Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 79,582	$ 139,330
Marketable securities, at fair value	125,583	125,012
Accounts and notes receivable, less allowance for doubtful accounts of $61,879 and $59,906 as of September 30, 2021 and December 31, 2020, respectively	289,725	255,474
Inventories and supplies	26,714	31,586
Prepaid expenses and other assets	44,460	21,001
Total current assets	566,064	572,403
Property and equipment, net	27,817	26,561
Goodwill	65,545	51,084
Other intangible assets, less accumulated amortization of $26,715 and $23,466 as of September 30, 2021 and December 31, 2020, respectively	17,039	18,187
Notes receivable — long–term portion, less allowance for doubtful accounts of $6,135 and $7,895 as of September 30, 2021 and December 31, 2020, respectively	30,651	34,417
Deferred compensation funding, at fair value	50,711	46,825
Deferred income taxes	35,776	35,554
Total assets	793,603	785,031
Current liabilities:
Accounts payable	50,493	52,239
Accrued payroll and related taxes	42,354	70,614
Other accrued expenses	36,843	17,797
Accrued insurance claims	24,164	21,610
Total current liabilities	153,854	162,260
Accrued insurance claims — long-term portion	63,135	60,818
Deferred compensation liability	50,747	46,827
Accrued payroll and related taxes - noncurrent	23,302	23,302
Lease liability — long-term portion	11,798	11,363
Other long-term liabilities	10,562	0
Commitments and contingencies (Note 14)
STOCKHOLDERS’ EQUITY:
Common stock, $0.01 par value; 100,000 shares authorized; 75,997 and 75,798 shares issued, and 74,565 and 74,485 shares outstanding as of September 30, 2021 and December 31, 2020, respectively	760	758
Additional paid-in capital	291,899	282,206
Retained earnings	197,550	200,893
Accumulated other comprehensive income, net of taxes	3,981	5,563
Common stock in treasury, at cost, 1,432 and 1,313 shares as of September 30, 2021 and December 31, 2020, respectively	(13,985)	(8,959)
Total stockholders’ equity	480,205	480,461
Total liabilities and stockholders’ equity	$ 793,603	$ 785,031