Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Current assets
Cash and cash equivalents	$ 494,485	$ 294,953
Accounts receivable, net	754,120	711,357
Current portion of notes receivable	30,256	35,253
Prepaid expenses and other current assets	91,166	88,144
Total current assets	1,370,027	1,129,707
Property and equipment, net	142,163	101,642
Operating lease assets	215,995	156,645
Goodwill	1,232,791	1,234,879
Intangible assets, net	31,990	41,550
Notes receivable, net	53,539	61,121
Other assets	54,404	51,819
Total assets	3,100,909	2,777,363
Current liabilities
Accounts payable, accrued expenses and other	165,025	170,066
Accrued compensation	507,556	455,933
Billings in excess of services provided	45,535	44,172
Total current liabilities	718,116	670,171
Long-term debt, net	297,158	286,131
Noncurrent operating lease liabilities	236,026	161,677
Deferred income taxes	170,612	158,342
Other liabilities	95,676	100,861
Total liabilities	1,517,588	1,377,182
Commitments and contingencies
Stockholders' equity
Preferred stock, $0.01 par value; shares authorized — 5,000; none    outstanding	0	0
Common stock, $0.01 par value; shares authorized — 75,000; shares issued and outstanding — 34,333 (2021) and 34,481 (2020)	343	345
Additional paid-in capital	13,662	0
Retained earnings	1,698,156	1,506,271
Accumulated other comprehensive loss	(128,840)	(106,435)
Total stockholders' equity	1,583,321	1,400,181
Total liabilities and stockholders' equity	$ 3,100,909	$ 2,777,363