CONSOLIDATED BALANCE SHEETS (USD $) In Thousands, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Current assets:
Cash and cash equivalents	$ 234,548	$ 211,208
Restricted cash	45,068	44,737
Marketable securities	56,981	56,987
Accounts receivable, net:
Trade	3,601	7,893
Unbilled	167,785	158,508
Other	4,575	4,532
Prepaid insurance	24,662	21,300
Other current assets	11,529	11,488
Income taxes receivable	617	2,902
Deferred income taxes	0	3,233
Total current assets	549,366	522,788
Property and equipment:
Land	3,653	3,653
Buildings and improvements	68,727	67,496
Computer hardware and software	77,287	76,105
Software development costs	33,519	32,699
Furniture and fixtures	36,207	36,133
Aircraft	35,866	35,866
Property and equipment, gross	255,259	251,952
Accumulated depreciation and amortization	(162,662)	(159,008)
Total property and equipment, net	92,597	92,944
Other assets:
Prepaid health insurance	9,000	9,000
Deposits - health insurance	2,840	2,640
Deposits - workers' compensation	55,665	52,320
Goodwill and other intangible assets, net	27,999	28,433
Other assets	4,163	4,134
Total other assets	99,667	96,527
Total assets	741,630	712,259
Current liabilities:
Accounts payable	3,437	5,085
Payroll taxes and other payroll deductions payable	177,991	168,652
Accrued worksite employee payroll cost	144,840	130,317
Accrued health insurance costs	9,200	9,427
Accrued workers' compensation costs	47,094	46,548
Accrued corporate payroll and commissions	13,703	22,383
Other accrued liabilities	14,092	13,814
Deferred income taxes	3,089	0
Total current liabilities	413,446	396,226
Noncurrent liabilities:
Accrued workers' compensation costs	61,895	60,054
Deferred income taxes	9,814	10,772
Total noncurrent liabilities	71,709	70,826
Stockholders' equity:
Common stock	309	309
Additional paid-in capital	136,670	135,871
Treasury stock, at cost	(134,198)	(134,647)
Accumulated other comprehensive income,net of tax	59	24
Retained earnings	253,635	243,650
Total stockholders' equity	256,475	245,207
Total liabilities and stockholders' equity	$ 741,630	$ 712,259