Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 47,579	$ 34,626
Accounts receivable, net of allowance for doubtful accounts of $5,271 and $4,255 at September 30, 2020 and December 31, 2019, respectively	432,525	286,989
Income taxes receivable	0	2,473
Prepaid expenses	8,607	8,999
Other current assets	3,026	3,106
Total current assets	491,736	336,193
Noncurrent assets:
Property and equipment, net of accumulated depreciation of $149,759 and $130,320 at September 30, 2020 and December 31, 2019, respectively	52,689	58,620
Goodwill	309,589	309,589
Intangible assets, net of accumulated amortization of $89,939 and $81,656 at September 30, 2020 and December 31, 2019, respectively	89,479	97,762
Operating lease assets	17,315	19,638
Other noncurrent assets	3,653	4,863
Total noncurrent assets	472,724	490,473
Total assets	964,460	826,666
Current liabilities:
Accounts payable	330,365	187,524
Due to seller, current	429	937
Accrued expenses	45,524	35,229
Other current liabilities	4,125	6,719
Income taxes payable	1,171	0
Total current liabilities	381,614	230,409
Noncurrent liabilities:
Long-term debt, net	143,934	0
Convertible notes, net	0	156,298
Due to seller, noncurrent	0	770
Other noncurrent liabilities	650	641
Deferred income taxes	23,132	23,761
Noncurrent operating lease liabilities	28,657	31,475
Total noncurrent liabilities	196,373	212,945
Total liabilities	577,987	443,353
Stockholders' equity:
Common stock, par value $0.0001 per share, 100,000,000 shares authorized, 31,718,589 shares issued and 25,951,489 shares outstanding at September 30, 2020; 31,507,247 shares issued and 26,229,809 shares outstanding at December 31, 2019	3	3
Treasury stock, 5,767,100 and 5,277,438 shares at September 30, 2020 and December 31, 2019, respectively	(118,679)	(109,239)
Additional paid-in capital	364,364	356,600
Retained earnings	140,784	135,948
Total stockholders' equity	386,473	383,312
Total liabilities and stockholders' equity	$ 964,460	$ 826,666