CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 308,711	$ 354,260
Restricted cash	41,827	41,137
Marketable securities	7,207	1,960
Accounts receivable, net:
Trade	4,066	12,292
Unbilled	344,685	318,431
Other	3,003	3,258
Prepaid insurance	17,648	10,782
Other current assets	22,640	26,991
Income taxes receivable	0	9,824
Total current assets	749,787	778,935
Property and equipment:
Land	6,215	6,215
Buildings and improvements	98,332	95,615
Computer hardware and software	108,665	105,060
Software development costs	65,348	60,568
Furniture, fixtures and other	44,603	42,891
Total property and equipment, gross	323,163	310,349
Accumulated depreciation and amortization	(224,135)	(214,690)
Total property and equipment, net	99,028	95,659
Other assets:
Prepaid health insurance	9,000	9,000
Deposits – health insurance	5,300	5,300
Deposits – workers’ compensation	165,150	154,215
Goodwill and other intangible assets, net	12,732	12,762
Deferred income taxes, net	4,538	4,283
Other assets	5,533	3,541
Total other assets	202,253	189,101
Total assets	1,051,068	1,063,695
Current liabilities:
Accounts payable	4,123	6,447
Payroll taxes and other payroll deductions payable	213,432	303,247
Accrued worksite employee payroll cost	295,596	267,402
Accrued health insurance costs	24,127	26,075
Accrued workers’ compensation costs	45,376	42,974
Accrued corporate payroll and commissions	41,059	52,595
Other accrued liabilities	24,094	27,741
Income taxes payable	6,984	0
Total current liabilities	654,791	726,481
Noncurrent liabilities:
Accrued workers’ compensation costs	174,017	166,493
Long-term debt	104,400	104,400
Total noncurrent liabilities	278,417	270,893
Commitments and contingencies
Stockholders’ equity:
Common stock	555	555
Additional paid-in capital	27,363	25,337
Treasury stock, at cost	(263,764)	(256,363)
Retained earnings	353,706	296,792
Total stockholders’ equity	117,860	66,321
Total liabilities and stockholders’ equity	$ 1,051,068	$ 1,063,695