Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Current Assets:
Cash and cash equivalents	$ 1,082,650	$ 923,735
Accounts receivable, less allowance for doubtful accounts of $13,391 at June 30, 2019 and $15,345 at December 31, 2018	1,382,070	1,581,530
Deferred contract costs	143,651	159,510
Other	103,089	70,041
Total current assets	2,711,460	2,734,816
Property and equipment, less accumulated depreciation and amortization of $465,983 at June 30, 2019 and $446,977 at December 31, 2018	499,233	504,105
Operating lease right-of-use assets	377,423	0
Goodwill	7,927	7,927
Deferred federal and state income taxes, net	33,617	40,465
Other assets, net	17,330	27,246
Total assets	3,646,990	3,314,559
Current Liabilities:
Accounts payable	811,144	902,259
Accrued expenses, primarily salaries and related costs	217,463	215,813
Contract liabilities	169,055	190,343
Current portion of operating lease liabilities	61,267	0
Federal, state and foreign income taxes	19,891	18,424
Total current liabilities	1,278,820	1,326,839
Noncurrent portion of operating lease liabilities	315,776	0
Commitments and contingencies
Shareholders’ Equity:
Preferred stock, none issued	0	0
Common stock, par value $0.01 per share. Issued and outstanding: 170,040 shares at June 30, 2019 and 171,582 shares at December 31, 2018	1,701	1,716
Additional paid-in capital	12,433	1,896
Retained earnings	2,140,935	2,088,707
Accumulated other comprehensive loss	(104,096)	(105,481)
Total shareholders’ equity	2,050,973	1,986,838
Noncontrolling interest	1,421	882
Total equity	2,052,394	1,987,720
Total liabilities and equity	$ 3,646,990	$ 3,314,559