CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Current assets
Cash and cash equivalents	$ 993,724	$ 936,552
Short-term investments	60,025	9
Trade receivables and contract assets, net of allowance of $6,070 and $2,920, respectively	506,908	497,716
Prepaid and other current assets	37,679	39,934
Total current assets	1,598,336	1,474,211
Property and equipment, net	167,359	165,259
Operating lease right-of-use assets	234,760	238,991
Intangible assets, net	55,887	56,258
Goodwill	199,039	195,043
Deferred tax assets	78,102	75,013
Other noncurrent assets	55,647	39,433
Total assets	2,389,130	2,244,208
Current liabilities
Accounts payable	7,596	7,831
Accrued compensation and benefits expenses	223,436	230,035
Accrued expenses and other current liabilities	62,639	82,476
Income taxes payable, current	10,972	9,064
Operating lease liabilities, current	60,937	57,542
Total current liabilities	365,580	386,948
Long-term debt	25,044	25,074
Income taxes payable, noncurrent	43,391	45,878
Operating lease liabilities, noncurrent	181,705	180,848
Other noncurrent liabilities	20,316	9,315
Total liabilities	636,036	648,063
Commitments and contingencies (Note 12)
Stockholders’ equity
Common stock, $0.001 par value; 160,000,000 authorized; 55,845,686 and 55,207,446 shares issued, 55,825,951 and 55,187,711 shares outstanding at June 30, 2020 and December 31, 2019, respectively	56	55
Additional paid-in capital	630,679	607,051
Retained earnings	1,172,909	1,020,590
Treasury stock	(177)	(177)
Accumulated other comprehensive loss	(50,373)	(31,374)
Total stockholders’ equity	1,753,094	1,596,145
Total liabilities and stockholders’ equity	$ 2,389,130	$ 2,244,208