CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011
Cash flows from operating activities:
Net income	$ 30,957	$ 19,626
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation and amortization	13,336	11,335
Loss on exchange of assets	(21)	4,396
Amortization of marketable securities	1,827	1,535
Stock-based compensation	7,385	6,455
Deferred income taxes	2,259	(96)
Changes in operating assets and liabilities,net of effects from acquisitions:
Restricted cash	(1,332)	(1,608)
Accounts receivable	(32,175)	(20,231)
Prepaid insurance	(2,439)	9,796
Other current assets	3,355	(2,339)
Other assets	(6,373)	4,876
Accounts payable	(1,997)	(650)
Payroll taxes and other payroll deductions payable	(60,704)	(40,892)
Accrued worksite employee payroll expense	43,947	21,091
Accrued health insurance costs	13,095	(10,210)
Accrued workers' compensation costs	5,231	6,013
Accrued corporate payroll, commissions and otheraccrued liabilities	2,155	3,656
Income taxes payable/receivable	6,529	479
Total adjustments	(5,922)	(6,394)
Net cash provided by operating activities	25,035	13,232
Cash flows from investing activities:
Marketable securities purchases	(23,585)	(43,607)
Marketable securities proceeds from dispositions	0	3,907
Marketable securities proceeds from maturities	27,119	26,194
Cash exchanged for acquisitions	(1,200)	(13,125)
Property and equipment	(11,996)	(23,404)
Net cash used in investing activities	(9,662)	(50,035)
Cash flows from financing activities:
Purchase of treasury stock	(13,770)	(22,459)
Dividends paid	(12,643)	(11,871)
Proceeds from the exercise of stock options	1,062	3,881
Income tax benefit from stock-based compensation	1,457	2,049
Other	(469)	284
Net cash used in financing activities	(24,363)	(28,116)
Net increase (decrease) in cash and cash equivalents	(8,990)	(64,919)
Cash and cash equivalents at beginning of period	211,208	234,829
Cash and cash equivalents at end of period	$ 202,218	$ 169,910