Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Current Assets:
Cash and cash equivalents	$ 1,793,393	$ 1,527,791
Accounts receivable, less allowance for credit loss of $5,941 at March 31, 2021 and $5,579 at December 31, 2020	2,227,039	1,998,055
Deferred contract costs	387,845	327,448
Other	85,918	110,250
Total current assets	4,494,195	3,963,544
Property and equipment, less accumulated depreciation and amortization of $523,829 at March 31, 2021 and $516,988 at December 31, 2020	497,376	506,425
Operating lease right-of-use assets	438,667	432,723
Goodwill	7,927	7,927
Other assets, net	16,832	16,884
Total assets	5,454,997	4,927,503
Current Liabilities:
Accounts payable	1,295,178	1,136,859
Accrued expenses, primarily salaries and related costs	311,767	257,021
Contract liabilities	447,779	379,722
Current portion of operating lease liabilities	76,128	74,004
Federal, state and foreign income taxes	64,170	45,437
Total current liabilities	2,195,022	1,893,043
Noncurrent portion of operating lease liabilities	369,286	364,185
Deferred federal and state income taxes, net	12,039	7,048
Commitments and contingencies
Shareholders’ Equity:
Preferred stock, none issued	0	0
Common stock, par value $0.01 per share. Issued and outstanding: 168,808 shares at March 31, 2021 and 169,294 shares at December 31, 2020	1,688	1,693
Additional paid-in capital	101,269	157,496
Retained earnings	2,887,323	2,600,201
Accumulated other comprehensive loss	(115,486)	(99,753)
Total shareholders’ equity	2,874,794	2,659,637
Noncontrolling interest	3,856	3,590
Total equity	2,878,650	2,663,227
Total liabilities and equity	$ 5,454,997	$ 4,927,503