Condensed Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Current Assets:
Cash and cash equivalents	$ 1,394,687	$ 1,260,842
Accounts receivable, less allowance for doubtful accounts of $10,093 at March 31, 2013 and $9,383 at December 31, 2012	982,119	1,031,376
Deferred Federal and state income taxes	11,867	12,102
Other	42,153	53,279
Total current assets	2,430,826	2,357,599
Property and equipment, less accumulated depreciation and amortization of $331,538 at March 31, 2013 and $325,595 at December 31, 2012	546,698	556,204
Goodwill	7,927	7,927
Other assets, net	32,348	32,395
Total assets	3,017,799	2,954,125
Current Liabilities:
Accounts payable	629,190	641,593
Accrued expenses, primarily salaries and related costs	175,212	178,995
Federal, state and foreign income taxes	27,278	21,970
Total current liabilities	831,680	842,558
Deferred Federal and state income taxes	81,498	78,997
Commitments and contingencies
Shareholders' Equity:
Preferred stock, none issued	0	0
Common stock, par value $.01 per share. Issued and outstanding 206,475,743 shares at March 31, 2013 and 206,392,013 shares at December 31, 2012	2,065	2,064
Additional paid-in capital	5,962	1,283
Retained earnings	2,098,933	2,018,618
Accumulated other comprehensive (loss) income	(4,265)	5,734
Total shareholders' equity	2,102,695	2,027,699
Noncontrolling interest	1,926	4,871
Total equity	2,104,621	2,032,570
Total liabilities and equity	$ 3,017,799	$ 2,954,125