CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 269,538	$ 276,456
Restricted cash	37,418	44,040
Marketable securities	9,875	28,631
Accounts receivable, net:
Trade	7,691	12,010
Unbilled	190,715	160,154
Other	2,259	2,952
Prepaid insurance	7,417	21,301
Other current assets	17,135	17,649
Total current assets	542,048	563,193
Property and equipment:
Land	5,214	5,214
Buildings and improvements	70,273	70,471
Computer hardware and software	90,654	89,204
Software development costs	45,762	41,314
Furniture, fixtures and other	39,919	38,604
Aircraft	0	35,879
Total property and equipment, gross	251,822	280,686
Accumulated depreciation and amortization	(190,063)	(196,341)
Total property and equipment, net	61,759	84,345
Other assets:
Prepaid health insurance	9,000	9,000
Deposits – health insurance	3,700	3,700
Deposits – workers’ compensation	136,462	113,934
Goodwill and other intangible assets, net	13,588	14,457
Deferred income taxes, net	16,976	2,241
Other assets	1,379	1,725
Total other assets	181,105	145,057
Total assets	784,912	792,595
Current liabilities:
Accounts payable	5,381	4,674
Payroll taxes and other payroll deductions payable	205,393	176,341
Accrued worksite employee payroll cost	161,917	192,396
Accrued health insurance costs	13,643	18,329
Accrued workers’ compensation costs	39,053	45,592
Accrued corporate payroll and commissions	39,103	32,644
Other accrued liabilities	20,250	22,444
Income tax payable	2,971	4,031
Total current liabilities	487,711	496,451
Noncurrent liabilities:
Accrued workers’ compensation costs	124,746	92,048
Total noncurrent liabilities	$ 124,746	$ 92,048
Commitments and contingencies
Stockholders’ equity:
Preferred stock, par value $0.01 per share: Shares authorized - 20,000 Shares issued and outstanding - none	$ 0	$ 0
Common stock, par value $0.01 per share: Shares authorized - 60,000 Shares issued - 30,758 at December 31, 2015 and 2014	308	308
Additional paid-in capital	144,701	137,769
Treasury stock, at cost – 6,493 and 5,425 at December 31, 2015 and 2014, respectively	(205,325)	(148,465)
Accumulated other comprehensive income, net of tax	0	3
Retained earnings	232,771	214,481
Total stockholders’ equity	172,455	204,096
Total liabilities and stockholders’ equity	$ 784,912	$ 792,595