		$ 888,000
Estimate of liability for unpaid safety incentives	25,800,000	$ 25,800,000		$ 28,000,000
Income taxes paid	$ 0		$ 0

Basis of Presentation of Inte_5

Basis of Presentation of Interim Period Statements - Schedule of Reconciles of Cash, Cash Equivalents and Restricted Cash Balances (Detail) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019	Jun. 30, 2019	Dec. 31, 2018
Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents [Abstract]
Cash and cash equivalents	$ 62,210	$ 44,570	$ 23,693	$ 35,371
Restricted cash, included in restricted cash and investments	93,320	228,771	193,596	105,331
Total cash, cash equivalents and restricted cash shown in the statement of cash flows	$ 155,530	$ 273,341	$ 217,289	$ 140,702

Basis of Presentation of Inte_6

Basis of Presentation of Interim Period Statements - Summary of Basic and Diluted Common Shares Outstanding (Detail) - shares shares in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Weighted Average Number Of Shares Outstanding Diluted Disclosure Items [Abstract]
Weighted average number of basic shares outstanding	7,557	7,410	7,539	7,408
Effect of dilutive securities	90	282	139	266
Weighted average number of diluted shares outstanding	7,647	7,692	7,678	7,674

Fair Value Measurement - Summar

Fair Value Measurement - Summary of Investments Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cost	$ 386,467	$ 361,468
Gross Unrealized Gains (Losses)	9,622	3,896
Recorded Basis	396,089	365,364
Cash and Cash Equivalents [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cost	58,299	35,526
Recorded Basis	58,299	35,526
Cash and Cash Equivalents [Member] | Money Market Funds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cost	58,299	35,526
Recorded Basis	58,299	35,526
Investments [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cost	67,257	82,155
Gross Unrealized Gains (Losses)	216	435
Recorded Basis	67,473	82,590
Investments [Member] | Corporate Bonds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cost	20,167	53,493
Gross Unrealized Gains (Losses)	499	156
Recorded Basis	20,666	53,649
Investments [Member] | Asset Backed Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cost	36,961	14,017
Gross Unrealized Gains (Losses)	(1,001)	(13)
Recorded Basis	35,960	14,004
Investments [Member] | U.S. Government Agency Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cost	7,402	7,408
Gross Unrealized Gains (Losses)	702	282
Recorded Basis	8,104	7,690
Investments [Member] | U.S. Treasuries [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cost	2,400	4,500
Gross Unrealized Gains (Losses)	5	9
Recorded Basis	2,405	4,509
Investments [Member] | Mortgage Backed Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cost	327	2,737
Gross Unrealized Gains (Losses)	11	1
Recorded Basis	338	2,738
Restricted Cash and Investments [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cost	260,911	243,787
Gross Unrealized Gains (Losses)	9,406	3,461
Recorded Basis	270,317	247,248
Restricted Cash and Investments [Member] | Money Market Funds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cost	32,864	29,046
Gross Unrealized Gains (Losses)	10
Recorded Basis	32,874	29,046
Restricted Cash and Investments [Member] | Corporate Bonds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cost	95,827	98,481
Gross Unrealized Gains (Losses)	4,506	1,931
Recorded Basis	100,333	100,412
Restricted Cash and Investments [Member] | Asset Backed Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cost	280	303
Gross Unrealized Gains (Losses)	5
Recorded Basis	285	303
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	25,718	27,885
Gross Unrealized Gains (Losses)	2,394	642
Recorded Basis	28,112	28,527
Restricted Cash and Investments [Member] | U.S. Treasuries [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cost	6,320	16,906
Gross Unrealized Gains (Losses)	46	21
Recorded Basis	6,366	16,927
Restricted Cash and Investments [Member] | Mortgage Backed Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cost	56,551	62,930
Gross Unrealized Gains (Losses)	2,356	837
Recorded Basis	58,907	63,767
Restricted Cash and Investments [Member] | Commercial Paper [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cost	31,844
Gross Unrealized Gains (Losses)	26
Recorded Basis	31,870
Restricted Cash and Investments [Member] | Municipal Bonds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cost	2,473
Gross Unrealized Gains (Losses)	7
Recorded Basis	2,480
Restricted Cash and Investments [Member] | Supranational Bonds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cost	4,772	4,770
Gross Unrealized Gains (Losses)	56	30
Recorded Basis	4,828	4,800
Restricted Cash and Investments [Member] | Mutual Funds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cost	4,262	3,466
Recorded Basis	$ 4,262	$ 3,466

Fair Value Measurement - Summ_2

Fair Value Measurement - Summary of Investments Measured at Fair Value on Recurring Basis (Parenthetical) (Detail) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Fair Value Disclosures [Abstract]
Restricted cash	$ 51.3	$ 197

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	Jun. 30, 2020	Dec. 31, 2019
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Recorded Basis	$ 396,089	$ 365,364
Other [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Recorded Basis	91,173	64,572
Level 1 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Recorded Basis	4,262	3,466
Level 2 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Recorded Basis	300,654	297,326
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	58,299	35,526
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	58,299	35,526
Investments [Member] | Corporate Bonds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Recorded Basis	20,666	53,649
Investments [Member] | Corporate Bonds [Member] | Level 2 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Recorded Basis	20,666	53,649
Investments [Member] | Mortgage Backed Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Recorded Basis	338	2,738
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	338	2,738
Investments [Member] | U.S. Treasuries [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Recorded Basis	2,405	4,509
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	2,405	4,509
Investments [Member] | U.S. Government Agency Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Recorded Basis	8,104	7,690
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	8,104	7,690
Investments [Member] | Asset Backed Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Recorded Basis	35,960	14,004
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	35,960	14,004
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	32,874	29,046
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	32,874	29,046
Restricted Cash and Investments [Member] | Corporate Bonds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Recorded Basis	100,333	100,412
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	100,333	100,412
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	58,907	63,767
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	58,907	63,767
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	6,366	16,927
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	6,366	16,927
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	28,112	28,527
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	28,112	28,527
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	285	303
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	285	303
Restricted Cash and Investments [Member] | Commercial Paper [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Recorded Basis	31,870
Restricted Cash and Investments [Member] | Commercial Paper [Member] | Level 2 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Recorded Basis	31,870
Restricted Cash and Investments [Member] | Mutual Funds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Recorded Basis	4,262	3,466
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	4,262	3,466
Restricted Cash and Investments [Member] | Supranational Bonds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Recorded Basis	4,828	4,800
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	4,828	$ 4,800
Restricted Cash and Investments [Member] | Municipal Bonds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Recorded Basis	2,480
Restricted Cash and Investments [Member] | Municipal Bonds [Member] | Level 2 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Recorded Basis	$ 2,480

Fair Value Measurement - Summ_4

Fair Value Measurement - Summary of Contractual Maturities of Available for Sale Securities (Detail) $ in Thousands	Jun. 30, 2020USD ($)
Schedule Of Available For Sale Securities [Line Items]
Available for sale securities, contractual maturities less than 1 year	$ 165,509
Available for sale securities, contractual maturities between 1 to 5 years	79,848
Available for sale securities, contractual maturities between 5 to 10 years	51,278
Available for sale securities, contractual maturities after 10 years	35,947
Available for sale securities, contractual maturities, Total	332,582
Corporate Bonds [Member]
Schedule Of Available For Sale Securities [Line Items]
Available for sale securities, contractual maturities less than 1 year	29,891
Available for sale securities, contractual maturities between 1 to 5 years	63,851
Available for sale securities, contractual maturities between 5 to 10 years	27,257
Available for sale securities, contractual maturities, Total	120,999
Money Market Funds [Member]
Schedule Of Available For Sale Securities [Line Items]
Available for sale securities, contractual maturities less than 1 year	91,173
Available for sale securities, contractual maturities, Total	91,173
U.S. Government Agency Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Available for sale securities, contractual maturities between 1 to 5 years	12,195
Available for sale securities, contractual maturities between 5 to 10 years	24,021
Available for sale securities, contractual maturities, Total	36,216
Asset Backed Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Available for sale securities, contractual maturities between 1 to 5 years	298
Available for sale securities, contractual maturities after 10 years	35,947
Available for sale securities, contractual maturities, Total	36,245
Commercial Paper [Member]
Schedule Of Available For Sale Securities [Line Items]
Available for sale securities, contractual maturities less than 1 year	31,870
Available for sale securities, contractual maturities, Total	31,870
U.S. Treasuries [Member]
Schedule Of Available For Sale Securities [Line Items]
Available for sale securities, contractual maturities less than 1 year	7,747
Available for sale securities, contractual maturities between 1 to 5 years	1,024
Available for sale securities, contractual maturities, Total	8,771
Supranational Bonds [Member]
Schedule Of Available For Sale Securities [Line Items]
Available for sale securities, contractual maturities less than 1 year	4,828
Available for sale securities, contractual maturities, Total	4,828
Municipal Bonds [Member]
Schedule Of Available For Sale Securities [Line Items]
Available for sale securities, contractual maturities between 1 to 5 years	2,480
Available for sale securities, contractual maturities, Total	$ 2,480

Fair Value Measurement - Additi

Fair Value Measurement - Additional Information (Detail)	6 Months Ended
	Jun. 30, 2020
Mortgage Backed Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Average contractual maturity period	17 years

Workers' Compensation Claims -

Workers' Compensation Claims - Summarizes Aggregate Workers' Compensation Reserve Activity (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Workers Compensation Reserve [Abstract]
Workers' compensation claims liabilities, Beginning balance	$ 445,310	$ 422,872	$ 438,986	$ 413,397
Add: claims expense accrual
Current period	32,729	41,145	71,221	81,530
Prior periods	(1,373)	(2,952)	(2,186)	(4,652)
Total expense accrual	31,356	38,193	69,035	76,878
Less: claim payments related to
Current period	4,527	4,145	6,077	5,604
Prior periods	135,853	26,088	165,530	53,804
Total paid	140,380	30,233	171,607	59,408
Change in claims incurred in excess of retention limits	218	(96)	90	(131)
Workers' compensation claims liabilities, Ending balance	336,504	430,736	336,504	430,736
Incurred but not reported (IBNR)	$ 206,521	$ 273,114	$ 206,521	$ 273,114
Ratio of IBNR to workers' compensation claims liabilities	61.00%	63.00%	61.00%	63.00%

Workers' Compensation Claims _2

Workers' Compensation Claims - Additional Information (Detail) - USD ($)	Jul. 01, 2020	Jun. 30, 2020	Dec. 31, 2019	Jun. 29, 2020	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Worker's compensation risk claim maximum		$ 5,000,000
Balance in Chubb trust accounts		264,600,000	$ 393,500,000	$ 115,700,000
Collateral securities maintain to cover potential workers compensation claims losses		59,700,000	59,700,000
Surety bonds and standby letters of credit		59,700,000
Claim payments receivable from Chubb		2,200,000
Estimated future liability for unsettled workers' compensation		336,504,000	438,986,000		$ 445,310,000	$ 430,736,000	$ 422,872,000	$ 413,397,000
Reserves incurred in excess of retention limits		3,400,000	3,300,000
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		3,400,000	$ 3,300,000
Wells Fargo Bank, National Association [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Letter of credit		63,700,000
Subsequent Event [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Worker's compensation risk claim maximum	$ 3,000,000
Maryland [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Reinsurance coverage		1,000,000
Maryland [Member] | Subsequent Event [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Reinsurance coverage	1,000,000
Colorado [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Reinsurance coverage		2,000,000
Colorado [Member] | Subsequent Event [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Reinsurance coverage	$ 2,000,000
California [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Surety bonds and standby letters of credit		$ 39,200,000

Revolving Credit Facility and_2

Revolving Credit Facility and Long-Term Debt - Additional Information (Detail) - USD ($)	1 Months Ended	3 Months Ended						6 Months Ended
	Jun. 30, 2018	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020	May 15, 2020	May 14, 2020	Dec. 31, 2019
Line of Credit Facility [Line Items]
Cash dividends on common stock per share				$ 0.30	$ 0.30	$ 0.25	$ 0.25
Agreement [Member]
Line of Credit Facility [Line Items]
Credit facility borrowing used				$ 5,800,000				$ 5,800,000
Line of credit facility commitment fee description								The Agreement also provides for an unused commitment fee of 0.50% 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.
Outstanding balance on term loan and revolving credit facility				$ 0				$ 0			$ 0
Maximum funded debt to EBITDA ratio				275.00%	275.00%
Ratio of restricted and unrestricted cash and investments to workers' compensation and claim liabilities				115.00%	115.00%
Cash dividends on common stock per share								$ 0.30
Acquisition of shares of common stock employee tax withholding equity compensation arrangement								$ 3,500,000
Agreement [Member] | Scenario Forecast [Member]
Line of Credit Facility [Line Items]
Maximum funded debt to EBITDA ratio		275.00%	275.00%
Ratio of restricted and unrestricted cash and investments to workers' compensation and claim liabilities		115.00%	115.00%
Agreement [Member] | Maximum [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
Agreement [Member] | Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Credit facility borrowing capacity									$ 50,000,000	$ 33,000,000
Credit facility, expiration date								Jul. 1, 2022
Unused commitment fee on unused amount during period								0.50%
Agreement [Member] | Revolving Credit Facility [Member] | Daily Floating Rate [Member]
Line of Credit Facility [Line Items]
Term loan from Bank, Interest rate description								the daily floating rate of one-month LIBOR plus 1.75% or (b) the fixed rate of LIBOR plus 1.75%
LIBOR plus rate								1.75%
Agreement [Member] | Revolving Credit Facility [Member] | Fixed Rate [Member]
Line of Credit Facility [Line Items]
Term loan from Bank, Interest rate description								the fixed rate of LIBOR plus 1.75%
LIBOR plus rate								1.75%
Agreement [Member] | Standby Letters of Credit [Member]
Line of Credit Facility [Line Items]
Credit facility borrowing capacity									$ 8,000,000
Agreement [Member] | Line of Credit [Member]
Line of Credit Facility [Line Items]
Unused commitment fee on unused amount								1.75%
Agreement [Member] | Chubb Letter of Credit [Member]
Line of Credit Facility [Line Items]
Credit facility borrowing capacity				$ 63,700,000				$ 63,700,000
Credit facility, expiration date								Jul. 1, 2021
Percentage of initial fee under letter of credit	2.50%							2.50%
Percentage of aggregate fee under letter of credit								95.00%
Percentage of annual fee under letter of credit				1.00%				1.00%
Agreement [Member] | Chubb Letter of Credit [Member] | Collateral Accounts [Member]
Line of Credit Facility [Line Items]
Percentage of deposit in collateral accounts								50.00%
Deposit in collateral accounts				$ 32,500,000				$ 32,500,000
Agreement [Member] | Chubb Letter of Credit [Member] | Collateral Accounts [Member] | Minimum [Member]
Line of Credit Facility [Line Items]
Deposit in collateral accounts				16,000,000				$ 16,000,000
Agreement [Member] | Term Loan [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				$ 3,800,000				$ 3,800,000			$ 4,000,000
Payment of monthly principal of term loan								$ 18,375
Agreement [Member] | Term Loan [Member] | London Interbank Offered Rate (LIBOR) [Member]
Line of Credit Facility [Line Items]
LIBOR plus rate								2.00%

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - Internal Revenue Service [Member] - USD ($)	1 Months Ended	6 Months Ended
	Jul. 31, 2020	Jun. 30, 2020
Income Tax Contingency [Line Items]
Open tax years		2011 2012 2013 2014
Subsequent Event [Member]
Income Tax Contingency [Line Items]
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 2014
Reserve for tax position	$ 0
Minimum [Member] | Subsequent Event [Member]
Income Tax Contingency [Line Items]
Ongoing audit for tax years	2011
Maximum [Member] | Subsequent Event [Member]
Income Tax Contingency [Line Items]
Ongoing audit for tax years	2014